Coupling reaction of electrocatalytic anode and Ni/MWCNTs-COOH/Ti cathode drives the efficient degradation of doxycycline hydrochloride

The extensive application of doxycycline hydrochloride (DOX) in cultivation industry concerns regarding its potential ecological ramifications. Electrocatalysis has emerged as a safe and efficient method for antibiotic removal from water. In this study, Ni/MWCNTs-COOH/Ti composite electrodes were prepared using anodic oxidation and constant-current electrodeposition techniques for the cathodic electrocatalytic degradation of DOX. The electrodes were characterized and evaluated using SEM, XRD , and XPS analysis . Under optimized conditions, 75.49 % of DOX was eliminated within 60 min with an energy consumption of 0.66 kWh/m 3 . Even after ten successive degradation cycles, the degradation rate of DOX remained at 70.78 %, confirming the exceptional stability of the electrodes. LC-MS analysis was employed to identify intermediates formed during the DOX degradation process. The results revealed that the hybrid orbital coordination structure formed by vacant d orbitals and d orbitals on the exoelectronic structure of Ni enhances catalytic activity and electrochemical stability. And the exposed reactive groups on the outer surface of MWCNTs-COOH, acting synergistically with Ni. Furthermore, the composite cathode generates reactive H ⁎ and the anode generates ·OH, resulting in a synergistic coupling that further enhances catalytic activity. This study presents a novel approach for addressing antibiotic contamination through environmental remediation.