Enhanced efficiency in organic wastewater treatment by synergetic cathodic produced H2O2 and anodic oxidation

Microbial Fuel Cells (MFCs) are bioelectrochemical devices that use microorganisms to oxidize organic compounds at the anode, pairing with cathodic oxidation-reduction reaction. Here, we propose an innovative MFCs that integrates anodic organic degradation with H2O2 production at the cathode through the two-electron oxygen reduction reaction(2e-ORR), facilitating direct disinfection of anode water. To this end, a highly efficient In2O3/rGO-2 catalyst toward the 2e−ORR has been designed and prepared as the cathode of MFCs, achieving a remarkable 100 % Faraday efficiency for H2O2 production in a gas diffusion electrode-based flow electrolytic cell. In situ FTIR and Density Functional Theory calculations reveal that this favorable 2e−ORR activity operates through a multi-channel mechanism. Moreover, the gas diffusion electrode-based flow MFCs demonstrates the capability to produce H2O2 at a rate of 14.84 mg L−1 h−1 while achieving a power density of 1455.82 mW m−2. Notably, the generated H2O2 is particularly effective for disinfecting the anode effluent.