Improving the Performance of Microbial Fuel Cells with Modified Carbon Aerogel Based Cathode Catalysts

Abstract

Microbial fuel cells (MFCs) are capable of converting the chemical energy of biodegradable organic matter directly into electricity, thus they can be applied in various fields: waste elimination, biosensor industry and production of renewable energy. In this study, the efficiency of noble metal free carbon aerogel based cathode catalysts was investigated and compared to plain glassy carbon cloth without catalyst (CC ) and platinum containing carbon powder catalyst ( PtC ) in H-type MFCs. Surface extension by carbon aerogel (CA ) enhanced the maximum power density by 34 % compared to CC, to 14.1 W m⁻³. With nitrogen doped carbon aerogel (NCA) the performance was further increased to 15.7 W m⁻³. Co-doping the resorcinol-melamine-formaldehyde based aerogel with graphene oxide (GNCA) resulted in an additional power increase of 70 %, indicating that the electrocatalytic activity of NCAs can be considerably improved by co-doping with graphene oxide. Although the performance of GNCA remained below that of PtC (50.2 W m⁻³) in our investigations, it can be concluded that GNCA based coatings may provide a noble metal free, and therefore competitive and sustainable alternatives for cathode catalysis in MFC based technologies.