Self-assembled cauliflower-like pyrite-S, N co-doped graphene quantum dots as free-standing anode with high conductivity and biocompatibility for bioelectricity production

Ferrous disulfide (FeS2) decorated S, N co-doped graphene quantum dots (S, N GQDs) (FeS2-S, N GQDs), were synthesized using a facile approach involving a straight hydrothermal method and tested as bioanode in acetate feeding microbial fuel cells (MFCs) based on a mixed bacterial culture with superior performances. The physical characterizations FeS2-S, N GQDs corroborate the unique configuration that is desirable for bacteria immobilization and effective electrolyte transport. The electrochemical measurements prove the superior performance of the bifunctional electrocatalysis of FeS2-S, N GQDs for the conversion of biomass into electricity through bacteria. Significantly, at a steady-state of the power generation, the acetate-feeding MFC with FeS2-S, N GQDs as activated biomass anode delivers a maximum power density 1128 +/- 9 mW/m(2), which is 48% and 76% higher than the one using S, N GQDs (585 +/- 7 mW/m(2)) and carbon cloth (265 +/- 3 mW/m(2)) as anode electrocatalyst. With these merits, the bioanode facilitates the activity towards redox reactions of cytochromes in bacteria and exhibits higher maximum power density and stronger stability than the conventional carbon cloth. This report provides a new concept of anode electrocatalyst fabrication for the application of MFC in electricity generation.

Automated summary

The FeS2-S, N GQDs synthesized in this study showed superior performance as a bioanode in microbial fuel cells, with a new concept of anode electrocatalyst fabrication for improved electricity generation.