Fe-based layered double hydroxides carbon cathode modulates oxygen reduction pathways and HO formation mechanism in electro-peroxone system

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology Pub Date : 2025-02-21 DOI:10.1016/j.seppur.2025.132212

Zekun Dong, Jiao Yang, Jie Yao, Yu Tang, Yan Zhang

{"title":"Fe-based layered double hydroxides carbon cathode modulates oxygen reduction pathways and HO formation mechanism in electro-peroxone system","authors":"Zekun Dong, Jiao Yang, Jie Yao, Yu Tang, Yan Zhang","doi":"10.1016/j.seppur.2025.132212","DOIUrl":null,"url":null,"abstract":"Electro-peroxone (EP) is an emerging technology that combines electrochemistry and O3 to remove contaminants. However, conventional carbon cathodes primarily contribute to the synthesis of H2O2 in the system, which may scavenge HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/>. Herein, a series of Fe-based layered double hydroxides (LDH) was loaded onto graphite felt cathodes to strengthen the removal of organic contaminants. The EP system with CuFe-LDH/GF cathode (EP-CuFe-LDH/GF) demonstrated the highest removal rate (91.2 % within 20 min) of oxalic acid (OA), a typical ozone-resistance substance, approximately twice that of the EP-GF system. HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/> was identified the main reactive species. A new pathway for O2 reduction and the generation of HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/> was found. The loading of CuFe-LDH altered the reduction pathway of O2 on the GF cathode from 2e− to 1e− or 4e− process. As a result, HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/> was produced by the combination of O3 and O2<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/>− instead of O3 and H2O2, which avoided the quenching of HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/> by H2O2 and enhanced the removal of OA. Moreover, the breaking complexation by O3, cathodic O3 reduction and metal-OH catalyzed O3 processes also contributed to the HO<img alt=\"radical dot\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/rad.gif\" style=\"vertical-align:middle\"/> formation. Furthermore, the system could efficiently remove OA across a broad pH range of 3.0 to 9.0, addressing the poor performance of conventional EP systems under acidic conditions. Overall, the finding of this significant mechanism advances the understanding of organic pollutants removal and broadens the potential applications of EP system.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"25 1","pages":""},"PeriodicalIF":8.1000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Separation and Purification Technology","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.seppur.2025.132212","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Electro-peroxone (EP) is an emerging technology that combines electrochemistry and O₃ to remove contaminants. However, conventional carbon cathodes primarily contribute to the synthesis of H₂O₂ in the system, which may scavenge HO. Herein, a series of Fe-based layered double hydroxides (LDH) was loaded onto graphite felt cathodes to strengthen the removal of organic contaminants. The EP system with CuFe-LDH/GF cathode (EP-CuFe-LDH/GF) demonstrated the highest removal rate (91.2 % within 20 min) of oxalic acid (OA), a typical ozone-resistance substance, approximately twice that of the EP-GF system. HO was identified the main reactive species. A new pathway for O₂ reduction and the generation of HO was found. The loading of CuFe-LDH altered the reduction pathway of O₂ on the GF cathode from 2e⁻ to 1e⁻ or 4e⁻ process. As a result, HO was produced by the combination of O₃ and O₂⁻ instead of O₃ and H₂O₂, which avoided the quenching of HO by H₂O₂ and enhanced the removal of OA. Moreover, the breaking complexation by O₃, cathodic O₃ reduction and metal-OH catalyzed O₃ processes also contributed to the HO formation. Furthermore, the system could efficiently remove OA across a broad pH range of 3.0 to 9.0, addressing the poor performance of conventional EP systems under acidic conditions. Overall, the finding of this significant mechanism advances the understanding of organic pollutants removal and broadens the potential applications of EP system.

Abstract Image

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Separation and Purification Technology 工程技术-工程：化工

CiteScore

14.00

自引率

12.80%

发文量

2347

审稿时长

43 days

期刊介绍： Separation and Purification Technology is a premier journal committed to sharing innovative methods for separation and purification in chemical and environmental engineering, encompassing both homogeneous solutions and heterogeneous mixtures. Our scope includes the separation and/or purification of liquids, vapors, and gases, as well as carbon capture and separation techniques. However, it's important to note that methods solely intended for analytical purposes are not within the scope of the journal. Additionally, disciplines such as soil science, polymer science, and metallurgy fall outside the purview of Separation and Purification Technology. Join us in advancing the field of separation and purification methods for sustainable solutions in chemical and environmental engineering.