Amplifying power generation in microbial fuel cells with cathode catalyst of graphite-based nanomaterials

Low catalytic activity, scarcity of resources, design complexity, high cost, and unfavourable nature of non-traditional metal and its composites limit their utilization as cathodes in microbial fuel cells (MFCs). This research aimed to identify the most effective new cathode catalyst for use in one chamber air cathode microbial fuel cells by comparing two graphite-based nanomaterials of Reduced Graphene Oxide Hydrogen iodide - Acetic acid (rGO_HI-AcOH) and Reduced Graphite Oxide Nickel Nanoparticles (rGO/Ni) composite. The behavior of microbial fuel cells was calculated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Since the rGO_HI-AcOH cathodes were more efficient, the MFCs produced maximum power (>37%) than the rGO/Ni Nanoparticles cathode MFCs. The double loading (DL) rGO_HI-AcOH cathodes in the Microbial Fuel Cells produced the maximal power densities at 1691 ± 34 mW/m² (CE = 73 ± 5%), covering 78% of the power densities calculated for Platinum/Carbon (Pt/C) (2203 ± 52 mW/m²; CE = 82 ± 3%). With a double catalyst load, MFCs using rGO/Ni Nanoparticles composite anodes produced more power than the others (1016 ± 31 mW/m², CE = 71 ± 3%). Excellent concordance was seen between CV and EIS and the MFC findings. Based on the results of this research, the rGO_HI-AcOH cathode loaded with two catalysts has the potential to produce long-lasting, environmentally friendly materials at low cost and maintain consistent power output and the reliable operation of MFCs throughout their useful lifetimes.