Electro-peroxone degradation of metamitron using a gas diffusion cathode with ZIF-derived heteroatom-doped porous carbon as the catalytic layer

Electro-peroxone (EP) is a new advanced oxidation water treatment technology that combines electrocatalysis and ozonation. The development and utilization of efficient composite cathode is a key factor for the improvement of oxygen reduction reaction (ORR) in EP process. Herein, a novel gas diffusion electrode (GDE) with the nickel foam (NF) as the substrate. The Co, N-FLC@CNT as the catalytic layer (Co, N-FLC@CNT/GDE) was fabricated by a coating method. Metamitron in the aquatic environment is capable of damaging non-target organs and poses a serious threat to human drinking water sources and health. The EP performance of Co, N-FLC@CNT/GDE was analyzed using metamitron as a model pollutant. Metal catalysts divalent cobalt ions (Co2+) or divalent zinc ions (Zn2+) promote the production of H2O2. Under the optimal process conditions, the metamitron removal and COD removal reached 94.74 and 62.22 %, respectively. Using Co, N/FLC@CNT/GDE that can effectively convert O2 to H2O2, the EP process degraded metamitron much more effectively than conventional ozonation and electrolysis processes. The study proves that the Co, N/FLC@CNT/GDE has a broad prospect for use in EP.