Performance of graphite felt as a cathode and anode in the electro-Fenton process

Abstract

Choosing an electrode material with good performance and low cost is of great significance for the practical application of the electro-Fenton process. In this study, graphite felt was systematically studied to determine its application performance in an electro-Fenton system. The influence of operating parameters, pH and voltage, on the H₂O₂ yield and the evolution of iron ions was investigated, which helped to select the optimal parameter values. The removal rate of methylene blue was 97.8% after 20 min electrolysis under the conditions of 7 V voltage and pH 3. Inhibition experiments showed the graphite felt E-Fenton system mainly relied on the indirect oxidation of ·OH and the direct oxidation of the graphite felt anode to degrade the methylene blue. The graphite felt showed good stability as a cathode during repeated use, but the anode conductivity and catalytic performance were decreased, and the adsorption performance was enhanced. Finally, the graphite felt electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS) to preliminarily analyze the reason for the change in anode performance.