title: Highly efficient electrochemical degradation of perfluorooctanoic acid (PFOA) by F-doped Ti/SnO2 electrode.
abstract: The novel F-doped Ti/SnO2 electrode prepared by SnF4 as the single-source precursor was used for electrochemical degradation of aqueous perfluorooctanoic acid (PFOA). Higher oxidation reactivity and significantly longer service life were achieved for Ti/SnO2-F electrode than Ti/SnO2-X (X=Cl, Br, I, or Sb) electrode, which could decomposed over 99% of PFOA (50 mL of 100 mg L(-1)) within 30-min electrolysis. The property of Ti/SnO2-F electrode and its electrooxidation mechanism were investigated by XRD, SEM-EDX, EIS, LSV, and interfacial resistance measurements. We propose that the similar ionic radii of F and O as well as strong electronegativity of F caused its electrochemical stability with high oxygen evolution potential (OEP) and smooth surface to generate weakly adsorbed OH. The preparation conditions of electrode were also optimized including F doping amount, calcination temperature, and dip coating times, which revealed the formation process of electrode. Additionally, the major mineralization product, F(-), and low concentration of shorter chain perfluorocarboxylic acids (PFCAs) were detected in solution. So the reaction pathway of PFOA electrooxidation was proposed by intermediate analysis. These results demonstrate that Ti/SnO2-F electrode is promising for highly efficient treatment of PFOA in wastewater.
authors.affiliation: Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China; School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China. Electronic address: boyang@szu.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Chaojin
authors.initials: C
authors.lastname: Jiang
authors.affiliation: School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China. Electronic address: yg-den@tsinghua.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.affiliation: South China Institute of Environmental Sciences, The Ministry of Environment Protection, Guangzhou 510655, PR China.
authors.forename: Qiongfang
authors.initials: Q
authors.lastname: Zhuo
authors.affiliation: School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.affiliation: School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
keywords: Electrochemical degradation; F doping; PFOA; Ti/SnO(2) electrode