Mechanism insights into customized 2D nanoconfined catalyst via peroxymonosulfate activation for efficient sulfamethoxazole degradation: Key roles of electronic structure and non-radical pathway

Siyi Gu; Kai Zhang; Miqi Xu; Liang Li; Haixiang Yu; Hong Tao

doi:10.1016/j.envres.2024.120732

Mechanism insights into customized 2D nanoconfined catalyst via peroxymonosulfate activation for efficient sulfamethoxazole degradation: Key roles of electronic structure and non-radical pathway

Environ Res. 2024 Dec 30:120732. doi: 10.1016/j.envres.2024.120732. Online ahead of print.

Authors

Siyi Gu¹, Kai Zhang¹, Miqi Xu², Liang Li¹, Haixiang Yu¹, Hong Tao³

Affiliations

¹ School of Environment and Architecture, University of Shanghai for Science and Technology, 516 Jungong Rd., Shanghai, 200093, PR China.
² Shanghai Luwan Senior High School, No. 885 Xietu Rd., PR China.
³ School of Environment and Architecture, University of Shanghai for Science and Technology, 516 Jungong Rd., Shanghai, 200093, PR China. Electronic address: taohong@usst.edu.cn.

PMID: 39743010
DOI: 10.1016/j.envres.2024.120732

Abstract

The technology to solve the problem of the efficient pollutant removal in peroxymonosulfate (PMS) activation was the ultimate goal. There was an urgent need to achieving higher catalytic activity and oxidation efficiency. Herein, we present a MgAl-based layered double hydroxide assembled as a 2D confined catalyst (MgAl-Co-LDH) with Co metal in chelated form (Co-EDTA) for highly efficient PMS activation degrading sulfamethoxazole (SMX). Co-EDTA as an active site enlarged the interlayer height of MgAl-LDH to form a nanoconfined space. The confinement interlayer structure acted as a mediator for electron transfer, which improved the effective collision of active sites with PMS and SMX. The confined catalyst had a rate constant of 0.2262 min^-1, which was much superior to the non-confined catalyst by 8.76 times. A series of experiments proved that the reactive species transformed the radical pathway into singlet oxygen (¹O₂). The density functional theory calculations proved that the capability of PMS cleavage was optimized and modulated the electronic structure of MgAl-Co-LDH, which enhanced the reactivity of the D-band center electrons of Co-active sites. This study offered a method to investigate the catalytic degradation mechanisms of confined catalysts used in wastewater treatment.

Keywords: 2D confined catalyst; Electronic structure; Non-radical; Peroxymonosulfate; Sulfamethoxazole.