Sustainable Bio-Energy Production in Microbial Fuel Cell Using MnO2 Nanoparticle-Decorated Hollow Carbon Nanofibers as Active Cathode Materials

The widespread use of renewable energy remains a challenging and complex multidisciplinary problem. Developing alternatives using new technology such as nanotechnology is necessary to increase renewable energy’s scalability. Microbial fuel cells (MFCs) combined with nanotechnology can improve bioelectricity generation during wastewater treatment. In this study, hollow carbon nanofibers (H-CNF) were decorated with manganese oxide (MnO2) via a simple chemical reduction method. MnO2-decorated H-CNF prepared with varying concentrations of manganese precursor (MnO2@H-CNF) were characterized via different spectroscopic and microscopic techniques. The cathode catalyst performance of the MnO2@H-CNF was investigated in an //-type constructed MFC system using Shewanella Oneidensis MR1. The MnO2@H-CNF-1 in the assembled MFC displayed excellent power density of 25.7 mW/m2, which is higher than pure H-CNF (8.66 mW/m2), carbon cloth (5.10 mW/m2), and MnO2@H-CNF-3 (16 mW/m2). The maximum power generated in the MFC coupled with MnO2@H-CNF as a cathode catalyst may have been due to the synergistic effect of the MnO2@H-CNF, which increased the electric conductivity and catalytic activity in the MFC’s cathode chamber. These results demonstrate that the developed MnO2@H-CNF cathode catalyst could improve the MFC’s performance and reduce the operational costs of practical applications.