A detailed electrochemical study of anti-malaria drug hydroxychloroquine: Application of a highly porous 3D multi-metal oxide carbon felt/β-PbO2-ZrO2−MoOx electrode for its electrocatalytic degradation

In this study, a 3D and porous carbon felt/β-PbO2 anodes has modified by ZrO2−MoOx nanoparticles to enhance the electrocatalytic degradation of hydroxychloroquine (HCQ). Modification of the anode surface with ZrO2−MoOx significantly increased the its active surface area (5.71 m2 g−1 vs. 1.63 m2 g−1) and OEP (2.2 V vs. 1.8 V) so that the efficiency of HCQ degradation after 105 min of reaction by CF/β-PbO2-ZrO2−MoOx and CF/β-PbO2 anodes was 94.2% and 61.2%, respectively. Additionally, in this work, the electrochemical behavior, adsorption activity and E-pH (Pourbaix) response of HCQ at various pH values in the range 1–13 were comprehensively studied by cyclic voltammetry (CV) and differential pulse voltammetry. These studies have led to the proposed mechanism for oxidation pathway of HCQ for the first time. The improved electrocatalytic performance of the CF/β-PbO2-ZrO2−MoOx anode increased the BOD/COD ratio of the pharmaceutical wastewater to more than 0.4 after 180 min, indicating that the treated wastewater is fully biodegradable.