Modified carbon felt made using CexA1−xO2 composites as a cathode in electro-Fenton system to degrade ciprofloxacin†
Abstract
Carbon felt (CF) was modified by CexA1−xO2 (A = Zr, Cu and Ni) and the role of these CexA1−xO2/CF (A = Zr, Cu and Ni) cathode materials in the oxidative degradation of antibiotic ciprofloxacin (CIP) was investigated in the electro-Fenton system. SEM, BET, TEM, XPS, TOC, HPLC-MS, CV and EIS were used to understand the characteristics of these cathode materials. The CIP degradation efficiency of the CexA1−xO2/CF (A = Zr, Cu and Ni) cathode was better than that of pure CF, and 2.0 wt% Ce0.75Zr0.25O2/CF was the most effective cathode material for degradation of CIP. It reached 100% degradation efficiency of CIP after 1 h and almost total mineralization (97.45%) after 6 h, owing to synergistic effects from the predominant role of homogeneous ˙OH produced electrocatalytically through the Fenton reaction of Fe2+ and H2O2 and heterogeneous ˙OH produced via the Fenton-like reaction of Ce3+ and H2O2 and the electrocatalytic activity of Ce0.75Zr0.25O2 composite and the strong electrosorption of carbon felt. A possible path of CIP degradation was proposed in the paper.