One-step electrosynthesis of polypyrrole (PPy)/graphene oxide (GO) composites on the graphite felt (GF) electrode was achieved by electropolymerization of pyrrole while using GO as the anionic dopant. The resulting PPy/GO composites were uniformly coated on the GF surface, with increased surface area, electronic conductivity, biocompatibility and stability as compared to PPy alone or graphene alone-modified GF electrode. The dual-chamber microbial fuel cell (MFC) equipped with the PPy/GO modified GF anode showed the maximum power density of 1326 mW m(-2) (obtained from linear sweep voltammetry at a scan rate of 0.5 my s(-1)), which was significantly larger than that associated with the unmodified GF anode (166 mW m(-2)), the electrochemically reduced GO-modified GF anode (318 mW m(-2)), the chemically reduced GO-modified GF anode (924 mW m(-2)), and the PPy-modified GF anode (1100 mW m(-2)). After 120 cycles of lactate feeding, the PPy/GO-GF anode exhibited good stability without noticeable performance degradation, but performance degradation was observed for the anodes modified with PPy alone or graphene alone. These results demonstrate that the PPy/GO composites, synthesized via the simple and facile electropolymerization approach, are effective anode modifying materials for improving electricity generation as well as long-term stability of MFCs. (C) 2013 Elsevier Ltd. All rights reserved.