Role variations of MnOx on monoclinic BiVO4 (110)/(040) facets for enhanced Photo-Fenton reactions

Haojie Wang; Xiaomei Liu; Di Wu; Yang Zhao; Ning Li; Yang Li; Xiaobin Fan; Qing Xia; Fengbao Zhang; Wenchao Peng

doi:10.1016/j.jcis.2023.05.048

Role variations of MnO_x on monoclinic BiVO₄ (110)/(040) facets for enhanced Photo-Fenton reactions

J Colloid Interface Sci. 2023 Sep 15:646:219-227. doi: 10.1016/j.jcis.2023.05.048. Epub 2023 May 12.

Authors

Haojie Wang¹, Xiaomei Liu¹, Di Wu¹, Yang Zhao¹, Ning Li², Yang Li³, Xiaobin Fan³, Qing Xia¹, Fengbao Zhang¹, Wenchao Peng⁴

Affiliations

¹ School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China.
² School of Environmental Science & Engineering, Tianjin University, Tianjin 300350, PR China.
³ School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China; Zhejiang Institute of Tianjin University, Shaoxing, Zhejiang 312300, PR China.
⁴ School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China; Zhejiang Institute of Tianjin University, Shaoxing, Zhejiang 312300, PR China. Electronic address: wenchao.peng@tju.edu.cn.

PMID: 37196495
DOI: 10.1016/j.jcis.2023.05.048

Abstract

Compared with traditional Fenton reaction, peroxymonosulfate based advanced oxidation processes (PMS-AOPs) are more effective to remove the organic pollutants in wastewater in a wider pH range. Herein, selective loading of MnO_x on monoclinic BiVO₄ (110) or (040) facets were achieved by photo-deposition method with addition of different Mn precursors and electron/hole trapping agents. MnO_x has good chemical catalysis activity for PMS activation, which can also enhance photogenerated charge separation, thus leading to enhanced activities than naked BiVO₄. The BPA degradation reaction rate constants of MnO_x(040)/BiVO₄ and MnO_x(110)/BiVO₄ system are 0.245 min^-1 and 0.116 min^-1, which are 6.45 and 3.05 times larger than that of naked BiVO₄, respectively. The roles of MnO_x on different facets are different, which will promote OER process on (110) facets and utilize the dissolved O₂ to produce O₂^•- and ¹O₂ more effectively on (040) facets. ¹O₂ is the dominated reactive oxidation species of MnO_x(040)/BiVO₄, while SO₄^•- and •OH play more important roles on MnO_x(110)/BiVO₄, which are proved by quenching experiments and chemical probe identifications, thus mechanism in MnO_x/BiVO₄-PMS-light system is proposed. The good degradation performance of MnO_x(110)/BiVO₄ and MnO_x(040)/BiVO₄ and mechanism theory may promote the application of photocatalysis in PMS based wastewater remediation.

Keywords: BiVO(4); Facet engineering; MnO(x); Photocatalysis; Selective photo-deposition.