Enhancing extracellular electron transfer through selective enrichment of Geobacter with Fe@CN-modified carbon-based anode in microbial fuel cells

Abstract

Microbial fuel cells (MFCs) have been demonstrated as a renewable energy strategy to e ciently recover chemical energy stored in wastewater into clean electricity by exoelectrogens through a combination of microbial metabolism and electrochemical processes, yet the limited power density limits their application. Here, Fe coped carbon and nitrogen (Fe@CN) nano-material was synthesized by direct pyrolysis of FeCl 3 and urea, which was further decorated to fabricate Fe@CN modi ed carbon paper anode to improve the bioelectrochemical performance of MFCs. With a higher electrochemically active surface area, the Fe@CN modi ed anode was bene cial for enhancing microorganisms adhesion and extracellular electron transfer (EET). Accordingly, the MFC with Fe@CN modi ed anode (MFC-Fe@CN) successfully achieved a highest voltage output of 792.76 mV and a prolonged stable voltage output of 300 h. Interestingly, Geobacter species (15.41% abundance) was signi cantly enriched in the EABs of MFC-Fe@CN, while MFC-CP (unmodi ed carbon paper anode) favored the other exoelectrogens (Dysgonomonas and Comamonas). This work demonstrated the feasibility of development on anode catalysts for the elaboration of the catalytic principle about interface modi cation, which may contribute to the practical application of MFC in energy generation and wastewater treatment.