title: In-situ generated H₂O₂ induced efficient visible light photo-electrochemical catalytic oxidation of PCP-Na with TiO₂.
abstract: In this study, we developed a novel photo-electrochemical catalytic oxidation wastewater treatment system by interacting the cathodic in-situ generated H₂O₂ with TiO₂ suspension to form interfacial ≡ Ti(IV)OOH species, which endowed the PEC system with superior efficiency for degrading sodium pentachlorophenate (PCP-Na) under visible light irradiation at neutral pH. The apparent PCP-Na degradation rate constant of the PEC system was more than 10 times that of the electrochemical oxidation counterpart. In the PEC system, the interfacial ≡ Ti(IV)OOH species injected electrons to the conduction band of TiO₂ to initiate the activation of O₂ and the in-situ generated H₂O₂ adsorbed on the surface of TiO₂, lead to producing reactive oxygen species of superoxide anions and hydroxyl radicals, which were responsible for the dechlorination and mineralization of PCP-Na during the PEC process, respectively. The dosage of TiO₂ catalyst and the current intensity applied on PCP-Na degradation were optimized. This study develops a high efficient PEC oxidation system for wastewater treatment and provides new insight into the role of cathodic in-situ generated H₂O₂ on PEC oxidation of PCP-Na with TiO₂ under visible light irradiation.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China.
authors.forename: Huichao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China. Electronic address: jennifer.ai@mail.ccnu.edu.cn.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Ai
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D006861:Hydrogen Peroxide / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D010084:Oxidation-Reduction; D010416:Pentachlorophenol / Q000737:chemistry* / Q000528:radiation effects*; D055668:Photochemical Processes; D017382:Reactive Oxygen Species / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium; D010416:Pentachlorophenol
keywords: H(2)O(2); PCP-Na; Photo-electrochemical catalysis; TiO(2); Visible light irradiation