Novel rolling-made gas-diffusion electrode loading trace transition metal for efficient heterogeneous electro-Fenton-like

A novel rolling-made gas-diffusion electrode loading with trace transition metal (M/GDE, M = Cu, Ce, Mn, Fe, Co) was prepared and used as cathode in heterogeneous electro-Fenton-like (EF-like) for methyl orange (MO) degradation. The rolling-made GDE showed a good activity and stability for H2O2 production, with a H2O2 concentration of 595 mg/L at 120 min and variation within 3.36% even after 10 times reuses. The effect of five metals and their loading contents on MO degradation were investigated, and the Co/GDE showed the highest activity when the loading content of Co was 0.7 wt%. Particularly this activity showed good stability toward pH variation (3-9), demonstrating promising advantage of this heterogeneous EF-like for application. Further it was proved that hydroxyl radical played an important role on pollutants degradation, and a possible degradation scheme for heterogeneous EF-like on Co/GDE was proposed based on the results and characterizations such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD).