A new method to fabricate the cathode by cyclic voltammetric electrodeposition for electro-Fenton application

To develop a stable and efficient cathode applied in electro-Fenton is indispensable. In current study, the carbon felt (CF) was modified by the cyclic voltammetric (CV) electrodeposited anthraquinone 2-sulfonate (AQS) and polypyrrole (PPy). The newly fabricated CF/AQS/PPy cathode by CV electrodeposition method was applied in electro-Fenton, which showed higher stability and efficiency compared with that of the traditional potentiostatic electrodeposited (TPED) method. The yield of the electro-generated H2O2 and the degradation efficiencies of the target pollutant (RhB) in electro-Fenton with the newly fabricated cathode were around 10 times and 5 times higher than those of the unmodified CF cathode respectively. Recyclability evaluation showed that the degradation efficiency kept a good stability and could reach 100% within 1 h reaction time. The significantly enhanced performance and stability were attributed to the reduced charge transfer resistance (Rct) of the fabricated CF/AQS/PPy cathode decorated by the high conductive PPy and catalytic activity of AQS for oxygen reduction. The modification could result in an elevated extent of oxygen reduction to generate more O-2(center dot-), which subsequently combined with the protons to produce H2O2, the indispensable reactant to form reactive OH center dot in the Fenton's process. The quenching experiment and EPR determination further confirmed the existence of OH center dot and O-2(center dot-) free radicals in electro-Fenton equipped with the newly fabricated cathode. (c) 2020 Elsevier Ltd. All rights reserved.