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Light induced generation and regeneration of oxygen vacancies in BiSbO4 for sustainable visible light photocatalysis.

Research paper by Maoxi M Ran, Hong H Wang, Wen W Cui, Jieyuan J Li, Peng P Chen, Yanjuan Y Sun, Jianping J Sheng, Ying Y Zhou, Yuxin Y Zhang, Fan F Dong

Indexed on: 07 Dec '19Published on: 06 Dec '19Published in: ACS Applied Materials & Interfaces



Abstract

The oxygen vacancy-containing semiconductor photocatalysts have been extensively studied and applied in environmental and energy fields, but there are a few studies concerning the mechanisms of inactivation and regeneration of oxygen vacancies to prevent the catalysts from deactivation. In this paper, we put forward a novel in situ method to introduce the oxygen vacancies into BiSbO4 (BiSbO4-OV) via UV-light induced breaking down of Bi-O and Sb-O bonds. The formation of oxygen vacancies could broaden the photo-response range and improve the charge carries separation as confirmed by DFT calculation, UV and PL spectra. The unique electronic structure of oxygen vacancies enabled the BiSbO4 with high visible light photocatalytic NO activity. It was significant to reveal that oxygen in the air could fill the oxygen vacancy sites during the photocatalytic reaction, and the consumption of the oxygen vacancies led to the direct deactivation of BiSbO4-OV. By re-irradiation of the deactivated photocatalysts, the BiSbO4-OV could get back to its initial state, realizing the refreshment of oxygen vacancies for sustainable photocatalysis. Additionally, the visible light photocatalytic NO conversion pathway on BiSbO4-OV was uncovered via in situ DRIFTS based on the identification of the reaction intermediates and products. The light induced generation and regeneration of oxygen vacancies could also be extended in other semiconductors for sustainable visible light photocatalysis.