Electron-hole separation and microcell-activated peroxymonosulfate driven by Mo/ZnO/NiF@GO/ZnFe2O4/CC dual electrodes for photocatalytic oxidation degradation of tetracycline hydrochloride

Abstract

Mo/ZnO/NiF@GO/ZnFe2O4/CC photo-electrochemical catalyzed oxidation system was developed for efficiently degrading tetracycline hydrochloride (TC-HCl) by enhanced photocatalytic action. Multifunctional dual electrodes served as oxidation interface and electron transport medium exhibited inconsistent morphology, promoting more catalytic reactions at active sites, photo-electro-catalytic activity and exchange current density of the novel electrodes prepared by hydro-deposition were revealed by Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Linear sweep voltammetry techniques. indicating the photoanode approximation to two-electron Oxygen Reduction Reaction at a voltage of about 0.11 V, thus producing H2O2 with oxidizing properties. Constructed system assisted by dual electrodes achieved efficient separation of electron-hole and microcell-activated peroxymonosulfate (PMS). Experimental results demonstrated the remarkable efficiency of the system (＞ 97.0 % for 20 mg/L TC-HCl in 20 min) under optimized conditions (0.2 mM PMS, R = 1800 Ω).The reusability and stability of the system are verified by cyclic experiments. The abiotic toxicity of the intermediates was analyzed and speculated, and the recommended degradation pathways and mechanisms of TC-HCl were elucidated. The experimental system is stable, efficient and an environmentally friendly method for pollution treatment.