Ultra-Fast Electrochemical Oxidation of Norfloxacin on Copper-Doped Ti/SnO2–Sb Anodes: Influencing Factors and Degradation Pathways

Abstract The sol-gel approach was utilized to make a copper-doped Ti/SnO 2 -Sb anode for electrochemical oxidation of norfloxacin (NOR). Sycanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), linear scan voltammograms (LSV), and cyclic voltammetry (CV) were used to examine the anode’s surface morphology and electrochemical characteristics. The results show that the doped metal makes the anode coating denser and smoother, which is more conducive to resistance to electrochemical corrosion. The electrochemical degradation of NOR utilizing the constructed anode was examined in relation to reaction circumstances such as current density, pH value, and initial NOR concentration. Within the selected range of reaction conditions, the removal rate of NOR using Ti/SnO 2 –Sb–Cu electrode was significantly higher than that of blank electrode. The following were the shifting trends: NOR removal efficiencies grew with applied current density and initial NOR concentration, and reduced with increasing pH value. Water samples with different reaction times were taken and tested by UV-Vis spectrum. As can be seen from the results, with the progress of the reaction, the intensity of the characteristic peak decreased, indicating that NOR is degraded gradually. The electrochemical degradation pathways of NOR were studied using liquid chromatography coupled with mass spectrometry (LC-MS). Six intermediates were detected and a possible reaction pathway for the degradation of NOR by electrochemical oxidation was proposed.