Template-free synthesis of a multilayer manganese oxide/graphene oxide nanoflake-modified carbon felt as an anode material for microbial fuel cells

A novel multilayer nanoflake structure of manganese oxide/graphene oxide (gamma-MnO2/GO) was fabricated via a simple template-free chemical precipitation method, and the modified carbon felt (CF) electrode with gamma-MnO2/GO composite was used as an anode material for microbial fuel cells (MFCs). The characterization results revealed that the gamma-MnO2/GO composite has a novel multilayer nanoflake structure and offers a large specific surface area for bacterial adhesion. The electrochemical analyses demonstrated that the gamma-MnO2/GO composite exhibited excellent electrocatalytic activity and enhanced the electrochemical reaction rate and reduced the electron transfer resistance, consequently facilitating extracellular electron transfer (EET) between the anode and bacteria. The maximum power density of MFC equipped with the gamma-MnO2/GO composite-modified carbon felt anode was 1.13 +/- 0.09 W m-2, which was 119% higher than that of the pure commercial carbon felt anode under the same conditions. Thus, the results demonstrate that the multilayer gamma-MnO2/GO nanoflake composite-modified carbon felt anode is a promising anode material for high-performance MFC applications.