ALBERT

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): S.P. Sun, J.L. Zhu, S. Gu, X.P. Li, W.N. Lei, Y. Jiang, D.Q. Yi, G.H. Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The surface stability and equilibrium morphology of MoO〈sub〉3〈/sub〉 were investigated by the first principles calculations. The thermodynamic energies of the stoichiometric surfaces of MoO〈sub〉3〈/sub〉 are in the order (0 1 0) 〈 (1 0 1) 〈 (0 0 1) 〈 (1 0 0). It is found that the (0 1 0) surface has a lowest surface energy, which agrees well with the previous calculations. The energies of the non-stoichiometric surfaces were evaluated as functions of temperature and oxygen partial pressure. The results show that the energies of Mo-terminated surfaces decrease with temperatures, and increase with oxygen partial pressures, while the energies of O-terminated surfaces show the opposite rule. The equilibrium morphology of MoO〈sub〉3〈/sub〉 was predicted by using the Gibbs-Wulff model, and then was compared with the other’s experiments and theoretical results.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sanju Gupta, Nicholas Dimakis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interfacial interactions between transition metal oxides (vanadium oxide VO〈sub〉2〈/sub〉, vanadium pentoxide V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, cobalt oxide CoO and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, manganese oxide MnO〈sub〉2〈/sub〉) and water adsorbates on graphene supports as solvated interfaces and influence of defects in graphene are studied using periodic density functional theory (DFT) calculations in view of their significance for applied electrochemistry. DFT complemented and synergized our experimental work. The optimized metal oxide adatom-graphene geometries identified the preferred adatom sites, whereas metal oxide-graphene strengths are correlated with the adatom distance from the graphene plane, the Metal-C overlap populations, and the adsorption energies. The presence of finite electronic density of states (DOS) near Fermi level and charge transfers between the adatom top layer and graphene supports reflect primarily covalent bonding nature. The presence of small orbital overlap integral of bonds between the s and p (and d) orbitals of the nearest carbon (graphene), carbon oxide (graphene oxide) and metal oxide atoms reveal localized orbital re-hybridization resulting in changes in DOS yielding high electrochemical activity. Moreover, for increased adatom coverage the extent of charge transfer reverses resulting in limited electroactivity. In fact, DFT calculations are corroborated with experimental findings, where graphene-based supports decorated with optimal mass loaded nanostructured Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and MnO〈sub〉2〈/sub〉 (as well as V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉) were capable of delivering maximum specific energy storage capacity (C〈sub〉s〈/sub〉) 〉 550 F·g〈sup〉−1〈/sup〉 (Gupta et al. J. Mater. Res. 32, 301 (2017)) in contrast to higher or lower loading. The presence of defects in graphene materials results in new electronic states to endow unique functionalities that is not otherwise possible in the bulk and with adsorbed water molecules besides optimum C/O ratio in graphene oxide nanosheets that show redshift thus a decreasing bandgap and finite charge transfer from graphene to water molecules. The case examples studied in this work represent a first glimpse of what may become routine and integral step in materials design and discovery for alternative energy and sustainable environmental technologies.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Xu Wu, Yalin Feng, Yali Du, Xuezhen Liu, Chunlei Zou, Zhe Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉LDHs templates (marked as CoAl-MnO〈sub〉2〈/sub〉-LDH and CoMnAl-CO〈sub〉3〈/sub〉-LDH) were fabricated via ion-exchange/redox reaction and hexamethylenetetramine (HMT) hydrolysis methods respectively. CoMnAl mixed metal oxides (marked as MnO〈sub〉2〈/sub〉/CoAl-LDO and CoMnAl-LDO) from the as-prepared LDHs templates were novelly prepared and tested as low-temperature NH〈sub〉3〈/sub〉-SCR catalysts. Catalytic evaluation pronouncedly affirmed that the catalytic performances of the as-acquired catalysts were vulnerable to the preparation method of precursor template, where MnO〈sub〉2〈/sub〉/CoAl-LDO presented preferable DeNOx activity (over 90% NOx conversion), N〈sub〉2〈/sub〉 selectivity and SO〈sub〉2〈/sub〉 resistance in much broader working temperature window (90–300 °C) than CoMnAl-LDO. Multiple characterizations revealed that the excellent catalytic performance of the MnO〈sub〉2〈/sub〉/CoAl-LDO could be attributed to its higher specific surface area which could promote dispersion of abundant Mn〈sup〉4+〈/sup〉 and Co〈sup〉3+〈/sup〉 species, and resultantly afforded stronger redox ability and more acid sites. Moreover, dynamic calculation confirmed that the relatively lower activation energy on MnO〈sub〉2〈/sub〉/CoAl-LDO for low-temperature NH〈sub〉3〈/sub〉-SCR reaction should be closely related to the occurrence of a more rapid redox cycle and in agreement with the excellent DeNOx performance.〈/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-S0169433218329702-ga1.jpg" width="413" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sandra Jendrzej, Leonard Gondecki, Jörg Debus, Henning Moldenhauer, Peter Tenberge, Stephan Barcikowski, Bilal Gökce〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The lubricant is a central element in the transmission design. It primarily separates the two contact partners through a pressure-induced solidification in the lubrication gap, thus enabling the operation of heavily loaded sliding-rolling contacts. On the one hand, the quality and properties of a lubricant depend on the base oils, which differ by their viscosity and process-technological parameters. The addition of particulate additives gives the lubricants further functional properties that are not contained in the base oil. In this study, the influence of laser-synthesized yttria-stabilized zirconia nano- or submicrometer spheres as dispersed functional elements in the lubricant is studied, and their impact on wear and fatigue on the tooth flank is investigated. The work includes systematic investigations on the influence of the particle’s shape and size by running tests on a FZG gear test rig. Finally, the potential of the laser-generated particles as a lubricant additive is evaluated in a first conclusion.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Cong Chen, Shouzhen Bao, Baoshun Zhang, Ying Chen, Wen Chen, Chengyu Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To reduce electromagnetic interference (EMI) and irradiation, one efficient path is to develop electromagnetic absorption (EMA) material with the aim of high-efficient convert electromagnetic wave into thermal energy. Presently strategy to design high-performance electromagnetic absorber is followed by the way of component optimization and microstructure design. This research reported an advanced HWCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 ternary absorber, which was fabricated by decorating H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 treated carbon nanotubes (HCNTs) with magnetic core-shell shaped Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles. This HCNTs/Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 composite exhibits various electromagnetic loss forms, including conductive, dipole, interface loss 〈em〉etc〈/em〉. which attribute to EMA ability. The largest qualified frequency width (〈em〉f〈sub〉E〈/sub〉〈/em〉) can up to 5.4 GHz with a thickness of 1.5 mm. To discuss the EMA loss mechanism, control experiments have been conducted by preparation of Fe@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, HCNTs@Fe@Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 composites. In this way, the attenuation mechanism can be better understood.〈/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-S0169433218329179-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Min Sun, Wei Hu, Tianqiong Cheng, Yusheng Chen, Peng Yao, Ming Zhao, Shandong Yuan, Yaoqiang Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A series of Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 samples were prepared by conventional coprecipitation, wet impregnation method and novel deposition precipitation, after the corresponding Pd-only close coupled catalysts were obtained by incipient wet impregnation. Differences in surface properties and catalytic performance were investigated systematically by a wealth of characterizations. XPS, H〈sub〉2〈/sub〉-TPR and CO chemisorption revealed that the different preparation methods of Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 led to different intensity of interaction between PdO species and support, thus forming different palladium dispersions. BET, XRD and activity evaluation indicated the catalyst obtained by novel deposition precipitation presented superior textural properties, catalytic performance and thermal stability, due to the strongest interaction proved by H〈sub〉2〈/sub〉-TPR, XPS and CO chemisorption, which could retard the sintering of noble metal during the aging process. HRTEM images indicate for the catalysts, PdO species are mainly dispersed and stabilized on the ceria resulting from the lower redox potential of Pd〈sup〉2+〈/sup〉/Pd〈sup〉0〈/sup〉 (0.95 V) than that of Ce〈sup〉4+〈/sup〉/Ce〈sup〉3+〈/sup〉 (1.72 V). Consequently, it owned higher surface PdO content and dispersion than the catalysts prepared by coprecipitation and impregnation method, presenting its higher catalytic properties.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The different preparation methods about ceria-zirconia modified alumina influence palladium dispersion by the interaction, which is main factor in influencing close coupled catalytic activity. The catalyst obtained by deposition precipitation owns higher surface palladium species than the sample synthesized by coprecipitation method, and higher palladium dispersion than the catalyst prepared by wet-impregnation method. A simple process is described as is shown above, and specific process is illustrated in my article.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218329696-ga1.jpg" width="198" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Yi Zhong, Zetian He, Daimei Chen, Ding Hao, Weichang Hao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The fluorine substitution on Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 (F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉) can be easily synthesized by a hydrothermal method. Based on the XRD result, it could be speculated that fluorine ion can substitute oxygen ion in the crystal lattice of Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉. The photodegradation activity of F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 almost is 1.9 times as high as the single Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 for degradation of RhB and 1.7 times for decomposition of 2, 4-CDP under the visible light. The enhanced catalytic activity of F-Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉 should be attributed to the wider band gap, the more positive VB potential and the higher concentration of OH〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉 radicals due to the F doping. Additionally, F doping formed the donor state below the Fermi energy, which can trap the electrons and increase the efficiency of charge separation remarkably.〈/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-S0169433218329647-ga1.jpg" width="387" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Hamad Ullah, Yu Qu, Tiankun Wang, Yongkai Wang, Zhimin Jing, Zhongyue Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Artificially engineered chiral plasmonic nanostructures (CPNs) have attracted considerable attention and have been widely studied in the recent decades because of their distinguishing optical properties. Researchers have focused on noble metal nanostructures, because of their strong chiroptical response in visible and near-infrared regions. In this study, a system of a nanorod coupled with a nanosurface, which were both made of silver, was proposed. Glancing angle deposition (GLAD) method was used to fabricate CPNs. The fabricated CPNs generated a strong circular dichroism (CD) signal under visible and near-infrared light illumination. A high peak was observed at approximately 600 nm, and an increasing trend of the CD intensity with a redshift was confirmed when the area of the nanosurface was increased. The generated CD could be tuned easily by changing the area of the nanosurface with an active control of the vapor deposition angle (glancing angle of the substrate) in the GLAD method.〈/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-S0169433218329775-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Lida Chen, Enzhou Liu, Feng Teng, Tianxi Zhang, Juan Feng, Yumeng Kou, Qian Sun, Jun Fan, Xiaoyun Hu, Hui Miao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two-dimensional (2D) metal dichalcogenides have attracted considerable attention in photoelectrochemical (PEC) water splitting because of their particular layer structure and strong interaction with light. Herein, in this article, we report a facile chemical vapor deposition (CVD) method, via low boiling point SnCl〈sub〉4〈/sub〉·5H〈sub〉2〈/sub〉O and S powders as precursors. Light trapping nanosheets arrays SnS〈sub〉2〈/sub〉 (SnS〈sub〉2〈/sub〉⊥FTO) have been deposited on conductive substrate. By optimizing the preparation conditions, included deposition temperature, flow rate of carrier gas and the distance between the Sn source and growth substrate. Moreover, the key factors to affect the growth of SnS〈sub〉2〈/sub〉 in CVD process have been investigated in detail. In PEC measurements, the as-synthesized thin film of 450 °C, 50 sccm, 11 cm shows the highest photocurrent density of up to 3.68 mA cm〈sup〉−2〈/sup〉 at 0.5 V 〈em〉vs.〈/em〉 SCE under the sunlight and high IPCE of up to 33.11% at 365 nm. The values much higher than conventional photoelectrode by spin-coating (SnS〈sub〉2〈/sub〉//FTO), which achieved efficient photoelectrochemical water splitting under the sunlight.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Linan Wang, Shuxian Zhuang, Liu Wang, Na Wang, Hengliang Mo, Yang Tang, Yongmei Chen, Yanzhi Sun, Pingyu Wan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Co(OH)〈sub〉2〈/sub〉 nanoflakes integrating with Cu nanoparticles were deposited on nickel foam (CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉) by a green and facile one-step deposition method and used for non-enzymatic glucose sensors. The CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 composite was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. Electrochemical oxidation of glucose on the CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 composite was investigated by chronoamperometry and cyclic voltammetry. The prepared CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 electrode shows not only an extremely high sensitivity of 42.7 mA mM〈sup〉−1〈/sup〉 cm〈sup〉−2〈/sup〉 in the concentration range from 1 to 250 μM for glucose detection but also an obvious current response to glucose at a level of 1 μM with a low detection limit of 73 nM (S/N = 3). Moreover, the glucose sensor based on CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 also exhibits high recovery ratio toward real sample analysis. This work indicates that the fast electron transfer, large surface area, and highly effective active sites based on the hierarchical structure of ultra-thin and open-interlaced Co(OH)〈sub〉2〈/sub〉Nfs interspersed by CuNps contribute to the excellent performance of CuNps-Co(OH)〈sub〉2〈/sub〉Nfs/Ni〈sub〉f〈/sub〉 electrodes. The proposed one-step preparation of hierarchical nanostructure of CuNps and Co(OH)〈sub〉2〈/sub〉Nfs provides a promising and efficient strategy in the development of outstanding non-enzymatic glucose biosensors.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Qiong Sun, Songhao Wu, Di You, Tao Zang, Lifeng Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic fuel cell (PFC) is a newly developed cell device that can effectively convert chemical energy resulted from photocatalytic process into electrical energy. In this research, a novel composite functional dual-chambered photocatalytic fuel cell is designed and optimized. In the cathode chamber, the Fenton-like reaction is introduced to produce strong oxidizing OH〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉 radicals, which thereby enhances the advanced oxidation of wastewater and is much faster than the anode reaction. Meanwhile, photo-induced charge transfer as well as electronic generation ability can be further improved compared with the system only with O〈sub〉2〈/sub〉 pumped in. With the help of this special PFC device, the electrode reactions can occur in two chambers independently, thus different types of organic substances can be degraded, accompanying with the generation of electrical energy simultaneously. According to the degradation of various dyes, it is found that the anode reaction is more suitable for the degradation of cationic dye rather than anionic dye, and just reverses for the cathode reaction. Among four selective types of dyes, the PFC shows the best purification effect to X3B, while the highest enhancement of electric output is found when methylene blue (MB) is employed.〈/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-S0169433218329672-ga1.jpg" width="312" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Beibei Liu, Shuo Wang, Zirui Ma, Jiawang Ma, Ruixin Ma, Chengyan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perovskite solar cell has gained wide attention due to its excellent photoelectric performance and economical fabrication process, with high-efficiency perovskite solar cell could be achieved by optimizing film morphology. In this work, a kind of Lewis-bases, urea(U), was used as a novel additive in synergy with DMSO to regulate the crystallization processes. Adding slight amount of DMSO can obviously improve the reproducibility of device and optimize the spin-coating process. The mechanism of the action can be explained by infrared spectroscopy. Under the coordination of the lead ion that could accept electron pairs and the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O bond in urea, introduction of urea in perovskite precursor solution to form MAI·PbI〈sub〉2〈/sub〉·DMSO·urea complex could significantly improve the photoelectric properties of the perovskite films. It formed a smooth and large grain-size perovskite film with no visible pinhole or crack found. Finally, the device fabricated with the incorporation of 50% urea presented a high performance with a PCE of 17.82%.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): İkram Orak, Hamit Eren, Necmi Bıyıklı, Aykutlu Dâna〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a methodology for producing highly controlled and uniformly dispersed metal nanoparticles were developed by atomic layer deposition (ALD) technique. All-ALD grown thin film flash memory (TFFM) cells and their applications were demonstrated with ultra-small platinum nanoparticles (Pt-NPs) as charge trapping layer and control tunnel oxide layer. The ultra-small Pt-NPs possessed sizes ranging from 2.3 to 2.6 nm and particle densities of about 2.5 × 10〈sup〉13〈/sup〉 cm〈sup〉–b〈/sup〉. The effect of Pt-NPs embedded on the storage layer for charging was investigated. The charging effect of ultra-small Pt-NPs the storage layer was observed using the electrical characteristics of TFFM. The Pt-NPs were observed by a high-resolution scanning electron microscopy (HR-SEM). The memory effect was manifested by hysteresis in the I〈sub〉DS〈/sub〉-V〈sub〉DS〈/sub〉 and I〈sub〉DS〈/sub〉-V〈sub〉GS〈/sub〉 curves. The charge storage capacity of the TFFM cells demonstrated that ALD-grown Pt-NPs in conjunction with ZnO layer can be considered as a promising candidate for memory devices. Moreover, ZnO TFFM showed a I〈sub〉ON〈/sub〉/I〈sub〉OFF〈/sub〉 ratio of up to 52 orders of magnitude and its threshold voltage (V〈sub〉th〈/sub〉) was approximately −4.1 V using I〈sub〉ds〈/sub〉〈sup〉−a/b〈/sup〉 – V〈sub〉gs〈/sub〉 curve. Fabricated TFFMs exhibited clear pinch-off and show n-type field effect transistor (FET) behavior. The role of atomic-scale controlled Pt-NPs for improvement of devices were also discussed and they indicated that ALD-grown Pt-NPs can be utilized in nanoscale electronic devices as alternative quantum dot structures.〈/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-S0169433218329945-ga1.jpg" width="345" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): A. Ladrón-de-Guevara, A. Boscá, J. Pedrós, E. Climent-Pascual, A. de Andrés, F. Calle, J. Martínez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the precise fabrication of low-cost high-performance electrochemical supercapacitors using reduced graphene oxide/polyaniline nanofiber composite electrodes. An infrared laser has been used to reduce the graphene oxide, converting the initial graphene oxide compact layer into a three dimensional open network of exfoliated graphene flakes. This highly conducting porous structure is very well suited for electrodepositing pseudocapacitive materials owing to its large surface area. Polyaniline nanofibers have been controllably electrodeposited on the graphene flake network, not only extending further the electrode surface area and providing it with a strong pseudocapacitance but also preventing the restacking of the graphene sheets during the subsequent device processing and charge-discharge cycling. The composite electrode presents a specific capacitance of 442 F g〈sup〉−1〈/sup〉, as compared to 81 F g〈sup〉−1〈/sup〉 for the bare reduced graphene oxide counterpart, and a capacitance retention of 84% over 2000 cycles.〈/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-S0169433218329738-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Sami Rtimi, Victor Nadtochenko, Inessa Khmel, Stéphanos Konstantinidis, Nikolay Britun, John Kiwi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cu-polyester (Cu-PES) was sputtered by high power impulse magnetron sputtering (HIPIMS) and by low energy direct current magnetron sputtering (DCMS). The total amount and distribution of the Ar〈sup〉+〈/sup〉, Cu〈sup〉+〈/sup〉 and Cu〈sup〉2+〈/sup〉 ions were determined as well as the bacterial inactivation kinetics mediated by DCMS and HIPIMS samples. The separation of extracellular and intracellular processes leading to bacterial inactivation was assessed on normal and genetically modified 〈em〉E. coli〈/em〉.〈/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-S0169433218329878-ga1.jpg" width="250" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volumes 467–468〈/p〉 〈p〉Author(s): Zheng-Wei Wu, Ming-Hung Chiang, Chien-Liang Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, a facile co-surfactant method has been reported for the synthesis of core-shell Pd/Pt saw-toothed nanocubes (Pd/Pt STNCs). In this method, saw-toothed morphologies increase with decreasing ratio (R) of the concentration of cetyltrimethylammonium bromide to cetyltrimethylammonium chloride in the synthesis solution. High-resolution transmission electron microscopy (HR-TEM) images reveal that the Pd/Pt STNC prepared using R = 4 (Pd/Pt STNC〈sub〉R=4〈/sub〉) has (3 1 0) and (4 1 0) facets on its edge, whereas the Pd/Pt STNCs prepared using R = 1 (Pd/Pt STNC〈sub〉R=1〈/sub〉) and 0.25 (Pd/Pt STNC〈sub〉R=0.25〈/sub〉) have (3 1 1) high-index facets. Furthermore, the comparison based on electrochemical surface area (ESA) shows that carbon-supported Pd/Pt STNC〈sub〉R=4〈/sub〉 used for catalysing acidic oxygen reduction exhibits a kinetic current of 0.44 mA at 0.9 V (vs. RHE), which is 1.4-times greater than that obtained for commercial Pt/C (0.31 mA). The higher activity could be caused by enriched electrons on the Pt outershell with less adsorbed Cl〈sup〉−〈/sup〉 ions, as confirmed by the X-ray photoelectron analyses. Accelerated durability test results show that the Pd/Pt STNC〈sub〉R=4〈/sub〉 catalyst is more stable than Pt/C.〈/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-S0169433218330058-ga1.jpg" width="296" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Youyi Sun, Congxu Wang, Guizheng Guo, Qiang Fu, Zhiyuan Xiong, Dan Li, Yaqing Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new metal-free organic molecular as co-catalyst was developed, which could drastically enhance the photocatalytic performance of photocatalyst (eg. g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, MoS〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉). The enhancing photocatalytic activity was evaluated for photocatalytic degradation of organic dyes. It showed ultra-high photocatalytic rate (4.17 mg/g·min) and ultra-short time (about 6.0 min) for photocatalytic degradation of organic dyes (25 mg/ml). The enhanced photocatalytic performance was attributed to suppress recombination of photogenerated charges and provide a new photoredox reaction pathway under molecular co-catalyst assistance. The study represents a facile method to develop ultra-effectively photocatalyst for applications in production of green and renew-able energy carrier, H〈sub〉2〈/sub〉 from water, reduction of CO〈sub〉2〈/sub〉, synthesis of fine chemicals and remediation of environmental pollutants.〈/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-S0169433218331611-ga1.jpg" width="400" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Siwei Xie, Quanquan Sun, Gaoyang Ying, Lingxi Guo, Qiu Huang, Qiyu Peng, Jianfeng Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Lutetium-Yttrium Oxyorthosilicate (LYSO) is one of the most widely used scintillation crystal in the high-performance Positron Emission Tomography (PET) systems. The quality of the surface finish of the LYSO has an important impact on the light output, the decoding performance, the energy resolution and timing resolution of the PET detectors and systems. In this paper, we present an ultra-precise method for processing the surface of LYSO crystals. The hardness and elastic modulus of the crystals were initially measured using Nano indentation technology. The scintillators were fixed onto the plate in sparse, serried and continuous arrangements and polished using an alumina (Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉) and cerium oxide (CeO〈sub〉2〈/sub〉) polishing solution with particles of varying size. We used a magnetorheological-polishing technique to polish the LYSO crystals. The polishing solution here included hydroxyl iron powder and hard abrasives. The hardness and elastic modulus of the crystals in question was, respectively, 11.18 ± 0.50 and 155.78 ± 4 gigapascals (GPa). A 3D optical surface profiler (3D-OPS) and an atomic force microscope (AFM) were used to evaluate the quality of the polished surfaces. The average roughness of Ra 0.55 nm measured by 3D-OPS was achieved using a precise plate grinding and polishing technique. The magnetorheological-polishing method also obtained an excellent roughness of Ra 0.75 nm (3D-OPS). Our report of the use of these processing technologies can serve as a foundation for further in-depth research regarding the optimal techniques for scintillator surface processing.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Two ultra-precision machining methods, including a plating grinding method and a magnetorheological-polishing method, were established for the surface treatments of the Lutetium–Yttrium Oxyorthosilicate (LYSO) scintillator crystals used in high-performance Positron Emission Tomography (PET) systems.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218330927-ga1.jpg" width="278" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Dezhi Qin, Guangrui Yang, Yabo Wang, Yanbiao Zhou, Li Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, water-soluble Ag nanoparticles were prepared in aqueous solution by using trypsin as reducing and capping agent. The protein-assisted synthetic strategy eliminates the need of intermediate protecting and linking agents compared with organometallic approach, which is simple, effect, less energy consuming, and closer to the requirements of green chemistry. The morphology, size and antibacterial activity properties could be controlled by varying experimental conditions. The results of FT-IR and SDS-PAGE analysis indicated that trypsin molecules could control the nucleation and growth of nanocrystals through chemical interaction between Ag and functional groups of trypsin. The binding of trypsin on the surface of Ag nanoparticles significantly reduced nano-toxicity through capping effect. The trypsin-conjugated Ag nanoparticles exhibited strong antibacterial activity toward both Gram-positive and Gram-negative bacteria due to small size and specific morphologies. Compared with traditional antibacterial materials, the water-solubility and biocompatibility make the products more suitable for the application in biological and medical science.〈/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-S016943321833126X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Meng Fu, Xiangming Li, Zepeng Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Here we demonstrate a novel magnetic functional material composed of montmorillonite (Mt) with superparamagnetic coating Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 dispersed in the aqueous solution. Colloidal stability can be obtained through keeping 2 〈 pH 〈 3. After applying an external magnetic field, Mt@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 exhibits long-range order and liquid crystalline phase. The transmittance of the liquid crystal is dependent on the solid content of Mt@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, magnetic field strength and magnetic field direction. We also observe reflective phenomena when we modulate the magnetic field. The photonic bandgap can be tuned by changing the angle between incident light and magnetic field. The varying observation points also make a difference to the reflection. This facile approach for fabricating Mt@Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 with ordered periodic structures and optically tunable property is of interest for a variety of advanced optics applications with low cost and environment-friendly.〈/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-S0169433218331313-ga1.jpg" width="320" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Imtisal Akhtar, Malik Abdul Rehman, Woosuk Choi, Sunil Kumar, Neasung Lee, Sang-Joon Cho, Hyeong-Ho Park, Kyung-Ho Park, Yongho Seo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional (3D) imaging of nanostructures with high aspect ratio features is a challenging problem of broad relevance to nanoscience and nanotechnology. Though a wide variety of experimental strategies to improve 3D imaging capabilities have been proposed, current measurement capabilities are mainly limited to imaging deep trenches, in large part due to the lack of truly 3D scanning algorithms and limited dynamic control of the tilt angle. Herein, we report a non-contact atomic force microscope (AFM) strategy that overcomes these challenges by employing an intelligent 3D scanning algorithm that combines sidewall detection and real-time adjustment of the probe’s direction. To test this approach, we measured the depth and sidewall topography of porous anodic aluminum oxide (trench), via holes and silicon nanopillar (protrusion) with precision tracing. Using a carbon nanotube-based AFM probe, it was possible to measure the depth of holes with an aspect ratio of 5.9. In addition to this, we have successfully achieved the 3D image of via holes with an aspect ratio of 4.3 and a resolution of 2 nm, which enables realistic profiling of the sidewall and bottom edge of holes. Taken together, our findings demonstrate how the intelligent scanning algorithm based on detection-and-decision with a high-aspect-ratio probe can be utilized as a broadly applicable nanoscience measurement tool to characterize 3D topographical features of nanostructures.〈/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-S0169433218330940-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Jun-Hui Yuan, Ya-Qian Song, Qi Chen, Kan-Hao Xue, Xiang-Shui Miao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using first principle calculations we have investigated the structure stabilities, electronic and optical properties of single layer planar penta-X〈sub〉2〈/sub〉N〈sub〉4〈/sub〉 (X = Ni, Pd and Pt). According to the calculated phonon dispersion relation and elastic constants, as well as ab initio molecular dynamics simulation results, monolayers of planar penta-X〈sub〉2〈/sub〉N〈sub〉4〈/sub〉 are dynamically, mechanically, and thermally stable. In addition, these monolayers are direct-gap semiconductors with bandgaps ranging from 0.92 eV to 1.11 eV, which can be further tuned by external strains. Besides, the bonding characteristics and the optical properties in these monolayers are investigated based on HSE06 calculations, where strong in-plane optical absorption with wide spectral range has been revealed. Our results indicate that planar penta-X〈sub〉2〈/sub〉N〈sub〉4〈/sub〉 monolayers possess excellent electrical and optical properties, and may find potential applications in solar cells and nanoelectronics.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A novel 2D planar penta-X〈sub〉2〈/sub〉N〈sub〉4〈/sub〉(X = Ni, Pd and Pt) monolayers with sizeable direct bandgaps ranging from 0.92 eV to 1.11 eV at HSE06 level.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S016943321833109X-ga1.jpg" width="211" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Jian Wang, Yunchuan Xie, Jingjing Liu, Zhicheng Zhang, Yanfeng Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Poly(vinylidene fluoride) (PVDF) based polymer/ceramic nanocomposites for high energy density dielectrics have long been plagued by their low discharging efficiency (40–60%), which originates from the matrix with high bulk ferroelectric relaxation and the high-k ceramics with large conduction loss. In this work, a linear-like PVDF-based polymer dielectric is synthesized through grafting poly(methyl methacrylate) (PMMA) onto main chains of poly(vinyl fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) terpolymer 〈em〉via〈/em〉 an atom transfer radical polymerization (ATRP) process. PMMA grafted terpolymer (P(VDF-TrFE-CTFE)-g-PMMA) shows linear-like dielectric characteristics accompanied with greatly enhanced discharging efficiency of ∼80% under 250 MV/m, which is over 100% higher than that of pristine terpolymer. To further improve its breakdown strength and discharging efficiency, the grafted terpolymer are then compounded with ultrasonic-exfoliated mica nanosheets (〈em〉e〈/em〉Mica) by solution-cast method. Thanks to the low hysteresis loss of linear-like dielectric matrix and the high insulating 2D mica nanosheets, the composite with the highest discharging efficiency of ∼78% under 250 MV/m is achieved. The maximum energy density of the optimized composite reaches 9.6 J/cm〈sup〉3〈/sup〉, which is nearly 290% that of the pristine terpolymer. Besides, its discharging efficiency is about 74% under 450 MV/m, which is much more advantageous than the other PVDF-based polymer/ceramics composite dielectrics. This work suggests that utilizing polymer matrix with linear dielectric property and fillers with high insulating 2D structure might be a facile strategy to achieve composite dielectrics with simultaneously high energy density and high discharging efficiency.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Stefano Curiotto, Pierre Müller, Ali El-Barraj, Fabien Cheynis, Olivier Pierre-Louis, Frédéric Leroy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanostructures on surfaces can be displaced by applying an electric field or electric currents through a material. This induced mass transport is referred to as electromigration. In this article we show that the anisotropy of diffusion may control the direction of motion of electromigrating nanostructures. For this purpose we study in situ and in real time, by Low Energy Electron Microscopy, the motion of 2D one-atom thick islands or one-atom deep holes on a highly anisotropic surface (reconstructed Si(1 0 0)). Based on experiments and Kinetic Monte Carlo simulations, we propose a simple analytical model that explains most of the observations. In particular, the direction of motion of the nanostructures depends on the diffusion anisotropy and does not necessarily coincide with the electric field direction. This work opens a way for the manipulation of 2D nanostructures by means of an electric field on anisotropic surfaces.〈/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-S0169433218331179-ga1.jpg" width="390" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Natthaphong Konkhunthot, Pat Photongkam, Pornwasa Wongpanya〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ti-doped diamond-like carbon (Ti-doped DLC) films were deposited on 304 stainless steel through a pulsed filtered cathodic vacuum arc deposition with an individual cathodic arc source. Structural dependent thermal stability, mechanical properties, adhesion, and corrosion performance were thoroughly investigated as a function of the Ti content. Only 0.8 at.% Ti content in the DLC films offers the relatively high hardness (28.8 GPa), high corrosion resistance, enhanced adhesion strength as well as improved thermal stability compared to the undoped DLC films. The reduction in the internal stress and the 〈em〉sp〈/em〉〈sup〉3〈/sup〉 content associated with a slight decrease in the mechanical properties is from Ti doping. Higher thermal stability is due to the TiC phase in the Ti-doped DLC structure. Enhancement of the adhesion strength is owing to the relief of the internal stress and the occurrence of the strong atomic intermixing bond at a Ti-doped DLC/Ti intermediate layer interface. Interestingly, the formation of the TiO〈sub〉2〈/sub〉 film on the Ti-doped DLC surface due to a small amount of Ti doping significantly exhibited a better corrosion performance. Ti-doped DLC films, therefore, are a promising coating for tribological 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-S0169433218330988-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Yapeng He, Xue Wang, Hui Huang, Panpan Zhang, Buming Chen, Zhongcheng Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Polyaniline (PANI) is considered as an attractive electrode material in energy storage devices. Here, self-supported porous conducting PANI fibrous network is in-situ deposited on carbon paper (CP) via a facile electropolymerization method for solid-state supercapacitor. We also explicate the possible growth mechanism of nanofiber network based on the morphology evolution. Combined with high specific surface area (42.2–96.3 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉), controllable loading capacity (10 μg cm〈sup〉−2〈/sup〉 cycle〈sup〉−1〈/sup〉) and superior conductivity (1.13–1.98 S cm〈sup〉−1〈/sup〉), the composite electrodes are further proved with FTIR, Raman, XPS and UV–Vis spectra. The capacitance performances are systematically investigated via cyclic voltammetry, galvanostatic charge/discharge curves and electrochemical impedance spectroscopy. As-prepared CP/PANI-80 hybrid electrode exhibits mass capacitance of 455.1 F g〈sup〉−1〈/sup〉 under 0.5 A g〈sup〉−1〈/sup〉 with pseudo-capacitive contribution ∼58.4%. Meanwhile, the gravimetric capacitances of composite electrodes follow a decline trend with increase of loading capacity as the effective utilization rate and specific surface area of active PANI. Then, the solid-state supercapacitor device assembled delivers mass capacitance of 149.3 F g〈sup〉−1〈/sup〉 and presents admirable energy density of 13.3 Wh kg〈sup〉−1〈/sup〉 with power density 80 W kg〈sup〉−1〈/sup〉 in PVA/H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 electrolyte. Moreover, solid-state device exhibits favorable self-discharge behavior with low leakage current as small as 27.5 µA, distinct long time cycling stability with capacitance retention of 81.6% after 4000 continuous cycles. Above encouraging results could illustrate the great promise of this method and tremendous potential of PANI fibrous network electrodes in solid-state energy-storage systems.〈/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-S016943321832957X-ga1.jpg" width="336" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Tao Feng, Jun-Min Wang, Shu-Tao Gao, Cheng Feng, Ning-Zhao Shang, Chun Wang, Xue-Li Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dehydrogenation of formic acid to yield molecular H〈sub〉2〈/sub〉 is a sustainable and promising route in hydrogen energy supply. Rational design of high-performance catalytic system for it remains a challenging task. Herein, CoPd nanoparticles supported on covalent triazine frameworks (CoPd/CTF) were fabricated for the first time. The prepared Co〈sub〉5〈/sub〉Pd〈sub〉5〈/sub〉/CTF-600 catalyst exhibited 100% H〈sub〉2〈/sub〉 selectivity and excellent catalytic activity (TOF = 2129 h〈sup〉−1〈/sup〉, n〈sub〉Pd〈/sub〉/n〈sub〉HCOOH〈/sub〉 = 0.007) toward the dehydrogenation of formic acid at 50 °C. Our study further demonstrated that not only the synergetic effect between CoPd nanoparticles and nitrogen-rich CTF support, but also the ultrafine sizes of CoPd play a key role for the efficient catalytic dehydrogenation from formic acid. This work provides a feasible strategy to design high-performance CTF-based heterogeneous catalyst for catalyzing different reactions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉CoPd nanoparticles supported on covalent triazine frameworks (CoPd/CTF) were fabricated for the first time. The prepared Co〈sub〉5〈/sub〉Pd〈sub〉5〈/sub〉/CTF-600 catalyst exhibited 100% H〈sub〉2〈/sub〉 selectivity and excellent catalytic activity toward the dehydrogenation of formic acid at 50 °C.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218331040-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Dongqin Su, Zehua Tang, Jinfeng Xie, Zhengxu Bian, Junhao Zhang, Dandan Yang, Di Zhang, Jincheng Wang, Yi Liu, Aihua Yuan, Qinghong Kong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To solve the agglomeration of layered double hydroxides (LDH) for improving their supercapacitor performances, Co, Mn-LDH nanoneedle arrays grown on Ni foam (Co, Mn-LDH@NF hybrid) was fabricated via a one-step hydrothermal strategy. The Ni foam served as the skeleton frame for anchoring Co, Mn-LDH nanoneedles to form three dimensional net structures, and open spaces among Co, Mn-LDH nanoneedles. When Co, Mn-LDH@NF hybrid was used as binder-free electrodes for supercapacitors, it displayed outstanding supercapacitor performances with a high specific capacitance of 2422 F g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉, and superior cyclic stability for maintaining a capacitance of 2096 F g〈sup〉−1〈/sup〉 after 3000 cycles, which was only 13.5% capacity loss ratio. The excellent supercapacitor performances were ascribed to three dimensional net structure and LDH nanoneedle structure, which provided abundant electrochemical active sites, alleviated volume expansion, and had good electrical conductivity.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Yuzhen Zhang, Peiquan Xu, Chuangen Liu, Jiangwei Ren, Hongying Gong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cladding layers were prepared on carbon steel using nanostructured carbide-strengthened cobalt (Co)-based alloy (using nanostructured tungsten carbide as hard phases) as a deposited material by multi-track laser cladding. In addition to Co-based alloy, the deposited materials contained nanostructured chromium carbide (Cr〈sub〉3〈/sub〉C〈sub〉2〈/sub〉), vanadium carbide (VC), or Cr〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 and VC. Compared with the substrate, all cladding layers had an improved oxidation resistance with an increased time (0–50 h) at 800 °C. Cr〈sub〉2〈/sub〉C〈sub〉3〈/sub〉 had a higher oxidation-resistance performance than VC and the mutual reaction of Cr〈sub〉2〈/sub〉C〈sub〉3〈/sub〉 and VC. The constitution and phases of the cladding layers indicated hexagonal-close-packed-α and body-centered-cubic-β cobalt and hard carbides, such as CoC〈sub〉x〈/sub〉, V〈sub〉8〈/sub〉C〈sub〉7〈/sub〉, and Cr〈sub〉3〈/sub〉C〈sub〉2〈/sub〉, and some decarburization as Co〈sub〉3〈/sub〉W〈sub〉3〈/sub〉C and WC〈sub〉1-x〈/sub〉. Elemental inter-diffusion occurred between the different phases as indicated by transmission electron microscopy and electron backscattered diffraction. Mixed carbide has a larger misorientation than the cobalt matrix, and electron backscattered diffraction has considerable potential to evaluate plastic deformation. The average grain size of the hard carbides was much larger than that of the original deposited material. The carbides grew rapidly through interfacial diffusion, boundary migration, and coalescence, which followed the Kirkendall effect and Ostwald-coarsening mechanism. This research helps to understanding the microstructure, oxidation resistance, grain growth, and interfacial behavior in multi-track laser-cladding layers.〈/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-S0169433218331684-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Yuan-dong Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A mistake of applying pseudo-first-order kinetic model has been pointed out. Also a correct pseudo-first-order kinetic equation is given. In addition, the citation for the pseudo-first-order model has been discussed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): D. Pavlov, S. Syubaev, A. Kuchmizhak, S. Gurbatov, O. Vitrik, E. Modin, S. Kudryashov, X. Wang, S. Juodkazis, M. Lapine〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the application of direct femtosecond laser printing for manufacturing periodic nanoantenna structures with various geometry and period, printed on pure or alloyed noble metal films over a silica substrate. By varying applied pulse energy, we have realised a wide range of possible morphologies, from smooth nano-bumps to protruding nanojets with up to 1 μm height, and finally to through microholes. Using several pulse energy levels, we have printed periodic nanojet arrays with periods from 1.75 to 4 μm, and measured their IR reflection spectra. The resonance frequency and magnitude of the resulting absorbance were found to essentially depend on both the periodicity of the arrays and nanojet geometry. We explain these observations by considering nanojet-assisted plasmon excitation running along the nanojets and along the surface, and found a convincing agreement to the experiments. To this end, we have shown that the reported approach is suitable for designing structures with distinct IR resonances, tunable over a range of at least 2–6 μm. Finally, we have also applied direct laser printing to a variety of noble metal alloys, involving gold, silver and palladium in various combinations and compositions, and showed that nanojets can be reliably printed for such alloys, preserving their chemical composition and its homogeneous volumetric distribution.〈/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-S0169433218331428-ga1.jpg" width="493" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Praveen Chapala, Pandu Sunil Kumar, Joydip Joardar, Vasundhra Bhandari, Swati Ghosh Acharyya〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ti-Nb alloys having compositions Ti-24Nb-4Zr-8Sn, Ti-29Nb-13Ta-7Zr and Ti-35Nb-4Sn were synthesized by vacuum arc melting followed by ageing at 1273 K for 6 h in Ar atmosphere. The alloys were characterized by field emmision scanning electron microscopy (FESEM), transmission electron microscopy (TEM), micro X-ray diffraction, friction coefficient and nanohardness tests. In-vitro corrosion of the alloys were studied by potentiodynamic polarisation in body simulated fluid at 37 〈sup〉○〈/sup〉C. The alloy surfaces were exposed to 〈em〉staphylococcus aureus bacteria〈/em〉 under controlled environment and the retention of the bacteria was examined by confocal laser scanning microscopy. The alloys had different ratios of α, β phases, different nature of inclusion, and dislocation pile-up resulting in high hardness. Alloys also had good resistance to in-vitro corrosion, low coefficient of friction and were resistant to bacterial growth as compared to commercially pure (CP) Ti. The coefficient of friction was lowest for Ti-24Nb-4Zr-8Sn and it increased with increasing Nb content. The resistance to bacterial growth on the surface increased with increasing volume fraction of β phase in the alloy.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Zhen Li, Yang Yang, Kai Dai, Jinfeng Zhang, Luhua Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉CdS, as semiconductor catalyst, has attracted much attention in photocatalytic production of hydrogen for the wide range utilization of visible light. Usually, noble metal deposited as a co-catalyst on CdS surface is required to achieve high photocatalytic activity. Thus, replacing noble metal via cheap and easy synthesis co-catalyst would be of great value for developing cost-effective photocatalyst. In this work, noble-metal-free defective Mo〈sub〉15〈/sub〉S〈sub〉19〈/sub〉 combined with CdS-diethylenetriamine (DETA) hybrid makes efficient separation of photoinduced carriers, and more importantly, reduced overpotential for hydrogen evolution reaction, thereby improved catalytic hydrogen evolution performance of designed composite. In particular, 3%Mo〈sub〉15〈/sub〉S〈sub〉19〈/sub〉/CdS-DETA systems exhibited a high rate of hydrogen production, reaching 3.61 mmol g〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉, which is similar with 3%Pt/CdS-DETA and 9.5 and 2.19 times as high as that of CdS nanoparticles (NPs) and CdS-DETA, respectively. At the same time, photocorrosion resistance of 3%Mo〈sub〉15〈/sub〉S〈sub〉19〈/sub〉/CdS-DETA systems was dramatically improved. According to DFT theoretical calculations, it was found that the enhanced photocatalytic performance and anticorrosion are mainly due to efficient transfer of photoexcited electrons from CdS-DETA to Mo〈sub〉15〈/sub〉S〈sub〉19〈/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-S0169433218331568-ga1.jpg" width="355" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Zhangxing He, Manman Li, Yuehua Li, Ling Wang, Jing Zhu, Wei Meng, Chuanchang Li, Huizhu Zhou, Lei Dai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Carbon nanofiber (CNF) was developed via electrospinning technique with polyacrylonitrile as precursor. Nitrogen-doped carbon nanofiber (NCNF), synthesized by liquid phase dispersion and carbonization processes with urea at 800–1000 °C, were investigated as negative electrode for vanadium redox flow battery (VRFB). Morphology and structure of CNF and NCNF were systematically investigated by SEM, Raman, XPS, etc. The morphology of CNF is not changed by nitrogen doping. However, nitrogen doping can lead to marked enhancement of surface defect and hydrophilicity. Electrochemical test results show that NCNF treated at 900 °C (CNF-N9) exhibits the best electrochemical performance. The excellent energy storage performance of the cell is obtained by using CNF-N9. Discharge capacity of cell for CNF-N9 arrives at 98.0 mA h, 30.0 mA h higher than that of the pristine cell at 90 mA cm〈sup〉−2〈/sup〉. And energy efficiency of the cell using CNF-N9 increases by 6.3% compared with pristine cell. Outstanding performances of CNF-N9 come from the increase of surface defect and the improvement of hydrophilicity and conductivity resulting from nitrogen doping, further promoting the electron and mass transfer between vanadium ion and electrode.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Minglong Yang, Ye Yuan, Weilong Yin, Shuang Yang, Qingyu Peng, Jianjun Li, Yibin Li, Xiaodong He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High performance broadband microwave absorption material is in urgent demand as the radar detection frequency range has been greatly broadened and electromagnetic radiation pollution has become increasingly serious. In this work, we fabricated a hierarchical bowknot-like Co/CoO@C nanocomposite with a two-step hydrothermal method, followed by high-temperature pyrolysis under argon atmosphere, which is composed of amorphous carbon and uniformly dispersed irregular Co/CoO nanoparticles. Complex permittivity and complex permeability were modulated by varying the calcination temperature (500–700 °C). Reflection loss (RL) curves of the Co/CoO@C nanocomposites show superior broadband electromagnetic wave absorption performance. Especially, the effective absorption bandwidth was maximized to 13.6 GHz (4.4–18 GHz) at the thickness of 6 mm, and a −45.0 dB minimum RL appears at 6 GHz. Such superior broadband electromagnetic wave absorption properties are attributed to the synergistic effect of the hierarchical bowknot-like structure and strong surface/interface polarization, as well as the eddy current and magnetic natural resonance. These results indicate the bowknot-like Co/CoO@C nanocomposite is promising in dealing with broadband electromagnetic radiation pollution and broadband military radar detection.〈/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-S0169433218327429-ga1.jpg" width="270" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Xuyang Zhou, Xiaoxiang Yu, David Jacobson, Gregory B. Thompson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molecular Dynamics (MD) simulations have been employed to model the growth stresses of body-centered cubic (BCC) metal thin films, with tungsten being the primary case study, as a function of various embryonic island textures, grain sizes, grain morphologies, deposition rates, and deposition energies. Depending on the shape and size of the islands, the tensile stress varied as a function of the available contact area. If the adatoms were sufficiently confined to the surface, the tops of these islands initiated the elastic strain for coalescence. This was particularly relevant for island morphologies that had varied curvature gradients near the contact points. Depending on the texture of the film, the roughness changed, with the 〈1 1 1〉 orientation being the roughest and 〈0 0 1〉 orientation being the smoothest. These topologies are explained by differences in surface diffusivities. The injection energy of adatoms was found to have a dramatic effect on film stress. Species with injection energies in excess of 50 eV resulted in a notable increase in the structural disorder at the grain boundary-free surface intersection which corresponded to a reduction of the tensile stress. Upon ceasing deposition, these disordered regions experienced a recovery to the BCC structure with an increase in the tensile stress. Upon resuming deposition, at the same energies, the disordered structure re-developed and the stress became less tensile and matched the prior deposited stress evolution. Finally, reducing the grain size resulted in an increase in tensile stress up to a critical size, whereupon it decreased. This reversion is explained in terms of grain growth and grain boundary structure during deposition. Through these series of systemically controlled MD simulations, the paper addresses the significance of different microstructures on the evolution of thin film stress.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Fatema H. Rajab, Peri Korshed, Zhu Liu, Tao Wang, Lin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Infectious bacterial biofilms represent a threat to public health, industry and economy. They are also considered as harmful organisms for marine animals, water systems, and food processing industry. In this paper, a method of rapidly growing antibacterial ZnO nanowire coatings on a variety of substrates using a fibre laser was demonstrated. Pure well ordered, hexagonal Wurtzite ZnO nanowires of around 90 nm diameter and 1.7 µm in length were successfully formed on a stainless steel, Cu, ITO coated glass and FTO coated glass substrates using a laser-induced hydrothermal process. The coating has been found to be rapidly switchable between being superhydrophobic and superhydrophilic with UV light irradiation. The findings show that long-term (〈em〉e.g.〈/em〉 4 months) antibacterial properties against 〈em〉Escherichia coli (E. coli)〈/em〉 bacteria under standard laboratory light and dark conditions were achieved. A micro/nanoflower-like structure was also produced by tuning the pH value of the used aqueous solution. The flower-like structure also showed high antibacterial activities.〈/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-S0169433218330319-ga1.jpg" width="311" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 469〈/p〉 〈p〉Author(s): Waldemar Nowicki〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Identification of the copper(II) ions complexes deposited on the amorphous silica surface was conducted using four different research techniques. The potentiometric titration in heterogeneous system was used to establish the forms of complexes with ligands immobilized on the surface. The types of Cu(II) complexes depend on the pH value. In the pH range 4–11, the presence of the following four types of Cu(II) complexes was evidenced: CuHSGL, CuSGL, Cu(SGL)〈sub〉2〈/sub〉, and Cu(SGL)〈sub〉2〈/sub〉(OH). Their stability constants were found to be log β〈sub〉CuHSGL〈/sub〉 = 14.01, log β〈sub〉CuSGL〈/sub〉 = 7.51, log β〈sub〉Cu(SGL)2〈/sub〉 = 14.12, and log β〈sub〉Cu(SGL)2(OH)〈/sub〉 = 4.84 for I = 0.1 M KNO〈sub〉3〈/sub〉. These complexes were characterized by X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and UV–Vis methods. According to the XPS results, close to pH 6, the partly protonated ligand can additionally form surface ion compounds of the type [R-NH〈sub〉2〈/sub〉〈sup〉+〈/sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉(CH〈sub〉2〈/sub〉)〈sub〉2〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉NH〈sub〉2〈/sub〉][NO〈sub〉3〈/sub〉〈sup〉–〈/sup〉]. EPR permitted determination of the spin-Hamiltonian, showing that Cu(II) ion was in the ground state d〈sub〉x〈/sub〉〈sup〉2〈/sup〉〈sub〉-y〈/sub〉〈sup〉2〈/sup〉, and the Cu(II) ions symmetry can be described as that of deformed tetragonal octahedrons. UV–Vis measurements in a flow cell confirmed the course of reaction in the heterogeneous system between Cu(II) and diamine ligand, N-(2-amineethyl-3-aminepropyl)trimethoxysilane, immobilized on the surface of amorphous silica gel.〈/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-S0169433218331350-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Yuriy Azhniuk, Volodymyr Dzhagan, Dmytro Solonenko, Vasyl Loya, Iaroslav Grytsyshche, Vasyl Lopushansky, Alexander Gomonnai, Dietrich R.T. Zahn〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Amorphous In-doped As〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 films with nominal indium contents 〈em〉x〈/em〉 up to 7 at.% were prepared by thermal evaporation. Atomic force microscopy studies confirm the uniform film structure with a surface roughness near 5 nm, noticeably higher than for similarly prepared undoped As〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 film. X-ray photoelectron spectroscopy (XPS) studies enabled the chemical composition of the films to be examined. As follows from the XPS data, the In content in the film strongly decreases with the film depth. For films with 〈em〉x〈/em〉 ≥ 2 at.%, Raman features attributed to transverse and longitudinal optical phonons of InAs are revealed in the Raman spectra as an evidence for the formation of InAs nanocrystallites in the As〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉:In film under laser illumination.〈/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-S0169433218334263-ga1.jpg" width="489" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Goli Nagaraju, S. Chandra Sekhar, Bhimanaboina Ramulu, Jae Su Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, battery-type electrode materials, such as transition metal oxides/molybdates, have attracted extensive attention in the development of high-performance supercapacitors (SCs), owing to their rich redox chemistry, high theoretical capacity and superior electrochemical activity. Herein, we prepared battery-type redox behavior-enabled tricopper dimolybdate (Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉) with versatile morphologies of nanoflakes (NFs) and nanoparticles (NPs) by a facile hydrothermal method for SCs. With different reactants, the shape of Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉 was altered under constant growth conditions. The morphological and structural characteristics of the prepared samples were investigated by FE-SEM, XRD and XPS analyses. Moreover, the electrochemical properties of the Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉 nanostructures were evaluated in 1 M KOH electrolyte. From these results, the Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉 NF sample exhibited a high areal capacity of 29.6 μAh/cm〈sup〉2〈/sup〉 at 1 mA/cm〈sup〉2〈/sup〉 with good rate capability of 61.1% at 20 mA/cm〈sup〉2〈/sup〉, which are higher compared to the NP sample. Furthermore, the capacity retention of 131.3% (after 2000 cycles) was observed without any capacity fading for the Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉 NFs, indicating the great cycling durability of the material. Such remarkable durability of the Cu〈sub〉3〈/sub〉Mo〈sub〉2〈/sub〉O〈sub〉9〈/sub〉 nanostructures could be served as an efficient electrode in energy storage 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-S0169433218333622-ga1.jpg" width="465" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Zahra Ghalami, Vanik Ghoulipour, Alireza Khanchi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, porous organic cages (POCs) have attracted considerable interests due to their nanoscale cavities and high surface area. In this study, the combined computational and experimental investigations were performed on POCs to examine their potential capabilities for the removal of Cs〈sup〉+〈/sup〉 and Sr〈sup〉2+〈/sup〉 ions from aqueous solution. CC3-R with interconnected tetrahedral pores is permeable to water. It has the ability to extract 1.86 mmol g〈sup〉−1〈/sup〉 Cs〈sup〉+〈/sup〉 (two ions per cage) and 2.77 mmol g〈sup〉−1〈/sup〉 Sr〈sup〉2+〈/sup〉 (three ions per cage) with distribution coefficients of 1.1 × 10〈sup〉4〈/sup〉 ml g〈sup〉−1〈/sup〉 and 2.4 × 10〈sup〉4〈/sup〉 ml g〈sup〉−1〈/sup〉, respectively. We have used computational methods to calculate the binding energies, strain energies and free energy perturbation (FEP). Effects of contact time and metal ion concentration on the removal of these ions, and extraction capacity of CC3-R for metal ions were examined in detail. Our simulation results are in reasonable agreement with the experimental reports. Thus, our simulation results plays an important role in the proper evaluation of solid phase extraction (SPE) with CC3-R cage.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): R. Jagdheesh, M. Diaz, S. Marimuthu, J.L. Ocaña〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel technique of post-vacuum processing the laser patterned surface was used for high speed fabrication of Ultrahydrophobic Ti6Al4V surface and the basics behind the transformation of surface chemistry is investigated in this paper. The wetting property of the laser patterned dual geometry structures transforms to ultrahydrophobic in 120 min of vacuum process without any chemical treatments to suppress the surface polarity. The surface recorded static contact angle of 180°, sliding angle less than 5, and exhibits bouncing and roll-off characteristic due to the presence of composite interface. The transformation of hydrophobic property establish a clear relationship between the vacuum process period and the improvement in static contact angle. The surface chemical analyses by XPS reveals that the amount of surface carbon content increases 2.3 times higher because of the adsorption of unstable organic molecules by vacuum process. The low partial pressure of the water molecules (120 min.) compared to those occurs at standard atmospheric pressure (days). The transformation of freshly laser processed Ti6Al4V hydrophilic surfaces into ultrahydrophobic surface is due to the development of carbonaceous layer over the laser patterned structures, which helps to sustain the Cassi-Baxter state.〈/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-S0169433218333762-ga1.jpg" width="265" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Yue Zhang, Xinying Lu, Dongsheng Song, Songbai Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption of water molecules on tricalcium silicate (C〈sub〉3〈/sub〉S), which influences the initial hydration of C〈sub〉3〈/sub〉S, is still unclear at the atomistic level. In the present paper, density functional theory is employed to depict the adsorption of a single water molecule on seven low-index M〈sub〉3〈/sub〉-C〈sub〉3〈/sub〉S surfaces. The calculations show that both molecular and dissociative adsorption can occur on the C〈sub〉3〈/sub〉S surfaces and that the latter mode is preferential. All of the ionic O atoms on the C〈sub〉3〈/sub〉S surfaces can adsorb the H atoms from dissociated water molecules, while only two-coordinated covalent O atoms on the surfaces can form O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H chemical bonds. The electronic structures of the ionic and two-coordinated covalent O atoms in the first atomic layer of the C〈sub〉3〈/sub〉S surfaces show similar charge density localization of the valence band maximum (VBM), which can describe the variations in the reactivity of the ionic O atoms in the bulk or exposed on the surface slab. The partial density of states (PDOS) analysis shows that the formation of new Ca〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O bonds is mainly due to the overlap of O-2s and Ca-3p orbitals and O-2p and Ca-3d orbitals. Furthermore, the position of the OH group generated from the dissociated water molecule is found to significantly affect the adsorption energy. The general order of the adsorption energy in terms of the position of the OH group is E〈sub〉hollow〈/sub〉 〉 E〈sub〉bridge〈/sub〉 〉 E〈sub〉top〈/sub〉. The findings in this study provide additional support for the fundamental understanding of C〈sub〉3〈/sub〉S hydration.〈/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-S0169433218333920-ga1.jpg" width="338" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Zijia Yin, Jun Zhao, Baowei Wang, Yan Xu, Zhenhua Li, Xinbin Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Unsupported MoS〈sub〉2〈/sub〉 catalysts were synthesized by a one-step hydrothermal method using ammonium heptamolybdate and thiourea at different temperatures ranging from 150 °C to 180 °C. With the decrease of hydrothermal temperature, the obtained MoS〈sub〉2〈/sub〉 catalyst showed an increased sulfur-resistant methanation performance. The physical structure and chemical characteristics of the catalysts were analyzed by N〈sub〉2〈/sub〉-physisorption, XRD, SEM, HRTEM, Elemental Analyzer, H〈sub〉2〈/sub〉-TPR, XPS and Raman techniques. Combining the catalytic performance trend with the characterization analysis results, we found that the catalysts obtained at lower temperature contain more bridging 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msubsup〉〈mtext〉S〈/mtext〉〈mrow〉〈mtext〉2〈/mtext〉〈/mrow〉〈mtext〉2-〈/mtext〉〈/msubsup〉〈/mrow〉〈/math〉 groups, that is beneficial for H〈sub〉2〈/sub〉 dissociation and methanation reaction. We deduced that over-stoichiometric sulfur in the catalyst existed in the form of bridging 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msubsup〉〈mtext〉S〈/mtext〉〈mrow〉〈mtext〉2〈/mtext〉〈/mrow〉〈mtext〉2-〈/mtext〉〈/msubsup〉〈/mrow〉〈/math〉 groups, which increased with the decrease of hydrothermal temperature. The finding that the positive role of the bridging 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msubsup〉〈mtext〉S〈/mtext〉〈mrow〉〈mtext〉2〈/mtext〉〈/mrow〉〈mtext〉2-〈/mtext〉〈/msubsup〉〈/mrow〉〈/math〉 groups rather than the S vacancies in MoS〈sub〉2〈/sub〉 catalyst is helpful for designing high efficient MoS〈sub〉2〈/sub〉 catalysts not only for methanation but also for other hydrogenation reactions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Unsupported MoS〈sub〉2〈/sub〉 catalysts were obtained by hydrothermal method at various temperatures ranging from 150 °C to 180 °C. The catalysts obtained at lower temperature show better CO conversion since they have more bridging 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msubsup〉〈mtext〉S〈/mtext〉〈mrow〉〈mtext〉2〈/mtext〉〈/mrow〉〈mtext〉2-〈/mtext〉〈/msubsup〉〈/mrow〉〈/math〉 groups that are beneficial for H〈sub〉2〈/sub〉 dissociation and formation of 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉SH group.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218333865-ga1.jpg" width="375" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Stephan Gräf, Clemens Kunz, Andreas Undisz, Robert Wonneberger, Markus Rettenmayr, Frank A. Müller〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new concept of mechano-responsive colour-change is introduced in the present work that allows for turning flexible materials into an optical mechano-sensitive sensor. For this purpose diffraction gratings based on laser-induced periodic surface structures (LIPSS) are produced on ductile stainless steel surfaces (X2CrNiMo17–12–2) using a femtosecond laser (fs-laser). When the material is deformed, the increase of the lattice spacing in the diffraction grating leads to a mechano-responsive change of the initial structural colour in the direction of longer wavelengths. With increasing plastic deformation of the metal, the formation of tilted and twisted slip bands leads to a disappearance of the structural colours before the material fails. Using metal masters, the LIPSS can be transferred to elastomers by replica casting. For elastomers produced by replica casting, the mechano-responsive colour change is reversible. The mechanically induced colour change of LIPSS is of particular interest for the development of novel switches, safety devices, strain gauges, sensors, hazard classification and early detection of material failure.〈/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-S0169433218333804-ga1.jpg" width="309" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Ievgen Brytavskyi, Kristína Hušeková, Valerii Myndrul, Mykola Pavlenko, Emerson Coy, Karol Zaleski, Dagmar Gregušová, Luis Yate, Valentyn Smyntyna, Igor Iatsunskyi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ruthenium oxide (RuO〈sub〉2〈/sub〉) has received significant attention in recent years for its photocatalytic properties and photoelectrochemical (PEC) performance. In the present research, RuO〈sub〉2〈/sub〉 nanolayers were grown on n-type porous silicon (PSi) by metal organic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD). The morphology, mechanical and optical properties of produced nanostructures were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, diffuse reflectance and photoluminescence (PL) spectroscopy. It was shown that that MOCVD gives non-uniform distribution of RuO〈sub〉2〈/sub〉 along the pore and it is deposited mainly in the near-surface of PSi, while distribution of ruthenium obtained by ALD looks conformal over the entire pore. The mean size of RuO〈sub〉2〈/sub〉 nanocrystallites and mechanical stresses were determined by TEM, XRD and Raman spectroscopy. It was demonstrated that samples obtained by ALD demonstrate a good crystallinity, while crystalline phase for samples produced by MOCVD improve with RuO〈sub〉2〈/sub〉 layer thickness increasing. It was established the formation of hydrated RuO〈sub〉2〈/sub〉 during ALD and MOCVD. It was shown that the samples produced by MOCVD have slightly higher electrical conductivity than ALD samples. The average value of energy gap (〈em〉E〈sub〉g〈/sub〉〈/em〉) for samples prepared by MOCVD depended on the number of injections. RuO〈sub〉2〈/sub〉 nanolayers quenched intrinsic PL from the PSi matrix. The correlation between structural, optical, and mechanical properties of samples produced by MOCVD and ALD was discussed.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Meng-Qiu Li, Ni Yang, Gui-Gen Wang, Hua-Yu Zhang, Jie-Cai Han〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a wide-bandgap semiconductor oxide material, Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 has great application prospects in various optoelectronic fields. At present, much attention has been paid to Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 deep ultraviolet (DUV) detectors, in which Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films are often poor-quality poly-crystalline or expensive mono-crystalline. In this paper, Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films with highly preferred orientation were deposited on hexagonal SiC (6H-SiC) substrate by magnetron sputtering, and the as-prepared Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films were then annealed. The influences of sputtering and annealing parameters on Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films were analyzed. Finally, DUV photo-detectors based on the as-obtained Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films were fabricated. The experimental results show, when choosing optimal sputtering parameters (RF power: 120 W, gas pressure: 1.5 Pa, film thickness: 400 nm), the sputtered Ga〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 films with (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈mspace width="0.166667em"〉〈/mspace〉〈mn〉0〈/mn〉〈mspace width="0.166667em"〉〈/mspace〉〈mn〉1〈/mn〉〈/mrow〉〈/math〉) highly preferred orientation after annealing at 800 °C, have good crystalline quality (FWHM = 0.108°) between single-crystal and polycrystal, showing good compromise between optoelectronic characteristics and preparation cost. The fabricated metal-semiconductor-metal (MSM) DUV photodetector operated at a bias voltage of 10 V can achieve excellent comprehensive photo-detection properties for 254 nm ultraviolet light: the responsivity, detectivity and quantum efficiency are high as 2.6 A/W, 1.6 × 10〈sup〉12〈/sup〉 Jones and 1265%, respectively, along with short response time of 0.26 s.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Qiaoyue Xi, Ge Gao, Manyu Jin, Yanqun Zhang, Hua Zhou, Cunqi Wu, Yongxia Zhao, Lidan Wang, Pengran Guo, Jingwei Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel ternary photocatalytic nanocomposite, Ag–Cu〈sub〉2〈/sub〉O/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, has been successfully synthesized via a facile two-step reduction procedure at room temperature, wherein Ag nanoparticles are directly growing on the surface of Cu〈sub〉2〈/sub〉O supported by C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets. The resulting ternary Ag–Cu〈sub〉2〈/sub〉O/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst exhibits enhanced photocatalytic activity towards methyl orange (MO) degradation compared with its counterparts (Cu〈sub〉2〈/sub〉O, spherical Ag–Cu〈sub〉2〈/sub〉O and Cu〈sub〉2〈/sub〉O/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉), demonstrating a removal rate of MO up to 95.7% within 30 min. The enhanced photocatalytic activity can be ascribed to the following factors: (1) the surface plasmon resonance effect of Ag nanoparticles broadening the visible light response of Cu〈sub〉2〈/sub〉O; (2) the introduction of C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 functioning not only as a fast electron delivery but also a fine stabilizer to prevent the Ag–Cu〈sub〉2〈/sub〉O composite from agglomeration. Mechanism studies reveal that MO is cracked into smaller fragments and the h〈sup〉+〈/sup〉 is the main reactive species participating in the photocatalytic process. Moreover, the Ag–Cu〈sub〉2〈/sub〉O/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst also shows high photodegradation ability for another two representative azo dyes, acid orange II and congo red. This study demonstrates the potential of Ag–Cu〈sub〉2〈/sub〉O/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 in the degradation of azo dyes and also provides a guide to design of Cu〈sub〉2〈/sub〉O-based ternary photocatalysts for further wastewater remediation.〈/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-S0169433218333695-ga1.jpg" width="310" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Mingyu Zhao, Rumeng Zhao, Wei Li, Tianxing Wang, Yaqiang Ma, Xianqi Dai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The SnS〈sub〉2〈/sub〉 is a new class of 2D materials with unique properties, which are still largely unexplored in the CO catalyst field. The modulation of electronic structures and chemical activities of the Mn atom substituted for S atom in SnS〈sub〉2〈/sub〉 monolayer sheet is studied based on density functional theory. The electrons of doped Mn are introduced to the dangling bond of monovacancy SnS〈sub〉2〈/sub〉 system, which can enhance the stability of Mn-Sn bond. The Mn-SnS〈sub〉2〈/sub〉 monolayer sheet prefers good catalytic activity for the CO oxidation via the more favorable Langmuir-Hinshelwood mechanism with a two-step route to the Eley-Rideal or the latest report of termolecular Eley-Rideal mechanisms. In summary, we show first-principles evidence toward the realization of SnS〈sub〉2〈/sub〉 based catalyst for CO catalytic oxidation which can facilitate the applications of SnS〈sub〉2〈/sub〉 in the fields of catalysis and air pollution prevention.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The Mn-SnS〈sub〉2〈/sub〉 monolayer sheet shows good catalytic activity for the CO oxidation via the Langmuir-Hinshelwood mechanism with a two-step route.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218333725-ga1.jpg" width="287" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): E.A. Konshina, D.P. Shcherbinin, M.M. Abboud, K.V. Bogdanov, I.A. Gladskikh, V.A. Polischuk〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) in a granulated film with thickness 2 nm was investigated at the interface of two amorphous hydrogenated carbon (a-C:H) films with optical gap 0.67 eV and 2.7 eV. In these hybrid structures, a blue shift of the LSPR wavelength was observed in contrast with Au NPs on quartz surface at a room temperature. The annealing of such hybrid structures at 200 °C resulted in forming spheroid Au NPs with the dimensions about 11 nm which promotes increasing blue shift of the LSPR spectra. The intensity of the LSPR peak increased significantly after annealing at 300 °C, but Au NPs film morphology and LSPR peak position have not changed. After annealing at 400 °C the LSPR peak intensity in hybrid structure with a narrow gap a-C:H film decreased dramatically but did not change in the sample with a wide gap a-C:H. The observed changes in the LSPR spectra as a result of hybrid structures annealing are associated with the difference in the electronic and atomic structure of a-C:H thin films, as shown by their studies using Raman spectroscopy.〈/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-S016943321833407X-ga1.jpg" width="319" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Zhen-Chun Chen, Yu Cheng, Chan-Cheng Lin, Chia-Shuo Li, Cheng-Che Hsu, Jian-Zhang Chen, Chih-I Wu, I-Chun Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of atmospheric-pressure dielectric barrier discharge (DBD) treatment on the properties of methylammonium lead iodide (CH〈sub〉3〈/sub〉NH〈sub〉3〈/sub〉PbI〈sub〉3〈/sub〉, MAPbI〈sub〉3〈/sub〉) perovskite thin films is investigated. The in-situ DBD-treated MAPbI〈sub〉3〈/sub〉 perovskite thin films are then used as the absorber layers for planar n-i-p perovskite solar cells (PSCs). N-O emission system is observed in the plasma during the treatment, indicating the reactions of reactive nitrogen plasma species with the organics in the precursor films. Long DBD treatment duration (60 s) leads to the phase precipitation of PbI〈sub〉2〈/sub〉 and degrades the cell efficiency, whereas short DBD treatment duration (20 s) significantly improves the PSC efficiency by nearly 40%. Only slight performance enhancement is observed in the PSCs prepared by conventional thermal treatment at the same substrate temperatures as that for DBD treatment, implying that DBD provides the synergetic effect of the reactivity and plasma heating. Electrochemical impedance spectroscopy (EIS) indicates that the charge recombination impedance increases and then decreases with DBD treatment duration. The shunt resistance also shows a similar trend, and it is consistent with the PSC performance. The PSC with the 20 s DBD-treated absorber layer shows energy conversion efficiency of 14.29%, open circuit voltage of 1.022 V, short circuit current density of 19.45 mA/cm〈sup〉2〈/sup〉, and fill factor of 0.72, whereas the corresponding values for the untreated counterpart are 10.32%, 0.976 V, 18.52 mA/cm〈sup〉2〈/sup〉, and 0.57. The result shows that short-duration low-temperature DBD treatment effectively enhances the performance of solution-processed PSCs.〈/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-S0169433218334561-ga1.jpg" width="415" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Gidon Ferdiman, Jacob Karni〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Thermionic materials are commonly used in high vacuum (〈10〈sup〉−5〈/sup〉 mbar). We measured thermionic emission of different doped metal-oxides cathodes – Zr doped Gd〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and Nb doped SrTiO〈sub〉3〈/sub〉 (1 1 1) – in a CO〈sub〉2〈/sub〉 surrounding, at T = 1300 °C and ∼10〈sup〉−4〈/sup〉 mbar ≤ p ≤ 300 mbar. Experimental setup validation and reference data were provided by measurements using cathodes made of CeB〈sub〉6〈/sub〉, a commercial thermionic material, and by using either helium or argon as the surrounding gas. The study’s results could be used when examining enhancement of CO〈sub〉2〈/sub〉 reduction to CO using vibration’s excitation.〈/p〉 〈p〉The thermionic emission of all cathodes decreased gradually as the pressure increased, as expected, but the exposure to CO〈sub〉2〈/sub〉 did not cause a deterioration of the Zr doped Gd〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 cathodes. They retained a reasonable emission, of ∼60% and ∼40% of the current in vacuum, at a CO〈sub〉2〈/sub〉 pressure of 50 mbar and 300 mbar, respectively, over 20 operation hours.〈/p〉 〈p〉The data suggest that in the presence of significant gas pressure in the cathodes surrounding, the electric dipole of CO〈sub〉2〈/sub〉 molecules and the cathode’s surface roughness may induce several mechanisms, which could affect the current emission.〈/p〉 〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉(a) Comparison of measured thermionic current in CO〈sub〉2〈/sub〉 using different cathodes.〈/p〉 〈p〉(b) Current ratio comparison of the emission of different thermionic cathodes. Temperature 1300 °C, Electric field −100 V/cm (67 V/cm in the Nb/SrTiO〈sub〉3〈/sub〉 tests).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218332641-ga1.jpg" width="443" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Shuo Wang, Guangshe Li, Zhihua Leng, Yan Wang, Shaofan Fang, Jianghao Wang, Yanhua Wei, Liping Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Constructing heterojunction semiconductor materials with a strong interfacial interaction are emerging as a forefront strategy for promoting excellent photocatalytic performance. Herein, we report a novel SnS〈sub〉2〈/sub〉/SnO〈sub〉2〈/sub〉 heterojunction material via in-situ trace vulcanization strategy to coat SnS〈sub〉2〈/sub〉 on the SnO〈sub〉2〈/sub〉. The thickness of the coating layer can be regulated by controlling the content of SnS〈sub〉2〈/sub〉. Moreover, molar ratio of S to Sn, particle size of SnO〈sub〉2〈/sub〉 precursor, and vulcanization time that governs the SnS〈sub〉2〈/sub〉 content of heterojunction catalyst were controlled to optimize photocatalytic performance. SnS〈sub〉2〈/sub〉/SnO〈sub〉2〈/sub〉 heterojunction catalyst with 19.5% SnS〈sub〉2〈/sub〉 content delivered a ultrahigh visible-light activity in Cr(VI) degradation, remarkably superior to the inert SnO〈sub〉2〈/sub〉 precursors and full-vulcanized SnS〈sub〉2〈/sub〉 under identical testing conditions. The enhanced interfacial interaction can remarkably enhance the separation and transfer of photogenerated charges. The systematic methodology of interface regulation in SnS〈sub〉2〈/sub〉/SnO〈sub〉2〈/sub〉 system reported in this work would promote the understanding of nano-heterojunction material for high-performance water treatment application.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉SnS〈sub〉2〈/sub〉 is obtained from SnO〈sub〉2〈/sub〉 in-situ transformed in the process of trace vulcanization. Strong interfacial interaction between SnO〈sub〉2〈/sub〉 and SnS〈sub〉2〈/sub〉 has promoted the separation of photoinduced electrons and holes effectively and provided more electrons to reduce the Cr(VI) to Cr(III).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218333610-ga1.jpg" width="294" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Guo Wang, Xinyu Wang, Yi Liao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A two-dimensional scandium monochloride sheet was investigated by using density functional theory. The cleavage energy from the bulk material is slightly lower than that of graphene. The sheet has a ferromagnetic ground state with a Curie temperature of 100 K. Moreover, the sheet becomes a half-metal under hole doping. The Curie temperature increases to 250 K with the doping amount of 0.4 per primitive cell. The two-dimensional scandium monochloride sheet should be a good candidate for two-dimensional spintronics.〈/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-S0169433218334470-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Bingtian Li, Haizhong Zheng, Guifa Li, Zheng Chen, Peifeng Zhou, Gang Wang, Ping Peng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The internal mechanism underlying the high surface activity of 〈em〉t〈/em〉-YSZ nanomaterials composed of low Miller index facets is not completely understood at present. Using first-principles calculations, the surface energies, as well as geometrical and electronic properties of 〈em〉t〈/em〉-YSZ morphology are simulated and analyzed by conventional bulk surface and new microfacet models. The results show that the surface energies follow the trend 〈em〉E〈/em〉〈sub〉surface〈/sub〉 [(0 1 0 × 0 1 0)] 〉 〈em〉E〈/em〉〈sub〉surface〈/sub〉 [(1 1 1 × 0 1 0)] 〉 〈em〉E〈/em〉〈sub〉surface〈/sub〉 [(1 0 1 × 0 1 0)] 〉 〈em〉E〈/em〉〈sub〉surface〈/sub〉 [(1 1 1 × 1 0 1)] 〉 〈em〉E〈/em〉〈sub〉surface〈/sub〉 [(1 0 1 × 1 0 1)] 〉 (1 1 1) bulk surface 〉 (1 0 1) bulk surface 〉 (0 1 0) bulk surface, where the surface energies of the microfacet models are several times greater than those of the bulk surfaces. The surface activity of the microfacet is therefore much more vigorous than that of the bulk surface. The very high chemical activity of the microfacets is derived from their large Fermi energy, pseudo energy gap, and change in Mulliken population. Although the low Miller index surfaces exhibit weak activity, their interface, such as [(0 1 0 × 0 1 0)], have high chemical activity, because of which they are easily and quickly corroded by CaO-MgO-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-SiO〈sub〉2〈/sub〉 (CMAS), as confirmed by experimental reports. Hence, our findings can be considered a first and vital step toward understanding the unusual properties of nano-YSZ.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The high surface activity of t-YSZ nanomaterials composed of low Miller index facets is found by a new microfacet model.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218334536-ga1.jpg" width="421" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Luyang Wang, Jiali Liu, Yulin Min, Kan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the past decade, crystal facet engineering of TiO〈sub〉2〈/sub〉 though various controllable strategies has attracted a lot of attention due to its strong facet dependent photoactivities. In this work, we report on nontopological transformation of titanium oxydifluoride (TiOF〈sub〉2〈/sub〉) to hierarchical TiO〈sub〉2〈/sub〉 structures by hydrothermal tailoring. The fluorine-containing species in TiOF〈sub〉2〈/sub〉 crystal perform the roles as either an etching agent or a capping agent, which can conveniently modulate morphologies and facets of TiO〈sub〉2〈/sub〉 crystals via dissolution or oriented collapse under hydrothermal condition. The Wulff construction and different surface energies of shape and facet lead to the controlled formation of hierarchical TiO〈sub〉2〈/sub〉, respectively with (1 0 1) faceted nanowalls, (0 0 1) and (1 1 1) faceted nanosheets, or their multi-facets. All TiO〈sub〉2〈/sub〉 with single exposed facet exhibit higher photocatalytic H〈sub〉2〈/sub〉 evolution performance than the commercial P25 TiO〈sub〉2〈/sub〉. Moreover, the (1 0 1) faceted nanowalls demonstrate superior photocatalytic H〈sub〉2〈/sub〉 evolution to (1 1 1) and (0 0 1) faceted TiO〈sub〉2〈/sub〉 nanosheets in presence of hole scavenger (methanol) due to favoured hole transfer at (1 0 1) facet/methanol interface. This work presents novel methodology for shape and facet control of TiO〈sub〉2〈/sub〉 towards solar to fuel conversion.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Guangzhao Wang, Xiaojiang Long, Kezhen Qi, Suihu Dang, Mingmin Zhong, Shuyuan Xiao, Tingwei Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have calculated and discussed the electronic and optical properties of two-dimensional (2D) CdS/g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 heterostructures by using hybrid density functional of HSE06. The CdS and g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 can form CdS/g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 heterostructures through weak van der Waals (vdW) interactions. The CdS/g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 composites are indirect bandgap semiconductors and type-II heterostructures. The visible light absorbtion of CdS/g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 composites is obviously improved, and the band alignment is beneficial for spontaneous water redox reactions. Furthermore, the electrons migrating from CdS layer to g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 leads to the built-in electric field formation, which promotes the effective separation of photogenerated carriers. These factors imply CdS/g-C〈sub〉6〈/sub〉N〈sub〉6〈/sub〉 composites are promising visible light water-splitting photocatalysts.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Xiaotao Liu, Zhenhua Wu, Yiqiang Zhang, Christos Tsamis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The properties of the perovskite solar cells (PSCs) are highly correlated with Fermi level, trap-state density and conductivity of inorganic electron transport layer. Metal elemental doping is an effective solution to largely improve the property of oxide semiconductor thin film. In this study, zinc dopant is successfully inserted into TiO〈sub〉2〈/sub〉 crystal lattice using low-temperature solution-processed route. We find that Zn-doped TiO〈sub〉2〈/sub〉 films possess less trap-state density and better conductivity, compared to undoped thin films, which contributes to the promotion of short circuit current. Ultraviolet photoelectron spectroscopy displays inserting Zn〈sup〉2+〈/sup〉 into TiO〈sub〉2〈/sub〉 compact layer can lift up TiO〈sub〉2〈/sub〉′s Fermi level, which reasonably improved the carrier dissociation and transportation. Consequently, CH〈sub〉3〈/sub〉NH〈sub〉3〈/sub〉PbI〈sub〉3〈/sub〉 PSCs based on 4.5% Zn-doped TiO〈sub〉2〈/sub〉 has obtained 17.6% power conversion efficiency (PCE), which is nearly 27.5% higher than control device (13.8%). In addition, triple-cation mixed-halide PSCs based on 4.5% Zn-doped TiO〈sub〉2〈/sub〉 has obtained a PCE of 19.04%, which is almost 13.7% higher than PCE of the device with undoped sample 16.75%. These findings offer a potential low-temperature doping method in TiO〈sub〉2〈/sub〉 ETL for flexible high-performance PSCs.〈/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-S0169433218333142-ga1.jpg" width="466" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Jingjing Dong, Ying Lin, Hanwen Zong, Haibo Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a core-shell hierarchical LiFe〈sub〉5〈/sub〉O〈sub〉8〈/sub〉@PPy nanocomposite has been successfully fabricated through a simple etching/regrowing method. The core buffer of highly conductive PPy nanotubes is introduced to enhance the electrochemical performance of LiFe〈sub〉5〈/sub〉O〈sub〉8〈/sub〉. Owing to improved electron transfer capability, charge transfer resistances of the core-shell nanostructured composites are decreased and the electrochemical properties are enhanced. The representative LiFe〈sub〉5〈/sub〉O〈sub〉8〈/sub〉@PPy nanocomposite exhibits a high specific capacitance of 292 F g〈sup〉−1〈/sup〉 at a scan rate of 5 mV s〈sup〉−1〈/sup〉, and an excellent cycling stability (82.99% after 10,000 cycles) because of the synergistic effect of LiFe〈sub〉5〈/sub〉O〈sub〉8〈/sub〉 nanosheets and PPy nanotubes. This study confirms that the as-prepared LiFe〈sub〉5〈/sub〉O〈sub〉8〈/sub〉@PPy nanocomposites are promising candidates for supercapacitor electrode 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-S0169433218332847-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Akarsh Verma, Avinash Parashar, M. Packirisamy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Aim of this article was to investigate the effect of grain boundaries on the interfacial properties of bi-crystalline graphene/polyethylene based nanocomposites. Molecular dynamics based atomistic simulations were performed in conjunction with the reactive force field parameters to capture atomic interactions within graphene and polyethylene atoms, whereas non-bonded interactions were considered for the interfacial properties. Atoms at the higher energy state in bi-crystalline graphene helps in improving the interaction at the nanocomposite interphase. Geometrical imperfections such as wrinkles and ripples helps the bi-crystalline graphene in increasing the number of adhesion points between the nanofiller and matrix, which eventually improves the strength and toughness of nanocomposite. These outcomes will help in opening new opportunities for defective nanofillers in the development of nanocomposites for future 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-S0169433218332975-ga1.jpg" width="251" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Le Yue, Rui Cheng, Weiqi Ding, Junwei Shao, Ji Li, Jinze Lyu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption ability and photoactivity of photocatalysts directly determine the mineralization efficiency of volatile organic compounds. In this study, a 2D–2D microporous structure of amorphous TiO〈sub〉2〈/sub〉 nanoparticles and graphene (GR) was constructed to simultaneously enhance the adsorption ability and charge separation efficiency of catalysts. N〈sub〉2〈/sub〉 adsorption–desorption, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction measurements were conducted to investigate the physical properties of the prepared samples. The atmospheric surface photovoltage (SPV) was utilized to study the separation process of the photogenerated charge carriers. Toluene was chosen as the model agent to estimate the adsorption ability and photoactivity of the samples. Results showed that the amorphous TiO〈sub〉2〈/sub〉 nanoparticles homogeneously deposited onto the GR surface and hence formed a 2D–2D microporous structure. Although the surface area of the GR–TiO〈sub〉2〈/sub〉 compositions increased by only 4–8% relative to that of microporous TiO〈sub〉2〈/sub〉 alone, the amount of adsorbed toluene for the GR–TiO〈sub〉2〈/sub〉 compositions was 156–193% times higher than that for the microporous TiO〈sub〉2〈/sub〉. The SPV result proved that the GR significantly enhanced the intrinsic separation of the photogenerated charge carriers. The contribution of O〈sub〉2〈/sub〉 and the GR to the charge separation was dependent on the weight addition ratio of the GR. The GR dominated the charge separation process as its weight addition ratio ≥5%. Given the advantages in adsorption ability and photoactivity, toluene showed mineralization efficiencies for the composite with 5.0 wt% GR of 1.4 and 2.7 folds those of microporous TiO〈sub〉2〈/sub〉 and P25, respectively, after 96 min irradiation.〈/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-S0169433218333105-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Chang Min Park, Dengjun Wang, Jonghun Han, Jiyong Heo, Chunming Su〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reduced graphene oxide (rGO) hybridized with magnetite and/or elemental silver (rGO/magnetite, rGO/silver, and rGO/magnetite/silver) nanoparticles were evaluated as potential adsorbents for toxic heavy metal ions (Cd(II), Ni(II), Zn(II), Co(II), Pb(II), and Cu(II)). Although the deposition of iron oxide and silver nanoparticles on the rGO nanosheets played an inhibitory role in metal ion adsorption, the metal adsorption efficiency by the nanohybrids (NHs) was still higher than that reported for many other sorbents (〈em〉e.g.〈/em〉, activated biochar, commercial resins, and nanosized hydrated Zr(IV) oxide particles). X-ray photoelectron spectroscopy analyses revealed that complexation with deprotonated adsorbents and cation exchange was an important mechanism for Cd(II) ion removal by the rGO and NHs. Competitive adsorption tests using multi metals showed that the adsorption affinity of metal ions on the rGO and its NHs follows the order (Cu(II), Zn(II)) 〉 Ni(II) 〉 Co(II) 〉 (Pb(II), Cd(II)), which is similar to the order observed for single-metal adsorption experiments. These results can be explained by the destabilization abilities of the rGO and NHs, as well as the ionic radii of the considered metal ions. Our findings demonstrate the feasibility of using rGO-based NHs as highly efficient adsorbents for heavy metal removal from water.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Hao Cui, Xiaoxing Zhang, Guozhi Zhang, Ju Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Density functional theory (DFT) method was carried out to simulate the adsorption of three dissolved gases on Pd-doped MOS〈sub〉2〈/sub〉 (Pd-MoS〈sub〉2〈/sub〉) monolayer. We initially studied the possible structures of Pd-MoS〈sub〉2〈/sub〉 monolayer and found that the Pd dopant preferred to be adsorbed onto the surface by T〈sub〉Mo〈/sub〉 site. The adsorption and desorption performance, along with the sensing principle of Pd-MoS〈sub〉2〈/sub〉 towards three typical gases, including H〈sub〉2〈/sub〉, CH〈sub〉4〈/sub〉 and C〈sub〉2〈/sub〉H〈sub〉2〈/sub〉, were analyzed. These analysis indicated that Pd-MoS〈sub〉2〈/sub〉 could be a satisfied material for C〈sub〉2〈/sub〉H〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉 sensing at specific condition; while it is unsuitable for detection of CH〈sub〉4〈/sub〉 due to the weak interaction and extremely short recovery time. All these give a first insight into the application of Pd-MoS〈sub〉2〈/sub〉 for DGA, evaluating the working operation of the transformer through sensitive detection of H〈sub〉2〈/sub〉 and C〈sub〉2〈/sub〉H〈sub〉2〈/sub〉. We are hopeful that this work would support informative knowledge for experimentalists to realize the potential of Pd-MoS〈sub〉2〈/sub〉 in the field of electrical engineering in the near future.〈/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-S0169433218333087-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Shuo Li, Lingling Ren, Zhimin Bai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mg/Al layered double hydroxides (LDHs) and the calcined products were prepared and the powders were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray fluorescence (XRF) and Fourier transform infrared spectrometer (FT-IR). The friction properties of LDHs and the calcined products were tested and the rubbed areas were analyzed by scanning electron microscope, energy disperse spectroscopy (EDS) and auger electron spectrometer (AES). The results showed that the diameter of LDHs was about 100–175 nm and the formula was Mg〈sub〉0.69〈/sub〉Al〈sub〉0.31〈/sub〉(OH)〈sub〉2〈/sub〉(CO〈sub〉3〈/sub〉)〈sub〉0.15〈/sub〉·0.16H〈sub〉2〈/sub〉O. All the calcined products had the laminated structure. The anti-wear properties of 1000 °C calcined products were superior to the LDHs, which was attributed to the supporting and mechanical polishing effects of the hard spinels. The distribution laws of elements of worn area in the horizontal and vertical direction were concluded. The tribological performance of calcined products can be attributed to the “multi-layer self-lubrication mechanisms”. The tribofilms consisted of “carbon-enriched layer”, “oxygen- enriched layer” and “transition layer” and combined strongly with the metal substrate.〈/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-S0169433218330939-ga1.jpg" width="195" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): I.N. Saraeva, S.I. Kudryashov, A.A. Rudenko, M.I. Zhilnikova, D.S. Ivanov, D.A. Zayarny, A.V. Simakin, A.A. Ionin, M.E. Garcia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of laser pulsewidth, tuned in the range 〈em〉τ〈/em〉 = 0.3–10 ps, on infrared (IR) laser ablation (LA) thresholds of bulk gold, silver and silicon in air and in liquid environments (deionized water, isopropyl alcohol (IPA)) was studied in this work. The influence of laser pulsewidth on the morphology and yield of the ejected nanoparticles (NPs), as well as its impact on the efficiency of NP generation, was studied by UV–vis spectral measurement of the extinction coefficient spectra of NP colloids, fabricated by multi-pass ablation of bulk targets in both solvents at different pulse duration values, by analytical disc centrifuge and by high-resolution scanning electron microscopy. The ablation thresholds are raising with the increase of laser pulsewidth, exhibiting sublinear dependences. The extinction coefficient dependence on 〈em〉τ〈/em〉 exhibited a non-monotonous character in case of water medium for all materials, and was gradually descending in case of LA in IPA. Additional MD-TTM (molecular dynamics- two-temperature model) modeling was performed for single-shot laser exposition of bulk Au target in air with 〈em〉τ〈/em〉 = 0.3 ps and 4 ps, which allowed distinguishing the main mechanisms of the material removal, the formation of NPs, and the observed crater topography. The performed simulations supported the trend on the ablation threshold increase with the increase of laser pulse duration.〈/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-S016943321833277X-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Zhiwei Wang, Xianglin Li, Chiew Kei Tan, Cheng Qian, Andrew Clive Grimsdale, Alfred Iing Yoong Tok〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A porous SnO〈sub〉2〈/sub〉 nanosheets/TiO〈sub〉2〈/sub〉/CdS quantum dots (SnO〈sub〉2〈/sub〉 NSs/TiO〈sub〉2〈/sub〉/CdS QDs) sandwich structure has been designed and fabricated as a “host-guest” photoanode for efficient solar water splitting applications. In this novel photoanode design, the highly porous SnO〈sub〉2〈/sub〉 NSs serve as the host skeleton for efficient electron collection, while CdS QDs serve as efficient visible light absorbers. A thin interlayer of TiO〈sub〉2〈/sub〉 is introduced for band alignment and reduction of charge recombination. Enhanced photoelectrochemical performance of the as fabricated photoanode is observed with introduction of the TiO〈sub〉2〈/sub〉 interlayer. The optimized host-guest SnO〈sub〉2〈/sub〉 NSs/TiO〈sub〉2〈/sub〉/CdS QDs photoanode shows a photocurrent density as high as 4.7 mA cm〈sup〉−2〈/sup〉 at 0 V versus Ag/AgCl, which is 7 times higher than that of the SnO〈sub〉2〈/sub〉 NSs/TiO〈sub〉2〈/sub〉 reference photoanode (0.7 mA cm〈sup〉−2〈/sup〉). Furthermore, it also shows lower charge recombination rate compared to the SnO〈sub〉2〈/sub〉 NSs/CdS QDs reference photoanode. Due to the high porosity and transparency of the as developed SnO〈sub〉2〈/sub〉 NSs arrays host, it has great potential in various applications, such as solar energy conversion and energy storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A highly porous SnO〈sub〉2〈/sub〉 nanosheets (NSs) sandwiched within TiO〈sub〉2〈/sub〉 and CdS quantum dots (QDs) structure has been designed and fabricated as a host-guest photoanode for efficient photoelectrochemical (PEC) water splitting. The introduction of a thin layer of TiO〈sub〉2〈/sub〉 significantly improved the PEC performance of SnO〈sub〉2〈/sub〉 NSs/TiO〈sub〉2〈/sub〉/CdS QDs, showing better PEC performance than SnO〈sub〉2〈/sub〉 NSs/CdS QDs and SnO〈sub〉2〈/sub〉 NSs/TiO〈sub〉2〈/sub〉.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218332604-ga1.jpg" width="498" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 470〈/p〉 〈p〉Author(s): Wenhui Chen, Qiufen Liu, Shouqin Tian, Xiujian Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ZnO micro/nanocrystals with small size and more exposed high-surface-energy facets usually exhibit better photocatalytic properties. However, the stability of ZnO micro/nanocrystals used as a photocatalyst is always ignored. In this work, ZnO micro/nanocrystals with different percentages of exposed (0 0 0 1) facets were employed as a photocatalyst in the degradation of methylene blue (MB) and their stability dependent on the exposed facets and grain size was discussed in detail. The higher percentages of exposed (0 0 0 1) facets can be obtained at a larger volume ratio of water/methanol (H〈sub〉2〈/sub〉O/CH〈sub〉3〈/sub〉OH) in the chemical bath method. It was found that ZnO micro/nanocrystals with a higher percentage of exposed (0 0 0 1) facets showed larger changes in the exposed (0 0 0 1) and (0 0 0 −1) facets after their photodegradation of MB in aqueous solution, indicating a poor stability, although they displayed a better photocatalytic performance. Interestingly, ZnO nanocrystals with small size exhibited no obvious changes in their shape after their application as a photocatalyst. In this sense, exposed facets played more important roles in the stability of ZnO micro/nanocrystals than crystal size. This may be because that the Zn and O atoms in the exposed (0 0 0 1) and (0 0 0 −1) facets preferred to be participated in the photocatalytic reaction and then formed Zn〈sup〉2+〈/sup〉 ions and oxygen species in the solution after the reaction. Therefore, this work can provide a new insight into the stability of metal oxide micro/nanocrystals as photocatalysts.〈/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-S016943321833280X-ga1.jpg" width="479" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Hyo-Ryoung Lim, Seung-Jae Jung, Tae-Yeon Hwang, Jimin Lee, Ki Hyeon Kim, Hong-baek Cho, Yong-Ho Choa〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electromagnetic (EM) wave absorbing materials consisting of iron (Fe) nanoparticles supported by magnesium oxide (MgO) matrix were synthesized by ultrasonic spray pyrolysis (USP) and subsequent hydrogen reduction. The Fe nanoparticles were formed by the selective reduction of iron oxide in the as-pyrolyzed powder, itself acting as a microreactor, and were successfully embedded in or at the MgO surface, allowing for magneto-dielectric structures without aggregation. Fe content in the composite particles was controlled only by the molar ratio of the precursor solution ([Fe〈sup〉3+〈/sup〉]:[Mg〈sup〉2+〈/sup〉]). The remarkable shielding effectiveness reached −65.6 dB at 12 GHz with a corresponding thickness of 1.5 mm and an absorption bandwidth for reflection loss (RL) of less than −20 dB is about 7.8 GHz. This design approach can be extended to realize magneto-dielectric materials with tailored absorption frequencies of high bandwidth due to the combination of the well-dispersed decoration of magnetic particles with controlled content and effective insulation. This type of material would be well suited for use in the research community and industry alike due to the reduction in energy required for synthesis and attendant oxidation losses.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Dewei Wang, Lang Xu, Jiawang Nai, Xiaoxia Bai, Tao Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controllable synthesis of nanocarbons with tunable morphologies from sustainable biomass through facile one-step route for ionic liquid based supercapacitors with high energy density and high power characteristics is of great interest but remains an ongoing challenge. Herein, we report the design and synthesis of nanocarbons with tunable morphologies (i.e., honeycomb-like porous carbons, carbon nanosheets and irregular-shaped carbon microparticles) from sustainable pine barks through reliable one-step chemical activation process. We found that the honeycomb-like porous carbons can be produced 〈em〉via〈/em〉 direct KOH activation while the uniform carbon nanosheets were obtained by employing magnesium powder as the reactive self-sacrificing template. These three samples have different morphologies and textural properties render them totally disparate electrochemical performance in ionic liquid electrolyte. Benefiting from its distinct structural advantages, the as-obtained porous carbon nanosheets has excellent electrochemical capacitive performance including large specific capacitance (193 F/g at 1 A/g), superior rate capability (superior specific capacitance retention of 69.4% at 40 A/g), good cycling stability (good capacitance retention after 8000 cycles) and integrated high energy density& high power characteristics (excellent energy density of 55.8 Wh/kg even at an ultrahigh power density of 39.375 kW/kg). We believed that this work reported here not only provides a versatile strategy towards nanocarbons with tunable morphologies from sustainable biomass but also sheds some new light to efficiently regulate the morphologies of nanocarbons for electrochemical energy storage 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-S0169433218336043-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Alexander Letzel, Marco Santoro, Julia Frohleiks, Anna R. Ziefuß, Stefan Reich, Anton Plech, Enza Fazio, Fortunato Neri, Stephan Barcikowski, Bilal Gökce〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fundamental theoretical and experimental studies on the formation of nanoparticles and cavitation during laser synthesis of colloids usually employ single-pulse conditions, whereas studies of the properties of nanoparticles naturally require prolonged ablation. We explored how a defined number of pulses changes a silver target’s surface geometry and thereby the dynamics of the laser-induced cavitation bubble and the resulting properties of the nanoparticles. The shape of the cavitation bubble transforms from hemispherical to almost spherical. The indirectly calculated mass concentration in the cavitation bubble follows a decay with the number of laser pulses. Surprisingly, the ablated mass does not set the volume of the extended cavitation bubble, as one would expect, because of the linear dependency of both the volume of the bubble and the ablation mass per pulse on the laser fluence. No influence of the altered cavitation bubble on the nanoparticles was identified. Instead, clear evidence of a high share of silver nanoclusters (d 〈 3 nm) with improved instrumentation (ultracentrifuge) was found in all samples at our low concentration conditions. The influence of these reactive species on the final particle size was found to be much larger than the cavitation bubble variations caused by prolonged surface ablation. In addition, no correlation was observed between the size of the primary particles (∼8 nm) and the mass concentration in the cavitation bubble.〈/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-S0169433218333555-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Estrella Serra-Pérez, Silvia Álvarez-Torrellas, V. Ismael Águeda, José Antonio Delgado, Gabriel Ovejero, Juan García〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we evaluate the feasibility of a ruthenium catalyst (CNS-Ru) supported on optimized carbon nanospheres (CNS) for the efficient removal by catalytic wet air oxidation of Bisphenol A (BPA), a micro-pollutant exhibiting highly estrogenic properties. The catalyst was fully characterized by several techniques, e.g., N〈sub〉2〈/sub〉 adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), X-ray fluorescence (XRF), Fourier transformed infrared spectrometry (FT-IR) and scanning and transmission electronic microscopy (SEM/TEM). The effect of operational conditions such as temperature (110–150 °C), total pressure (20–50 bar), catalyst dose (0.5–3.0 g∙L〈sup〉−1〈/sup〉), BPA concentration (5–30 mg∙L〈sup〉−1〈/sup〉) and initial pH (3–8) on the BPA degradation by CWAO was evaluated. The synthesized catalyst showed an outstanding catalytic activity over the micro-pollutant degradation, obtaining the complete removal of BPA in only 90 min for a compound concentration of 20 mg∙L〈sup〉−1〈/sup〉, using 2.0 g∙L〈sup〉−1〈/sup〉 of catalyst, at mild reaction conditions (130 °C, 20 bar). No ruthenium leaching into the reaction medium was observed during the experiments (measured by XRF technique). The stability of the catalyst was confirmed upon two sequential tests, observing that the removal rate and the activity were not affected. Thus, the toxicity of BPA solution could be remarkably reduced after the treatment (from 3.37 to 1.38 TUs). Finally, eight major intermediates were detected in the process, containing most of them both quinonoid derivatives and carboxylic acids. With this information a BPA degradation mechanism by CWAO reaction 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-S0169433218335505-ga1.jpg" width="276" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Huan Liu, Dongqi Yu, Tianbiao Sun, Hongyun Du, Wentao Jiang, Yaseen Muhammad, Lei Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work reports the fabrication of alkalinized g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and its composite with TiO〈sub〉2〈/sub〉 via recrystallization-annealing strategy. The increased surface basicity boosted the fast adsorptive removal of methylene blue (MB) while the cooperated TiO〈sub〉2〈/sub〉 enhanced the degradation of adsorbed MB via photocatalysis. The synthesized materials were characterized by XPS, SEM, TEM, PXRD, BET surface area, FT-IR, EDX and TG analyses. TiO〈sub〉2〈/sub〉 nanoparticles were uniformly distributed in the framework of alkalinized g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 which increased the surface area of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Na was incorporated into g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 via thermal treatment, and the bond between C and N was dissociated while that between C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉OH was formed. The alkaline and negatively charged surface of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 upon Na addition established a strong electrostatic interaction adsorption scenario with MB leading to higher adsorption efficiency of TiO〈sub〉2〈/sub〉/Na-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (90%) than pristine g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (80%). MB removal efficiency was further intensified (from 90% to 100% within 120 min) upon the sequential operation of adsorption followed by photocatalytic degradation over TiO〈sub〉2〈/sub〉/Na-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 under visible light irradiation. This study can be deemed of potential applications for the removal of MB and similar dyes on industrial level using the newly synthesized TiO〈sub〉2〈/sub〉/Na-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and synergistic adsorption-photocatalytic oxidation approach.〈/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-S0169433218335001-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Nagendra Singh Neeraj, Bablu Mordina, Alok Kumar Srivastava, Kingsuk Mukhopadhyay, Namburi Eswara Prasad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉NiMoO〈sub〉4〈/sub〉 nanorods of different properties were synthesized via facile and scalable hydrothermal route by varying the reaction time and temperature and the effect of synthesis parameters on their electrochemical performances was investigated. Optimization of the synthesis parameters was carried out based on the electrochemical performance. Experimental analysis revealed that NiMoO〈sub〉4〈/sub〉 nanorods synthesized at 150 °C for 6 h showed optimum electrochemical performance with specific capacitance, as high as 594 Fg〈sup〉−1〈/sup〉 at 1 Ag〈sup〉−1〈/sup〉 current density due to greater mesoporous nature and optimum crystallinity index. NiMoO〈sub〉4〈/sub〉//activated carbon asymmetric supercapacitor device was fabricated using the optimized NiMoO〈sub〉4〈/sub〉 nanorods and characterized for the electrochemical performances. Specific capacitance of 66 Fg〈sup〉−1〈/sup〉 was obtained for the fabricated supercapacitor device at 1 Ag〈sup〉−1〈/sup〉 current density and 56% retention of the specific capacitance was observed after 1000 cycles. An energy density of 18 Whkg〈sup〉−1〈/sup〉 and power density of 704 Wkg〈sup〉−1〈/sup〉 were achieved at 1 Ag〈sup〉−1〈/sup〉 current density which offer great promise for supercapacitor application of this material.〈/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-S0169433218335645-ga1.jpg" width="249" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Xia Zhan, Juan Lu, Hengli Xu, Jihui Liu, Xiaoshuang Liu, Xingzhong Cao, Jiding Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A homogeneous distribution of inorganic fillers and their integration with polymer matrix is the primary challenge for advancement of mixed matrix membranes (MMMs) in pervaporation. Due to well-defined structure and multi-functional groups attached to the apex silicon atoms, polyhedral oligomeric silsesquioxane (POSS) provides a high possibility of good compatibility with diverse polymer matrix at the molecular level. In this work, soluble and reactive octa[(trimethoxysilyl)ethyl]-POSS(OPS) was synthesized, which was used as macro-crosslinker and reinforced porous fillers of polydimethylsiloxane (PDMS) synchronously to prepare a series of OPS/PDMS MMMs. The OPS/PDMS MMMs were characterized by FT-IR, XRD, SEM, TGA, DSC, PALS, vapor adsorption measurement and tensile test. It was found that OPS dispersed homogeneously in PDMS matrix and achieved good integration with PDMS based on SEM and DSC characterization. PALS results indicated that compared with pure PDMS membrane, OPS/PDMS MMMs with proper OPS loading showed much larger radii of free volume cavities (〈em〉r〈sub〉3〈/sub〉〈/em〉, 〈em〉r〈sub〉4〈/sub〉〈/em〉) and fractional free volumes (〈em〉f〈sub〉v3〈/sub〉〈/em〉, 〈em〉f〈sub〉v4〈/sub〉〈/em〉 and 〈em〉f〈sub〉v〈/sub〉〈/em〉). The numerous hydrophobic POSS cages and enlarged PDMS’ free volume would effectively improve the diffusion selectivity towards ethanol. Vapor adsorption results showed that the chemical incorporation of moderate amount OPS into PDMS not only improved ethanol vapor adsorption amount, but also depressed water adsorption amount in PDMS, which would obviously improve PDMS’ sorption selectivity to ethanol. As applied to the bio-ethanol recovery from aqueous solutions, the prepared OPS/PDMS MMMs exhibited a simultaneous increase in permeation flux and separation factor, breaking the permeation flux-separation factor trade-off limitation. As OPS loading was 7.5 wt%, the separation factor of OPS/PDMS MMMs reached the maximum value of 16.4 (109% higher than that of pure PDMS membrane), with permeation flux of 253.1 g/m〈sup〉2〈/sup〉h (32% higher than that of pure PDMS membrane). Experimental results showed that an increase in operation temperature resulted in an increase in permeation flux, but decrease in permeability, separation factor and selectivity. The pervaporation performance of OPS/PDMS MMMs kept stable during two days operation time. This work may provide useful insights of high-performance MMMs with a POSS embedded selective layer for biofuel separation.〈/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-S0169433218334226-ga1.jpg" width="465" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Guangxu Yan, Balasubramanian Nagarajan, Ayan Bhowmik, Sung Chyn Tan, Ray Xu, Ming Jen Tan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Generally, transient liquid phase (TLP) bonding is conducted with an overdose of filler metal in a vacuum furnace that necessitates excessive post machining. Recently, a new form of filler metal, the sintered brazing preforms (SBP) has been introduced to achieve a neat TLP bonding joint, which undergoes partial melting and retains its original shape. This paper studies the microstructure and mechanical properties of induction TLP bonding (IB) of the Inconel 718 using nickel-based SBP. Firstly, the surface roughness effect on the tensile bonding strength of the brazed joint was investigated. Further, a comparative study between IB and furnace TLP bonding (FB) on the microstructure and mechanical properties of the TLP joints was performed. The results clearly show that neat bonding joints can be obtained through the IB of Inconel 718 using nickel-based SBP. Besides, the strongest tensile bonding strength (240.76 MPa) of the SBP joint after IB was achieved with an optimal bonding surface roughness of around 0.9 μm (〈em〉R〈sub〉a〈/sub〉〈/em〉). The strength was approximately 16% higher than that of the SBP joint after FB. Furthermore, the IB could accelerate the diffusion process, leading to fewer porosities and borides in the SBP, and a lesser amount of precipitates in the precipitation layer than that after FB.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Hua-Wen Huang, Shan-Shan Fan, Wenda Dong, Wei Zou, Min Yan, Zhao Deng, Xianfeng Zheng, Jing Liu, Hong-En Wang, Lihua Chen, Yu Li, Bao-Lian Su〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the nitrogen-doped graphene (NG) 〈em〉in-situ〈/em〉 modifying MnO nanoparticles (MnO/NG) to improve the electrochemistry performance for lithium storage. The NG 〈em〉in-situ〈/em〉 modification not only improves the electrical conductivity but also alleviates the agglomeration and accommodates the volume change of MnO nanoparticles during the cycling process. More importantly, the non-heat treatment is beneficial to maintain the original structure and crystal shape of MnO. As a results, the MnO/NG exhibits a high reversible capacity of 1005 mAh/g after 100 cycles at 100 mA/g, four times that of pure MnO nanoparticles (209 mAh/g) and almost twice that of 〈em〉in-situ〈/em〉 carbonization of MnO nanoparticles (MnO/C) (490 mAh/g). Particularly, the MnO/NG demonstrates a stable cycling capacity of 549 mAh/g after 1000 cycles at 1000 mA/g without pulverization. This work confirms that nitrogen-doped graphene 〈em〉in-situ〈/em〉 modification is a more efficient strategy comparing to carbon modification for transition metal oxides as anode materials for highly improved lithium storage.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The nitrogen-doped graphene (NG) 〈em〉in-situ〈/em〉 modification of MnO nanoparticles (MnO/NG) can largely improve the electrochemistry performance for lithium storage.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218335748-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Haibo Ren, Cuiping Gu, Jingjuan Zhao, Sang Woo Joo, Jiarui Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Co〈sub〉9〈/sub〉S〈sub〉8〈/sub〉@MoS〈sub〉2〈/sub〉 core-shell nanoparticles anchored on both sides of reduced graphene oxide (Co〈sub〉9〈/sub〉S〈sub〉8〈/sub〉@MoS〈sub〉2〈/sub〉/rGO) were synthesized via hydrothermal reaction. The core-shell composites were used as an anode material and demonstrated enhanced electrochemical performance with high capacity, capacity retention, cycling stability, and rate capability during cycling tests. The nanocomposites deliver a reversible capacity of 2014.5 mAh g〈sup〉−1〈/sup〉 at a high rate of 0.3 A g〈sup〉−1〈/sup〉 with a capacity retention efficiency of 82.8% after 200 cycles. The reduced graphene oxide-based three-dimensional framework of the core-shell structure can reduce the internal resistance of the whole electrode, facilitate more Li〈sup〉+〈/sup〉 ion insertion and extraction from the crystal structure, and relieve the strain caused by volume change during the lithiation/delithiation process. The electrochemical behaviors could make the composites a great potential anode material for lithium-ion batteries.〈/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-S0169433218336055-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Xunyan Lyu, Daming Zhuang, Ming Zhao, Ning Zhang, Xinping Yu, Leng Zhang, Rujun Sun, Yaowei Wei, Xiao Peng, Yixuan Wu, Guoan Ren, Jinquan Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉CIGSeS (Cu(In,Ga)(Se,S)〈sub〉2〈/sub〉, (CIGSeS)) absorbers were fabricated by sputtering a quaternary ceramic CIGSe targets and annealing in sulfur-containing atmosphere. Sulfurization was applied at various temperatures to study the variation of composition and microstructure. The performances of cells were also investigated. Sulfurization at high temperature (550 °C) benefits the diffusion of S atoms into absorbers. Gallium tends to diffuse towards surface, and Indium towards the back as absorbers annealed at 550 °C, leading to an enlarged band gap at the surface. With the improvement of anion-deficiency and the band gap gradient introduced by sulfurization, the conversion efficiency of CIGSeS solar cell reaches 13.9%, with the V〈sub〉OC〈/sub〉 566 mV.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Xiaoping Gao, Yanan Zhou, Yujia Tan, Bowen Yang, Zhiwen Cheng, Zhemin Shen, Jinping Jia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The high-efficient electrochemical hydrogen evolution reaction (HER) is a promising pathway to provide clean energy. An electrocatalyst was computer-aided designed with Mo isolated single atoms (Mo-ISA) supported on heteroatom S, N-codoped carbon having excellent HER performance. Here, by performing comprehensive density functional theory (DFT) computations, we investigated the influence of the N dopent concentration and the sites of S atom doping on the HER performance. Our computed results demonstrate that the Mo-ISA/N1C and Mo-ISA/S〈sub〉6〈/sub〉N1C catalysts possess good stability and high HER reactivity. Moreover, the interactions between hydrogen and the Mo atoms could be controlled by the N dopent concentration on carbon support, and the Mo-ISA/N1C catalyst showed best HER reactivity. In particular, the S atom was introduced into Mo-ISA/N1C at the S〈sub〉6〈/sub〉 site showing an enhanced HER performance due to the competitive effect of the S-induced tensile strain and charge transfer. Our DFT computations open up new opportunities for application of S, N-codoped Mo-based high-efficient catalysts for HER.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉An efficient S, N-codoped carbon supported isolated single Mo atoms catalyst is computer-aided designed, and shows excellent HER performance.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218335517-ga1.jpg" width="306" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Jean Constant〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the advancement of computer and image-based technologies, imaging has come to be a pervasive medium by way of which we access, interpret and communicate information. Applying Knowledge Visualization framework principles to the study of a mineral at the unit cell level provides a fertile ground from which to extract significant representations. Using data collected from rigorous scientific analysis, the author extracted meaningful information from the crystal’s geometry and physical properties to create new representations according to the Knowledge-Visualization methodology. The outcome was assessed in several interactive platforms and opened a new perspective on joint collaboration between Science, Humanities, and the Arts. Additionally, the experiment provided a new ground of investigation for unexpected connections between geometry, earth sciences, and local cultures.〈/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-S0169433218335463-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): T. Maulouet, B. Fatou, C. Focsa, M. Salzet, I. Fournier, M. Ziskind〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Laser micro-sampling is a promising tool for ambient pressure chemical imaging of biological material by mass spectrometry. Conventional approaches use laser energy coupling into the analyzed sample through electronic (UV) or vibrational (IR) channels. In a recent study [B. Fatou, M. Wisztorski, C. Focsa, M. Salzet, M. Ziskind, I. Fournier, Sci. Rep. 5:18135, 2015], we have demonstrated efficient micro-sampling of biological material through a substrate-mediate laser ablation (SMLA) mechanism using non-resonant visible radiation. Taking advantage of this effect, a large-scale proteomic analysis of micro-sampled tissue sections was performed, demonstrating the possible identification of about 400 proteins, including minor species, from an irradiated surface of 400 μm diameter. Fundamental investigations on biological standards revealed the role of the substrate optical properties in the ejection process. In the present work, we extend these studies by considering the substrate thermal properties. A systematic investigation on the sampling efficiency of homogeneous tissue sections placed on top of various selected substrates was performed. Two ejection mechanisms are clearly evidenced and interpreted in the frame of a simple model based on the substrate properties and the laser beam profile. Improvement of the ejection yield and spatial resolution is also discussed in this frame, in view of the practical application of this technique in the field of (bio)chemical mass spectrometry imaging.〈/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-S0169433218335128-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Dongguang Zhang, Linghan Li, Yali Wu, Bin Zhu, Honglie Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Functional surfaces provided by nature, especially some typical examples, such as lotus leaf, legs of water spiders, and shells of beetles, which inspire the study of biomimetic superhydrophobic surfaces. These natural surfaces exhibit fantastic wetting behavior with spatially, micro-nano hierarchical structures. Inspired by this, a one-step, facile electrodeposition process was developed for the fabrication of superhydrophobic surface on aluminum alloy. A Danxia-landform-like morphology surface is obtained by electrodeposition, with micro-nano-binary scale structure and low surface energy coating. The surface with convex microscale pillars and fractals in nanoscale, which are the key points of superhydrophobicity. Also, wettability is controlled by changing the anodization voltages, and roughness of the surface increased with a higher voltage. Due to the spatially, hierarchical morphology, the as-prepared surface possessed robust mechanically stability, for the nano coating layer located in ‘concave valleys’ is well protect. Experiments results verified that the prepared superhydrophobic surface have good performances of mechanical durability, as well as corrosion resistance. Thus, such a fabrication method would flourish approaches of water-repellence surface on aluminum alloy engineering 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-S0169433218335116-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): A. Rozmysłowska-Wojciechowska, T. Wojciechowski, W. Ziemkowska, L. Chlubny, A. Olszyna, A.M. Jastrzębska〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work presents a comprehensive study on the surface-property changes of 2D flakes of MXenes (Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 and Ti〈sub〉2〈/sub〉C) upon interacting with the model cationic protein – lysozyme, using time-resolved dynamic light scattering and zeta potential. The study was also aimed at investigating how MXenes stoichiometry, structure, surface chemistry and exposure concentration effects its interactions with lysozyme. We found that the adsorption of lysozyme on 2D Ti〈sub〉2〈/sub〉C and Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 flakes occurred effectively, leading to changes in MXenes zeta potential in a concentration-dependent manner. The lysozyme adsorption efficiency varied, depending on the surface chemistry and stoichiometry of the investigated MXenes. The results showed that the Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 MXene exhibited a higher adsorption of lysozyme in comparison to Ti〈sub〉2〈/sub〉C MXene. The zeta potential assays revealed that the adsorption mechanism for MXenes was mainly electrostatic. We also demonstrated the lysozyme release from the MXene surface during pH changes to basic environment. Our findings highlight the importance of evaluating MXenes interactions with biomacromolecules and the mechanism for potential protein adsorption prior to designing e.g. drug delivery systems. We have shown that protein adsorption dramatically changes the surface-physicochemical properties of the MXenes, which may have a significant impact on the effectiveness and safety of future delivery, separation and purification systems dedicated to particular proteins.〈/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-S016943321833410X-ga1.jpg" width="278" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): V.I. Popkov, V.P. Tolstoy, S.O. Omarov, V.N. Nevedomskiy〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉α-CeO〈sub〉2〈/sub〉 and α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanocrystals were successfully synthesized by successive ionic layer deposition (SILD). The size of the prepared nanocrystals of α-CeO〈sub〉2〈/sub〉 and α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 is 6–8 nm and 13–14 nm, correspondingly. The developed method was used to modify silica gel. The obtained samples were characterized by EDX, SEM, TEM-ED, PXRD; and N〈sub〉2〈/sub〉 adsorption-desorption analysis and analysis of acid-base properties were made. There was established that the silica gel modification with 4.1 mass % of α-CeO〈sub〉2〈/sub〉 and α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanocrystals lead to increase of acidic/basic sites in 6.6 and 13.6 times, correspondingly, while maintaining the surface area of modified silica about 311 m〈sup〉2〈/sup〉/g and almost unchanged pore structure. It was shown that α-CeO〈sub〉2〈/sub〉 and α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanocrystals forming by SILD modification of silica gel are mainly found in the micropores and mesopores and define the phenomenon of the increase of active sites concentration in the prepared composite. The resulting materials can be used as the basis for promising acid-base catalysts and sorbents of toxic heavy metal cations and oxyanions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The procedure aimed at synthesis of ultrafine CeO〈sub〉2〈/sub〉-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanocrystals by SILD method was elaborated. The procedure was applied for silica modification. It was found that the concentration of Lewis acidic and basic sites was increased in 6.6–16.3 times as a result of the silica modification.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218334676-ga1.jpg" width="286" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Shatha Kaassamani, Wassim Kassem, Malek Tabbal〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we report on the synthesis of highly textured c-oriented zinc oxide (ZnO) thin films on single crystal c-plane sapphire substrates using pulsed laser deposition (PLD). The growth experiments were performed at different substrate temperatures and oxygen pressures. The crystalline properties and surface morphology of the resulting films were studied using XRD peak analysis, rocking curve measurements, and SEM imaging. By varying deposition pressure and temperature, we observe different surface morphologies of the ZnO thin films, from smooth surfaces to clusters of grains and nanorods. The surface and volume structure of the films were found to be correlated. Within the range of experimental parameters used in this work, a growth temperature of 825 °C and a pressure of 10 mTorr lead to nearly epitaxial ZnO thin films having the largest grain size and the lowest strain perpendicular to the substrate surface i.e. along the growth axis.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Laísa C.S. Belusso, Guilherme F. Lenz, Evandir E. Fiorini, Anderson J. Pereira, Rodrigo Sequinel, Rafael A. Bini, Jorlandio F. Felix, Ricardo Schneider〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, we report a facile, low cost synthesis and characterization of silver nanoparticles (AgNPs) on borophosphate glass by a two-step process involving a melting quenching technique and a post-annealing method. The structural, optical properties and several applications of silver-doped borophosphate glasses as a function of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 concentration are reported here. Micro Raman and infrared spectroscopies revealed that the addition of aluminium ions leads to depolymerization and the formation of phosphate-aluminium structures. Moreover, the addition of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 increases the glass transition temperature, improve the chemical stability, and the AgNPs remain firmly grafted (i.e., not released) when the glass surface is exposed to water. The presence of silver ions and metallic silver on glass surface was confirmed by the X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD), respectively. The fabricated AgNPs have many advantages, such as low growth temperature and good uniform nanoparticle clusters over large areas, size-controlled, and easy to fabricate. Finally, the silver-doped glasses have proved to be an ideal substrate for highly efficient SERS applications, antibacterial materials and great potential in 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-S0169433218334937-ga1.jpg" width="360" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Cecil N.M. Ouma, Phillimon M. Modisha, Dmitri Bessarabov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Ab initio〈/em〉 calculations based on dispersion-corrected density functional theory were used to gain insight into the adsorption properties of reactants and products involved in the catalytic dehydrogenation of octahydroindole on a Pt (1 1 1) surface. Octahydroindole is the hydrogen-rich form of a liquid organic hydrogen carrier (LOHC); indole is the hydrogen-lean form of the LOHC, and indoline is a possible dehydrogenation intermediate of the LOHC. The adsorption of octahydroindole, indoline, and indole on a Pt (1 1 1) surface were found to be energetically favored. Dehydrogenation of octahydroindole proceeded by the systematic removal of H〈sub〉2〈/sub〉 molecules along different dehydrogenation reaction paths. Investigation of these paths revealed that dehydrogenation of octahydroindole to indole can take place with or without indoline as intermediate. This observation was consistent with experimental results.〈/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-S0169433218334500-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): C. Bigi, P. Orgiani, A. Nardi, A. Troglia, J. Fujii, G. Panaccione, I. Vobornik, G. Rossi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the reproducible surface topological electron states in Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 topological insulator thin films when epitaxially grown by Pulsed Laser Deposition (PLD) on (0 0 1)-oriented SrTiO〈sub〉3〈/sub〉 (STO) perovskite substrates. Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 has been reproducibly grown with single (0 0 1)-orientation and low surface roughness as controlled by ex-situ X-ray diffraction and in situ scanning tunnel microscopy and low-energy electron diffraction. Finally, in situ synchrotron radiation angle-resolved photo-emission spectroscopy measurements show a single Dirac cone and Dirac point at 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉E〈/mi〉〈/mrow〉〈mrow〉〈mi〉B〈/mi〉〈/mrow〉〈/msub〉〈mo〉∼〈/mo〉〈mn〉0.38〈/mn〉〈/mrow〉〈/math〉 eV located in the center of the Brillouin zone likewise found from exfoliated single-crystals. These results demonstrate that the topological surface electron properties of PLD-grown Bi〈sub〉2〈/sub〉Se〈sub〉3〈/sub〉 thin films grown on (0 0 1)-oriented STO substrates open new perspectives for applications of multi-layered materials based on oxide perovskites.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Amogelang S. Bolokang, David E. Motaung〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanocrystalline composite VO〈sub〉2〈/sub〉-WO〈sub〉3〈/sub〉 powder was produced via mechanical milling (MM) and annealing. SEM images showed the formation of rod-shaped and hollow-shaped like structures surrounded by nanoparticles. Transmission electron microscopy and selected area electron diffraction analyses demonstrated that the nanorods are single crystalline. X-ray diffraction technique was used to determine the structural transformation of the powder after mechanical milling and annealing. The mechanism related to the formation of ceramic composite powder was discussed in detail. The findings showed that the MM has created the instability in the crystal structure, inducing additional surfaces on the V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉-W-C powder, which made it more reactive and some oxygen atoms were depleted. The presence of W which has high affinity for oxygen adsorption and oxidization, resulted to a formation of WO〈sub〉3〈/sub〉. In addition, the prospective application of V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉-W-C composite in gas sensing was investigated towards H〈sub〉2〈/sub〉S and H〈sub〉2〈/sub〉 gases at 300 °C. The 30 h V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉-W-C-650 °C-based sensor exhibited improved sensing response and excellent sensitivity towards H〈sub〉2〈/sub〉S gas. The fundamental sensing mechanism related to H〈sub〉2〈/sub〉S gas was also discussed.〈/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-S0169433218334354-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Nur Fajrina, Muhammad Tahir〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Montmorillonite (MMT) dispersed g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 hybrid nanocomposite for enhanced photo-catalytic hydrogen production from glycerol-water mixture has been investigated. The newly designed composite photo-catalysts were fabricated through a sol-gel assisted hydrothermal method and were characterized by XRD, XPS, SEM, EDX, TEM, FTIR, UV–Vis, Raman and PL spectroscopy. Well-designed g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/MMT/TiO〈sub〉2〈/sub〉 heterojunction composite was obtained with 2D MMT structure, which promoted both visible light absorption and hindered charges recombination rate. The modification of 2D/0D g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 heterojunction with 2D MMT sheets enhances H〈sub〉2〈/sub〉 production due to MMT works as a mediator for effective charges trapping and transportation within the composite structure. The g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/MMT/TiO〈sub〉2〈/sub〉 photo-catalyst exhibits highest H〈sub〉2〈/sub〉 production of 4425 ppm h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉 at pH 7.0, which was 2.12 times higher than the pure TiO〈sub〉2〈/sub〉 (2085 ppm h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉). In addition, increasing catalyst loading promotes more H〈sub〉2〈/sub〉 evolution and among the different sacrificial reagents, glycerol-water mixture gave highest H〈sub〉2〈/sub〉 production due to the presence of α-hydrogen atoms attached to carbon atoms. The enhanced photo-catalytic efficiency can be attributed to synergistic effect of MMT with g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 heterojunction composite, appropriate band structure and transportation of electrons–holes with their hindered recombination rate. These composite catalysts exhibited excellent photo-catalytic stability for H〈sub〉2〈/sub〉 production in cyclic runs. Possible reaction mechanism for hydrogen production over g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/MMT/TiO〈sub〉2〈/sub〉 composite has been explained based on the experimental results. The finding of this work would be fruitful for hydrogen production applications with all sustainable systems.〈/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-S0169433218334056-ga1.jpg" width="332" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Zhixiang Li, Jieqing Shen, Lijun Ye, Kangyuan Xie, Jichun You, Yongjin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reversible and facile transition between adhesive and antiadhesive performances on superhydrophobic surface is desired but still challenging. In this work, a composite membrane has been fabricated by filtering multi-walled carbon nanotubes (MWCNTs) suspensions on thermoplastic polyurethane (TPU) nonwovens. This surface exhibits superhydrophobic properties because of the hierarchical roughness. The water droplet adhesion behaviors on the surface depend crucially on the stretching or recovery state of the composite membranes. Upon stretching, the groove among fibers is so wide that more and more hydrophilic defects (TPU fibers) have been exposed to water droplets, resulting in the adhesive surface with higher sliding angle; on the contrary, the CNTs network covers the whole membrane after recovery, leading to the Cassie state and antiadhesive performance with enhanced mobility of droplet on the surface. Our result opens a new avenue for tailoring the water droplets adhesion behaviors on superhydrophobic 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-S0169433218334214-ga1.jpg" width="386" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Zhi-Gang Mei, Sumit Bhattacharya, Abdellatif M. Yacout〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To understand the role of alumina interlayer in the adhesion of ZrN coating on U-Mo surface using atomic layer deposition technique, we investigate the interfaces of ZrN/U, Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/U, and ZrN/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 using first-principles density-functional theory calculations. The preferred interfacial plane orientation relationships and terminations for all the interfaces are predicted. Calculations show that both lattice mismatch and interfacial bonding play crucial roles in determining the adhesion strength of ZrN and Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 coatings on U metal surface. The strength of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/U and ZrN/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 interfaces are found to be substantially higher than that of ZrN/U interface. The strong interfacial adhesion of Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/U and ZrN/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 interfaces is ascribed to the formation of ionic bonds at the interface, as compared to weak metallic bonds formed in ZrN/U interface. Therefore, the formation of metal-oxygen ionic bonds at interface explains the role of alumina layer in the improved adhesion of ZrN coating on U-Mo 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-S0169433218334512-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Maolin Bo, Li Lei, Chuang Yao, Zhongkai Huang, Cheng Peng, Chang Q. Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We investigated the bond relaxation and electronic and magnetic behaviour of yttrium (Y) atoms adsorbed on lithium (Li)(1 1 0) surface by using a combination of bond-order-length-strength (BOLS) correlation and density-functional theory (DFT). We found that adsorption of Y atoms on Li(1 1 0) surfaces forms two-dimensional (2D) geometric structures of hexagon, nonagon, solid hexagon, quadrangle and triangle. Their magnetic moments are 6.66 µB, 5.54 µB, 2.81 µB, 0.28 µB and 1.04 µB, respectively. In addition, this work could pave the way for design of new 2D metals and understanding of their electronic and magnetic 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-S016943321833383X-ga1.jpg" width="308" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 471〈/p〉 〈p〉Author(s): Heon Lee, In-Soo Park, Hye-Jin Bang, Young-Kwon Park, Hangun Kim, Hyung-Ho Ha, Byung-Joo Kim, Sang-Chul Jung〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉TiO〈sub〉2〈/sub〉 was doped simultaneously with Gd and La using a liquid phase plasma (LPP) reaction to produce a photocatalyst with excellent photoactivity in the visible light region. Gadolinium chloride hexahydrate and lanthanum chloride heptahydrate precursors were used to dope the TiO〈sub〉2〈/sub〉 powder with polycrystalline Gd〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 particles. The doping of TiO〈sub〉2〈/sub〉 with rare earth elements using LPP reaction decreased the band gap; the band gap of Gd-La codoped TiO〈sub〉2〈/sub〉 photocatalysts (GLTP) was the lowest. The photodegradation efficiency of the TiO〈sub〉2〈/sub〉 photocatalysts doped with either Gd or La was superior that of bare TiO〈sub〉2〈/sub〉 but the photodegradation efficiency of GLTP was highest in both ultraviolet and visible light sources. Acetaminophen (Acetyl-para-aminophen, APAP) was ultimately decomposed to CO〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉O via intermediates, such as p-nitrophenol, hydroquinone and hydroxylhydroquinone, by hydroxyl radicals (HO〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉) formed on the surface of GLTP.〈/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-S0169433218333270-ga1.jpg" width="339" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): I. Kitsou, P. Panagopoulos, Th. Maggos, A. Tsetsekou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Core-shell nanospheres, CSNp, consisting of silica as a core and zinc oxide as a shell were prepared via a simple and environmentally friendly procedure. Silica cores with a mean diameter of 300 nm were prepared through the hydrolysis-condensation reactions in the presence of hyperbranched poly(ethylene)imine (HBPEI) followed by calcination and chemical surface modification with the use of HBPEI. To fabricate the core-shell structure, various amounts of zinc nitrate hexahydrate were precipitated using the carboxymethyl poly(ethylene)imine polymer (Trilon P) as a precipitator. To this suspension, the as synthesized modified silica powder was added with the aim to develop electrostatic bonds between the carboxyl groups of TRILON P and the amino groups of the cationic HBPEI polymer. The optimization of processing parameters led to the development of homogeneous core-shell structures bearing a well-developed nanocrystalline zinc oxide shell over each silica core. The material with the optimum shell showed excellent photocatalytic activity over nitric oxides as the photocatalytic yield reached 72.9%.〈/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-S0169433218334846-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Meng Zhang, Xinxin Huang, Hailin Xin, Dongzhi Li, Yong Zhao, Ludi Shi, Yemao Lin, Jiali Yu, Zhenqiang Yu, Caizhen Zhu, Jian Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hollow Mo〈sub〉2〈/sub〉C@C core-shell nanofibers (H-Mo〈sub〉2〈/sub〉C@C/NFs) have been successfully synthesized via an integrated procedure including coaxial electrospinning, oil extraction and carbonization. As an anode of lithium-ion batteries, H-Mo〈sub〉2〈/sub〉C@C/NFs delivers high discharge capacity of 1176.3 mA h g〈sup〉−1〈/sup〉 in the first cycle at a current density of 0.1 A g〈sup〉−1〈/sup〉 and exhibits good rate capability and reversibility. The capacity can maintain at 595.1 mA h g〈sup〉−1〈/sup〉 even when the current density is up to 5 A g〈sup〉−1〈/sup〉. In addition, at a high current density of 1 A g〈sup〉−1〈/sup〉, H-Mo〈sub〉2〈/sub〉C@C/NFs also displays extraordinary long-term cycling performance with a capacity of 674.4 mA h g〈sup〉−1〈/sup〉. The excellent rate performance and cycling stability result from the synergistic effect of Mo〈sub〉2〈/sub〉C nanoparticles and hollow structure nanofiber matrix. Coaxial electrospinning technology can be widely extended to manufacture other metal carbide/carbon composites to achieve important energy storage and other applications.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A simple electrospinning approach has been developed to fabricate the Mo〈sub〉2〈/sub〉C@C core-shell nanofibers, which significantly improves the structural stability and conductivity, exhibit excellent cycling and rate performance as anode of lithium-ion batteries.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218334287-ga1.jpg" width="196" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Aijun Hong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we systematically study on crystal and electronic structures and optical absorption properties of perfect monolayer MoS〈sub〉2〈/sub〉 (M), M with S vacancy (M@SV), M with N doping at S site (M@ND) and M with both S vacancy and N doping at S site (M@V-D) using first-principles method. It is showed that the N atom is tend to located between Mo and S layers, leaving one vacancy at original site, to form interstitial N atom. Thus, the interstitial N atom and the S vacancy make up the N〈sub〉I〈/sub〉-V〈sub〉S〈/sub〉 dimer. We study M@V-D with five atomic configurations and find the most stable structure having the N〈sub〉I〈/sub〉-V〈sub〉S〈/sub〉-V〈sub〉S〈/sub〉 trimer. It is showed that the absorbance for the stable M@V-D in the most infrared region is obviously higher than that for the other systems. It is revealed that large enhancement of infrared absorption for the stable M@V-D is mainly attributable to the special electronic structure determined by the crystal structure with the trimer. It is considered that M@V-D could be the promising candidate for infrared materials.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Meenakshi Talukdar, Sushant Kumar Behera, Kakoli Bhattacharya, Pritam Deb〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efficient oil adsorption and recovery is a generous universal importance for future energy demand and environmental protection. Adsorbents based on 2D flatland with engineered surfaces can overcome the limitations of conventional methods for selective oil adsorption. Here, we report magnetic hydrophobic/oleophilic graphitic C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets that exhibit excellent oil sorption performance and rapid removal of adsorbed oil using an external magnet. Combining porous and nanosheets structure along with magnetic FeNi〈sub〉3〈/sub〉 and fatty acid surface functionalization make the system an efficient adsorbent for adsorbing and separating crude oil from water. The graphitic sheets selectively adsorb crude oil with enhancement of thickness up to 9 folds and mass by 4.5 times than the pristine nanocomposite system. The smart adsorption property of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉@FeNi〈sub〉3〈/sub〉 has been realized through comprehensive adsorption kinetics and inclusive isotherm studies. The nanocomposite can be further recycled and reused in an eco-friendly manner for oil adsorption and recovery.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Schematic description of oil-water separation by g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉@FeNi〈sub〉3〈/sub〉 nanocomposite. The as-prepared nanocomposite and surface modification for wettability transition of the nanocomposite are shown. Surface displays hydrophilicity and underwater oleophobicity, while fatty acid modified surface exhibits hydrophobicity and oleophilicity. The final surface topography of the material is shown after oil adsorption.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169433218335037-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Helena Brunckova, Maria Kanuchova, Hristo Kolev, Erika Mudra, Lubomir Medvecky〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Samarium niobate SmNbO〈sub〉4〈/sub〉 (SNO) and tantalate SmTaO〈sub〉4〈/sub〉 (STO) precursors were prepared by sol-gel method and annealing at 1000 °C. The different polymorphs, orthorhombic and monoclinic SmNbO〈sub〉4〈/sub〉 or tetragonal SmTa〈sub〉7〈/sub〉O〈sub〉19〈/sub〉 and monoclinic SmTaO〈sub〉4〈/sub〉 were identified. Structural properties of precursors were investigated by the X-ray photoelectron spectroscopy (XPS). Core-level XPS studies of sol-gel SNO and STO were performed for the first time. The binding energy differences Δ(O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Nb) = B〈sub〉E〈/sub〉 (O 1s) – B〈sub〉E〈/sub〉 (Nb 3d〈sub〉5/2〈/sub〉) and Δ(O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Ta) = B〈sub〉E〈/sub〉 (O 1s) – B〈sub〉E〈/sub〉 (Ta 4f〈sub〉7/2〈/sub〉) were used as suitable parameter to characterize average Nb〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O bonding in SNO (323.1 eV) and Ta〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O bonding in STO (503.9 eV). The Sm 3d〈sub〉5/2〈/sub〉 peak consists of strong features characteristic for Sm〈sup〉3+〈/sup〉 (1083.0 eV) with (4f〈sup〉5〈/sup〉) electron configuration and Sm〈sup〉2+〈/sup〉 (1072 eV) with (4f〈sup〉6〈/sup〉) electron configuration. The molar concentration of Sm〈sup〉3+〈/sup〉 in SNO and STO was higher (21.0 and 24.7 at.%) than Sm〈sup〉2+〈/sup〉 in SNO (1.0 at.%) and STO (0.3 at.%). The XPS demonstrated two valence states of Sm in precursors for application as nanophosphors for lighting and display technologies.〈/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-S0169433218334834-ga1.jpg" width="294" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Surface Science, Volume 473〈/p〉 〈p〉Author(s): Soon Bo Lee, Youngwon Ju, Yongwoon Lee, Joohoon Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we studied indium tin oxides (ITOs) modified with dendrimer-encapsulated Pt nanoparticles (Pt DENs) to develop efficient 〈em〉p〈/em〉-aminophenol (〈em〉p〈/em〉-AP) redox cycling platforms. The ITO surfaces were modified via electro-oxidative grafting of the terminal amine groups of the dendrimers encapsulating catalytic Pt nanoparticles (〈em〉i.e.〈/em〉, Pt DENs). Compared to conventional ITO surfaces, the Pt DEN-modified ITOs showed highly enhanced electrochemical oxidation current of 〈em〉p〈/em〉-AP even at low potentials with no significant background oxidation current due to the catalytic activity of Pt nanoparticles, leading to high signal-to-background ratio for sensitive 〈em〉p〈/em〉-AP redox cycling. The enhanced 〈em〉p〈/em〉-AP redox cycling on the Pt DEN-modified ITOs led to ∼17.8 times higher sensitivity of the 〈em〉p〈/em〉-AP redox cycling than that obtained with conventional ITOs. In addition, the Pt DEN-modified ITOs were found to be suitable as platforms for the immobilization of oligonucleotides due to the globular structure of dendrimers, which have a high surface-to-volume ratio and multiple terminal functional groups, grafted on ITO surfaces. The DEN-modified ITOs could be further functionalized by the immobilization of single-strand DNA oligonucleotides with high surface density (〈em〉i.e.〈/em〉, (2.2 ± 0.4) × 10〈sup〉12〈/sup〉 molecules/cm〈sup〉2〈/sup〉), which is ∼4.4-fold higher than that on the surface of conventional ITOs.〈/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-S0169433218334822-ga1.jpg" width="285" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉