Enhanced visible light assisted peroxymonosulfate process by biochar in-situ enriched with γ-Fe2O3 for p-chlorophenol degradation: performance, mechanism and DFT calculation

Chengyu Zhang; Zhisheng Yu; Xiangyang Wang; Bobo Wang

doi:10.1016/j.jhazmat.2022.130593

Enhanced visible light assisted peroxymonosulfate process by biochar in-situ enriched with γ-Fe₂O₃ for p-chlorophenol degradation: performance, mechanism and DFT calculation

J Hazard Mater. 2023 Mar 5:445:130593. doi: 10.1016/j.jhazmat.2022.130593. Epub 2022 Dec 12.

Authors

Chengyu Zhang¹, Zhisheng Yu², Xiangyang Wang¹, Bobo Wang¹

Affiliations

¹ College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China; Binzhou Institute of Technology, Weiqiao-UCAS Science and Technology Park, Binzhou City 256606, Shandong Province, PR China; RCEES-IMCAS-UCAS Joint-Lab of Microbial Technology for Environmental Science, Beijing 100085, PR China.
² College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China; Binzhou Institute of Technology, Weiqiao-UCAS Science and Technology Park, Binzhou City 256606, Shandong Province, PR China; RCEES-IMCAS-UCAS Joint-Lab of Microbial Technology for Environmental Science, Beijing 100085, PR China. Electronic address: yuzs@ucas.ac.cn.

PMID: 37055996
DOI: 10.1016/j.jhazmat.2022.130593

Abstract

In this study, a novel γ-Fe₂O₃/biochar (BF_γ) composite by a plant in-situ enrichment and one-step pyrolysis strategy was prepared, which was applied as a photocatalyst to activate peroxymonosulfate (PMS) for the degradation of p-chlorophenol (4-CP) under visible light irradiation (BF_γ/PMS/Vis) system. The characterization results exhibited that γ-Fe₂O₃ with localized carbon doping was evenly embedded in biochar during the pyrolysis. BF_γ exhibited better photoresponse properties than biochar (BC) and γ-Fe₂O₃. The removal efficiency of this system for 4-CP reached 96.41% under optimal conditions. This system showed high removal efficiency with a wide pH range (3.0-13.0) and under conditions of different organic pollutants. It also showed strong resistance to interference with co-existing inorganic ions and humic acid (HA). Electron paramagnetic resonance (EPR) and radical scavenging experiments revealed that the reactive oxygen species (ROS) in this system included SO₄^-·, ·OH, ·O₂^- and ¹O₂. The density functional theoretical (DFT) calculations further revealed the promotion of localized carbon doping in γ-Fe₂O₃ on electron transfer and photoresponse, including C-O bond (d=1.29 Å), C-Fe bond (d=1.80 Å) and band gap value (E_gap < 0.72 eV). This study provides new insights into constructing environmentally-friendly catalysts and the possibility of the solid waste recycling for other wetland plants.

Keywords: Biochar; P-chlorophenol, DFT calculations; Peroxymonosulfate; Photocatalyst; γ-Fe(2)O(3).