Synthesis of buckhorn-like BiVO4 with a shell of CeOx nanodots: Effect of heteroj unction structure on the enhancement of photocatalytic activity
Synthesis of buckhorn-like BiVO4 with a shell of CeOx nanodots: Effect of heteroj unction structure on the enhancement of photocatalytic activity
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DOI：
10.1016/j.apcatb.2015.01.044
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发表时间：
2015-07-01
影响因子：
22.1
通讯作者：
Li, Hongda
中科院分区：
文献类型：
--
作者：
Gu, Shaonan;Li, Wenjun;Li, Hongda
采用水热法和离子浸渍法合成了具有异质结结构的CeOx/BiVO 4复合光催化剂。采用X射线衍射、BET比表面积、高分辨透射电子显微镜、选区电子衍射和X射线光电子能谱等手段对复合材料进行了表征。利用紫外-可见漫反射光谱研究了光催化剂的吸收范围和带隙。以亚甲基蓝溶液为降解对象，考察了所制备样品的可见光催化活性。结果表明，5.7wt. CeOx/BiVO 4在所研究的范围内表现出最高的光催化活性。基于异质结结构并考虑费米能级，可以很好地解释光生电荷的分离以及异质结结构对光催化活性的影响。光致发光谱和电子顺磁共振谱证实了电荷分离过程和沉积铈的重要作用。结果表明，异质结结构和铈的电子俘获效应大大抑制了复合材料中光生电荷的复合。(C)2015 Elsevier B. V.版权所有。
Composite photocatalysts CeOx/BiVO4 with a heterojunction structure were synthesized using hydrothermal and ion-impregnation method. The composites were characterized by X-ray diffraction, BET, high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. UV-vis diffuse reflectance spectroscopy was used to investigate the absorption range and band gap of photocatalysts. The photocatalytic activities of the prepared samples were also examined by studying the degradation of methylene blue under visible-light irradiation. Results showed that the composite with 5.7 wt.% CeOx/BiVO4 exhibited the highest photocatalytic activity within the studied range. The separation of the photogenerated charge and the effect of heterojunction structure on photocatalytic activities could be well interpreted based on the heterojunction structure with consideration of the Fermi level. The charge-separation process and the important role of deposited cerium were proven by photoluminescence spectroscopy and electron paramagnetiC resonance spectra. Results demonstrated that the heterojunction structure and the electron-trapping effect of cerium greatly depressed the recombination of photogenerated charges in the composites. (C) 2015 Elsevier B.V. All rights reserved.