A graphene modified anode to improve the performance of microbial fuel cells

Graphene with a Brunauer–Emmett–Teller (BET) specific surface area of 264 m2 g−1 has been used as anodic catalyst of microbial fuel cells (MFCs) based on Escherichia coli (ATCC 25922). The electrochemical activities of plain stainless steel mesh (SSM), polytetrafluoroethylene (PTFE) modified SSM (PMS) and graphene modified SSM (GMS) have been investigated by cyclic voltammetry (CV), discharge experiment and polarization curve measurement. The GMS shows better electrochemical performance than those of SSM and PMS. The MFC equipped with GMS anode delivers a maximum power density of 2668 mW m−2, which is 18 times larger than that obtained from the MFC with the SSM anode and is 17 times larger than that obtained from the MFC with the PMS anode. Scanning electron microscopy (SEM) results indicate that the increase in power generation could be attributed to the high surface area of anode and an increase in the number of bacteria attached to anode.

► Graphene enhances the charge transfer capability of the bacteria to the anode.
► Microbial fuel cell with graphene anode delivers a power density of 2668 mW m−2.
► Graphene is promising in application of microbial fuel cells.