Anisotropic Electronic Characteristics, Adsorption, and Stability of Low-Index BiVO4 Surfaces for Photoelectrochemical Applications
Anisotropic Electronic Characteristics, Adsorption, and Stability of Low-Index BiVO4 Surfaces for Photoelectrochemical Applications
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用于光电化学应用的低折射率 BiVO4 表面的各向异性电子特性、吸附和稳定性
DOI：
10.1021/acsami.7b15243
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发表时间：
2018-02-14
影响因子：
9.5
通讯作者：
Chen, Zhong
中科院分区：
文献类型：
--
作者：
Hu, Jun;Chen, Wei;Chen, Zhong
大量的实验结果揭示了不同低折射率表面的光催化剂活性的差异。目前的调查集中在不同的低指数表面的BiVO 4对水分裂的电子特性，表面活性和稳定性的理论认识，使用第一原理计算。结果表明，BiVO_4具有四种低折射率表面，即（0 I 0）T_1，（010）T_2，（110）1 ′_1和（（1）过条11）T_1。由于静电势的变化而引起的表面带边电位的不同，使（010）T1和（010）1 ′ 2表面的氧化能力高于（110）T1和（（1）over bar 11）T1表面。在光催化过程中，电子倾向于在（010）T1和（010）T2表面上积累，而空穴倾向于在（110）T1和（（1）在棒11）T1表面上积累。此外，对BiVO_4表面上吸附的中间产物的研究表明，BiVO_4表面上的析氧反应主要由OH ~（**）O ~（**）+ H ~（++）e ~（-）反应控制，（110）T_1和（1-14）T_1表面比（010）T_2和（010）T_1表面更适合作为光阳极进行水分解.此外，作为光阳极的BiVO 4表面往往是不稳定的，并且在存在或不存在氧化环境的情况下都容易被腐蚀，然而，BiVO 4（010）T1和（010）T2表面是例外，当没有强氧化物质时，它们在溶液中是化学稳定的。这些结果提供了重要的见解BiVO 4的低指数表面的光催化反应的各向异性行为。
Many experimental results reveal different activities among different low-index surfaces of photocatalysts. The current investigation focuses on the theoretical understanding of the electronic characteristics, surface activity, and stability of different low-index surfaces of BiVO4 toward water splitting-using first-principle calculations. The results indicate that BiVO4 has four types of low-index surfaces, namely, (0I0)T1, (010)T2, (110)1'1, and ((1) over bar 11)T1. The different band edge potentials of the surfaces, resulting from the variation of the electrostatic potential, lead to a higher oxidation ability for (010)T1 and (010)1'2 than for (110)T1 and ((1) over bar 11)T1 surfaces. The electrons prefer to accumulate on (010)T1 and (010)T2 surfaces, whereas holes like to accumulate on (110)T1 and ((1) over bar 11)T1 surfaces during, a photocatalytic process. Moreover, investigation on the adsorbed intermediates during the water-splitting, process indicates that the oxygen evolution reaction on BiVO4 surfaces is mainly dominated by the reaction OH* * 0* + H+ + e(-), and (110)T1 and (1-14)T1 surfaces are energetically more favorable as photoanodes for water splitting than (010)11 arid (010)T2. Furthermore, the BiVO4 surface as photoanodes tend to be=,unstable and can easily be corroded with or without the presence "of an oxidative environment, however, there is an exception for the BiVO4 (010)T1 and (010)T2 surfaces, which are thermodynamically stable in the solution when there are no strong oxidative species. These results provide important insights into the anisotropy behaviors among low-index surfaces of BiVO4 for photocatalytic reactions.