Homogeneous Electro-Fenton Oxidative Degradation of Reactive Brilliant Blue Using a Graphene Doped Gas-Diffusion Cathode

A novel graphene doped gas diffusion electrode (GE/graphite-PTFE GDE) was prepared in this work with graphite powder and PTFE as starting materials. An undivided electro-Fenton system with this self-made GDE as cathode was fabricated to evaluate the activity of GE/graphite-PTFE GDE for H2O2 electro-generation. Compared with bare graphite-PTFE GDE, the electro-generated H2O2 concentration on GE/graphite-PTFE GDE was improved three times and can be reached to ca. 187 mg/L after 3 h electrolysis. The maximum production of H2O2 was obtained at pH 3.0, the current density of 2.0 mA/cm 2 and Mgraphite:MGE:MPTFE = 8:1:2. The influences of operating parameters including solution pH and Fe 2+ concentration were investigated on Reactive brilliant blue (KN-R) removal by the proposed electro-Fenton oxidation process. Under the optimal condition, nearly 80 % of KN-R and 33.3 % total organic carbon (TOC) could be removed after 180 min electrolysis, indicating that the GE/graphite/PTFE GDE was effective in H2O2 electro-generation and the proposed homogeneous electro-Fenton system was effective in KN-R oxidative degradation