Guo Yali, Sui Minghao, Liu Shuan, Li Tian, Lv Xinyuan, Yu Miao, Mo Yaojun
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
J Hazard Mater. 2024 Jan 5;461:132662. doi: 10.1016/j.jhazmat.2023.132662. Epub 2023 Sep 29.
In this study, a hollow sphere-like Co-modified LaFeO perovskite catalyst (LFC73O) was developed for peracetic acid (PAA) activation to degrade sulfamethoxazole (SMX). Results indicated that the constructed heterogeneous system achieved a 99.7% abatement of SMX within 30 min, exhibiting preferable degradation performance. Chemical quenching experiments, probe experiments, and EPR techniques were adopted to elucidate the involved mechanism. It was revealed that the superior synergistic effect of electron transfer and oxygen defects in the LFC73O/PAA system enhanced the oxidation ability of PAA. The Co atoms doped into LaFeO as the main active site with the original Fe atoms as an auxiliary site exhibited high activity to mediate PAA activation via the Co(III)/Co(II) cycle, generating carbon-centered radicals (RO·) including CHC(O)O· and CHC(O)OO·. The oxygen vacancies induced by cobalt substitution also served as reaction sites, facilitating the dissociation of PAA and production of ROS. Furthermore, the degradation pathways were postulated by DFT calculation and intermediates identification, demonstrating that the electron-rich sites of SMX molecules such as amino group, aromatic ring, and S-N bond, were more susceptible to oxidation by reactive species. This study offers a novel perspective on developing catalysts with the coexistence of multiple active units for PAA activation in environmental remediation.
在本研究中，开发了一种空心球状的钴改性镧铁氧体钙钛矿催化剂（LFC73O）用于活化过氧乙酸（PAA）以降解磺胺甲恶唑（SMX）。结果表明，构建的多相体系在30分钟内实现了99.7%的SMX去除率，表现出较好的降解性能。采用化学猝灭实验、探针实验和电子顺磁共振技术来阐明相关机制。结果表明，LFC73O/PAA体系中电子转移和氧缺陷的优异协同效应增强了PAA的氧化能力。掺杂到镧铁氧体中的钴原子作为主要活性位点，原始的铁原子作为辅助位点，通过Co(III)/Co(II)循环对PAA活化表现出高活性，产生以碳为中心的自由基（RO·），包括CHC(O)O·和CHC(O)OO·。钴取代诱导的氧空位也作为反应位点，促进了PAA的解离和活性氧的产生。此外，通过密度泛函理论计算和中间体鉴定推测了降解途径，表明SMX分子的富电子位点，如氨基、芳环和S-N键，更容易被活性物种氧化。本研究为开发具有多个活性单元共存的催化剂用于环境修复中PAA活化提供了新的视角。
