Mn3O4-g-C3N4 composite to activate peroxymonosulfate for organic pollutants degradation: Electron transfer and structure-dependence

Jinhong Fan; Qiaoqiao Wang; Wei Yan; Jiabin Chen; Xuefei Zhou; Haijiao Xie

doi:10.1016/j.jhazmat.2022.128818

Mn₃O₄-g-C₃N₄ composite to activate peroxymonosulfate for organic pollutants degradation: Electron transfer and structure-dependence

J Hazard Mater. 2022 Jul 15:434:128818. doi: 10.1016/j.jhazmat.2022.128818. Epub 2022 Mar 31.

Authors

Jinhong Fan¹, Qiaoqiao Wang², Wei Yan², Jiabin Chen², Xuefei Zhou³, Haijiao Xie⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: jinhongfan@tongji.edu.cn.
² State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China.
³ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: zhouxuefei@tongji.edu.cn.
⁴ Hangzhou Yanqu Information Technology Co., Ltd, PR China.

PMID: 35427973
DOI: 10.1016/j.jhazmat.2022.128818

Abstract

A novel heterogeneous manganese/graphitic carbon nitride (Mn₃O₄-CN) catalyst for activating peroxymonosulfate (PMS) was successfully assembled using alkali precipitation. The g-C₃N₄ improved the composite's surface morphology, micro-porous structure, surface area, and particle size distribution, and an electron-rich center with Mn site was created. The Mn₃O₄-CN/PMS system exhibited high efficiency and stability when the solution pH varied from 3.0 to 9.0, with more than 90% of p-acetaminophen (ACT) removal in 30 min under experimental conditions. A possible reaction mechanism was proposed, primarily involving electron transfer from Mn (II) and Mn (III) to PMS along with the generation of·O₂^- and ¹O₂, and the degradation of ACT was attributed to the ¹O₂. Specifically, the degradation rate of phenolic compounds varied with their molecular structure in the following order: ACT > bisphenol A (BPA) > p-cresol (MP) > p-chlorophenol (CP) > phenol (Ph) > p-nitrophenol (NP). Further, the density functional theory (DFT) calculations indicated that the phenols' degradation efficiency was related to their adsorption energy and Bader charge value. These results improved our understanding of the manganese-based PMS non-radical dominated process and provided a method for predicting the degradation performance of phenols for the first time.

Keywords: Mn(3)O(4); Non-radical mechanism; Peroxymonosulfate; Phenols; Structure-dependence; g-C(3)N(4).