Photochemical pollutant degradation on facet junction-engineered TiO 2 promoted by organic arsenical: Governing roles of arsenic-terminated surface chemistry and bulk-free radical speciation.

Autor: Zhang AY; Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China. Electronic address: ayzhang@hfut.edu.cn., Zhou Y; Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China., Liu X; Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China., Huang NH; Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, 230009, China., Niu HH; School of Electrical Engineering and Automation, Hefei University of Technology, Hefei, 230009, China.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2020 May 15; Vol. 390, pp. 122159. Date of Electronic Publication: 2020 Jan 21.
DOI: 10.1016/j.jhazmat.2020.122159
Abstrakt: Photochemical oxidation based on semiconducting metal oxides is an efficient strategy to remove environmental pollutants in water, air and soil. The fine manipulation of photo-carriers separation, surface chemistry and radical speciation is of considerable interest for environmental remediation. In this work, the morphology- and structure-tailored TiO 2 single crystals with epitaxial {101}/{001} facet junction were designed, prepared and tested for photochemical pollutant oxidation in the presence of organic arsenicals, the main component in swine wastewater from livestock industry, although they have been forbidden for several years. The facet junction-tailored TiO 2 deserved an efficient photo-carriers separation with high quantum efficiency. The photochemical oxidation of 4-chlorophenol (4-CP), phenol and bisphenol A (BPA) was substantially improved by roxarsone (ROX). ROX-enhanced photochemical activity of TiO 2 was mainly attributed to the in-situ arsenic-terminated surface chemistry by Ti-OAs V O 3 /-OAs III O 2 . This surface played governing roles in water/TiO 2 interactions, and changed water adsorption from dissociative to molecular configuration. Furthermore, ·OH was finely regulated from low-activity surface-bound to high-activity bulk-free speciation between as-generated photo-holes with free water molecules. Our findings provided a new chance to refine the TiO 2 -based photochemical oxidation, and a modifying technology to treat swine wastewater from livestock industry with much reduced secondary pollution.
Competing Interests: Declaration of Competing Interest The authors declared that they have no conflicts of interest to this work.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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