Enhancement of photoelectrocatalytic degradation of diclofenac with persulfate activated by Cu cathode

By Liu, Shanshan; Zhao, Xu; Zeng, Huabin; Wang, Yanbin; Qiao, Meng; Guan, Wei
Published in Chemical Engineering Journal NULL 2017

Abstract

Abstract In this work, persulfate (S2O82?, PS) was introduced to the photoelectrocatalytic (PEC) system, which consisted of a ?-Bi2MoO6 photoanode and a copper foil cathode (Bi2MoO6/Cu/PEC/PS system). Significant enhancement of diclofenac sodium (DCF) degradation efficiency was observed in this system under visible light irradiation. At an applied bias of 1.5 V and initial solution pH of 5.62, the removal efficiency of {DCF} with an initial concentration of 10 mg/L was increased from 19.4% in the {PEC} process to 86.3% in the {PEC} process with 10 mM {PS} addition. The pseudo-first-order kinetic rate constant of {DCF} degradation was increased from 0.1112 h?1 to 1.0498 h?1. Active free radicals involving SO4? and {HO} were produced in this process, which were confirmed by electron spin resonance analysis. Furthermore, the surface variation of copper foil cathode was characterized by FE-SEM, GI-XRD, {XPS} and in situ Raman spectroscopy. It was demonstrated that Cu2O formed on the surface in the reaction process with the S2O82? addition, which was further confirmed by the photoelectrochemical analysis of the cathode. The surface Cu(0)

Read » Back