title: Dechlorination of Trichloroacetic Acid Using a Noble Metal-Free Graphene-Cu Foam Electrode via Direct Cathodic Reduction and Atomic H.
abstract: A three-dimensional graphene-copper (3D GR-Cu) foam electrode prepared by chemical vapor deposition method exhibited superior electrocatalytic activity toward the dechlorination of trichloroacetic acid (TCAA) as compared to the Cu foam electrode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that GR accelerated the electron transfer from the cathode surface to TCAA. With the applied cathode potential of -1.2 V (vs SCE), 95.3% of TCAA (500 μg/L) was removed within 20 min at pH 6.8. TCAA dechlorination at the Cu foam electrode was enhanced at acidic pH, while a slight pH effect was observed at the GR-Cu foam electrode with a significant inhibition for Cu leaching. The electrocatalytic dechlorination of TCAA was accomplished via a combined stepwise and concerted pathway on both electrodes, whereas the concerted pathway was efficiently promoted on the GR-Cu foam electrode. The direct reduction by electrons was responsible for TCAA dechlorination at Cu foam electrode, while at GR-Cu foam electrode, the surface-adsorbed atomic H* also contributed to TCAA dechlorination owing to the chemical storage of hydrogen in the GR structure. Finally, the potential applicability of GR-Cu foam was revealed by its stability in the electrocatalytic dechlorination over 25 cycles.
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.|University of Chinese Academy of Sciences , Beijing, 100049, P. R. China.
authors.forename: Ran
authors.initials: R
authors.lastname: Mao
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.|University of Chinese Academy of Sciences , Beijing, 100049, P. R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.
authors.forename: Huachun
authors.initials: H
authors.lastname: Lan
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.|University of Chinese Academy of Sciences , Beijing, 100049, P. R. China.
authors.forename: Meng
authors.initials: M
authors.lastname: Sun
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry; D058266:Dielectric Spectroscopy; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry; D054879:Halogenation; D006859:Hydrogen / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D014238:Trichloroacetic Acid / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D010165:Palladium; D014238:Trichloroacetic Acid; D006108:Graphite; D003300:Copper; D006859:Hydrogen