Peroxymonosulfate activation by oxygen vacancies-enriched MXene nano-Co3O4 co-catalyst for efficient degradation of refractory organic matter: Efficiency, mechanism, and stability

Wei Li; Wei Li; Kuanchang He; Longxiang Tang; Qian Liu; Kui Yang; Yi-Di Chen; Xin Zhao; Kai Wang; Hui Lin; Sihao Lv

doi:10.1016/j.jhazmat.2022.128719

Peroxymonosulfate activation by oxygen vacancies-enriched MXene nano-Co₃O₄ co-catalyst for efficient degradation of refractory organic matter: Efficiency, mechanism, and stability

J Hazard Mater. 2022 Jun 15:432:128719. doi: 10.1016/j.jhazmat.2022.128719. Epub 2022 Mar 17.

Authors

Wei Li¹, Wei Li², Kuanchang He¹, Longxiang Tang¹, Qian Liu¹, Kui Yang¹, Yi-Di Chen³, Xin Zhao⁴, Kai Wang¹, Hui Lin⁵, Sihao Lv¹

Affiliations

¹ Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China.
² Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China. Electronic address: liwei@dgut.edu.cn.
³ State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
⁴ College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
⁵ Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China. Electronic address: linhui@dgut.edu.cn.

PMID: 35325862
DOI: 10.1016/j.jhazmat.2022.128719

Abstract

Cobalt-based catalysts have been widely explored in the degradation of organic pollutants based on peroxymonosulfate (PMS) activation. Herein, we report an MXene nano-Co₃O₄ co-catalyst enriched with oxygen vacancies (O_v) and steadily fixed in nickel foam (NF) plates, which is used as an efficient and stable PMS activator for the removal of 1,4-dioxane (1,4-D). Ti originating from MXene was doped into the Co₃O₄ crystal, generating large amounts of O_v, which could provide more active sites to enhance PMS activation and facilitate the transformation of Co²⁺ and Co³⁺, causing a high stability. As a result, the 1,4-D removal efficiency of the NF/MXene-Co₃O₄/PMS system (k_app: 2.41 min^-1) was about four times higher than that of the NF/Co₃O₄/PMS system (k_app: 0.62 min^-1). In addition, singlet oxygen was the predominant reactive oxygen species. Notably, the 1,4-D removal of the NF/MXene-Co₃O₄/PMS system was over 95% after 20 h operation in the single-pass filtration mode with only 3.72% accumulative Co leaching, showing excellent stability and reusability of NF/MXene-Co₃O₄. This work provides a defect engineering strategy to design a robust and stable catalytic system for water treatment, which expands the application of MXene in the field of environmental remediation.

Keywords: (1)O(2) nonradical; 1,4-dioxane; MXene nano-Co(3)O(4) co-catalyst; Oxygen vacancies; Peroxymonosulfate (PMS).