Performance of Modified Graphite Felt as Cathode in the Electro-Fenton System

Abstract

The graphite felt (GF) was modified by the impregnation method and the potentiostatic oxidation method to improve its application performance in the electro-Fenton (E-Fenton) system. Sulfuric acid and ammonia water were used as modifying reagents. After the GF was modified, its conductivity, adsorption performance and hydrogen peroxide production performance were improved. The original graphite felt (GF0) and the modified GF were used as cathode to degrade methylene blue in the E-Fenton system to explore the practical application performance. The reaction kinetics of the methylene blue degradation process was fitted. The results showed the degradation of methylene blue followed the first-order kinetics. The GF was modified by the potentiostatic oxidation with ammonia as modifying reagent (GFEN) had the best application performance in the E-Fenton system. Degradation of methylene blue for 30 min, the reaction rate constant of GFEN cathode system was 1.71 times higher than GF0 cathode system. The GFEN electrode was reused 10 times in the E-Fenton system, the removal rate of methylene blue was only decreased by 7.14%, and the current was only decreased by 4 mA, which showed its good stability. Finally, the comparison of the electrical energy per order (EE/O) values showed that GFEN can significantly improve the current efficiency of the E-Fenton system.