In-depth insights into Fe(III)-doped g-C3N4 activated peracetic acid: Intrinsic reactive species, catalytic mechanism and environmental application

Hailing Zhao; Yi Ren; Chao Liu; Longguo Li; Naiwen Li; Bo Lai; Jun Li

doi:10.1016/j.jhazmat.2023.132117

In-depth insights into Fe(III)-doped g-C₃N₄ activated peracetic acid: Intrinsic reactive species, catalytic mechanism and environmental application

J Hazard Mater. 2023 Oct 5:459:132117. doi: 10.1016/j.jhazmat.2023.132117. Epub 2023 Jul 22.

Authors

Hailing Zhao¹, Yi Ren¹, Chao Liu¹, Longguo Li¹, Naiwen Li¹, Bo Lai², Jun Li³

Affiliations

¹ State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China.
² Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065, China.
³ State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China. Electronic address: drlijun@scu.edu.cn.

PMID: 37531769
DOI: 10.1016/j.jhazmat.2023.132117

Abstract

In this study, we demonstrate that Fe(III)-doped g-C₃N₄ can efficiently activate peracetic acid (PAA) to degrade electron-rich pollutants (e.g., sulfamethoxazole, SMX) over a wide pH range (3-7). Almost ∼100% high-valent iron-oxo species (Fe(V)) was generated and acted as the dominant reactive species responsible for the micropollutants oxidation based on the analysis result of quenching experiments, ¹⁸O isotope-labeling examination and methyl phenyl sulfoxide (PMSO) probe method. Electrochemical testing (e.g., amperometric i-t and linear sweep voltammetry (LSV)) and density functional theory (DFT) calculations illustrated that the main active site Fe atom and PAA underwent electron transfer to form Fe(V) for attacking SMX. Linear free energy relationship (LFER) between the pseudo-first-order rates of different substituted phenols (SPs) and the Hammett constant σ⁺ depicted the electrophilic oxidation properties. The selective oxidation of Fe(V) endows the established system remarkable anti-interference capacity against water matrices, while the Fe(V) lead to the formation of iodinated disinfection by-products (I-DBPs) in the presence of I^-. Fe(III)-doped g-C₃N₄/PAA system showed excellent degradation efficiency of aquaculture antibiotics. This study enriches the knowledge and research of high-valent iron-oxo species and provides a novel perspective for the activation of PAA via heterogeneous iron-based catalysts and practical environmental applications.

Keywords: Fe(III)-doped g-C(3)N(4); High-valent iron-oxo species; Iodinated disinfection by-products; Peracetic acid; Sulfamethoxazole.