In situ formation of graphene/biofilm composites for enhanced oxygen reduction in biocathode microbial fuel cells

Here we reported a novel one-pot method for biocathode fabrication in microbial fuel cell (MFC), by which the microbially-reduced graphene was implanted into cathodic biofilm, leading to the in situ construction of graphene/biofilm composites with a three-dimensional structure. The maximum power density of the MFC with graphene-biocathode increased by 103% compared with the MFC with carbon cloth-biocathode. Electrochemical analyses showed that the graphene-biocathode had faster electron transfer kinetics and less internal resistance than the carbon cloth-biocathode. As an effective biocathode material, graphene/biofilm composites could enhance the electrocatalytic activity towards oxygen reduction, and facilitate the electron transfer between bacteria and electrode.

► Reported a novel one-pot method for biocathode fabrication in microbial fuel cell.
► Graphene/biofilm composites with a 3-D structure were in situ formed on cathode.
► The maximum power density of the MFC increased by 103% after fabrication.
► Graphene/biofilm has higher electrocatalytic activity towards oxygen reduction.
► This work developed a facile method to assemble a new biocathode MFC.