Sulfuration of Fe-N/C porous nanosheets as bifunctional catalyst with remarkable biocompatibility for high-efficient microbial fuel cells

The development of efficient electrode catalysts is of great significance for the evolution of microbial fuel cells (MFCs). In this work, Fe, N, and S co-doped porous carbon nanosheets (Fe-N-S/C) are synthesized by hightemperature sulfuration from Fe and N co-doped carbon (Fe-N/C). Fe-N-S/C not only exhibits superior oxygen reduction activity than Pt/C (20%) with a half-wave potential of 0.86 V, but also exhibits remarkable biocompatibility while facilitating electron transfer between microorganism and electrode. Satisfactorily, the MFCs with Fe-N-S/C as the catalysts for both cathode and anode show outstanding performance with a maximum power density of 923 +/- 21 mW m- 2 and favorable durability after 30 days of operation. Furthermore, 16srDNA results confirm that Fe-N-S/C effectively promotes the growth of functional colonies in anode biofilms, leading to high-efficient electricity production. The development of bifunctional electrode materials in this study can improve the performance of MFCs and facilitate their practical application.