Catalytic performance of nano-hybrid graphene and titanium dioxide modified cathodes fabricated with facile and green technique in microbial fuel cell

Finite resources of the world's fossil fuel give rise to the irresistible urge to explore alternative renewable energy routes such as microbial fuel cells (MFCs). The limited productivity is one of the main obstacles for MFC scalability. In this study, a dual-chamber MFC was assembled and equipped with fabricated modified cathodes with titanium dioxide (TiO2) or hybrid graphene (HG) which mainly improved the catalytic activity of the cathode. The graphite paste (GP) bare electrode was modified by both nanomaterials using a green and facile technique. The results showed that the modified cathodes resulted in a considerable improvement for the MFC performance, i.e., the power density reaching levels of 80 mW/m2 for GP-TiO2 and 220 mW/m2 for GP-HG compared to 30 mW/m2 for GP electrode. Additionally, the modified electrodes exhibited lower charge transfer resistance (Rct) compared to the bare electrode. Therefore, these modified electrodes, fabricated by an eco-friendly method, could be used as alternatives to the precious expensive metals like Pt.