Photo-induced dissolution of Bi2O3 during photocatalysis reactions: Mechanisms and inhibition method

Wenyue Dou; Xingyun Hu; Linghao Kong; Xianjia Peng

doi:10.1016/j.jhazmat.2021.125267

Photo-induced dissolution of Bi₂O₃ during photocatalysis reactions: Mechanisms and inhibition method

J Hazard Mater. 2021 Jun 15:412:125267. doi: 10.1016/j.jhazmat.2021.125267. Epub 2021 Jan 30.

Authors

Wenyue Dou¹, Xingyun Hu², Linghao Kong², Xianjia Peng³

Affiliations

¹ State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
³ State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xjpeng@rcees.ac.cn.

PMID: 33548778
DOI: 10.1016/j.jhazmat.2021.125267

Abstract

Photo-induced dissolution greatly limits the application of Bi₂O₃ photocatalyst in water treatment. In this study, mechanisms for the photo-induced dissolution of Bi₂O₃ were proposed. (1) Under UV light, h⁺ forms and diffuses through Bi₂O₃. (2) The h⁺, which reaches the surface of Bi₂O₃ and can be regarded as a monatomic oxygen ion (O_S^-), is weakly bonded to the crystal lattice. (3) Two O_S^- combine and the generated (O-O)^2- ionic group is oxidized by h⁺, resulting in the release of O₂ and dissolution of Bi₂O₃. However, modification of Bi₂O₃ using polyaniline (PANI) greatly inhibits Bi₂O₃ dissolution under UV. Under the PANI to Bi₂O₃ mass ratio of 1.5%, the concentration of produced Bi³⁺ significantly decreased from 2.02 to 0.27 mg/m² with a high methylene blue (MB) degradation efficiency of 98.3%, thanks to the separation of h⁺ from VB-Bi₂O₃ to HOMO-PANI. This study provided the theoretical foundation for the modification and application of Bi₂O₃ in water treatment.

Keywords: Bi(2)O(3) photocatalyst; Generation of O(2); Oxidation by h(+); Photo-induced dissolution.