Publication Date:
2018
Description:
〈p〉Publication date: 5 March 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉
〈p〉Author(s): Sai Huang, Zhihao Wang, Qi Zhu, Xiaofei Shi, Xuejiao Wang, Xiaodong Li, Xudong Sun, Ji-Guang Li〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉RE(OH)〈sub〉2.94〈/sub〉(NO〈sub〉3〈/sub〉)〈sub〉0.06〈/sub〉·〈em〉n〈/em〉H〈sub〉2〈/sub〉O nanosquares were first employed as template to synthesize YVO〈sub〉4〈/sub〉:Ln luminescent crystallites (Ln = Eu, Sm, and Dy) via hydrothermal nanoconversion in the presence of NH〈sub〉4〈/sub〉VO〈sub〉3〈/sub〉. Product properties and the course of phase/morphology evolution were characterized in detail by XRD, SEM, TEM, FT-IR, TG, and optical spectroscopy. It was clearly demonstrated that the nanosquares templated vanadate crystallization, owing to structure similarity, but was accompanied by subsequent dissolution and reprecipitation. The resultant vanadate phosphors, mostly in the form of bundles containing platelike and fibrous crystallites, exhibited strong red emission at ∼618 nm for Eu〈sup〉3+〈/sup〉, orange-red emission at ∼604 nm for Sm〈sup〉3+〈/sup〉 and greenish yellow emission at ∼575 nm for Dy〈sup〉3+〈/sup〉 upon exciting the VO〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 ligand. Dehydration at 500 °C further improved the emission by ∼2.5 times for Eu〈sup〉3+〈/sup〉 and ∼1.5 times for Sm〈sup〉3+〈/sup〉 and Dy〈sup〉3+〈/sup〉. The Eu〈sup〉3+〈/sup〉 (5 at%), Sm〈sup〉3+〈/sup〉 (1 at%) and Dy〈sup〉3+〈/sup〉 (1 at%) activators were analyzed to have quantum yields of ∼48, 9 and 16% and color coordinates of around (0.65, 0.33), (0.60, 0.39) and (0.38, 0.43) for their luminescence, and fluorescence lifetimes of ∼1.52, 1.40 and 0.89 ms for their dominant emissions, respectively. It is also interesting to find out that replacing only 15% of the total OH〈sup〉−〈/sup〉 and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 anions in the template by VO〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 produced ∼20 times stronger Eu〈sup〉3+〈/sup〉 luminescence, indicating that VO〈sub〉4〈/sub〉〈sup〉3-〈/sup〉→ Eu〈sup〉3+〈/sup〉 energy transfer is very efficient. The protocol would be extendable to other types of functional rare-earth compounds.〈/p〉〈/div〉
〈/div〉
〈h5〉Graphical abstract〈/h5〉
〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339719-fx1.jpg" width="245" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
Print ISSN:
0925-8388
Electronic ISSN:
1873-4669
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
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