Degradation of trichloroethylene by photoelectrochemically activated persulfate. (September 2020)

• Record Type: Journal Article
• Authors: Peng, Yen-Ping; Peng, Ling-Chen; Chen, Ku-Fan; Chen, Chia-Hung; Chang, Ken-Lin; Chen, Kang-Shin; Dang, Zhi; Lu, Gui-Ning; Sun, Jian
• Is Part Of: Chemosphere. Volume 254(2020)
• Publication Date: 2020-09
• Subjects: Titanium dioxide nanotube arrays -- Photoelectrochemical system -- Persulfate -- Trichloroethylene; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.126796
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Chlorine-containing organic compounds were discharged informally as a result of untreated industrial wastewater, which caused groundwater pollution. In this study, titanium dioxide nanotube arrays (TNAs) were modified with copper oxide to photoelectrochemical (PEC) active persulfate to degrade trichloroethylene (TCE). The SEM results show copper nano-particles with a cubic shape were successfully deposited on the surface of TNAs. The results of UV–vis analysis indicate the absorption wavelengths red-shift to 550–600 nm for better light utilization. CuO/TNAs were dominated by the anatase phase after sintering at 450 °C with significant visible light response. The chemical contents for the surface of CuO/TNAs are 23.7, 53.4, 18.4 and 4.4% for C, O, Ti and Cu, respectively. The photocurrent of CuO/TNAs is 1.89 times higher than that of TNAs-93 cm^2–1hr under 100 W Hg-lamp illuminations. This demonstrates the efficiency of light utilization of TNAs was improved by the modification with copper nanoparticles. The degradation rate of TCE in the anodic chamber is more effective than that in the cathodic chamber because of the synergistic effect of hydroxyl and sulfate radicals. The mechanism of TCE degradation via persulfate in the PEC system was proposed and discussed in detail. Graphical abstract: Image 1 Highlights: CuO/TNAs was synthesized successfully via square wave voltammetry electrochemical deposition method. Recombination of photo-generated holes and electrons were greatly reduced. TCE degradation was enhanced by synergetic effect of OH⋅ and SO4 − . Mechanism of TCE degradation via persulfate in PEC system was proposed.