ALBERT

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Yiyong Yang, Weiwei Zhang, Yong Xu, Haiqing Sun, Xiaomeng Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ag〈sub〉2〈/sub〉S quantum dots decorated TiO〈sub〉2〈/sub〉 nanosheets with highly reactive {001} facets exposed were grown on carbon fibers by hydrothermal technology and successive ionic layer adsorption and reaction method. The ternary CFs-TiO〈sub〉2〈/sub〉-Ag〈sub〉2〈/sub〉S heterostructure exhibits excellent photoelectrochemical protection performance for the coupled 304 stainless steel. Ag〈sub〉2〈/sub〉S quantum dots with narrow band gap enhance the sunlight harvest of the hybrid. The carbon fibers act as transmission channels for the photo-induced electrons that facilitate the photogenerated carrier separation. Schottky barrier formed in the heterostructure interface and the increased inner electric field promote the electron dissociation and migration from the hybrid semiconductor to the coupled metal, resulting in enhancement of photoelectrochemical protection of the 304 stainless steel.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Cheng-Lun Hsin, Jian-Hao Huang, Piotr Spiewak, Łukasz Ciupiński, Sheng-Wei Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this report, α-In〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 single-crystal nanobelts and nanowires were grown in the thermal chemical vapor deposition furnace. The growth direction of the nanobelts was identified by standard microscopy techniques and was along the in-plane direction, while that of the nanowire was along the c-axis. The temperature-dependent thermal conductivity of the nanostructures was measured by a suspended-pattern technique, and it was found to fall into two ranges of values between 300 and 400 K owing to the difference in growth orientation. The experimental evidence presented herein is the anisotropy of phonon transport of the layered α-In〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉, and the effect of bonding strength on the thermal conductivity at the nanoscale. This study would be helpful to the physical understanding and future design of In〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉–based thermoelectric materials.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932269X-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Sepideh Khoee, Maryam Soleymani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanogels with ordered structures have attracted extraordinary attention for biomedical applications. Among the preparations of hierarchical nanogels, the fabrication of Janus nanocarriers is an important branch. In this study, a two-faced magnetite structure has been constructed from a thermosensitive terpolymer 〈em〉i.e.〈/em〉 N-isopropylacrylamide-〈em〉co〈/em〉-acrylamide-〈em〉co〈/em〉-allylamine (NIPAAm-〈em〉co〈/em〉-AAm-〈em〉co〈/em〉-AA) terpolymer and hydrophobic polymer 〈em〉i.e.〈/em〉 PCL, through solvent evaporation from emulsion droplets (SEED) technique. The amphiphilic copolymers with Janus morphology were prepared from click reaction between PCL and terpolymer and in order to fix this morphology, the PCL chains tails of clicked adduct were tied together by magnetite nanoparticles. Moreover, to evaluate the potential of this prototype sharp-shaped nanogel in drug delivery, the comparative core-shell structure was nano-engineered 〈em〉via〈/em〉 a challengeable emulsion method! The prepared polymers and their Janus and core-shell nanogels were fully characterized by various methods.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322512-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Debasrita Dash, N.R. Panda, Dojalisa Sahu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study describes the effect of europium doping in enhancing the optical properties of ZnO nanoparticles. Eu doped ZnO (EZ) nanoparticles were prepared by the soft-solution method with varying the dopant concentration. The structure and phase analysis have been carried out by x-ray diffraction (XRD) measurement which shows the size of the particles lies in 30–60 nm range. Improved crystallinity in ZnO is also observed along with lower angle shift of XRD peaks and increase in lattice parameters like unit cell volume which may be explained as the substitutional effect of Eu at Zn sites. Microstructure of the sample has been studied by transmission electron microscopy (TEM) and the images show the average size of EZ nanoparticles is in the range of 30–50 nm. Both XRD and TEM studies give the evidence of Eu incorporation in ZnO lattice. The EZ nanoparticles exhibit intense red emission upon excitation of 400 nm light which are characteristic 4f-intra-shell (〈sup〉5〈/sup〉D〈sub〉0〈/sub〉-〈sup〉7〈/sup〉F〈sub〉2〈/sub〉) transitions of Eu〈sup〉3+〈/sup〉 other than the defect emissions of host ZnO. The dopant ions are located in ZnO by substituting Zn〈sup〉2+〈/sup〉 at a low-symmetry site (C〈sub〉3v〈/sub〉) and also near the surface in some distorted lattice sites. The photocatalytic activity has been evaluated by degradation of hazardous methyl orange (MO) dye with exposure to UV light. Among the tested samples, the sample with optimal doping concentration shows notable photocatalytic activity and achieved 90% degradation of MO dye within 180 min of UV irradiation. This photocatalytic activity of EZ has been found to be better as compared to that of ZnO in identical experimental conditions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321257-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Hui Yang, Xin Hao, Jia Tang, Wei Jin, Changqing Liu, Hongshuai Hou, Xiaobo Ji, Jiugang Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dual-functional porous copper films were prepared by dynamic hydrogen bubble template (DHBT) technique to achieve in situ SERS monitoring of electrocatalytic reaction. The morphology and SERS activity of porous copper films were effectively modulated by electrolyte additive, current density, and deposition time. The interfacial evolution behaviors of porous copper films were monitored by in situ synchrotron radiation X-ray imaging. The three-dimensional porous copper films in the presence of CTAB additive present a thinner leaf-like dendritic structure and excellent SERS activity. Although the diverse morphologies of porous copper films are obtained with inorganic additives including (NH〈sub〉4〈/sub〉)〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, Na〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, or NaCl, they are deleterious to the SERS activity due to the microstructural changes of copper films, even significantly lower than that of the additive-free condition. The obtained porous copper films exhibit high sensitivity (10〈sup〉−9〈/sup〉 mol/L) and good reproducibility for efficient SERS detection. Furthermore, the electrocatalytic reduction process of 4-nitrophenol on the porous copper films was successfully in situ monitored based on their excellent SERS activity.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Jiyu Liu, Yang Chen, Huanxi Zheng, Jichao Zhang, Ziai Liu, Fan Zhang, Faze Chen, Liu Huang, Jing Sun, Zhuji Jin, Danyang Zhao, Xin Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wettability patterns have significant application potential in liquid transportation and water collection. Plasma hydrophilization is high-efficient and less-destructive, and has been widely used for preparing wettability patterns. However, the plasma-treated surfaces tend to recover to its original wettability, causing invalidation of the patterns. As a green treatment method, boiled water treatment could construct nanostructures, which is favorable for hydrophilicity-retaining; while the hydrophilization effect of plasma treatment would promote the reaction. Therefore, it should be possible to combine plasma and boiled water treatments to prepare long-lasting wettability patterns. In this paper, superhydrophobic aluminum surfaces were modified by plasma jet followed by boiled water treatment. The time stability, microstructures and chemical compositions of the treated surfaces were investigated by testing contact angles, scanning electron microscope, X-ray diffractometer, and X-ray photoelectron spectroscopy. The surfaces treated by plasma jet and boiled water could retain superhydrophilicity for a long time under various storage conditions, including normal ambient, high temperature or high humidity. On the basis of this technique, long-lasting patterns could be prepared on different metal substrates. The green method proposed is expected to have promising application potential in fabricating wettability patterns and lab-on-chip devices, especially for those used in severe conditions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322664-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): N. Srinivasan, M. Anbuchezhiyan, S. Harish, S. Ponnusamy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For the first time, C-ZnO/BiVO〈sub〉4〈/sub〉 heterostructured nanocomposite has been synthesized from BiVO〈sub〉4〈/sub〉 and carbon-doped ZnO nanoparticles. X-ray diffraction (XRD) study showed themonoclinic scheelite structure of BiVO〈sub〉4〈/sub〉 and the hexagonal wurtzite structure of ZnO in the C-ZnO/BiVO〈sub〉4〈/sub〉 composite. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) images revealed the spherical nanoparticles of size 20 to 30 nm for C-ZnO. The band gap of the ZnO has turned towards the visible region by doping with carbon as well as a composite formation with visible light active material BiVO〈sub〉4〈/sub〉. The chemical states of Zn, O, C and Zn, O, C, Bi, V species in C-ZnO, and C-ZnO/BiVO〈sub〉4〈/sub〉 composite respectively were confirmed by X-ray photoelectron microscopy (XPS) analysis. Also, the XPS spectra showed the significant peaks shift in the electronic states of Zn, O, and C for the heterojunction composite. The suppression of the electron-hole recombination rate was confirmed from the quenching of photoluminescence (PL) intensity for the composite. The adsorption study has performed, and the experimental results fit well with the Langmuir isotherm model for understanding the catalytic activity of the samples. The possible 〈em〉Z〈/em〉-scheme photocatalytic mechanism of the C-ZnO/BiVO〈sub〉4〈/sub〉 nanocomposite photocatalyst has proposed. The nanocomposite exhibited the enhanced catalytic activity with the higher degradation rate constant of 0.050 min〈sup〉−1〈/sup〉 for 50 min irradiation of visible light compared with their counterparts.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Rajesh Gudala, Songhee Kim, Mee-Ree Kim, Kiran Kumar Challa, Dong-Bum Seo, Vinaya Kumar Arepalli, Eui-Tae Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solar absorber Cu〈sub〉2〈/sub〉ZnSnS〈sub〉4〈/sub〉 (CZTS) films were uniformly deposited on Si/Mo substrates via a facile, cost-effective chemical bath deposition (CBD) by using ribonucleic acid (RNA) nucleobase uracil as the functional building block. The functional sites of uracil, i.e., C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O and N〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H, played a critical role in the complexation of metals via uracil-quartet functional architectures. Stable metal–uracil complexes significantly affected the growth kinetics, enhancing the uniform delivery of multimetal components into films and suppressing the undesirable formation of CuS particles. CZTS films obtained with the addition of 0.05 and 0.5 M uracil exhibited a smooth surface morphology and significantly improved photoconductive performance. The developed RNA-nucleobase-mediated CBD method demonstrates promise as multicomponent compound absorber films, including CZTS and CuInGaSe〈sub〉2〈/sub〉, in cost-effective solar cells.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322482-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Indu Gupta, Kunal J. Tiwari, P. Malar, Bhaskar Chandra Mohanty〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although non-toxic solution processing offers a scalable approach for growth of Cu〈sub〉2〈/sub〉ZnSnS〈sub〉4〈/sub〉 (CZTS) thin films, it must suppress the formation of secondary phases and yield facile conformal large grained films with minimum process steps. While growing CZTS films from environment-friendly ethanol based solutions, here we demonstrate how precursor concentration and post sulfurization critically affect the reaction pathway and morphology of the films. Deposition from lower ionic concentration precursor solution and sulfurization with nominal sulfur amount yielded phase-pure films. However, the thickness and grain size of these films were far lower than that desired for solar cell application, thus necessitating overlay depositions to achieve desired thickness and grain size. This issue was alleviated by increasing the ionic concentration in the precursor solution and the sulfur amount during sulfurization. It was found that coating from 1 M Cu-solution in just two dipping cycles followed by sulfurization at 500 °C yielded phase pure kesterite CZTS films of ~850 nm thickness. In addition, differently with the reported bilayered structure, the films exhibit a uniform microstructure with reasonably large grains. The resulting films showed the bandgap of 1.42 eV and very high photosensitivity upon illumination of white light.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322895-ga1.jpg" width="343" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Jianglai Xiang, Meng Dan, Qing Cai, Shan Yu, Ying Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic hydrogen production from hydrogen sulfide (H〈sub〉2〈/sub〉S) splitting has been considered as an appealing and sustainable approach to resolve both energy crisis and environment problem. It remains challenging to quest suitable photocatalysts for highly efficient H〈sub〉2〈/sub〉S splitting. Herein, a series of graphene oxide (GO)/MnS-Mn〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composites were successfully prepared via a mild method. The results demonstrated that the GO plays three roles in enhancing the photocatalytic H〈sub〉2〈/sub〉S splitting performance (i) enhancing sunlight response, (ii) promoting electrons transfer, (iii) inducing manganese oxide specie (Mn〈sub〉3〈/sub〉O〈sub〉4〈/sub〉) in-situ produced for hole trapping. As a result, the GO/MnS-Mn〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composites exhibit enhanced visible-light photocatalytic H〈sub〉2〈/sub〉S splitting activity, which is 6 folds higher than that of bare MnS. Finally, the photocatalytic mechanism is proposed over GO/MnS-Mn〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composites. This work provides a facile strategy for fabricating double cocatalyst on metal sulfides to realize improved photocatalytic H〈sub〉2〈/sub〉S splitting activity.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Constructing GO/MnS-Mn〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 dual cocatalysts system via GO-induced strategy for enhancing photocatalytic hydrogen production from hydrogen sulfide.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932255X-ga1.jpg" width="334" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): V. Tiron, E.-L. Ursu, D. Cristea, D. Munteanu, G. Bulai, A. Ceban, I.-L. Velicu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study aims to demonstrate that operating the HiPIMS discharge in bipolar regime (BP-HiPIMS) enables an energy-enhanced deposition process of high-quality hydrogen-free DLC thin films (high hardness, low coefficient of friction, good wear resistance, good adherence to the substrate and very low surface roughness). The structural and mechanical properties of DLC thin films deposited using the BP-HiPIMS technique were compared to those of the films prepared using a conventional HiPIMS process, under various deposition conditions. The BP-HiPIMS technique generates an energetic ion population and a substantial increase in the ion flux as compared to the conventional (monopolar) HiPIMS. This phenomenon overcomes the limitations when working with insulating or high electrical resistivity materials (both substrates and coatings), i.e. the need to accelerate the film-forming species. Energetic enhanced deposition conditions during bipolar HiPIMS facilitate the densification (up to 2.7 g/cm〈sup〉3〈/sup〉) of amorphous carbon thin films which results in an increase in the film hardness (23 GPa) when depositing on Si substrates, without using substrate bias voltage, adhesion interfacial layer or substrate pre-treatment. Besides high hardness, the BP-HiPIMS process allows growing DLC coatings with good elastic strain to failure and high resistance to plastic deformation and cracking.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322755-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Guangqun Tan, Qilin Liu, Xiaopeng Li, Yong Liu, Dan Xiao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Porous carbon materials were synthesized by a simple one-step pyrolysis of disodium ethylenediamine tetraacetate (Na〈sub〉2〈/sub〉EDTA) under different temperature (650, 750 and 850 °C). Several characterization technologies were employed to evaluate the as-synthesized samples. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy tests were carried out to study the electrochemical property of the samples. The capacitive deionization (CDI) performance of the three samples-based electrodes was investigated and compared. The obtained results showed that pyrolysis temperature played a key role in the formation of the final products with different pore structure and heteroatom content, such as nitrogen and oxygen. Electrochemical performance measurement revealed that 750 °C sample exhibited the highest specific capacitance, the smallest diffusive resistance and charge-transfer resistance, and good conductivity. The salt electrosorption capacity of 750 °C samples were 8.02 mg g〈sup〉−1〈/sup〉 at a low initial concentration of NaCl solution (25 mg L〈sup〉−1〈/sup〉) and 27.75 mg g〈sup〉−1〈/sup〉 at a high initial concentration of NaCl (500 mg L〈sup〉−1〈/sup〉). The outstanding CDI performance of 750 °C material can be contributed to its high specific surface area and suitable pore structure. As a low-cost and processable precursor, Na〈sub〉2〈/sub〉EDTA exhibited promising application prospect in large-scale CDI process.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yongliang Chen, Milos Toth, Chunju He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We propose an interfacial design strategy to prepare novel, highly structure-stable thin film nanocomposite (TFN) nanofiltration (NF) membranes. It employs NMG-assisted dopamine modification on nanoparticles and a substrate, followed by interfacial polymerization. Our approach overcomes two problems that are typical of composite membranes – a weak interlayer interactive force, and poor compatibility between inorganic nanoparticles and a polymer matrix in nanocomposite membranes. The TFN membrane presented here has a high methanol permeance (2.18 L·m〈sup〉−2〈/sup〉 ·h〈sup〉−1〈/sup〉·bar〈sup〉−1〈/sup〉) and a high rejection (99.1%) to acid red 18 (MW = 509 g·mol〈sup〉−1〈/sup〉), which is superior to commercial solvent resistant NF (SRNF) membranes and most literature on SRNF membranes. More importantly, our TFN membranes exhibit a high degree of structural stability, demonstrated by immersion in three organic solvents for 15 days and a two day continuous filtration test. Our strategy is facile and highly flexible, has high potential for deployment in SRNF, and may stimulate the development of practical SRNF applications in the near future.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Qianqian Yu, Linjie Zhou, Yanlei Su, Hong Wu, Xinda You, Jianliang Shen, Runnan Zhang, Zhongyi Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Most membrane-based separation technologies for water treatment are severely limited by fouling-induced flux decline. Herein, a self-cleaning coating with weak chargeability was achieved by assembly of perfluorooctane sulfonate (PFOS) and polyethyleneimine (PEI) on hydrolyzed polyacrylonitrile (HPAN) membrane. The -NH〈sub〉3〈/sub〉〈sup〉+〈/sup〉 endowed the membrane with hydrophilicity, thus introducing fouling-resistance property. The -CF〈sub〉X〈/sub〉 in the coating endowed the ultrafiltration membrane with low surface energy (23.3 mJ/m〈sup〉2〈/sup〉), thus introducing fouling-release property. Besides, a weakly-charged surface (8.4 mV) was obtained by the charge counteract between -SO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 on PFOS and -NH〈sub〉3〈/sub〉〈sup〉+〈/sup〉 on PEI, which further intensified the fouling-release property. The resultant membrane with such a self-cleaning coating exhibited superior antifouling property during oil/water emulsion and bovine serum albumin solution filtration. This facile assembly method may open up a new avenue towards engineering antifouling membrane surface for efficient water treatment.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324717-ga1.jpg" width="336" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Dongdong Zhang, Feng Peng, Ji Tan, Xuanyong Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Layered double hydroxide (LDH) films have been widely used for corrosion protection and medical applications. The most common synthesis methods for 〈em〉in-situ〈/em〉 growth of LDH films on magnesium (Mg) alloys are hydrothermal treatment and steam coating. However, both the methods are mainly used for preparing Mg〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Al LDH films and have limitations to 〈em〉in-situ〈/em〉 fabricate other Mg-based LDH films which are suitable for biomedical application. Herein, a novel synthesis strategy for 〈em〉in-situ〈/em〉 growth of LDH films on Mg alloys is proposed. Firstly, amorphous ferric oxyhydroxide (FeOOH) film was developed on Mg-Nd-Zn-Zr (JDBM) alloy by electrodeposition technique. Then, the as-prepared FeOOH films were transformed into Mg〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Fe LDH film 〈em〉via〈/em〉 hydrothermal treatment in water. In the LDH formation process, Mg〈sup〉2+〈/sup〉 would enter into amorphous FeOOH and replace the Fe〈sup〉3+〈/sup〉 quickly to form LDH. The thickness of the LDH films can be easily controlled by adjusting electrodeposition time. Electrochemical tests and cells culture experiments indicated that the as-prepared Mg〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Fe LDH films improved corrosion resistance and biocompatibility of JDBM alloy. In addition, Mg〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Mn LDH can also be prepared from amorphous manganese oxyhydroxide (MnOOH) 〈em〉via〈/em〉 this newly developed two-step method. The present work provides a new strategy for preparation of LDH films on Mg alloys surface.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324870-ga1.jpg" width="462" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Diogo Costa, João Oliveira, Marco S. Rodrigues, Joel Borges, Cacilda Moura, Paula Sampaio, Filipe Vaz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work focused on the production of nanocomposite thin films, composed of noble nanoparticles embedded in a dielectric matrix, to be tested as biocompatible plasmonic platforms for detection of molecules using Surface Enhance Raman Spectroscopy (SERS). Three different thin films systems were deposited by reactive DC magnetron sputtering, namely Au-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, Au-TiO〈sub〉2〈/sub〉 and Ag-TiO〈sub〉2〈/sub〉. The depositions were followed by a thermal treatment at different temperatures to promote the growth of the nanoparticles. Localized Surface Plasmon Resonance (LSPR) bands appeared already at 300 °C, related to the presence of Au nanoparticles, and at 500 °C in the case of Ag nanoparticles. Furthermore, at 700 °C, the Ag-TiO〈sub〉2〈/sub〉 films showed a broadband optical response due to the formation of Ag clusters at the film's surface. The biological experiments showed that the presence of the thin films didn't affect the growth of 〈em〉C〈/em〉. 〈em〉albicans〈/em〉, which is very convenient if one needs to detect low concentrations of this microorganism using SERS platforms. As for the SERS measurements, an enhancement of R6G Raman spectra intensity was clearly perceivable, but only for the TiO〈sub〉2〈/sub〉 matrix. Furthermore, the application of a plasma treatment allowed to better expose the nanoparticles, providing a further enhancement of Raman signals.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Heguang Liu, Yuan Li, I.I. Todd Gilliam, Wenwu Shi, Nitin Chopra〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we demonstrate a novel and flexible Surface enhanced Raman scattering (SERS) substrate comprised of thermally-responsive polymer film coated with ZnO nanowire-Au nanoparticle heterostructures. The heterostructure fabrication involved vapor-solid growth of ZnO nanowires and their subsequent decoration with Au nanoparticles via a wet-chemical and surfactant-free route. These heterostructures were further loaded with an analyte, methylene blue (MB). The mechanism of SERS relied on the Raman laser-based local heating of the thermally-responsive polymer substrate coated with MB-loaded heterostructures. This in-situ heating process caused the substrate to shrink and resulted in suitable hot spots between the heterostructures (“self-closing” mechanism) leading to MB Raman signal enhancement. The SERS effect was studied as a function of the substrate heating duration (0–10 s) and MB concentration (10〈sup〉−5〈/sup〉–10〈sup〉−7〈/sup〉 M). In addition, SERS substrate reusability was demonstrated by performing multi-spot analysis and photo-decomposition of loaded MB allowed for regeneration of the analyzed spot. The temperature distribution for the polymeric substrate under the incident Raman laser was calculated using finite element method (FEM). The plasmonic characteristics or hot spot formation for the self-closing heterostructures with varying distances between the two heterostructured targets was simulated using discrete dipole approximation (DDA) method.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Self-closing ZnO nanowire-Au nanoparticle heterostructures for surface enhanced Raman scattering effect.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932478X-ga1.jpg" width="266" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): MD Zahidul Islam, Yubing Dong, Nazakat Ali Khoso, Arsalan Ahmed, Hridam Deb, Yaofeng Zhu, Yang Wentong, Yaqin Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, Graphene oxide dyed on the cotton fabric through an efficient and industrially used continuous dyeing method. The graphene oxide dyed cotton fabric was reduced by using green reducing L-ascorbic at 100 °C microwave-assisted reduction. The effect of with different weight percent of rGO on sheet resistance and active electromagnetic interference (EMI) shielding of the studied. The surface modification of the fabric was achieved by using dopamine; the results showed significant improvements for the adhesion of (rGO) distributed uniformly on the fibre surface. Also, the rGO dyed fabric showed higher electrical conductivity 2.3 × 10〈sup〉−1〈/sup〉S/cm〈sup〉−1〈/sup〉 and EMI SE of −26 to −35 dB in the range of 30–1530 MHz in X-band.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932433X-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Ana Belén Ruiz-Muelle, Christian Kuttner, Carlos Alarcón-Fernández, Juan Manuel López-Romero, Petra Uhlmann, Rafael Contreras-Cáceres, Ignacio Fernández〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present hybrid systems bearing both plasmonic colloids and redox-active molecules that have demonstrated excellent performances in the catalytic reduction of nitrophenol (Nip) to aminophenol (Amp) in the presence of sodium borohydride. First, amino-functionalized spherical and triangular gold nanoparticles (AuNSs and AuNTs, respectively) were covalently incorporated onto polyacrylic acid (PAA) brushes attached to silicon surfaces. Next, a redox-active anthraquinone derivative (AQ-COOH) was immobilized onto the AuNPs surface by amidation reactions. The AuNP concentrations were varied to increase the incorporation and distribution of gold onto the PAA brushes. The catalytic activity in the reduction of 3-Nip and 4-Nip to Amp by NaBH〈sub〉4〈/sub〉 was evaluated by 〈sup〉1〈/sup〉H NMR spectroscopy. Colloidal size and morphology are analyzed by transmission electron microscopy (TEM) and UV–visible spectroscopy. Particle distribution on the silicon wafer was analyzed by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The presence of bonded cysteamine (Cys) and anthraquinone (AQ) derivatives on the gold surface was confirmed by X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman spectroscopy (SERS). The hybrid system could perform seven consecutive catalytic runs without loss of catalytic activity with conversions higher than 80%.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉New hybrid systems bearing both plasmonic colloids and redox-active molecules active in catalytic reduction processes.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323955-ga1.jpg" width="386" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Sittichain Pramchu, Atchara Punya Jaroenjittichai, Yongyut Laosiritaworn〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉First-principles density functional theory (DFT) and the variable-cell nudged-elastic-band (VC-NEB) method were used to investigate the roles of bromine substitution for iodine in perovskite to non-perovskite phase transition of CsPbI〈sub〉3〈/sub〉. CsPb(I〈sub〉1-〈em〉x〈/em〉〈/sub〉Br〈sub〉〈em〉x〈/em〉〈/sub〉)〈sub〉3〈/sub〉 mixed halide alloys with 〈em〉x〈/em〉 = 0, 1/6, 1/3, and 1 have been inspected to understand the effects of this bromine substitution. From the VC-NEB simulation results, the phase transition mechanism has been elucidated. The perovskite cubic to non-perovskite orthorhombic phase transition of CsPbI〈sub〉3〈/sub〉 could be described based on the following processes: the cubic symmetry breaking, which leads to monoclinic intermediate states; distortion and deformation of octahedral cages in response to the cubic symmetry breaking, which differentiate the length of Pb〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉I bond in PbI〈sub〉6〈/sub〉 octahedra; loss of 3D corner-sharing octahedral connectivity due to some Pb〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉I bond becomes too long; and the formation of 1D edge-sharing octahedral chain, which is the type of octahedral connectivity for the non-perovskite yellow phase. From the results of mixed halide alloys, using bromine to replace iodine was found to increase the perovskite to non-perovskite phase's energy barrier. Thus, the bromine substitution has been clarified to be useful to prevent phase transition to the yellow phase. Surprisingly, the non-perovskite to perovskite phase's energy barrier of CsPbI〈sub〉2〈/sub〉Br is anomalously low with large deviation from the linear trend. This indicates that the non-perovskite to perovskite phase's transformation is significantly easier to occur for CsPbI〈sub〉2〈/sub〉Br. Therefore, the results from this study’ calculation suggest that bromine substitution not only prevents the formation of non-perovskite yellow phase but also exhibits capability to transform the yellow phase back to the desirable black phase.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The simulation results of (a) perovskite to (f) non-perovskite phase transition, (a-f) transition pathway, (e) energy barrier, and change of octahedral connectivity from (a) 3D corner-sharing to (f) 1D edge-sharing structure have been elucidated in this work.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323906-ga1.jpg" width="390" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Lu Wang, Hongying Yu, Shaoyang Wang, Lei Qiao, Dongbai Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The self-healing of passive film on Ti after being damaged in Hank's physiological solution greatly fluctuates with time and its mechanism has been investigated by in-situ X-ray absorption fine structure spectroscopy (XAFS) and surface enhanced Raman spectroscopy (SERS) in a novel electrochemical repassivation set-up. The self-healing response is instant and the current density decays within 50 s due to the increase of the ratio of O and Ti atoms. The increase of the coordination number of Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O contributes to the decrease of current density until 6000 s. Moreover, the in-situ structure evolution is vastly different from that of ex-situ. Two time-dependent adsorbed intermediates exist during self-healing, the adsorption layers of Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉OH〈sub〉ads〈/sub〉 and Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉OH, and finally the interface forms a stable passive film of O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉OH after 1000 s with good corrosion resistance. Besides, in-situ XAFS and SERS exhibit a high disorder and amorphous nature of passive film on Ti, and the crystallinity increases from 300 s to 6000 s. Additionally, the time-dependent structure evolution and mechanism of self-healing of titanium passive film in local atomic scale will help to understand the corrosion science and protection in healthcare.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324547-ga1.jpg" width="376" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Si-Han Tsai, Yuan-Chu Shen, Chiung-Yi Huang, Ray-Hua Horng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A single-crystalline ZnGa〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 epilayer was successfully grown on a c-plane (0001) sapphire substrate through metalorganic chemical vapor deposition. A metal-semiconductor-metal Schottky deep-ultraviolet (DUV) photodetector based on a ZnGa〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film was fabricated through a simple process of E-gun evaporation and thermal annealing. At a bias of 10 V, the ZnGa〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 photodetectors exhibited excellent performance characteristics such as an extremely low dark current (0.86 pA), a responsivity of 0.46 A/W under 230-nm DUV, a high photo/dark current ratio (up to 4.68 × 10〈sup〉4〈/sup〉), a sharp cutoff wavelength of approximately 270 nm, and short rise and fall times of 0.96 and 0.34 s. The photogenerated holes trapped in the Schottky barrier and the shrinking of the depletion region under DUV illumination enabled high DUV/visible rejection ratio (3–4 orders with a 20-V bias). Therefore, the Fowler–Nordheim field tunneling emission functioned as the main electron transport mechanism under DUV illumination and improved the photoelectric characteristics of the epilayer.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Avgustina Boretskaya, Il'dar Il'yasov, Alexander Lamberov, Andrey Popov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The purpose of this paper is to identify the phase inhomogeneity, undetectable by X-ray method, and the reason for its occurrence in the composition of aluminum oxide. It is shown that even a trace amount of carbon (0.23 wt%) in the precursor of aluminum oxide can cause a high content of amorphous phase (38%). Carbon is present due to the products of incomplete hydrolysis of the aluminum alkoxides (alumoxanes) in the commercial sample of boehmite. The fact that the amorphous and crystalline phases in the composition of aluminum oxide differ in reactivity under hydrothermal treatment is first described. It is shown in a split endothermic peak on the differential scanning calorimetry curve. It is investigated that the brief hydrothermal treatment of the phase-inhomogeneous aluminum oxide and its subsequent calcination lead to formation of a defective structure with greater acidity in the composition of the aluminum oxide. This aluminum oxide was used as a support of the palladium catalyst in the 1,3-butadiene hydrogenation. This catalyst showed higher selectivity to 1-butene and low selectivity to butane, compared to the catalyst on alumina with amorphous phase.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324328-ga1.jpg" width="331" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yangyu Zhang, Jihui Cai, Yi Liu, Xiuyun Wang, Chak-Tong Au, Lilong Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel strategy for the synthesis of sintering-resistant Pt/Ce-Ti-T catalyst with high activity and stability for water-gas shift (WGS) reaction is demonstrated. By adding dopamine followed by thermal treatment under an inert atmosphere, the Pt/Ce-Ti-T catalyst was obtained after the removal of sacrificial dopamine through oxidation. For a Pt/Ce-Ti catalyst subjected to ageing but without the participation of dopamine, it showed a sharp decrease of CO conversion from ca. 90% to 48% at 400 °C within 12 h, while the similarly aged Pt/Ce-Ti-T catalyst displays a CO conversion of ca. 82% and no obvious sign of deactivation. It was found that in the case of Pt/Ce-Ti, there was increase of Pt nanoparticle size from 7.25 to 20.72 nm, while there was no significant increase in the Pt/Ce-Ti-T case (from 7.80 to 8.55 nm). The observation can be associated with the strengthening of metal-support contact as a result of dopamine mediation. The outcome is enhanced interfacial bonding between Pt nanoparticles and the Ce-Ti support, making the Pt/Ce-Ti-T catalyst highly resistant to sintering and has commendable durability for WGS reaction.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The synthesis of Pt/Ce-Ti-T and Pt/Ce-Ti.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324663-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Feng Ning, Shi-Zhang Chen, Yong Zhang, Gao-Hua Liao, Ping-Ying Tang, Zheng-Liang Li, Li-Ming Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Vertical heterostructures of two-dimensional (2D) materials are excellent candidates for designing next-generation electronic devices with superior performance. By using both 〈em〉ab initio〈/em〉 electronic calculations and quantum transport simulations, we investigated the electronic and transport properties of InAs/graphene heterostructure. The results reveal that electrons and holes accumulate at different layers after the adsorption of InAs layer, forming the built-in electronic field at the interface. The electrostatic potential energy of InAs layer is higher than that of graphene, and it favors more electrons transferring from InAs to graphene layer. Comparing the comment methods by introducing impurity and carriers' injection, rectifying and negative differential resistance behaviors can also be realized by the combined effects of electron-hole distribution, interfacial hybridization, and contact barrier in InAs/graphene heterostructure device. It shows that the rectifying ration gradually increases with bias voltage, and the negative differential resistance effect happens at either positive or at negative bias voltage regions. Electrostatic potential distribution and contact barrier play important roles in determining transport properties. Increasing interfacial hybridization is helpful for transmission enhancement in the weak interlayer interaction van der Waals heterostructure.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324262-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): G. Mohan Kumar, P. Ilanchezhiyan, C. Siva, A. Madhankumar, T.W. Kang, D.Y. Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tungsten-titania (WO〈sub〉3〈/sub〉-TiO〈sub〉2〈/sub〉) based binary oxide was fabricated by an eco-friendly chemical route for electrocatalytic water splitting and photoelectrical applications. Ambiguous evidence for the coexistence of W/Ti oxides and their binary feature were extensively studied by different analytical tools and also affirmed using high-resolution microscopy. The existence of multiple defects in the binary material and their 2.68 eV optical band gap was evaluated using the room-temperature photoluminescence data and Tauc's plot, respectively. Nature of conductivity in WO〈sub〉3〈/sub〉-TiO〈sub〉2〈/sub〉 and its flat band potential was inferred using Mott–Schottky type electrochemical impedance spectroscopic results. The enhanced photosensitivity in WO〈sub〉3〈/sub〉-TiO〈sub〉2〈/sub〉 was demonstrated using a flip-chip Schottky diode architecture and reasoned to the improved charge transfer kinetics across the same. Next, the potential of WO〈sub〉3〈/sub〉-TiO〈sub〉2〈/sub〉 for stable water splitting functions was examined. Here, WO〈sub〉3〈/sub〉-TiO〈sub〉2〈/sub〉 interface was found to provide an enriched surface area for effective charge transfer, complementing towards the effective oxygen evolution reaction (OER) performance. The results demonstrated a smaller overpotential of 270 mV, authenticating the oxide system as an effective anode material for water splitting reactions with excellent stability.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Guanqiong Li, Tong Xu, Ruifang He, Chunping Li, Jie Bai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic water splitting is a promising method to obtain clean hydrogen energy, and the corresponding catalyst has received extensive attention. Among them, cadmium sulfide (CdS) has a relatively narrow band gap (2.4 eV) and a high conduction band position. It can be considered to be a good visible light photocatalyst in response to visible light. However, its application is limited because the existence of rapid photo-electron-hole recombination and photo-corrosion. In this work, a series of hollow CdS tubes have been successfully prepared with the novel morphology via simple one-step solvo-thermal method. The as-prepared catalysts displayed great photocatalytic activity for photocatalytic split water product H〈sub〉2〈/sub〉 under light (λ ≥ 350 nm). Due to the presence of the solvent carbon layer, the photo-corrosion of CdS was prevented, so it had good cycle performance. Meanwhile, the appropriate mole of cadmium sulfur dosage was explored and found that 3 mmol was the most suitable. The CdS-3 sample performed the optimal hydrogen (H〈sub〉2〈/sub〉) evolution rate (312.6 μmol g〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉) within 4 h. In addition, based on various characterization results of the photocatalyst, the novel structure and probable catalytic mechanism were further explored.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Possible photocatalytic mechanism of the CdS-3 sample under light irradiation.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324390-ga1.jpg" width="360" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Ts. Lazarova, D. Kovacheva, M. Georgieva, D. Tzankov, G. Tyuliev, I. Spassova, A. Naydenov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of the glycine-glycerol fuel mixing ratio on the structure, morphology, magnetic and catalytic properties of nanosized MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 prepared by solution combustion method was investigated. The samples were synthesized using mixture of glycerol and glycine in the reducing power ratios 1:0, 0.75:0.25, 0.5:0.5, and 0.25:0.75. All samples were characterized by powder X-ray diffraction, N〈sub〉2〈/sub〉-physisorption at 77 K, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and H〈sub〉2〈/sub〉-thermal programmed reduction. Magnetic behavior of the ferrites at room temperature was investigated. It was demonstrated that by varying the glycerol to glycine ratio, samples with different magnetic properties can be prepared. The catalytic properties of MnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 were studied in reactions of complete oxidation of hydrocarbons (methane, ethane, propane, butane) as model substances. The results reveal that structural, surface and morphological characteristics of the prepared spinels could be tuned by varying the ratios in the fuel mixtures. The nanoparticles obtained with glycerol and with a mixture fuel with glycine up to 50% show better catalytic oxidation properties than the sample obtained with a fuel containing 75% glycine. After the catalytic tests these samples do not undergo any substantial phase and morphological changes, thus they could be applied in low temperature combustion.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323682-ga1.jpg" width="377" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Riming Hu, Jiaxiang Shang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantum capacitance is one of the key parameters determining the energy density of graphene-based supercapacitors. The present article explored the effects of the co-doping of transition metal (Mn, Fe, Co, Ni) and N atoms (TMN〈sub〉x〈/sub〉, x = 1–4) on the structural stability, quantum capacitance and surface storage charge of graphene using density functional theory calculations. We find that the formation energies and magnetic moments can be regulated by changing the type of dopant transition metal and the number of dopants N atoms. The quantum capacitance and surface storage charge of graphene are enhanced significantly with the co-doping of transition metal and N atoms. By checking the density of states, it can be found that the quantum capacitance is directly related to the density of state around the Fermi level. The enhancement of quantum capacitance is caused by the introduced localized states around the Fermi level contributed mainly from transition metal. In addition, the quantum capacitance and surface storage charge are found to increase monotonically with the increase of co-doping concentrations of transition metal and N atoms. The results can provide an effective and simple new idea for the design of graphene-based supercapacitors with high energy density.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324560-ga1.jpg" width="129" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Fei Liu, Thien-Phap Nguyen, Qin Wang, Florian Massuyeau, Yi Dan, Long Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Constructing a conductive interface is crucial for the transfer of photoexcited charges in the photocatalytic heterojunction system. In this study, we introduced Ag into g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/P3HT system to construct a conductive interface which benefits for transfer of photoexcited charges between g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and P3HT. A series of characterizations were employed to investigate the chemical structure, morphology and optical property of the obtained catalysts. And the photocatalytic activity of the as-prepared g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Ag/P3HT composites were evaluated by the degradation of tetracycline (TC) and methyl orange (MO) aqueous solution under visible light irradiation. Results show that the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Ag/P3HT exhibits a broad absorption band in the region of 400–700 nm and the photocatalytic activity of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Ag/P3HT obtains a great improvement comparing with that of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Ag and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/P3HT. In addition, the optimized loading content of P3HT is 0.3 mass% based on g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. The enhanced photocatalytic performance is due to the introduction of Ag, which improves the transfer of photoexcited charges between g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and P3HT. The active species trapping experiment shows that the main active specie is 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉O〈sup〉2−〈/sup〉. After five recycling experiments, the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Ag/P3HT shows high stability in the photocatalytic performance.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yanzhao Zou, Yang Xie, Shan Yu, Lvcun Chen, Wen Cui, Fan Dong, Ying Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) has been extensively applied for NO removal due to its striking visible-light response and outstanding stability. However, the toxic NO〈sub〉2〈/sub〉 product is not completely suppressed in the reaction process due to its poor photo-oxidation ability. Herein, a series of SnO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composites were successfully prepared by the decorated of SnO〈sub〉2〈/sub〉 quantum dots (QDs) onto g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 sheets. The experimental results demonstrated that SnO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 exhibited excellent visible-light response and enhanced photo-oxidization ability to inhibit the generation of NO〈sub〉2〈/sub〉. Moreover, the heterostructure between SnO〈sub〉2〈/sub〉 and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 promotes the separation of photogenerated electron-hole pairs, which is resulted in enhanced photocatalytic NO removal performance. More importantly, the in-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) measurement and electron spin resonance (ESR) are conducted to investigate the reaction pathway via detecting the generated intermediates, products and active radicals during NO removal process. This study provides a facile and effective method to enhance the efficiency of photocatalytic NO removal and suppress the concentration of NO〈sub〉2〈/sub〉 significantly.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Anchoring SnO〈sub〉2〈/sub〉 quantum dots on g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 sheets could enhance the photo-oxidation ability of SnO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalysts for inhibited the generation of toxic NO〈sub〉2〈/sub〉, and promote separation of photogenerated electron-hole pairs for enhanced photocatalytic NO removal under visible-light irradiation.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324274-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Qian Zhao, Yunli Ge, Kaixuan Fu, Yanfei Zheng, Qingling Liu, Chunfeng Song, Na Ji, Degang Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The key component of the catalytic oxidation technology is regarded to develop a stable and high activity catalyst. Herein, a series of PdMn/Ti catalysts have been prepared to oxidize acetone. By controlling the Mn amount, Pd dispersion on TiO〈sub〉2〈/sub〉 has been adjusted, which has been confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The X-ray photoelectron spectroscopy (XPS) results show that catalysts possessed more adsorbed oxygen content and an increasing proportion of palladium oxides after introducing manganese with multivalent states. Hydrogen-temperature programmed reduction (H〈sub〉2〈/sub〉-TPR) shows that the introduction of Mn has improved the low temperature reducibility of the catalyst. Catalytic activities of catalysts with manganese are much higher than that of their counterparts without manganese. Among the prepared catalysts, the Pd〈sub〉0.01〈/sub〉Mn〈sub〉0.2〈/sub〉/Ti catalyst exhibited the excellent catalytic activity toward acetone oxidation. The T〈sub〉95〈/sub〉 of acetone is 259 °C under the conditions of 1000 ppm of acetone concentration and 30,000 mL/(g h) of WHSV. The high catalytically activity of the Pd〈sub〉0.01〈/sub〉Mn〈sub〉0.2〈/sub〉/Ti catalyst could be ascribed to its good low temperature reducibility and abundant adsorbed oxygen and palladium oxides content. In addition, high valence states of Mn also contributed to the good catalytic activity of the Pd〈sub〉0.01〈/sub〉Mn〈sub〉0.2〈/sub〉/Ti catalyst.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323761-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): L. Fialho, S. Carvalho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surface modifications have been deeply investigated to improve their properties (nano-morphology/topography and chemistry), mainly to enhance surface bioactivity and consequently to overcome the current dental implants failures. For this purpose, the main goal of this work is to mimic the bone morphology as well as its chemical composition by the incorporation of calcium (Ca), phosphorus (P) and magnesium (Mg) on a tantalum (Ta) surface. Two approaches were used: reverse polarization (RP) and/or anodization, under different applied potential and acid-free electrolytes. It was observed that RP followed by anodization promoted the incorporation of cations (Ca〈sup〉2+〈/sup〉, Mg〈sup〉2+〈/sup〉 and Na〈sup〉+〈/sup〉) in a competitive way. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses showed formation of amorphous calcium phosphate compounds. Moreover, a surface enriched with Ca, P and Mg achieved a Ca/P ratio of 1.4 similar to the stoichiometric hydroxyapatite (1.67). The surfaces subsequently became rougher and hydrophilic with their biofunctionalization. All these surface features are good pointers towards a better implant osseointegration.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323700-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Yuxuan Zhang, Wen Zeng, Yanqiong Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption of hazardous CO and H〈sub〉2〈/sub〉S on four low-index surfaces of rutile TiO〈sub〉2〈/sub〉 surfaces was investigated using first-principle calculations, in an effort to distinguish the difference of surface reactivity on these surfaces in sensing process. We predicted that rutile TiO〈sub〉2〈/sub〉 possessed excellent capacity for H〈sub〉2〈/sub〉S detection than CO based on adsorptive structure, density of states (DOS) analysis and charge density difference (CDD) plots. Particularly, in H〈sub〉2〈/sub〉S adsorption, the dissociative adsorption process occurred on the (001) surface of TiO〈sub〉2〈/sub〉 with largest adsorption energy as 1.17 eV and noticeable modification in the electronic structure, rendering high sensitivity on this surface. The decomposition of H〈sub〉2〈/sub〉S yielded HS and H species, whose bonding features were also analyzed. It was suggested that 3p states of HS were able to mix with surface titanium and the 1 s states of H were considerably overlapped with 2p states of surface bridging oxygen, forming OH radicals on (001) surface. The reason for different sensing properties on these surfaces was pinpointed, and the significance of rutile (100) facet in H〈sub〉2〈/sub〉S monitoring was underlined. These preliminary investigations would provide a basic understanding for CO and H〈sub〉2〈/sub〉S adsorption for pursuing high-performance sensor toward targeted gas.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yan Zhuang, Yunfei Liu, Xianfeng Meng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Semiconductor based photocatalytic water splitting as a most bright method to solve the energy crisis has been widely studied in the past decade. Among them, MXene has become the focus of current research as a new, effective and inexpensive promoter-free catalyst. Herein, a novel 1D/2D photocatalyst of TiO〈sub〉2〈/sub〉/Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 is successfully prepared by electrostatic self-assembly technique. The maximum H〈sub〉2〈/sub〉 production rate of TiO〈sub〉2〈/sub〉/Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 nanocomposites is up to 6.979 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉, which is 3.8 times that of pure TiO〈sub〉2〈/sub〉 nanofibers (NFs). This improvement in photocatalytic H〈sub〉2〈/sub〉 production of TiO〈sub〉2〈/sub〉/Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 is originated from the heterogenous interface between TiO〈sub〉2〈/sub〉 NFs and Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 nanosheets. It brings higher photocatalytic efficiency and maintains its cycle H〈sub〉2〈/sub〉 production capacity. There is almost no decrease in photocatalytic H〈sub〉2〈/sub〉 production efficiency after 5 cycles. It is believed that this study can offer an innovative pathway to design high performance and low-cost photocatalytic materials composed of MXene co-catalyst for efficient water splitting H〈sub〉2〈/sub〉 production over semiconductors.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324444-ga1.jpg" width="378" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Deluo Ji, Gang Liu, Xiaolai Zhang, Changqiao Zhang, Shiling Yuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption of C5Pe molecules on silica surfaces with different hydrophobicity is systematically studied by a series of molecular dynamics simulations. For probing the effect of hydrophobicity of silica surfaces on the adsorption of C5Pe molecules, the properties of the silica surfaces were changed by controlling the ratio of hydrophilic and hydrophobic groups. According to the difference of interface properties, five systems were studied including the fully hydrophilic system, the 25% hydrophobic system, the 50% hydrophobic system, the 75% hydrophobic system and the fully hydrophobic system. We focused on analyzing C5Pe molecules morphology that directly contact with silica surfaces in different systems. Two adsorption configurations, tilted adsorption and tiled adsorption, were first presented in our study. The relationship between adsorption configuration and hydrophobicity was analyzed quantitatively. The results proved that the C5Pe of 25% hydrophobic silica interface prefer to adsorb in the form of tiled configuration and have strongest adsorption stability. Besides, the tiled adsorption C5Pe molecules were found to have better adsorption stability than tilted adsorption C5Pe molecules. And the study of C5Pe transforming from tilted adsorption to tiled adsorption revealed that C5Pe molecules have to surmount two energy barriers in the transforming process.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The adsorption process of a tiled adsorption C5Pe molecule was analyzed in the 25% hydrophobic system. (a) two energy barriers in the transformation of adsorption configuration (b) the snapshots of adsorption configuration in different adsorption stages.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324213-ga1.jpg" width="294" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Ezequiel Tosi, David Comedi, Guillermo Zampieri〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have analysed the surface band bending (SBB) at the clean ZnO(0001)-Zn surface and after its modification by electropositive, electronegative and atmospheric adsorbates. The evolution of the band bending with increasing adsorption was monitored by measuring core-level and valence-band X-ray photoelectron spectra. We found that the SBB produced by the adsorption of electropositive elements was always downwards, reaching in all cases the limit imposed by the crossing of the conduction-band minimum with the Fermi level. The adsorption of electronegative elements produced always upward band bending, but in this case a pinning of the SBB was observed that kept the valence-band maximum far from the Fermi level. A self-consistent equation relating the adsorbate level occupation with the band bending is shown to qualitatively reproduce the observed SBB pinning effect. In contrary to the commonly assumed upwards SBB for the ZnO/air interface, a 〈em〉downward〈/em〉 SBB was observed after exposing the clean surface to atmospheric air. A downward SBB was also observed when the surface was bombarded with 1 keV Ar〈sup〉+〈/sup〉 in vacuum.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932389X-ga1.jpg" width="329" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Gi Dae Park, Yun Chan Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spherical carbon materials with porous and hollow structures have been developed as efficient sulfur host materials for Li〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉S batteries through various synthetic strategies. However, nanostructured carbon materials, generally synthesized by liquid solution processes, have disadvantages of low electrical conductivity as sulfur host materials. In this study, highly porous hollow carbon-carbon nanotubes (CNTs) composite microspheres, with a high loading rate of ultrafine S and high electrical conductivity, are designed and successfully synthesized by an aerosol-assisted process (ultrasonic spray pyrolysis) as efficient sulfur host materials. The carbon-CNTs composite microspheres, with a high sulfur loading rate of 70 wt%, exhibit superior electrochemical performance as a cathode compared to that of S-loaded CNTs balls for Li〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉S batteries. The S-loaded carbon-CNTs composite microspheres exhibit a discharge capacity of 697 mA h g〈sup〉−1〈/sup〉 for the 250th cycle at a current density of 1.0C and show high reversible discharge capacities of 685 mA h g〈sup〉−1〈/sup〉, even at a high current density of 3.0C. The outstanding cycling and rate performance of S-loaded carbon-CNTs composite microspheres are attributed to the structural flexibility of the hollow structure, loading of ultrafine sulfur in micro- and mesopores of dextrin-derived carbon, and good electrical conductivity due to uniformly dispersed CNTs.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324341-ga1.jpg" width="390" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Hamideh Babazadeh K., Masumeh Foroutan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nano-structures play an important role in oil-water separation, and it has recently been shown that nano-particles of titanium dioxide succeed in oil-water separation. In the current study, the behavior of oil-water mixture on a titanium dioxide substrate in the presence and in the absence of surfactant was studied using molecular dynamics simulation. Simulation results indicate that in the presence of surfactant, the oil-water interfacial tension decreases as a result of hydrogen bonding between water and the hydrophilic head of the surfactant. This is particularly illustrated by the calculation of both lifetime as well as number of hydrogen bonds and leads to the separation of water from oil.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉a) Wetting contours of water and oil molecules in the presence of surfactants, pale green color related to the water molecule and the color of the green color associated with the molecule of oil. b) Contouring of the molecule of water and oil in the absence of surfactant. The blue color is due to the presence of the water molecule and the yellow color associated with the presence of the molecule of oil, the low points of the water and the tall points associated with the oil.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324250-ga1.jpg" width="393" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Junru Wang, Siyun Qi, Xiaohan Song, Yuanyuan Qu, Weifeng Li, Mingwen Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrogen evolution reaction (HER) plays an important role in water splitting to produce hydrogen. The high price of precious platinum-based catalysts that are the best HER electrocatalysts by now hampers the commercial application. Low-cost, earth-abundant and highly-efficient HER electrocatalysts are thus long-desired. On the basis of first-principles calculations, we investigated the HER electrocatalytic performance of the non-precious TiF〈sub〉3〈/sub〉 and its analogs. Our calculations showed that TiF〈sub〉3〈/sub〉 and WO〈sub〉3〈/sub〉 can serve as efficient HER electrocatalysts with the overpotentials comparable to those of the platinum-based catalysts. To uncover the origins of electrocatalytic performance, we established a relationship between the surface adsorption ability of a material and its electronic structure. The low HER overpotentials, unique porous structure and high abundance in earth make these materials promising candidates for high-performance HER electrocatalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324201-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Seung Jun Lee, Hyeon Jin Jung, Ravindranadh Koutavarapu, Seung Heon Lee, Malathi Arumugam, Ju Hyun Kim, Myong Yong Choi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, photocatalysis has attracted great attention due to its potential applications in the environmental sector. Visible light driven metal–semiconductor photocatalysts with efficient light absorption, high charge separation, enhanced surface plasmon resonance, and utilized active sites have emerged as promising materials for the degradation of organic pollutants. Here, plasmonic ZnO/Au/Pd nanocomposites, with various concentrations of Au (5, 10, and 15 wt%) and 5 wt% of Pd nanoparticles (NPs) were prepared by a facile and eco–friendly three–step pulsed laser ablation in liquid and photodeposition technique without utilizing any surfactants or capping agents to enhance the photocatalytic performance under visible light illumination. The plasmonic properties of Au NPs and an excellent trapping of photogenerated electrons on the surface of Pd led to the improved photocatalytic activity (PCA). The as-prepared ZnO/Au/Pd nanocomposites were characterized by numerous spectroscopic and microscopic techniques, and the results confirmed the fabrication of Au and Pd NPs homogeneously decorated on the surface of ZnO nanospheres. The effect of plasmon improved photocatalytic activity of the ZnO/Au/Pd photocatalysts was investigated by the degradation of methylene blue dye under visible light illumination. The optimum ZnO/Au/Pd nanocomposite was ca. 5.4 times more efficient at degrading methylene blue than pure ZnO. This exceptional improvement of photocatalytic activity for the ZnO/Au/Pd catalysts was due to the enhanced surface plasmon resonance effect of the Au NPs under visible light illumination, and the deposited Pd NPs assisted as an electron storage chamber for the degradation of methylene blue, thus, enabling the separation of charge carriers. Based on the experimental results, a possible photocatalytic mechanism for the degradation of methylene blue catalyzed by the ZnO/Au/Pd nanocomposite was proposed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324626-ga1.jpg" width="300" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Yonghui Wang, Fen Wang, Yuan Fang, Jianfeng Zhu, Hongjie Luo, Ji Qi, Wenling Wu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The urea-formaldehyde resins carbon (UFC) and Fe-containing UFC (Fe-UFC) have been prepared by direct carbonization of urea-formaldehyde resins (UF resins) without any surfactants. On this basis, N-doped materials of UFC/MnO〈sub〉2〈/sub〉 and Fe-UFC/MnO〈sub〉2〈/sub〉 composites were successfully synthesized by the situ redox method. UF resins played both roles of carbon source and nitrogen source. The specific surface areas are 265.7 m〈sup〉2〈/sup〉·g〈sup〉−〈/sup〉〈sup〉1〈/sup〉 and 229.4 m〈sup〉2〈/sup〉·g〈sup〉−〈/sup〉〈sup〉1〈/sup〉 for UFC/MnO〈sub〉2〈/sub〉 and Fe-UFC/MnO〈sub〉2〈/sub〉, respectively. Direct methanol fuel cells (DMFCs) were assembled with the prepared catalyst as cathode catalyst, polymer fiber membrane (PFM) as electrolyte film and PtRu/C as anode catalyst. DMFCs and cyclic voltammetry (CV) performance tests indicate that Fe-UFC/MnO〈sub〉2〈/sub〉-based DMFC displays superior oxygen reduction reaction (ORR) catalytic activity than UFC/MnO〈sub〉2〈/sub〉 owing to Fe-N〈sub〉x〈/sub〉 existing and a large number of pyridine-N in Fe-UFC/MnO〈sub〉2〈/sub〉. The lone pair electrons of pyridine-N can coordinate with transition metal elements and form Fe-N〈sub〉x〈/sub〉 groups on Fe-UFC/MnO〈sub〉2〈/sub〉, which can be used as the electrocatalytic active sites for ORR. On the other hand, the presence of iron on the prepared catalyst can reduce the band gap, facilitate the transfer from Mn〈sup〉III〈/sup〉 to Mn〈sup〉IV〈/sup〉, and provide free electrons for adsorbed O〈sub〉2〈/sub〉 or active oxygen species, thus accelerating the conductivity and ORR catalytic efficiency.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Wei Tao, Minkang Wang, Rashad Ali, Song Nie, Qinlin Zeng, Ruiquan Yang, Woon-Ming Lau, Liang He, Hui Tang, Xian Jian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Traditional photocatalysts are difficile to conform the provision of visible light catalysis, conducive recycling and eminent efficiency, which limits their practical applications for decomposing organic pollutants in wastewater. Herein, a multi-layered porous hierarchical titanium dioxide/graphitic carbon nitride (TiO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) hybrid coating is 〈em〉in-situ〈/em〉 generated on titanium (Ti) substrate by sequentially employing plasma electrolytic oxidation (PEO), alkali immersing and hydrothermal reaction. The as-prepared coating exhibits surpassing photocatalytic performance to decay Rhodamine B (RhB) than g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and TiO〈sub〉2〈/sub〉 photocatalysts under 5 W LED visible light with 240 h cyclic stability. Moreover, the electrons transport and 〈em〉Z〈/em〉-scheme mechanism for TiO〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 hetero-junction is pursued to account for the ultralow recombination of photo-induced electron-hole and the enhanced catalytic properties. Not only that, it inhibits the secondary pollution which has further intensified its significance for degradation of organic pollution in sewage treatment systems.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Maloy Kr. Mondal, Suprabhat Mukherjee, Nikhilesh Joardar, Debiprasad Roy, Pranesh Chowdhury, Santi P. Sinha Babu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study portrays the synthesis, characterization and different biological applications of hetero atoms (N and S) doped smart graphene quantum dots (NS-GQD). NS-GQD has been fruitfully conjugated with commercially available antibiotic streptomycin to develop drug conjugated quantum dot (DCQ) for the improvement of drug efficacy. Furthermore the smartness of NS-GQD has also been investigated in terms of intracellular imaging and biocompatibility study. Different spectroscopic and microscopic analyses reveal the successful development of NS-GQD and DCQ. Therefore these findings demonstrate some astonishing capabilities of NS-GQD towards different real field applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323591-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 16 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science〈/p〉 〈p〉Author(s): X. He, R.G. Song, D.J. Kong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The composite coatings were prepared on S355 offshore steel by laser cladding combined with micro-arc oxidation technology. The microstructure and corrosion behaviours such as immersion corrosion, corrosive wear of the as-prepared composite coatings were investigated, and the corrosion properties of the coatings were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The composite coating was well bonded with the substrate layer and showed good mechanical properties. The interaction between corrosion and wear was mainly corrosion accelerating abrasion in the substrate, while it was wear accelerating corrosion in the coating. The immersion corrosion mechanism of the cladding coating was pitting corrosion. When the current density was 5A·dm〈sup〉−2〈/sup〉, the composite coating could significantly improve the corrosion resistance of the substrate.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 14 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science〈/p〉 〈p〉Author(s): C.I. da Silva-Oliveira, D. Martinez-Martinez, F.M. Couto, L. Cunha, F. Macedo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Modulated Infrared Radiometry is a photothermal technique which allows thermal characterization of coatings, whose properties are determined by applying the “Extremum Method”. The objective is to apply this method on a set of films where all the parameters influencing the model are adjusted systematically in a matrix of 36 different samples. Zr-O-N films were deposited by sputtering varying three factors: i) composition/bonding of the film: metallic Zr, crystalline metallic-type Zr-O-N and disordered Zr-O-N (films deposited in the metallic, reactive and poisoned regimes of the hysteresis curve, respectively); ii) each film was deposited simultaneously on three different substrates: steel, glass and silicon; iii) in each batch, four different thicknesses were grown. Each type of film was deposited with 4 different thicknesses, on top of 3 different substrates, in the same batch, maximizing their similarity.〈/p〉 〈p〉In general, the results allow to discriminate among films and are consistent regardless the type of substrate, although some dispersion of data is observed. The trends of the thermal parameters depending on the thickness were explained in terms of the films' microstructural/chemical characteristics, and the influence of each substrate. The values of the thermal parameters agree with those found in literature, reflecting the nature of the films.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Fatima Zohra Bourib, Douniazad Mezdour, Mohamed Tabellout〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a polystyrene/polyaniline powder of core-shell structure was prepared by chemical polymerization of aniline, using tartaric acid as a dopant and ammonium persulfate as an oxidizer in presence of polystyrene. The matrix effect on the electrical properties of pure polyaniline was studied by means of dielectric relaxation spectroscopy (DRS) and electron paramagnetic resonance (EPR) technique at room temperature. AC conductivity and dielectric permittivity of the polystyrene/polyaniline were investigated in the frequency range of 10〈sup〉−1〈/sup〉 - 10〈sup〉6〈/sup〉 Hz. The doped polyaniline showed a DC conductivity of 10〈sup〉−5〈/sup〉 S/cm. Its incorporation in a polystyrene matrix lowered the conductivity of the mixture up to 10〈sup〉−7〈/sup〉 S/cm. This value remains acceptable for semi conductive applications. EPR characterization confirmed this behavior, it gave 〈em〉g〈/em〉-factor values equal to 2.0046 and 2.0093 for polyaniline and polystyrene/polyaniline respectively, close to the free electron 〈em〉g〈/em〉-factor value (2.0023), suggesting that the resonance comes from the delocalized electrons in the main chain of polyaniline. High dielectric constants were obtained for both polyaniline and polystyrene/polyaniline allowing their use as high k-dielectrics. The composite material showed two different relaxation processes. The first one may originate from the electrode polarization while the second is associated to the bulk relaxation of charge carriers.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323232-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Alekha Tyagi, Amit Yadav, Prerna Sinha, Shashank Singh, Pradip Paik, Kamal K. Kar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heteroatom doped carbon structures are widely recognized as efficient catalysts for oxygen reduction reaction (ORR). Herein, chicken feather rachis (FR), a poultry industry biowaste is explored as a novel precursor for ORR catalysis. This study comprises the effect of pyrolysis temperature on the structural characteristics and electrocatalytic performance of prepared electrocatalysts. N-doped carbon (NC) synthesized at 950 °C is further activated using KOH, ZnCl〈sub〉2〈/sub〉, and H〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 at different temperatures. Poultry feather fiber (FF) derived samples were also prepared for comparison. KOH activated NCA-900 (NCA-K-900) exhibits the superior electrochemical performance in terms of onset potential (−0.02 V vs Ag/AgCl) in comparison to similar catalysts previously reported and prepared from feather fiber, which exhibits ~ −0.2 V vs Ag/AgCl. This is attributed to the mesoporous structure and increased ORR active C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N sites in FR derived samples as confirmed by adsorption isotherm and XPS analysis, respectively. In addition, it shows 96% current stability in chronoamperometric measurements for 15 h. It is better than the previously reported electrocatalyst prepared from coconut shell (90%, 13 h) and egg yolk (91%, 9 h) respectively. Hence, this study presents an improved environment friendly substitute for ORR catalysis.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324006-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Yanting Xu, Binling Chen, Jun Nie, Guiping Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efficient catalysts for activating peroxymonosulfate (PMS) during advanced oxidation processes (AOPs) were essential for organic degradation efficiency. Herein, we reported the synthesis of N, S-doped FeCo bimetal oxides and phosphides nanoparticles-encapsulated porous carbon microspheres (FeCoO〈sub〉X〈/sub〉/FeCoP〈sub〉X〈/sub〉@C), where both nanoparticles and carbon microspheres act as active sites for the activation of PMS. The FeCoO〈sub〉X〈/sub〉/FeCoP〈sub〉X〈/sub〉@C and PMS system exhibited excellent organic catalytic degradation performances and its activation mechanism was proposed. For the first time, the activation of PMS was realized through nonradical and radical pathways simultaneously on FeCoO〈sub〉X〈/sub〉/FeCoP〈sub〉X〈/sub〉@C, which can be an extraordinary contribution for the design of efficient heterogeneous catalysts with superior degradation performance.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉In the radical process, FeCoO〈sub〉X〈/sub〉 and FeCoP〈sub〉X〈/sub〉 nanoparticles, acting as main active sites, catalyzed HSO〈sub〉5〈/sub〉〈sup〉−〈/sup〉 in PMS to generate SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉−〈/sup〉 and HO〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉, and these produced radicals then decomposed RhB into intermediates or CO〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉O, where SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉−〈/sup〉 served as the main active species. In the nonradical process, the N and S dopants in FeCoO〈sub〉X〈/sub〉/FeCoP〈sub〉X〈/sub〉@C can promote the adsorption of HSO〈sub〉5〈/sub〉〈sup〉−〈/sup〉. The π electrons between the graphitic structure of FeCoO〈sub〉X〈/sub〉/FeCoP〈sub〉X〈/sub〉@C and aromatic rings of adsorbed RhB then activated the O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O bond in HSO〈sub〉5〈/sub〉〈sup〉−〈/sup〉, enabling the decomposition of RhB.〈/p〉 〈p〉Mechanisms for RhB degradation in FeCoOX/FeCoPX@C and PMS system.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323748-ga1.jpg" width="272" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Jiankui Jia, Caiyun Jiang, Xiaorui Zhang, Panjie Li, Jianxi Xiong, Zheng Zhang, Ting Wu, Yuping Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel urea modified carbon quantum dots (NCDs) decorated g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉 〈em〉Z〈/em〉-scheme heterojunction was prepared through in situ calcination and physical deposition way in the article. The analysis data of UV–vis spectroscopy demonstrated that the introduction of NCDs and the construction of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉 〈em〉Z〈/em〉-scheme heterojunction can significantly improve the visible-light utilization. The enhanced photocurrent response and the reduced fluorescence intensity indicated the recombination of photogenerated electron-hole pairs in g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉/NCDs composites is significantly inhibited. In addition, the results of cyclic experiment and the XRD diffraction peak of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉/NCDs before and after the experiment declared that g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉/NCDs possess strong structural stability. Obviously, the excellent photocatalytic performance of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉/NCDs can be ascribed to the above three experimental processes. Experimental analysis of free radical capture confirmed that superoxide ion radicals (·O〈sub〉2〈/sub〉〈sup〉−〈/sup〉) was the main active component in photocatalytic degradation, and the possible degradation mechanism of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/WO〈sub〉3〈/sub〉/NCDs was proposed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323128-ga1.jpg" width="271" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Silvana R. Matkovic, Marta Bosco, Sebastián E. Collins, Laura E. Briand〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The synthesis of transition metals Wells Dawson heteropoly salts along with their elemental composition, water content, structure and specific surface area were thoroughly investigated. Additionally, the use of a molecular probe such as pyridine allowed the quantification of Lewis and Brønsted surface acid sites. The transition metals counter-cations provide both Lewis and Brønsted acid sites. The concentration of Brønsted acid sites is influenced by the crystallization water associated with the heteropoly anion.〈/p〉 〈p〉Additionally, the dispersion of the phosphotungstic Wells Dawson heteropolyacid over transition metal oxides evidenced the presence of both Brønsted and Lewis surface acid sites. The concentration of these sites is related to the surface dispersion of the crystals of the HPA over the oxide supports and the degree of hydration of the HPA.〈/p〉 〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Surface acid properties of the phosphotungstic Wells Dawson HPC tailored made with transition metals.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323621-ga1.jpg" width="249" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Luis A. Pérez, Noelia Bajales, Gabriela I. Lacconi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Raman spectroscopy is a typical technique used for quality control and identification of graphene oxide, able to generate a laser-induced reduction process, even at low power, during spectroscopic characterization of such systems. This phenomenon, far from being a problem, brought up novel routes to obtain hybrid carbonaceous materials for diverse applications. Motivated by this feature, the present study provides new insights into controllable patterning of graphene oxide by introducing the combined use of Raman spectroscopy with synchronized X-Y scanning using an AFM head, as lithographical approach for tailoring conducting/insulating reduced graphene oxide/graphene oxide channels pattern. Thus, a systematic study of spectral, topographical and chemical characterizations performed on laser-induced hybrid structures is presented, showing the dependence on a proper selection of laser wavelength, power, and irradiation times as well as scanning parameters to achieve the effective fabrication of microchanneled patterns with nanometric depths of interest in nanotechnology applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323335-ga1.jpg" width="318" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Yijie Wang, Min Zhong, Wu Wang, Qiuyu Wang, Wenduo Wu, Xingchuan Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ZnO as electron transfer layer in perovskite solar cells (PSCs) has a lot of advantages including high electron mobility and low processing temperature. However, because of the reported instabilities of perovskite layers deposited on ZnO, the application of ZnO in perovskite solar cells has been restricted. In this paper, highly ordered ZnO nanorod arrays have been synthesized by a polymer soft template method, and then modified by ZnSe via a successive ion layer adsorption and reaction method (SILAR). Field emission scanning electron microscope, X-ray diffractometer, UV–vis spectrophotometer, fluorophotometer and photovoltaic measurements were used to study the effects of ZnSe modification on the morphology, structure, light absorption and charge transfer of perovskite films and the performance of the PSCs based on ZnO nanorod arrays. The photoelectric conversion efficiency (PCE) of the PSC with ZnSe modification significantly enhanced by 27%, as compared to that of the pristine one, which is attributed to the suitable band alignment, better carrier separation and higher charge transfer efficiency with ZnSe modification. Meanwhile, ZnSe modification can also improve the air stability of the PSCs. This study promotes the development of ZnO nanorod arrays based PSCs with some new approaches and provides a useful reference.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The PCE of the PSC with ZnSe modification improved 27% and retained 80% after 168 h, compared to that of the pristine one which decreased to 〈40%.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323499-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Kunchang Mu, Yong Tao, Zhongdong Peng, Guorong Hu, Ke Du, Yanbing Cao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lithium-rich layered oxide is considered to be a very promising cathode material for next-generation lithium-ion batteries for its high specific capacity. However, some intrinsic drawbacks, such as large initial irreversible capacity, poor rate performance and inferior cycling stability, limit its commercialization process. Here, acidic lithium polyacrylate (LiPPA) and polypyrrole (PPy) mixed coating layer is designed to modify Li〈sub〉1.2〈/sub〉Ni〈sub〉0.2〈/sub〉Mn〈sub〉0.6〈/sub〉O〈sub〉2〈/sub〉 cathode materials. The characterization results of morphology, structure and element analysis technologies confirm that a mixed conductive network of LiPPA-PPy layer is uniformly coated on the surface of Li〈sub〉1.2〈/sub〉Ni〈sub〉0.2〈/sub〉Mn〈sub〉0.6〈/sub〉O〈sub〉2〈/sub〉 particles. The LiPPA-PPy coating layer has ion and electron conductivity, and it can protect the active materials from the corrosion of acidic species and alleviate superficial side reactions. In addition, a portion of lithium can be chemically pre-extracted during the coating process. Therefore, the LiPPA-PPy coated Li〈sub〉1.2〈/sub〉Ni〈sub〉0.2〈/sub〉Mn〈sub〉0.6〈/sub〉O〈sub〉2〈/sub〉 shows a greatly improved electrochemical performance. Specifically, it can deliver the higher initial coulombic efficiency (~83.09%), enhanced rate capability (120 mAh g〈sup〉−〈/sup〉〈sup〉1〈/sup〉 at 5 C) and superior cycle performance.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Xiaoli Deng, Qingxiao Zhou, Haifu Huang, Wenzheng Zhou, Xianqing Liang, Guangxu Li, Jin Guo, Shaolong Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, it reports the design and synthesis of NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 core/shell arrays on Ni foam using a two-step method of hydrothermal method and electrodeposition. The hetero-structures are composed of NiCoO〈sub〉2〈/sub〉 flakes as the core-material and Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 ultrathin nanosheets as the shell-material. Due to the unique core/shell hetero-structure and positive synergistic effect of two components, hierarchical NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 arrays exhibit excellent capacitive performance as energy storage materials. The mass specific capacity of NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 is as high as 1599.5C g〈sup〉−1〈/sup〉 at 1.0 A g〈sup〉−1〈/sup〉, which is higher than the sum of the capacity of the two samples NiCoO〈sub〉2〈/sub〉/NF(640.0C g〈sup〉−1〈/sup〉) and Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/NF(695.3C g〈sup〉−1〈/sup〉). NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/NF also shows a very high areal specific capacity of 4.06 C cm〈sup〉−2〈/sup〉. Therefore, NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 arrays greatly releases the energy storage potential of the NiCoO〈sub〉2〈/sub〉 and Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 materials in supercapacitors. Furthermore, a hybrid supercapacitor device fabricated using NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/NF as positive electrode and the graphene as negative electrode possesses a high energy density of 73.97 Wh kg〈sup〉−1〈/sup〉 at a power density of 800 W kg〈sup〉−1〈/sup〉, and maintain 22.01 Wh kg〈sup〉−1〈/sup〉 at a high power density of 12.8 kW kg〈sup〉−1〈/sup〉. These results demonstrate that hierarchical NiCoO〈sub〉2〈/sub〉@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 core/shell arrays have great potential as a positive electrode in supercapacitor with high energy density.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323542-ga1.jpg" width="390" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Quanjun Xiang, Fang Li, Dainan Zhang, Yulong Liao, Haiping Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The surface properties of photocatalysts strongly affect interfacial catalytic reaction and determine photocatalytic activity. In this work, surface-modified graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) nanosheets were prepared via plasma treatment in H〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉-CH〈sub〉4〈/sub〉, and Ar atmosphere. Hydrogenated g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets with hydrophilic group C-N-H, defect state, and exfoliated morphology were obtained via treating g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets with H〈sub〉2〈/sub〉 plasma at room temperature. The hydrogenated g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets possessed the improved photocatalytic activity for hydrogen evolution, and the rate of hydrogen evolution exceeded that of pristine g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 by a factor of 4.8. Photocatalytic activity improvement is due to the introduction of hydrophilic group C-N-H, defect states, and exfoliated nanosheet morphology. Hydrophilic functional group of C-N-H can effectively capture water molecules. Defect states generated via plasma treatment acted as a capture center to suppress carrier recombination and transfer the trapped electrons to the adsorbed water molecules. Exfoliated nanosheet morphology provided a large number of active sites for catalytic reaction. Optical emission spectroscopy supported the introduction of hydrogen species during H〈sub〉2〈/sub〉 plasma treatment of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. First-principle density functional theory calculations confirmed the enhanced adsorption capacity of hydrogenated g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 for water molecules. The mechanism of enhanced photocatalytic H〈sub〉2〈/sub〉-production activity was further proposed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Hydrogenated g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 with hydrophilic group C-N-H, defect states and exfoliated morphology, fabricated by treating g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 with H〈sub〉2〈/sub〉 at room temperature, exhibit an enhanced visible-light photocatalytic H〈sub〉2〈/sub〉-production activity.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323086-ga1.jpg" width="408" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): K. Rudharachari Maiyelvaganan, Shanmugasundaram Kamalakannan, Muthuramalingam Prakash〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The investigation of interface materials is very important for the development of functional materials for energy storage applications. In this work, the microscopic adsorption mechanism of various ionic liquids (ILs) on the carbonaceous surface such as graphene sheet (G) and carbon nanotube (CNT) models are investigated using density functional theory (DFT) method. To study the interfacial interaction between ILs and different carbon surfaces, we have selected dodecabenzocoronene (DBC) as a model surface for graphene sheet and curved surface for CNT. In order to understand the adsorption mechanism and effect of curvature on the stability of the complexes, we used hydrophobic and hydrophilic ILs ([MMIm]〈sup〉+〈/sup〉[X]〈sup〉−〈/sup〉, where X = DCA, Cl, OTf, PF〈sub〉6〈/sub〉 and BF〈sub〉4〈/sub〉) at these surfaces. It is found from our calculations that the adsorption mechanism of ILs at DBC and curved surfaces is different and it depends on the existence of fluoro and non-fluoro anions in ILs. The adsorption of ILs on DBC surface is mostly dominated by dispersive nature, whereas ILs@CNT predominated by electrostatic and exchange-repulsion interactions which is confirmed by energy decomposition analysis (EDA). The selection of anion play a significant role in the stability of the complexes and also this will affect the interfacial interaction between ion-pair and surfaces. Close scrutiny of the results reveal that hydrophilic ILs are strongly adsorbed on both the surface whereas in the case of hydrophobic ILs, the cationic part of ILs ([MMIm]〈sup〉+〈/sup〉) predominantly interacted with surface, except [MMIm]〈sup〉+〈/sup〉[OTf]〈sup〉−〈/sup〉. The oxygen atom of [OTf]〈sup〉−〈/sup〉 anion directly interacts with the edge of carbon surface which is confirmed through EDA, AIM and MESP analyses.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323268-ga1.jpg" width="480" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): He Chen, Jin-Tao Chen, Lin Shao, Lei Wang, Xian-Zhu Fu, Jing-Li Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Conformal deposition and effective use of catalysts based on 3D electrode architectures are of great importance in electrocatalytic applications. In this work, 3D porous Ni substrate is first fabricated through a hydrogen bubbles dynamic templated method, and well-dispersed Pt nanoparticles are loaded on the substrate subsequently 〈em〉via〈/em〉 atomic layer deposition. The 3D porous Ni/Pt is utilized as an efficient hydrogen evolution reaction catalyst. The 3D and high surface area structure is realized through the hydrogen bubbles dynamic templated method. The synergistic effect between atomic-layer-deposited Pt and the 3D structure of porous Ni substrate finds a new approach of minimal yet effective utilization of Pt for much enhanced HER activity. The 3D porous Ni/Pt samples show comparable activity performance with commercial 20 wt% Pt/C. Furthermore, according to the Pt mass-based calculation, only ~0.1 wt% Pt was deposited on 3D porous Ni substrate electrocatalysts which exhibits a much higher activity than the commercial 20 wt% Pt/C catalyst.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322974-ga1.jpg" width="449" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Jun Neoung Heo, Jongmin Shin, Jeong Yeon Do, Raeyeong Kim, Misook Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein we focused on developing a narrow-bandgap oxide catalyst as a light absorber and on improving the selectivity of the desired product upon conversion to CO〈sub〉2〈/sub〉. CdS/Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalysts were prepared by heterogeneously joining CdS nanorods, which have well-known activity as a water splitting catalyst, and cheap Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 particles, which are easily absorbed at wavelength range 550–600 nm. After 10 h of UV irradiation, the cumulative amount of CO〈sub〉2〈/sub〉 intermediate and CH〈sub〉4〈/sub〉 product in the 1CdS/1Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 heterojunction catalyst was 16.5 μmolg〈sup〉−1〈/sup〉 after 10 h. The amount of CO increased with increasing Fe content. Conversely, the amount of total reduction product was greatly reduced, to 0.41 μmolg〈sup〉−1〈/sup〉 after 10 h of visible irradiation, but the CH〈sub〉4〈/sub〉 produced increased more than 5 times compared with the amount of CO. GC–MS spectrometry analysis of 〈sup〉13〈/sup〉C labeling showed that the CH〈sub〉4〈/sub〉 conversion of CO〈sub〉2〈/sub〉 on the CdS/Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 heterojunction catalyst proceeds by the proton-assisted multi-electron reduction via the carbene pathway. From the results of PL and photocurrent analysis, we conclude that in CdS/Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 heterojunction particles, the excited electrons move between the two particles to inhibit the recombination of electrons and holes, whereby the catalytic activity is greatly improved. In particular, the movement of electrons in the heterojunction particles was observed flowing naturally without clogging based on the Z-scheme system. Furthermore, the electrons emitted from CdS do not recombine with their holes, but move to the VBs of adjacent Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and fill them, exciting more electrons. Eventually, the rational electron transfer cycle between Cd〈sup〉2+〈/sup〉/Fe〈sup〉3+〈/sup〉 redox couples in the CdS/Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 heterojunction catalyst could act a driving force for promoting the photocatalytic reaction by naturally filling or moving electrons and holes in the photocatalyst system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323645-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Giuseppe Giannuzzi, Caterina Gaudiuso, Rosa Di Mundo, Luciana Mirenghi, Fotis Fraggelakis, Rainer Kling, Pietro Mario Lugarà, Antonio Ancona〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We investigate the short and long term wettability of laser textured stainless steel samples in order to better understand the interplay between surface topography and chemistry. Very different 1D and 2D periodic as well as non-periodic surface patterns were produced by exploiting the extreme flexibility of a setup consisting of five rotating birefringent crystals, which allows generating bursts of up to 32 femtosecond laser pulses with fixed intra-burst delay of 1.5 ps. The change of the surface morphology as a function of the pulse splitting, the burst polarization state and the fluence was systematically studied. The surface topography was characterized by SEM and AFM microscopy. The laser textured samples exhibited, initially, superhydrophilic behaviour which, during exposure to ambient air, turned into superhydrophobic with an exponential growth of the static contact angle. The dynamic contact angle measurements revealed a water adhesive character which was explained by XPS analyses of the surfaces that showed an increase of hydrocarbons and more oxidized metal species with the aging. The characteristic water adhesiveness and superhydrophobicity of laser textured surfaces can be exploited for no loss droplet reversible transportation or harvesting.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Time dependence of the contact angle for the 1D-LIPSS obtained with bursts of 〈em〉n〈/em〉 = 16, linearly polarized pulses (black open square) and for the 2D-LIPSS obtained with bursts of 〈em〉n〈/em〉 = 4, crossed polarized pulses (red open circle). The time delay in both cases is 1.5 ps.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321622-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Yue Su, Siqi Wang, Danwen Yao, Yao Fu, Hongwei Zang, Huailiang Xu, Pavel Polynkin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Multi-functional metal surfaces with simultaneous superhydrophobic and antireflective properties have a wide range of industrial, medical, and defense applications. Rapid fabrication of such multifunctional surfaces on irregularly shaped metals and on a large scale has been a challenge. Here we demonstrate an approach for rapid, standoff fabrication of multi-functional surfaces with super-hydrophobic and antireflective properties on irregularly-shaped samples, by texturing them with femtosecond laser filaments in air, followed by chemical fluorination treatment. Two types of metals with a variety of curved surfaces have been processed at a standoff distance of 1 m: the type 304 stainless steel and the type Ti–6Al–4V titanium alloy. Through laser processing and fluorination, multi-functional surfaces with the water contact angle of over 150° and diffused reflectance below 9%, over the wavelength range from 240 to 2500 nm, have been realized on both metals. Our results suggest that this technique could enable cost-effective and large-scale fabrication of irregularly-shaped, multi-functional surfaces that can be useful for various applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323074-ga1.jpg" width="326" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Cong Chen, Ming Gao, Hongyu Mu, Xiaoyan Zeng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The purification of laser keyhole and improving molten pool flow are important means to restrain the porosity of laser-MIG hybrid welding of aluminum alloy. In this paper, four kinds of kerf were prefabricated by four common gases (Argon, Nitrogen, Air, Oxygen), which are used for studying the effect of kerf remelted layer on weld porosity. The experimental results show that the porosity is affected by the composition and thickness of the remelted layer. The porosity of Argon-weld and Nitrogen-weld is low, and that of Air-weld and Oxygen-weld is high. It increased linearly with the thickness of remelted layer (〈em〉d〈/em〉). Regardless of the types of kerf, when the 〈em〉d〈/em〉 is less than 136 μm, the porosity is less than 2%. When the 〈em〉d〈/em〉 is thin, the purification of laser keyhole avoids the adverse effect of remelted layer oxide on the molten pool and reduces the porosity. When the 〈em〉d〈/em〉 is thick, the influence of oxygen on surface tension and molten pool flow driven by it starts to dominate. It makes the temperature coefficient of surface tension change from negative to positive, and the molten pool change from ‘outward flow’ to ‘inward flow’, which prevent bubbles from escaping and increasing the porosity.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Yoonkyung Park, Jinseon Park, Sangho Cho, Myung Mo Sung〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report a one-step fabrication method for large-area single-crystal organic thin films guided through vertically confined lateral crystal growth via capillary force lithography (VC-LCG via CLF). In this method, organic molecules in ink solutions self-assemble and crystallize within the vertically confined channels of patterned molds. Vertical confinement, determined by the channel depth, played a major role with regard to the crystallization and formation of single-crystalline organic thin films. We also demonstrated its usefulness by fabricating wafer-scale arrays of single-crystal organic thin film transistors with high performance and uniformly distributed electrical properties, which could be attributed to their large-scale single-crystalline nature, homogeneous film morphologies and the suppression of multiple crystal orientations. Especially, the versatility to various organic molecules, ease of processing optimization, and uniform crystallinity all over the patterned area increase the possibility of VC-LCG to apply in the industrial process.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322202-ga1.jpg" width="372" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Niroj Maharjan, Vinod K. Murugan, Wei Zhou, Matteo Seita〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surface laser treatments are often used on metals and metal alloys to improve the material's hardness and corrosion resistance. Investigating the reasons for this property enhancement is not trivial because the resulting microstructure changes gradually from the surface to the bulk. Here we report a simple serial-sectioning technique to assess the hardness and corrosion behavior of a laser hardened chromoly steel at depth intervals of 30 μm. The method consists of indenting the sample surface to a controlled depth and then mechanically polishing the sample until the indents are no longer visible. By performing corrosion tests and recording the surface hardness at each depth interval, we assess the corrosion behavior and hardness of the material throughout the laser-induced microstructure gradient. Our measurements show that the improved corrosion resistance stems from the chromium-enriched oxide layer at the top surface of the steel alloy. Surprisingly, the phase content and grain size, whose distribution varies significantly throughout the sample thickness, has little to no effect on the corrosion behavior of the steel.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322081-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Amin Mohammadi, Esmaeil Zaminpayma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉By applying non-equilibrium Green's functions (NEGF) in combination with tight-binding (TB) model, the electronic transport properties of pristine and defected zigzag α-graphyne nanotubes (〈em〉Z〈/em〉-α-GYNTs) are studied under finite bias. We have considered single vacancy (SV) and double vacancy (DV) and also the effect of tube size. Depending on the position of absent atom(s), different modes arise. Initially the formation energy is calculated for each mode and we observed that in all cases an endothermic process in needed. Moreover by studying the band structure we found that all defects cause gap closing, but not enough to change the semiconducting nature of 〈em〉Z〈/em〉-α-GYNTs entirely. Considering p as a positive integer, I-V characteristics show that for (3〈em〉p〈/em〉-1, 0) tubes, all defects are found to increase the current but on the contrary presence of them in a (3〈em〉p〈/em〉, 0) tube results in current reduction. (3〈em〉p〈/em〉 + 1, 0) tubes does not show a defined and specific reaction to the defects. Band structure of electrodes, transmission spectrum, Density of states, molecular energy spectrum and molecular projected self-consistent Hamiltonian (MPSH) are analyzed subsequently to make the electronic transport properties of GYNT devices clearer. Our results can be used in developing nano-scale devices.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932272X-ga1.jpg" width="370" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): L. Selva Roselin, Nainesh Patel, Suzan A. Khayyat〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Removal of dye pigments from oily waste water is one of the challenges for paint industries. Thus the present work is focused on developing efficient photocatalyst based on gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 to degrade Rhodamine B (RhB) dye from oily water. In order to enhance the photocatalytic activity low concentration of B and Ag was doped and codoped in gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 by facile methods. XRD and XPS results showed that B is doped in gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 matrix by replacing C while metallic Ag nanoparticles are decorated on gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 sheet-like morphology as confirmed from TEM images. The maximum narrowing of band gap to 2.55 eV was achieved upon codoping with Ag and B as estimated from UV–Vis spectra. As observed by emission spectra, both B and Ag effectively reduces the recombination process by trapping the photogenerated charges and fast transfer of electron from gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 to Ag. The maximum surface area is also recorded for Ag-B-codoped gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Improvising all three factors namely surface area, visible light absorption, and charge separation in Ag-B-codoped gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 creates synergic effect to increase the photocatalytic RhB degradation rate by 4.2 times as compared to undoped gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Codoped gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 also displayed significantly higher photo-degradation performance than Ag or B monodoped gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321130-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Hongtao Zhao, Mingwei Tian, Zengqing Li, Yuying Zhang, Zhihua Chen, Weidong Zhang, Shifeng Zhu, Yaning Sun, Zhenhui Zhou, Lijun Qu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wear-resistant performance is a critical property of the surface coated functional fabric during the cyclical abrasion of wearing procedure. However, inorganic nano-materials cannot easily graft onto the hydrophobic fabric substrate with weak interface interaction resulting in the unsatisfactory washing and wearing performance. Herein, the wear-resistant conductive polyester fabric with polyurethane - silver - polyurethane (PU-Ag-PU) sandwich micro-structure decoration was successfully fabricated via a facile spray coating route of water soluble polyurethane (WPU) and the in-situ synthesis of silver nanoparticles (AgNPs). The obtained fabric exhibits excellent conductivity with surface resistance of 4.95 Ω/sq. which is far below than the case without sandwich micro-structure (1.32 × 10〈sup〉4〈/sup〉 Ω/sq) because of the rearrangement and quantum tunneling effect of AgNPs in the nanocomposite coating layer. More importantly, the wear resistance of the modified fabric has been greatly enhanced owing to the two-phase structure of polyurethane and sandwich micro-structure of coating. The weight loss of the sandwich micro-structure coated fabric is only 1.28% while it is 5.58% of the case without PU outer coating layer. Meanwhile, surface resistance of the sandwich fabric is merely increased an order of magnitude even after 1500 times of abrasion cycle test, showing a qualitative enhancement compared with that of the common structure (increased seven orders of magnitude). In short, the designed sandwich micro-structure significantly enhanced the electrical conductivity and wear-resistance of silver decorated fabric. The strategy of sandwich micro-structure design in this paper has indicated a potential way for the durable wear-resistant functional fabrics.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321385-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Wei Yan, Xiaojia Yuan, Xiaojie Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interaction between acetic acid and TiO〈sub〉2〈/sub〉-B surfaces are investigated by first-principles calculations based on density functional theory (DFT). We found non-dissociative adsorption configurations are energetic favorable. We also found that the favorable adsorption configuration is not only determined by the matched interface structures, but also by the electrostatic potential distribution on the Lewis acid (Ti*) and basic (O*) sites. Although the TiO〈sub〉2〈/sub〉-B (100) surface exhibits the highest surface energy among the all low-index clean surface, the TiO〈sub〉2〈/sub〉-B (010) surface displaces a stronger oscillation of electrostatic potential between the Lewis acid and basic sites which provides an extra driving force to promote acetic acid dissociation and leads to larger adsorption energy. Such strong oscillatory electrostatic potential provides an extra driving force to promote acetic acid dissociation, which leads to larger adsorption energy. Our results provide a detailed insight into the adsorption structure and mechanism and further shed light on the photochemistry on surface at the molecular level.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322342-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Jeong Yeon Do, Rama Krishna Chava, Young Il Kim, Dae Won Cho, Misook Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solar driven visible photocatalytic H〈sub〉2〈/sub〉 evolution using semiconductors is recognized as one of the most promising routes for clean energy technology; however, efficient visible light utilization and charge separation are the key roles in a photocatalyst system for high activity. Herein, Ag based ternary nanocomposite system, Ag〈sub〉2〈/sub〉S/Ag/Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 was synthesized by chemical reduction and subsequent hydrothermal methods. The prepared nanocomposites were characterized by Powder X-ray diffraction, X-ray photoelectron spectroscopy, Scanning and transmission electron microscopy, UV–vis diffuse reflectance and photoluminescence spectroscopy methods. The Ag〈sub〉2〈/sub〉S/Ag/Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 ternary nanocomposite system displayed a higher photocatalytic H〈sub〉2〈/sub〉 evolution activity than that of pure Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉, Ag〈sub〉2〈/sub〉S and their binary composites under visible light irradiation. In the present work, Ag〈sub〉2〈/sub〉S/Ag/Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 exhibited a photocatalytic H〈sub〉2〈/sub〉 evolution activity of ~8.5 mmol·g〈sup〉−〈/sup〉〈sup〉1〈/sup〉. The enhanced photocatalytic activity can be attributed to the improved visible light absorption and effective charge separation between Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 and Ag〈sub〉2〈/sub〉S via the electron shuttle mediator Ag.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322639-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Jiameng Wang, Chao Zhang, Yongqiang Yang, Ailan Fan, Ruifang Chi, Jing Shi, Xiangyu Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bacteria induced infectious are one of the major problems during wound healing process. The overuse of antibiotics has resulted in the spread of resistant bacteria. In this work, Ag-doped TiO〈sub〉2〈/sub〉 (Ag/TiO〈sub〉2〈/sub〉) nanoparticles were embedded in PVA hydrogel to combat antibiotic-resistant bacteria efficiently by light-induced reactive oxygen species (ROS). The hybrid hydrogel was prepared via a simple two-step process. Ag/TiO〈sub〉2〈/sub〉 nanoparticles were obtained via chemical reduction process followed by Ag/TiO〈sub〉2〈/sub〉 nanoparticles were dispersed in PVA and freeze-thaw cycles five times to fabricate Ag/TiO〈sub〉2〈/sub〉-incorporated hybrid hydrogel. The hydrogel exhibited excellent antibacterial activities against both 〈em〉Escherichia coli〈/em〉 (〈em〉E. coli〈/em〉) and 〈em〉Staphylococcus aureus〈/em〉 (〈em〉S. aureus〈/em〉) under irradiation of 660 nm visible light (VL) within 5 min due to the release of ROS by photodynamic action. The hydrogel also possessed excellent biocompatibility. In addition, the hydrogel could efficiently prevent the 〈em〉S. aureus〈/em〉- accompanied wound infection in vivo and significantly accelerate wound healing in rat model compare with traditional 3 M dressing.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Xiong Zhao, Changfeng Chen, Qiao Sun, Yingchao Li, Haobo Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Imidazoline derivatives with 7 levels of HOMO energy and imidazoline quaternary ammonium salts with 4 different LUMO energy levels were designed by adjusting the hydrophilic and hydrophobic groups of the imidazoline molecule. The changes in adsorption bonding and electron transfer of the imidazoline molecule on the metal surface were calculated by the density functional based tight binding method (DFTB+). It was found that when the HOMO and LUMO energy levels matched the iron Fermi level more closely, the imidazoline molecule could undergo more electron transfer with the iron substrate, thereby forming a stronger adsorption bond with the matrix. The corrosion inhibition performance of the imidazoline groups was further tested by electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Finally, a clear correspondence between the frontier orbital energy level of the imidazoline molecule and its corrosion inhibition performance was discussed, which could provide an effective solution for designing high performance corrosion inhibitor molecules.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Hao Cui, Xiaoxing Zhang, Yi Li, Dachang Chen, Ying Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using first-principles theory, we theoretically investigate the most stable doping site of Ni atom on pristine InN monolayer and adsorption behavior of Ni-doped InN (Ni-InN) monolayer upon four noxious gases (NO, CO〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉S and NH〈sub〉3〈/sub〉). Electron localization function (ELF), electron deformation density (EDD) as well as density of state (DOS) are considered to further understand the adsorption behavior of Ni-InN monolayer towards gas molecules. For possible application of our proposed material, work function and band structure of the isolated and gas adsorbed Ni-InN monolayer are analyzed as well. It is found that the Ni dopant prefers to be adsorbed on the pristine InN monolayer at the T〈sub〉N〈/sub〉 site with the lowest biding force (〈em〉E〈/em〉〈sub〉b〈/sub〉) of −3.02 eV. Four gases could be stably adsorbed on the Ni-InN monolayer surface wherein the chemisorption is identified due to the large adsorption energy (〈em〉E〈/em〉〈sub〉ad〈/sub〉) and charge transfer (〈em〉Q〈/em〉〈sub〉T〈/sub〉). ELF, EDD and DOS analyses corroborate the strong chemical interaction between Ni dopant and activated atoms in gas molecules. The band structure analysis provides the sensing mechanism of Ni-InN based resistance-type chemical sensor for detection of such four gaseous species. Our calculations can supply some guidance to explore promising novel gas sensors using group III-V nitrides in the gas-sensing field and environmental monitoring fields.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322548-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Kaiqiang Xu, Jie Shen, Difa Xu, Zhongfu Li, Shumin Zhang, Zhaohui Wu, Wenhui Feng, Xiangyi Xiao, Shiying Zhang, Jiaqing Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bulk doping plays an important role in BiOCl since both its intrinsic light absorption and carriers transport are improved. However, bulk doped BiOCl is difficult to prepare by hydrothermal method due to the well-known self-purification effect. Hence, it is still a challenge to develop a convenient method for synthesizing bulk doped BiOCl. In this study, we describe a novel bulk doping strategy to produce stable and efficient W-doped BiOCl by molten salt method. The intrinsic optical absorption and carriers transport are improved after bulk W doping. Thus, the photocatalytic activity towards RhB degradation is significantly increased under visible light and 2%W-BiOCl exhibited 10 times higher photocatalytic degradation rate of RhB than that of pristine BiOCl. This work not only verifies a novel and feasible method of W-doping modification for BiOCl, but also develops an efficient strategy for synthesizing bulk doped semiconductors.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Qi Wang, Bin Xu, Caili Xu, Yi Wang, Yun Zhang, Jie Wu, Guangyin Fan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Synthesis of Rh-based material with low loading as efficient and pH-universal electrocatalyst for hydrogen evolution reaction (HER) remains challenging. Here, ultrafine and well-dispersed Rh nanoparticles (NPs) (1.92 nm in diameter) were synthesized and fixed on nitrogen (N)-doped carbon nanotubes with encapsulated nickel NPs (Rh/Ni@NCNTs) by a simple and sustainable strategy without any organic solvents, capping agents, and reducing agents. Rh/Ni@NCNTs with a low Rh loading of 2.84 wt% exhibited an outperforming catalytic activity with overpotentials of 14, 26, and 45 mV at 10 mA cm〈sup〉−2〈/sup〉 in 1.0 M KOH, 1.0 M PBS, and 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, respectively. Moreover, Rh/Ni@NCNTs displayed a high turnover frequency (TOF) of 1.67 s〈sup〉−1〈/sup〉 at 100 mV in alkaline solution. The high HER performance should be attributed to the catalytically active nature of metal Rh, unique structure characteristics of Ni@NCNTs induced positive synergistic effects with the anchored Rh NPs, and metal Ni promoted N-rich feature of Rh/Ni@NCNTs. The NCNTs with ultrathin wrinkle graphitic carbon walls could efficiently wrap the as-synthesized ultrasmall Rh NPs, prohibiting their aggregations and leading to high stability and durability of Rh/Ni@NCNTs. The present study may open a new frontier for preparing high-dispersed and high-active HER catalyst.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323669-ga1.jpg" width="291" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Parisa Nematollahi, Erik C. Neyts〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The ever increasing global production and dispersion of methane requires novel chemistry to transform it into easily condensable energy carriers that can be integrated into the chemical infrastructure. In this context, single atom catalysts have attracted considerable interest due to their outstanding catalytic activity. We here use density functional theory (DFT) computations to compare the reaction and activation energies of M and MN〈sub〉4〈/sub〉 embedded graphene (M = Ni and Si) on the methane-to-methanol conversion near room temperature. Thermodynamically, conversion of methane to methanol is energetically favorable at ambient conditions. Both singlet and triplet spin state of the studied systems are considered in all of the calculations. The DFT results show that the barriers are significantly lower when the complexes are in the triplet state than in the singlet state. In particular, Si-G with the preferred spin multiplicity of triplet seems to be viable catalysts for methane oxidation thanks to the corresponding lower energy barriers and higher stability of the obtained configurations. Our results provide insights into the nature of methane conversion and may serve as guidance for fabricating cost-effective graphene-based single atom catalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324158-ga1.jpg" width="393" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Sumit Barthwal, Bokhyun Lee, Si-Hyung Lim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A facile and durable biomimetic slippery anti-icing coating was prepared by infusing nontoxic and inexpensive lubricating silicone oil into superhydrophobic dual-scale micro/nano-structured (MNS) aluminum surfaces. Superhydrophobic surfaces were fabricated via the combination of simple chemical etching and anodization, followed by surface modification with poly(dimethylsiloxane) (PDMS). Compared to superhydrophobic coatings, silicone oil-infused polydimethylsiloxane (SOIP) coating displays a low ice-adhesion strength of 22 ± 5 kPa on the structured surface. Moreover, the SOIP coating sustained low ice-adhesion strength (35 ± 15 kPa) even when the temperature was lowered to −25 °C. The MNS-surface exhibits excellent durability, showing a low ice-adhesion (108 kPa) after 20 icing/de-icing cycles and long-term icephobicity (55 ± 13 kPa) after four months' exposure in ambient environment. We also examined the influence of surface morphology on ice-adhesion strength, the SOIP modified MNS-surface displays better anti-icing properties compared to a nano-structured (NS) surface under harsh conditions; icing/deicing and abrasion cycles. The MNS-surface act as reservoir to hold the excess amount of oil, thus reducing the loss of lubricant during icing/deicing cycles. The proposed technique is very simple and cost-effective, and most importantly it can be applied for production of durable and scalable anti-icing coatings for various practical applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324742-ga1.jpg" width="290" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science〈/p〉 〈p〉Author(s): Ilya A. Morozov, Alexander S. Kamenetskikh, Marina G. Scherban, Roman I. Izumov, Dmitriy M. Kiselkov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Development of discontinuous (islet) plasma coatings is of interest in the design of materials with non-uniform (selective) surface properties. In comparison with similar continuous coatings, they are more resistant to a damage induced by deformation of an elastic substrate. In this work, a formation of carbon islet coating obtained by a pulsed magnetron sputtering of a graphite target on the surface of nitrogen-activated elastic polyurethane is studied. Roughness, stiffness and surface energy of the polymer substrate are increased after the activation. High surface energy makes possible the adhesion of carbon islets (the size is ~100 μm and the thickness is 4…30 nm). The structure of such coatings depends both on the activation time and on the number of pulses of the magnetron discharge. At the initial stage of formation, the islets consist of individual shards ~1 μm in plane, further carbon deposition covers them by a continuous layer. Certain areas of the islets with a thickness 〉 10 nm have an inhomogeneous wrinkled surface. The folds are formed at the initial stage of the islet growth, and the subsequent carbon deposition flattens them. Preliminary studies of stretched samples up to 20% showed good fracture toughness of the given coatings.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219325036-ga1.jpg" width="356" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 16 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science〈/p〉 〈p〉Author(s): Jeff Th. M. de Hosson, Nasar Ali, Giuseppe Fierro, Mahmood Aliofkhazraei, Mircea Chipara〈/p〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 496〈/p〉 〈p〉Author(s): Suraj Kumar, Lokesh K. Gangwar, Amit Choudhary, Surinder P. Singh, Rajesh, Ashok M. Biradar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interfacial molecular dynamics at the interface of solid substrate and paraelectric phase liquid crystal is investigated by dielectric spectroscopy in surface stabilized geometry of strongly and weakly rubbed cells. The material under study is ferroelectric liquid crystal (FLC) below the paraelectric phase. The studies are intended to explore the well-known surface stabilized memory effect in thin cells. The memory effect in weakly rubbed cells is long lasting than strongly rubbed cell. The studies near transition temperature (T〈sub〉c〈/sub〉) of ferroelectric (chiral smectic C) to paraelectric (chiral smectic A) phase is carried out. The molecular interface of FLC with substrate causes the phason mode to appear abnormally in paraelectric phase. The phason mode is the character of ferroelectric phase in liquid crystals. In strongly rubbed cell, the amplitude of phason mode is appeared just in ferroelectric phase only whereas in the weakly rubbed cells, the phason mode and soft mode are seen simultaneously at separate frequencies in paraelectric phase near T〈sub〉c〈/sub〉. The appearance of phason mode at the interface of FLC and solid substrate indicates towards the unusual ferroelectric molecular interface of FLC with substrate which is responsible for the longer duration memory effect in weakly rubbed cell.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The interfacial molecular dynamics at the interface of solid substrate and ferroelectric liquid crystal (FLC) phase is investigated by dielectric spectroscopy in surface stabilized geometry of strongly and weakly rubbed cells. The studies are intended to explore the well-known surface stabilized memory effect in thin cells. The memory effect in weakly rubbed cells is long lasting than strongly rubbed which is explained by the studies near transition temperature (T〈sub〉c〈/sub〉) of ferro (chiral smectic C) to paraelectric (chiral smectic A) phase. The molecular interface of FLC with substrate cause the phason mode to appear abnormally in paraelectric phase. The phason mode is the character of ferroelectric phase. In strongly rubbed cell, the amplitude of phason mode is appeared just in ferroelectric phase only whereas in the weakly rubbed cells, the phason mode and soft mode are seen simultaneously at separate frequencies in paraelectric phase near T〈sub〉c〈/sub〉. The appearance of phason mode at the interface of FLC and solid substrate indicates towards the unusual ferroelectric molecular interface of FLC with substrate which is responsible for the longer duration memory effect in weakly rubbed cell.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219324924-ga1.jpg" width="371" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Akbar Mohammad, Mohammad Ehtisham Khan, Md Rezaul Karim, Moo Hwan Cho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper reports the facile and scalable fabrication of mesoporous and high surface area tin oxide and tin oxide-graphitic carbon nitride nanostructures {SnO〈sub〉2〈/sub〉, SnO〈sub〉2〈/sub〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (2 mM) and SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (4 mM)} using a template-free hydrothermal approach. The overall characterisation revealed a high surface area (~181 m〈sup〉2〈/sup〉g〈sup〉−1〈/sup〉) with a mesoporous nature, relatively small particle size of SnO〈sub〉2〈/sub〉 (~2–3 nm) grown successfully on 〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 sheets, and significantly improved optical behaviour for visible light utilisation. Comparative screening of different SnO〈sub〉2〈/sub〉-based nanostructures revealed significant improvements in visible-light induced photocatalytic degradation and photoelectrochemical performance. The visible light-induced degradation of model pollutants, such as Methylene blue (MB) and Congo red (CR), was achieved using SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (4 mM) with total efficiencies of ~99.38% and ~96%, respectively. The optimal SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (4 mM) as a photocatalyst showed first order rate constants for MB and CR degradation of 6.39 × 10〈sup〉−2〈/sup〉 min〈sup〉−1〈/sup〉 and 2.9 × 10〈sup〉−2〈/sup〉 min〈sup〉−1〈/sup〉, respectively. Moreover, the investigation of different modified photoelectrodes of SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (4 mM) and SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (2 mM) show more than eight and five times higher photoelectrochemical performance than that of SnO〈sub〉2〈/sub〉, respectively. The possible synergistic effect makes the SnO〈sub〉2〈/sub〉-〈em〉g〈/em〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (4 mM) nanostructure an exceptional photocatalytic and photoresponsive material under visible light that can be used for future environmental and energy-related purposes.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321932210X-ga1.jpg" width="399" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 494〈/p〉 〈p〉Author(s): Qin Zou, Yuhui Zhao, Xing Jin, Jian Fang, Danyang Li, Kongzhai Li, Jichang Lu, Yongming Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉CeO〈sub〉2〈/sub〉 with four different morphologies (sphere, rod, octahedron, cube) are used as the supports to synthesize the CuCe catalysts for the CO preferential oxidation in the H〈sub〉2〈/sub〉-rich gas and characterized by various techniques (TEM, HR-TEM, SEM, XRD, N〈sub〉2〈/sub〉 physisorption, XPS, Raman spectra, CO-TPD, CO-DRIFTS, O〈sub〉2〈/sub〉-TPD, CO pulses, H〈sub〉2〈/sub〉-TPR) to obtain an insight into the impact of the CeO〈sub〉2〈/sub〉 morphology on the surface structure, composition and redox properties, especially the active species. The four supports expose {111}, {110} and {100} planes, and sphere-shape CeO〈sub〉2〈/sub〉 has a higher ratio of {111}, which can form more reductive copper species and active oxygen species. And the catalytic performance followed by this order: spheres (28.5 kJ/mol) 〉 rods (31.0 kJ/mol) 〉 octahedrons (34.1 kJ/mol) 〉 cubes (40.3 kJ/mol). By further analysis of the characterization results, a series of structure-activity relationships are established to confirm that the active oxygen species is the decisive factor of preferential oxidation of CO in the H〈sub〉2〈/sub〉-rich stream.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322469-ga1.jpg" width="430" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Sui Mao, Jiliang Liu, Yuyong Pan, Jihoon Lee, Zhao Yao, Puran Pandey, Sundar Kunwar, Zhijun Zhu, Wenfei Shen, Laurence A. Belfiore, Jianguo Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hybrid metal-oxide (MO)/metal nanostructures (MNSs) have been appealing in widespread optoelectronic devices due to their strong and tunable plasmonic activity encompassing selective scattering and absorption of wavelength depending upon the surface morphology and surrounding dielectric environment. In this paper, the various MO/Au NSs hybrid thin-films are fabricated via the solid-state-dewetting growth of Au NSs and sol-gel deposition of MO top-layers including ZrO〈sub〉x〈/sub〉, CeO〈sub〉x〈/sub〉, YO〈sub〉x〈/sub〉 and AlO〈sub〉x〈/sub〉. Over 450% enhancements in maximum absorption are observed along with the peak redshift of 168 nm for the series of MO/Au NS films. The overall plasmonic properties undergo three regimes by the systematical control of film morphology: (I) Rapid enhancement, (II) Slow enhancement and (III) Decay. The optical evolution is correspondingly investigated with the assistant of finite-different time-domain (FDTD) calculation. This work may give an aid to the photo-electronic applications, such as photovoltaics, sensing and surface enhanced Raman scattering, based on hybrid MNSs especially on control of their plasmonic properties.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323724-ga1.jpg" width="266" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Junkyeong Jeong, Donghee Kang, Do Hyung Chun, Dongguen Shin, Jong Hyeok Park, Sang Wan Cho, Kwangho Jeong, Hyunbok Lee, Yeonjin Yi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Direct evidence of chemical interaction and origin of electron accumulation at a “buried” methylammonium lead triiodide (CH〈sub〉3〈/sub〉NH〈sub〉3〈/sub〉PbI〈sub〉3〈/sub〉, hereafter “MAPI”)/TiO〈sub〉2〈/sub〉 interface is presented in this study for the first time. Despite the high power conversion efficiency of perovskite solar cells (PSCs) using a TiO〈sub〉2〈/sub〉 electron transport layer, the MAPI/TiO〈sub〉2〈/sub〉 interface is believed as an electron accumulation position during device operation. To elucidate the cause of the electron accumulation, the energy level alignment at the MAPI/TiO〈sub〉2〈/sub〉 interface should be understood. However, a buried MAPI/TiO〈sub〉2〈/sub〉 interface forms after a thick MAPI layer deposition; thus, the electronic structure of the MAPI/TiO〈sub〉2〈/sub〉 interface cannot be measured using surface-sensitive photoelectron spectroscopy in a conventional stack-up manner. In this study, we investigated the electronic structure of a buried MAPI/TiO〈sub〉2〈/sub〉 interface by removing the MAPI and organic layers using solvent immersion. As a result, we reveal that a conduction band minimum (CBM) mismatch occurs owing to the Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Pb bonding on the TiO〈sub〉2〈/sub〉 surface. The Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Pb bonds form by the Pb ions penetrating during the spin coating of the MAPI solution. When a [6,6]-phenyl C〈sub〉61〈/sub〉 butyric acid methyl ester (PCBM) layer was inserted, the CBM mismatch was removed owing to the high work function of PCBM.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322688-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Guangxu Yan, Ayan Bhowmik, Balasubramanian Nagarajan, Xu Song, Sung Chyn Tan, Ming Jen Tan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent times, sintered brazing preform is used in the TLP bonding applications as it only undergoes partial melting during bonding, thus preserving its designed geometries. In this paper, the effects of bonding time on the transient liquid phase bonding joint of Inconel 718 using a new nickel-based sintered brazing preform was investigated. The microstructure and mechanical properties of SBP joints before and after bonding for different time were investigated. The results show that the ultimate tensile bonding strength of the joint was improved from 120 MPa to 410 MPa with the bonding time increasing from 2 to 300 min, due to the corresponding reduction of porosity and Ni〈sub〉3〈/sub〉B type borides in the bonded sintered brazing preform. However, the strength decreased from 410 MPa to 370 MPa after bonding for 600 min. This was attributed to the grain coarsening that weakened the joint. In addition, the grain growth of Ni matrix in the sintered brazing preform was greatly impeded and its growth rate was nearly constant for the periods of bonding time tested, which are attributed to the relatively homogenous distribution of borides and Si-enriched particles. Moreover, more precipitates formed in the precipitation layer with increasing bonding time.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322433-ga1.jpg" width="491" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Liping Wang, Guangpeng Yang, Dong Wang, Changyu Lu, Weisheng Guan, Yuliang Li, Jing Deng, John Crittenden〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective sunlight harvesting to realize environmental remediation remains great challenge for photocatalysis technique. Herein, the visible-light-driven CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 hierarchical nanocomposites were synthesized via a facile hydrothermal method. Compared to the pristine CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉, all the CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 nanocomposites exhibited the superior photocatalytic activity toward tetracycline (TC) degradation under visible light irradiation (λ 〉 420 nm). Particularly, 60 wt% CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 nanocomposite displayed the best photocatalytic activity, which can degrade 93% TC (20 mg/L) in 1 h with the rate constant of 0.0286 min〈sup〉−1〈/sup〉. Based on the COD removal, the apparent quantum yield was calculated to be 0.32%. The superior photocatalytic performance of the CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 nanocomposite is mainly attributed to: 〈strong〉I〈/strong〉) the efficient interfacial charge separation of the Z-scheme heterojunction; 〈strong〉II〈/strong〉) the prolonged lifetime of the charge carriers; 〈strong〉III〈/strong〉) the enlarged hierarchical surface area; 〈strong〉IV〈/strong〉) the strengthened visible light absorption. The DFT calculations suggested that the photoexcited electrons were transferred from the Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 conduction band consisting of W5d orbital to recombine with the holes in the CuBi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 valence band consisting of O2p orbital of, which greatly facilitated the charge separation in the heterostructure. This study could provide some enlightment to the heterojunction construction and visible light utilization for other catalytic system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323098-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Yanjie Ren, Huayue Du, Chenyang Du, Jian Chen, Wei Li, Wei Qiu, Jyh-Ping Hsu, Jizhou Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Considering their excellent chemical stability and conductivity, transition metal carbide and transition metal nitride coatings are adopted to protect metallic bipolar plates in this study. However, the inevitable adsorption of oxygen on these coatings in the cathodic environment of proton exchange membrane fuel cell (PEMFC) influences their chemical stabilities and conductivities. To asses this influence, first-principle calculations are conducted using CrN, TiC and TiN as examples. We show that in the case of CrN〈sub〉,〈/sub〉 CrO〈sub〉x〈/sub〉 ionic bonds are formed on CrN (111), and TiO〈sub〉x〈/sub〉 formed on TiC (111) and TiN (111) for the case of TiC and TiN, respectively. In addition, the overlapping in the electron density difference distribution of Cr〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O is more significant than that of Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O (TiN) and Ti〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O (TiC). This suggests that CrN has a better chemical stability than TiN or TiC, and therefore, is more suitable for the protective coating of metallic bipolar plates, especially in the cathodic environment of PEMFC.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323189-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Nasreen Bibi, Mian Zahid Hussain, Shahid Hussain, Safeer Ahmed, Iqbal Ahmad, Shaowei Zhang, Azhar Iqbal〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To meet the demands of modern energy storage devices it is essential to synthesize novel electrode materials with unique morphologies that could have high porosity, high cyclic stability and high electrical conductivity. The high electrical conductivity enables the electrode materials to achieve high specific capacitance with high energy density. Herein, we have synthesized perovskite SrZrO〈sub〉3〈/sub〉 nanorods, which exhibit superior electrochemical performance due to high specific surface area of 146.13 m〈sup〉2〈/sup〉/g and a pore width of 1.475 nm. The fabricated electrode consisting of SrZrO3 nanorods achieves a specific capacitance of ⁓1225.8 F/g, at low current density (10 A/g) and high energy density (65 Wh/kg) with a power deliverance of ~4000 W/kg, which is almost twice higher than previously reported results. The electrode consisting of SrZrO〈sub〉3〈/sub〉 nanorods exhibits high cyclic stability up to 1000 CV cycles. High energy & power density and excellent cyclic stability suggest a significant promise for SrZrO〈sub〉3〈/sub〉 nanorods to be used as an electrode material in future supercapacitor devices.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323840-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Cristina Romero-Rangel, Alfredo Guillén-López, L.M. Mejía-Mendoza, Miguel Robles, Néstor David Espinosa-Torres, Jesús Muñiz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Correlations among atomic structure, chemical reactivity, charge transfer and electronic structure properties were investigated in nanoporous carbon at different mass densities. The model structures have been generated by a heat-quench procedure using Density Functional Theory calculations and first-principles quantum molecular dynamics simulations. Reactive points seem to be highly dependent of the local structure of the material. The results showed that sponge-like nanoporous carbons are good candidates to graft polyoxometalates since they presented a stronger interaction with the carbon substrate. The charge transfer is from the nanoporous carbon to the polyoxometalate and a covalent interaction was observed for a density of 0.75 g/cm〈sup〉3〈/sup〉. Our materials developed an electronic band around the Fermi level.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321695-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): C. Barbay, S. Saada, C. Mer-Calfati, S. Temgoua, J. Barjon, J.C. Arnault〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A contrast clearly correlated with the linear defect network into boron-doped diamond epilayers was evidenced by FE-SEM observations performed at 20 kV. According to this study, this effect is dependent on the incident electron energy, the boron concentration, the thickness of the epilayer and the surface termination. These contrasts are confirmed to correspond to dislocations by revealing the etch pits using a H〈sub〉2〈/sub〉/O〈sub〉2〈/sub〉 plasma and by cathodoluminescence analyses. Boron impurities seem to play a major role in the contrast formation.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Subi Joseph, Sinoj Abraham, Thomas Abraham, Ragam N. Priyanka, Beena Mathew〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A sheet on sheet (2D/2D) structure of highly conductive S-rGO on S-gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 promote effective transfer of electrons for Cr(VI) reduction and subsequent degradation of organic pollutants. The photocatalytic activity of the 2D/2D hybrid material is significantly increased by the decoration of α-Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 hollow nanoflowers through ultrasonic assisted Kirkendall effect. The inter-particle electronic coupling in hollow nanoflower leads to self-narrowing of the band gap. The in-situ fabrication of β-AgVO〈sub〉3〈/sub〉 nanowires to form a quaternary catalyst enhanced the photocatalytic activity and corrosion inhibition by supporting a combined conventional and Z-scheme mechanism. This enhanced photocatalytic activity is due to the synergistic effects of heterostructured semiconductor photocatalysis, increased surface area, improved utilization of solar light due to hollow structure, decreased photocorrosion and the surface plasmon resonance(SPR) of Ag〈sup〉0〈/sup〉. The photocatalytic activities of S-gC〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/S-rGO/Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉/AgVO〈sub〉3〈/sub〉(SGO-SGA-x) composite photocatalysts were measured by the degradation of methylene blue(MB), methyl Orange(MO), 2,4-dichlorophenoxy acetic acid(2,4-D) and Cr(VI) reduction under visible-NIR irradiation. Electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectral analysis indicated that the in-situ formation of β-AgVO〈sub〉3〈/sub〉 from Ag〈sub〉3〈/sub〉VO〈sub〉4〈/sub〉 could efficiently promote the separation efficiency of photogenerated charge carriers. Our present work indicated that the photocatalytic activity can be significantly enhanced by judiciously designing the semiconductor nanomaterials.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322561-ga1.jpg" width="272" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Ting Gong, Yu Huang, Lijun Qin, Wangle Zhang, Jianguo Li, Longfei Hui, Hao Feng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the chemical industry palladium-based catalysts are commonly used to remove trace amounts of acetylene from ethylene feed. In this work atomic layer deposition (ALD) is utilized to synthesize uniformly dispersed Pd nanoparticles inside the meso-pores of a silica molecular sieve MCM-41. The space confinement effect from the internal channels of the molecular sieve leads to a very narrow size distribution (2–3 nm) of Pd nanoparticles and effectively prevents the particles from sintering during high temperature treatments. In selective hydrogenation of acetylene the ALD Pd nanoparticle catalysts exhibit excellent catalytic performances under ambient temperature and pressure. The excellent performance of the ALD catalyst is attributed to small Pd nanoparticles uniformly dispersed in the meso-pores of MCM-41 so that more Pd surface sites are available for the catalytic reaction. The strong metal support interaction between Pd and TiO〈sub〉2〈/sub〉 can be induced by high temperature treatments, which suppresses the surface adsorption of both acetylene and ethylene, leading to decreased acetylene conversion and improved ethylene selectivity. The high temperature treatment also helps improve the stability of the catalysts.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322731-ga1.jpg" width="384" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Sang-Chul Shin, Young-Jun You, Ji Soo Goo, Jae Won Shim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Alternative approaches to interlayer optimization are urgently required to realize efficient indoor organic photovoltaics owing to the substantially different indoor light conditions compared to outdoor light conditions (1 sun). In this work, an in-depth study was undertaken on electron-collecting interlayers (ECIs) comprising poly-(ethyleneimine)-ethoxylated (PEIE) modification, zinc oxide (ZnO) nanoparticles (NPs), or a combination of the ZnO NPs and PEIE modification. Morphological, optical, and electrochemical properties of the ECIs were investigated using atomic force microscopy (AFM), ultraviolet-visible (UV–vis) spectrometry, and a Kelvin probe, respectively. Inverted poly(3-hexylthiophene-2,5-diyl):indene-C〈sub〉60〈/sub〉 bisadduct (P3HT:ICBA)-OPVs with the ECIs were fabricated. While poor photovoltaic behavior was observed for OPVs with the ZnO NPs owing to the relatively large work function of the ECI under LED light in the absence of UV light, outstanding indoor performance was achieved by OPVs with PEIE modification as the PEIE contributed to work function reduction of the ECI. In particular, OPVs with the ZnO NPs/PEIE ECI yielded the highest efficiencies of up to 14.1 ± 0.3% under 1000-lx LED lamp.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉In this study, we have fabricated OPVs with various electron-collecting interlayers (ECIs) and studied electrical and optical mechanisms under indoor light conditions. The ECI Bilayer improves device performance by minimizing the leakage current of the device under indoor light conditions and effectively controlling the work function of the ITO substrate.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219323530-ga1.jpg" width="319" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Shuangying Lei, Sijia Guo, Xiaolong Sun, Hong Yu, Feng Xu, Neng Wan, Ziang Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Based on first-principles density functional theory (DFT), the capture and dissociation of dichloromethane (CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉) on Fe, Ni, Pd and Pt decorated phosphorene have been investigated. The results show that all the four metal decorations can enhance the capture ability of phosphorene to CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉, and the dissociations of CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉 on the four metal decorated phosphorenes are exothermic. Especially for Fe-decorated case, the adsorption energy of CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉 is as high as −1.034 eV, and the reaction energy barrier of CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉 dissociated process is as low as 0.674 eV, suggesting that the Fe-decorated phosphorene could have potential application in the capture and dissociation of CH〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Miqi Wang, Zehua Zhou, Qijie Wang, Lintao Wu, Zehua Wang, Xin Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The long term electrochemical corrosion behavior and passive film properties of a novel dense Fe48Cr15Mo14C15B6Y2 (at.%) amorphous coating were investigated using electrochemical measurement, Mott-Schottky test, effective capacitance model and XPS technique. The coating exhibited a superior corrosion resistance with a relative low current density of 5.305 × 10〈sup〉−〈/sup〉〈sup〉6〈/sup〉 A cm〈sup〉−〈/sup〉〈sup〉2〈/sup〉 even after 1000 h immersion in 3.5 wt% NaCl solution. The film composition changed slightly and made no difference to the corrosion behavior. Noting that point defect density in the passive film and film thickness played a dominant role in the corrosion resistance of the amorphous coating in chloride electrolyte. The enhanced long term corrosion resistance of the coating may be attributed to an inactive mass transport behavior in the passive film in the early immersion age.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): W.G. Knupp, M.S. Ribeiro, M. Mir, I. Camps〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this work is to study the interaction of hydroxyapatite (HA) with carbon nanotubes (CNTs). The HA, a biomaterial with known low mechanical resistance, is put to interact with CNTs known for having high mechanical resistance. The systems studied were complexes formed by hydroxyapatite and pristine and functionalized CNTs with 〈em〉x〈/em〉 = 5〈em〉%〈/em〉, 10〈em〉%〈/em〉, 15〈em〉%〈/em〉, 20〈em〉%〈/em〉, 25〈em〉%〈/em〉 concentration of hydroxyl (OH) and carboxyl (COOH) organic groups. The software used to perform the simulations was GULP together with the DREIDING force field. The lattice dynamics revealed that pristine CNTs had lower interaction with HA due to their high chemical stability whereas the functionalized CNTs interacted better with the HA matrix. The dependence of mechanical properties such as bulk and Young modulus and the Poisson's ratio with the percent of functionalization indicate the possibility to modify the elastic properties selecting the type and concentration of functionalization, giving is such a way, control over the mechanical properties of the complexes.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219322718-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Srilok Srinivasan, Suprem R. Das, Ganesh Balasubramanian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The role of interfacial thermal (Kapitza) resistance on the heated evaporation rates of water thin films over nanostructured graphene-coated surfaces is investigated. The Kapitza resistance between graphene and water, when the graphene flakes are parallel (φ = 0°) and perpendicular (φ = 90°) to the interface, are calculated using molecular dynamics simulations. The hydrophilicity of graphene when φ = 0° leads to enhanced liquid layering adjacent to the surface resulting in a lower Kapitza resistance relative to the φ = 90° case. The predicted evaporation rate on φ = 0° surface is relatively higher than for the φ = 90° surface due to an enhanced heat transfer between the substrate and water thin film. Results from our simulation aid in understanding the role of Kapitza resistance on heated evaporation rates, and suggest a possibility of engineering interfaces with tunable evaporation rates using nanostructured graphene coating.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Xiaopeng Niu, Jianhua Chen, Yuqiong Li, Liuyin Xia, Li Li, Heyun Sun, Renman Ruan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Various studies have emphasized the importance of surface oxidation of sulfide minerals with regard to xanthate adsorption and their flotation response. However, the correlation between pyrite surface oxidation, xanthate adsorption and its flotation response has not been clearly established. The complexity lies in various intermediate sulfur oxidation products in different solution conditions. Thus, investigation of sulfur oxidation behavior is the key to understand pyrite oxidation. Ion chromatography (IC) and high performance liquid chromatography (HPLC) results showed an increase in the total amounts of occurring sulfur species with increasing slurry pH. Meanwhile, the ratio of S〈sup〉0〈/sup〉/sulfur oxyanions was to become lower; X-ray Photoelectron Spectroscopy (XPS) identified the oxidized pyrite surface was rich in SO〈sub〉4〈/sub〉〈sup〉2〈/sup〉〈sup〉−〈/sup〉 and FeOOH. Both the contact angle results and single mineral flotation data indicated that the more pyrite surface oxidized, the lower hydrophobicity and floatability were. Time-of-flight secondary ion mass spectroscopy (Tof-SIMS) was adopted to analyse xanthate adsorption on the surface of pyrite under conditions of either sufficient oxidation or on freshly polished surface which is assumed little oxidation. A significantly lower intensities of C〈sub〉4〈/sub〉H〈sub〉9〈/sub〉O and C〈sub〉4〈/sub〉H〈sub〉9〈/sub〉OCSS was found on the intensely oxidized pyrite surface, indicating xanthate adsorption had strong selectivity on FeS〈sub〉2〈/sub〉 rather than FeOOH. The experimental results were further confirmed by theoretical calculation. The self-consistent charge density functional tight binding (SCC-DFTB) calculations indicated that the distances between the xanthate S atoms and surface Fe atoms of FeOOH were larger than the atomic radius of S〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Fe. Essentially, the different electron configurations of their Fe atoms led to the selective adsorption of xanthate on FeOOH and FeS〈sub〉2〈/sub〉 surfaces in terms of the coordination chemistry theory. This work provides valuable implications for understanding the correlation of surface oxidation, xanthate adsorption and its floatation behavior to mediate pyrite flotation.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433219321890-ga1.jpg" width="206" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Kwang-Ho Jung, Kyung Deuk Min, Choong-Jae Lee, Bum-Geun Park, Haksan Jeong, Ja-Myeong Koo, Byunghoon Lee, Seung-Boo Jung〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ag particles have been attractive candidates for highly reliable interconnections in electronic packages due to an absence of IMCs, high melting temperature, and high electrical and thermal conductivity. We fabricated various Ag-nanoparticle (NP) pastes containing different epoxy/binder percent weight (epoxy: 4.5, 9.0, 13.5, and 18 wt%) to investigate the effect on the bonding strength and electrical performance of multilayer ceramic capacitor (MLCC) components. MLCC joints were obtained by stencil printing Ag NP pastes on an Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 substrate with Cu electrodes followed by pressureless bonding at 250 °C for 15 min. When using Ag NP pastes containing higher epoxy compositions, more residues were identified while the other organic additives, such as the binder and dispersant, were removed by debinding during the bonding process. The Ag NP-18 wt% epoxy paste showed bonding strength approximately 8.6 times that of the paste containing 4.5 wt% epoxy. However, the electrical resistivity of MLCC components of 18 wt% epoxy paste showed an electrical resistance of 3.5 Ω, which was about 1.8 times that with the 4.5 wt% epoxy paste. We designed Ag NP pastes with varying epoxy ratio, and studied their chemical, bonding, and electrical characteristics for the development of advanced interconnection.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): Yue Cao, Hongwei Qin, Yanping Chen, Jifan Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉DFT calculations are used to investigate the acetone sensing mechanism of PdO-modified hexagonal WO〈sub〉3〈/sub〉 (001) surface. It is concluded that compared to the pure h-WO3 (001) surface, modifying the surface with PdO could increase the available adsorption sites for acetone and leads to a sharp increase in the amount of charge transferred from acetone to the surface of the material, which contributes to a decrease in the resistance of h-WO〈sub〉3〈/sub〉 (n-type semiconductor material). Moreover, we found that the oxygen concentration and experimental temperature have significant effects on the acetone sensitivity of the PdO-modified h-WO〈sub〉3〈/sub〉 (001) surface. In an anoxic environment, the O originating from acetone easily adsorbs on a W or Pd site. With increasing temperature, acetone desorbs from the material, explaining the optimal operating temperature of h-WO〈sub〉3〈/sub〉 sensors for acetone observed in experiments. Moreover, in oxygen-rich environments, some intermediate products were generated, which suggests an alternative consideration for the interpretation of acetone sensing mechanism.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 495〈/p〉 〈p〉Author(s): T. Auzelle, F. Ullrich, S. Hietzschold, S. Brackmann, S. Hillebrandt, W. Kowalsky, E. Mankel, R. Lovrincic, S. Fernández-Garrido〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the electronic properties of GaN〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mo stretchy="false"〉(〈/mo〉〈mn〉1〈/mn〉〈mover accent="true"〉〈mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mo〉¯〈/mo〉〈/mover〉〈mn〉00〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉 and (0001) surfaces after three different and subsequent device processing compatible cleaning steps: HCl etching, annealing at 400 °C in N〈sub〉2〈/sub〉 atmosphere, and O〈sub〉2〈/sub〉 plasma exposure. The surface electronic properties are quantified, in the dark and under ultraviolet illumination, using X-ray photoelectron spectroscopy and a Kelvin probe. We find that the cleaning steps largely affect the work function and the band bending of both GaN orientations. These modifications are attributed to the presence of different surface states as well as to the formation of adsorbates building up distinct surface dipoles. Besides these results, we detect that under ultraviolet illumination the work function of the surfaces exposed to HCl decreases by at least 0.2 eV without screening of the band bending. We thus attribute the observed surface photovoltage to a photo-induced modification of the surface dipole. Overall, these results emphasize the strong dependence of the electronic properties of air-exposed GaN surfaces on adsorbates. As a result, we advocate the use of the common cleaning steps analyzed here to re-initialize at will GaN〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mo stretchy="false"〉(〈/mo〉〈mn〉1〈/mn〉〈mover accent="true"〉〈mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mo〉¯〈/mo〉〈/mover〉〈mn〉00〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉 and (0001) surfaces into pre-defined states.〈/p〉〈/div〉 〈/div〉