کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6465925 | 1422958 | 2017 | 10 صفحه PDF | دانلود رایگان |
- Photoelectro-oxidation of diclofenac was largely enhanced with persulfate addition.
- Cu2O was identified at copper cathode by in situ Raman technique.
- Activation mechanism of persulfate to SO4â at copper cathode was proposed.
In this work, persulfate (S2O82â, PS) was introduced to the photoelectrocatalytic (PEC) system, which consisted of a γ-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 hâ1 to 1.0498 hâ1. Active free radicals involving SO4â 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 S2O82â addition, which was further confirmed by the photoelectrochemical analysis of the cathode. The surface Cu(0)-Cu(I)-Cu(II)-Cu(0) redox cycle of cathode was proposed, which was responsible for the persulfate activation, leading to the generation of free radicals. This work may provide a new perspective on the combined utilization of different technologies for catalytic contaminant removal.
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Journal: Chemical Engineering Journal - Volume 320, 15 July 2017, Pages 168-177