Xiaoyue Zhang, Jun Nan, Hui Zhang, Peijie Li, Xiaoying Lin
{"title":"Efficient PFOA decontamination using photoelectrocatalytic coupled PMS activation: unleashing electrons and superoxide radicals for rapid degradation","authors":"Xiaoyue Zhang, Jun Nan, Hui Zhang, Peijie Li, Xiaoying Lin","doi":"10.1016/j.watres.2025.124182","DOIUrl":null,"url":null,"abstract":"Direct oxidation of per- and polyfluoroalkyl substances (PFAS) necessitates excessive energy or prolonged treatment, while reductive defluorination effectively cleaves C-F bonds. However, strict anaerobic requirements hinder its practical implementation. Herein, a photoelectrocatalytic-peroxymonosulfate (PEC-PMS) integrated system was developed for perfluorooctanoic acid (PFOA) degradation under ambient conditions. The PEC-PMS system with the sophisticated MoSe<sub>2</sub>/TiO<sub>2</sub> photoelectrode demonstrated 93.6% PFOA removal within 40 minutes. Density functional theory (DFT) calculations revealed enhanced PFOA adsorption on MoSe<sub>2</sub>/TiO<sub>2</sub> (E<sub>ads</sub> = -4.25 eV) compared to TiO<sub>2</sub> (E<sub>ads</sub> = -0.89 eV). Furthermore, the Mo<sup>4+</sup>/Mo<sup>5+</sup> redox pairs promote PMS activation to accelerate reaction kinetics. The quenching experiments and electron paramagnetic resonance spectra elucidated the crucial role of electrons (63.7%) and superoxide radicals (42.2%) during the degradation. Moreover, DFT calculations and intermediate product analyses clarified the main degradation pathway of PFOA. PFOA reacted with electrons to generate C<sub>7</sub>H<sub>15</sub>· (Gibbs free energy, ΔG = -0.267 eV/mol), which was subsequently oxidized by superoxide radicals (ΔG = -4.379 eV) to form short-chain PFAS. Overall, our investigations achieved efficient PFOA elimination under air conditions and clarified their degradation mechanisms, providing a new perspective for the treatment of PFAS-contaminated wastewater.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"197 1","pages":""},"PeriodicalIF":11.4000,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2025.124182","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Direct oxidation of per- and polyfluoroalkyl substances (PFAS) necessitates excessive energy or prolonged treatment, while reductive defluorination effectively cleaves C-F bonds. However, strict anaerobic requirements hinder its practical implementation. Herein, a photoelectrocatalytic-peroxymonosulfate (PEC-PMS) integrated system was developed for perfluorooctanoic acid (PFOA) degradation under ambient conditions. The PEC-PMS system with the sophisticated MoSe2/TiO2 photoelectrode demonstrated 93.6% PFOA removal within 40 minutes. Density functional theory (DFT) calculations revealed enhanced PFOA adsorption on MoSe2/TiO2 (Eads = -4.25 eV) compared to TiO2 (Eads = -0.89 eV). Furthermore, the Mo4+/Mo5+ redox pairs promote PMS activation to accelerate reaction kinetics. The quenching experiments and electron paramagnetic resonance spectra elucidated the crucial role of electrons (63.7%) and superoxide radicals (42.2%) during the degradation. Moreover, DFT calculations and intermediate product analyses clarified the main degradation pathway of PFOA. PFOA reacted with electrons to generate C7H15· (Gibbs free energy, ΔG = -0.267 eV/mol), which was subsequently oxidized by superoxide radicals (ΔG = -4.379 eV) to form short-chain PFAS. Overall, our investigations achieved efficient PFOA elimination under air conditions and clarified their degradation mechanisms, providing a new perspective for the treatment of PFAS-contaminated wastewater.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.