Preparation of electrocatalytic KC-GR/GF membrane cathode and its application in electro-Fenton

Tetracycline is a common antibiotic that threatens the water environment and requires more stable and efficient ways to degrade it. In this paper, a novel filtered cathode material was prepared by proportionally loading Ketjen Black Carbon (KC) and Graphene (GR) onto Graphite Felt(GF) by coating method, and applied to remove tetracycline from water by electro-Fenton system. The results showed that the highest hydrogen peroxide yield of up to 28.86 mg/L was achieved at the electrodes prepared with a carbon loading of 0.228 g, m (KC):m(polytetrafluoroethylene) = 1:9, and m (KC):m (GR) = 2:2. By characterisation, the contact angle of the loaded graphite felt electrode increased from 71.5° to 126.3°, with faster current responsiveness and larger electrochemically active area than the unloaded electrode. Furthermore, in the application of electro-Fenton: when I = 100 mA, Air = 0.45 L/min, pH = 3 and Fe2+ = 0.3 mol/L, the optimal removal rate of 50 mg/L tetracycline was 99.1%, and the energy consumption was only 8.49 kWh/kg. This electrode has a great advantage in treating the low concentration of tetracycline, and 99.4% of tetracycline can be removed within 30 min. After 8 cycles of tests, the removal rate of tetracycline by this electrode was above 95%. The article demonstrated that the reactor coupled with electrochemical advanced oxidation technology and membrane filtration technology has the effect of enhanced mass transfer, and the Ketjen Black Carbon-Graphene/Graphite Felt (KC-GR/GF) electrocatalytic membrane cathode has the potential and practical significance to be applied for the removal of tetracycline under the electro-Fenton system.