CuxO@Cu mesh electrode with {111} facet for efficient photo-electro-Fenton reaction and low voltage robustness

In this work, CuxO nanoarrays containing Cu2O and CuO with different morphologies were synthesized on the surface of copper mesh by anodic oxidation method, and the prepared CuxO@Cu mesh electrodes were confirmed by X-ray diffraction (XRD), field emission scanning microscope (SEM), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) and photocurrent were used to characterize the composite elec-trode. The photo-electro-Fenton (PEF) catalytic system constructed with the prepared CuxO@Cu electrode anode has excellent H2O2 utilization efficiency and pollutant degradation rate. Degradation efficiency of methylene blue (MB) by electro-Fenton (EF), photo-Fenton (PF) and photo-electro-Fenton (PEF) processes were investi-gated, which was in order: PEF > PF > EF. The effects of applied voltage, current density, pH and H2O2 con-centration on MB degradation were investigated. MB could be quickly degraded at CuxO@Cu electrode during heterogeneous photo-electro-Fenton process with a first-order kinetic constant of 3.61 h-1 under 300 W simu-lated sunlight irradiation at 0.6 V, pH 7.0, 4.9 mmol H2O2. The CuxO@Cu electrode anode was stable and could be reused without catalytic reduction, and also had good degradation efficiency on other organic compounds (p-nitrophenol, tetracycline, norfloxacin), having potential application value in wastewater treatment.