Vacancy-rich NiFe-LDH/carbon paper as a novel self-supporting electrode for the electro-Fenton degradation of polyvinyl chloride microplastics

Yuan Wang; Haihong Zhong; Qianqian Xu; Miao Dong; Jianxin Yang; Weiting Yang; Yongjun Feng; Zhong-Min Su

doi:10.1016/j.jhazmat.2024.136797

Vacancy-rich NiFe-LDH/carbon paper as a novel self-supporting electrode for the electro-Fenton degradation of polyvinyl chloride microplastics

J Hazard Mater. 2024 Dec 9:485:136797. doi: 10.1016/j.jhazmat.2024.136797. Online ahead of print.

Authors

Yuan Wang¹, Haihong Zhong², Qianqian Xu³, Miao Dong¹, Jianxin Yang¹, Weiting Yang⁴, Yongjun Feng⁵, Zhong-Min Su⁶

Affiliations

¹ School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, No. 58 Renmin Road, Haikou 570228, China.
² School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, No. 58 Renmin Road, Haikou 570228, China. Electronic address: [email protected].
³ State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Beijing 100029, China.
⁴ School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, No. 58 Renmin Road, Haikou 570228, China. Electronic address: [email protected].
⁵ State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Beijing 100029, China. Electronic address: [email protected].
⁶ School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, No. 58 Renmin Road, Haikou 570228, China; State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130021, China.

PMID: 39657496
DOI: 10.1016/j.jhazmat.2024.136797

Abstract

Electrochemically upcycling polyvinyl chloride (PVC) into high-value small molecules represents a sustainable strategy for mitigating plastic pollution. Herein, a cost-effective self-supporting electrode with abundant vacancies, i.e., NiFe-layered double hydroxide nanoarrays in-situ grown on the surface of carbon paper (denoted as NiFe_V-LDH/CP), is developed for the electro-Fenton degradation of PVC microplastics (MPs). The NiFe_V-LDH catalyst shows a high selectivity of 76 % towards H₂O₂ production via two-electron oxygen reduction reaction (2e^- ORR). Density functional theory (DFT) calculations reveal that the energy barrier of rate-determining step (*H₂O₂ desorption) decreases over the vacancy-enriched NiFe_V-LDH related to the pristine NiFeZn-LDH. The influence of vacancy concentration, reaction temperature and initial concentration of PVC MPs were systematically investigated. Under optimized conditions, the NiFe_V-LDH/CP electrode exhibits an outstanding degradation performance of PVC MPs via direct cathodic reduction and oxidation by hydroxyl radicals. This work demonstrates that the electro-Fenton technology using LDH-based self-supporting electrodes is a promising and environmentally-friendly approach for waste plastic treatment.

Keywords: Electro-Fenton; H(2)O(2); LDH; PVC; Waste plastic.