Effect of Modified MnO2 Anodes on the Electrolytic Effect of Doxycycline Hydrochloride

To effectively degrade antibiotics, a series of MnO₂ modified electrodes were prepared by using a thermal decomposition method in this study. The corrosion resistance of the coated electrodes was evaluated by characterizing the microscopic morphology of the electrodes using scanning electron microscopy (SEM). Moreover, electrochemical tests, including cyclic voltammetry (CV) curves, linear sweep voltammetry (LSV) curves, as well as alternating-current (AC) electrochemical impedance spectroscopy (EIS), were applied to study the electrocatalytic ability of the electrode for the degradation of doxycycline hydrochloride in simulated wastewater. Based on the findings, the MnO₂/CuO-mesoporous silica (SBA)-15 electrode displayed a long lifetime and excellent catalytic performance. The peroxynitrite (PMS) was further combined with above electrodes to construct an electrocatalytic oxidation (EC) system for the removing of doxycycline hydrochloride from wastewater. Under optimized conditions (current density of 30 mA/cm², initial pH of 5, PMS dosing of 350 mg/L), the MnO₂/CuO-SBA-15/PMS system can remove 79.44% doxycycline hydrochloride (initial concentration of 20 mg/L) after 180 min of electrolysis, 24.71% higher than that in the MnO₂/PMS system.

Graphical Abstract