Effective degradation of tetracycline by Pd/AG/ITO electrode: Electrode preparation, characterization, kinetics, degradation mechanism and toxicity assessment

The presence of antibiotics such as Tetracycline (TC) in the water environment poses new challenges to traditional water treatment technologies . Simple and clean electrocatalytic technology has been widely used in the degradation of antibiotic-based wastewater. In this study, agarose (AG) was loaded onto ITO using an impregnation method, and Pd was deposited onto the AG/ITO electrode by electrodeposition , the Pd/AG/ITO composite electrode was prepared. The electrode was then observed and analyzed using SEM , XRD , FT-IR, and XPS . The optimal conditions for the electrocatalytic reaction were explored as follows: PdCl 2 concentration of 0.20 mmol/L, PdCl 2 deposition current of 3 mA, deposition time of 10 min, and degradation current of 8 mA. Under these optimal working conditions, the Pd/AG/ITO composite electrode achieved a degradation efficiency of 85.21% within 120 min. Through five replications, the degradation efficiency of the electrodes decreased by less than 3.50%, which indicated its good reusability and stability. Based on the generation of active substances during degradation and the analysis of LC-MS, potential degradation products , and degradation pathways were deduced, and it was proposed that the degradation of TC was completed by a synchronous redox reaction co-led by·OH and H*. Toxicity analysis of TC and its degradation products was performed using ECOSAR software. This study will promise to provide an effective method of degrading TC wastewater.