Novel AgI/BiSbO4 heterojunction for efficient photocatalytic degradation of organic pollutants under visible light: Interfacial electron transfer pathway, DFT calculation and degradation mechanism study

Zhuangzhuang Wang; Lisha Jiang; Kai Wang; Yuan Li; Gaoke Zhang

doi:10.1016/j.jhazmat.2020.124948

Novel AgI/BiSbO₄ heterojunction for efficient photocatalytic degradation of organic pollutants under visible light: Interfacial electron transfer pathway, DFT calculation and degradation mechanism study

J Hazard Mater. 2021 May 15:410:124948. doi: 10.1016/j.jhazmat.2020.124948. Epub 2020 Dec 24.

Authors

Zhuangzhuang Wang¹, Lisha Jiang¹, Kai Wang¹, Yuan Li¹, Gaoke Zhang²

Affiliations

¹ Hubei Key Laboratory of Mineral Resources Processing and Environment, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, People's Republic of China.
² Hubei Key Laboratory of Mineral Resources Processing and Environment, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, People's Republic of China; Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450052, People's Republic of China. Electronic address: gkzhang@whut.edu.cn.

PMID: 33465516
DOI: 10.1016/j.jhazmat.2020.124948

Abstract

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 Ag⁰ 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.

Keywords: AgI/BiSbO(4) heterojunction; Degradation; Photocatalytic; Visible light.