Systematic research on Ag2X (X = O, S, Se, Te) as visible and near-infrared light driven photocatalysts and effects of their electronic structures
Systematic research on Ag2X (X = O, S, Se, Te) as visible and near-infrared light driven photocatalysts and effects of their electronic structures
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Ag2X（X=O、S、Se、Te）作为可见光和近红外光驱动光催化剂及其电子结构效应的系统研究
DOI：
10.1016/j.apsusc.2017.08.053
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发表时间：
2018-01-01
影响因子：
6.7
通讯作者：
Liang, Bin
中科院分区：
文献类型：
--
作者：
Jiang, Wei;Wu, Zhaomei;Liang, Bin
四种银硫族化合物Ag2O、Ag2S、Ag2Se和Ag2Te可用作可见光驱动的光催化剂。本研究通过模拟和实验对这些化合物的电子结构进行了分析，系统地揭示了光催化性能与含能结构之间的关系。四种硫属化合物在紫外、可见光和近红外光下均表现出有趣的光催化活性。但是，它们的光催化性能和稳定性显著地取决于它们的组成所决定的带隙宽度、价带和导带位置。随着X原子序数从O增加到Te，价带顶和导带底向上移动，禁带宽度变窄，吸收光谱变宽，光氧化能力变弱，空穴和电子对复合几率增大，量子效率降低，稳定性变差.其中，Ag2O由于其最宽的带隙和最低的VB和CB位置而具有最高的光催化性能和稳定性。光生空穴和不同的自由基，包括阴离子的臭氧自由基，氢氧化物自由基，和超氧自由基，根据不同的电子结构的联合行动进行了观察和理解。对四种银硫族化合物的实验观察和模拟结果表明，在开发新型光催化剂时，适当的电子结构是获得光催化性能和可吸收光区域之间平衡的必要条件。(C)2017爱思唯尔B.V.保留所有权利。
Four silver chalcogen compounds, Ag2O, Ag2S, Ag2Se and Ag2Te, can be utilized as visible-light-driven photocatalysts. In this research, the electronic structures of these compounds were analyzed by simulation and experiments to systematically reveal the relationship between photocatalytic performance and energetic structure. All four chalcogenides exhibited interesting photocatalytic activities under ultraviolet, visible and near-infrared light. However, their photocatalytic performances and stability significantly depended on the band gap width, and the valence band and conduct band position, which was determined by their composition. Increasing the X atomic number from O to Te resulted in the upward movement of the valence band top and the conduct band bottom, which resulted in narrower band gaps, a wider absorption spectrum, a weaker photo-oxidization capacity, a higher recombination probability of hole and electron pairs, lower quantum efficiency, and worse stability. Among them, Ag2O has the highest photocatalytic performance and stability due to its widest band gap and lowest position of VB and CB. The combined action of photogenerated holes and different radicals, depending on the different electronic structures, including anion ozone radical, hydroxide radical, and superoxide radical, was observed and understood. The results of experimental observations and simulations of the four silver chalcogen compounds suggested that a proper electronic structure is necessary to obtain a balance between photocatalytic performance and absorbable light region in the development of new photocatalysts. (C) 2017 Elsevier B.V. All rights reserved.