Novel AgI/BiSbO4 heterojunction for efficient photocatalytic degradation of organic pollutants under visible light: Interfacial electron transfer pathway, DFT calculation and degradation mechanism study
Novel AgI/BiSbO4 heterojunction for efficient photocatalytic degradation of organic pollutants under visible light: Interfacial electron transfer pathway, DFT calculation and degradation mechanism study
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DOI：
10.1016/j.jhazmat.2020.124948
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发表时间：
2021-01-16
影响因子：
13.6
通讯作者：
Zhang, Gaoke
中科院分区：
文献类型：
--
作者：
Wang, Zhuangzhuang;Jiang, Lisha;Zhang, Gaoke
在此，我们通过水热沉淀法构建了一个新的AgI/BiSbO4异质结。异质结结构促进羟基和超氧自由基的产生，有效降解有机污染物。最佳样品对ARG和TC的光催化活性分别比裸AgI高10倍和1.6倍。表征和理论计算共同证实了AgI和BiSbO4的中间层之间存在很强的界面电荷转移，通过形成Ag-O键，使得O原子从AgI的Ag原子中获得丰富的自由电子，从而形成超高的电子转移隧道，最终加速了光致电子的分离。更有趣的是，在光催化过程中形成了少量的Ag-0 NPs，由于其SPR（表面等离子体共振）效应，增强了可见光吸收，进一步促进了光诱导载流子的分离。通过对中间体的分析，详细提出了光催化降解途径，揭示了合理的光催化机理。这项工作扩展了基于agi的异质结光催化剂的发展。
Herein, we constructed a novel AgI/BiSbO4 heterojunction via a hydrothermal-precipitation method. The heterojunction structure boosts the generation of hydroxyl and superoxide radicals for efficient degradation of organic pollutants. The photocatalytic activities of the optimal sample for ARG and TC degradation are 10 and 1.6 times higher than those of bare AgI, respectively. Characterizations and theoretical calculations together confirm a strong interfacial charge transfer exists between the interlayer in AgI and BiSbO4 by the formation of Ag-O bond, making O atoms obtain rich free electrons from Ag atoms of AgI, thus forming an ultrahigh electron transfer tunnel, and ultimately accelerating the separation of photoinduced electrons. More interestingly, low amounts of Ag-0 NPs formed during the photocatalytic process, enhancing the visible light absorption because of its SPR (surface plasmon resonance) effect and further promoting the separation of photoinduced carriers. Furthermore, photocatalytic degradation pathways were proposed in detail by analyzing intermediates and a reasonable photocatalytic mechanism was unearthed. This work extends the development of AgI-based heterojunction photocatalysts.