Soil Microbial Fuel Cells Using Co-MnO2/C as an Effective Air–Cathode Catalyst

Microbial fuel cells (MFCs) use biomass as fuel and are expected to improve domestic waste treatment issues while producing bioelectricity. However, MFC technology has many unsolved challenges, such as low power output. This study used a soil microbial fuel cell (SMFC) that uses activated carbon sheets to fabricate the electrodes. We adopted Co-MnO2/C as a catalyst to improve the catalytic activity of the air cathode. The air cathode with the catalyst was evaluated by cyclic voltammetry measurements. The SMFC was also evaluated by measuring the power density. The SMFC with the air cathode loaded the catalyst showed a maximum power density of 1 µW/cm2, while that of the SMFC with the air cathode without the catalyst was 0.45 µW/cm2. In other words, the air cathode with catalyst showed about twice the output power density as the air cathode without catalyst. In addition, the 500 h experimental result confirmed the long-term stability of the catalyst. This study suggests that the use of the fabricated catalyst can improve SMFC output.