MnO2–graphene hybrid as an alternative cathodic catalyst to platinum in microbial fuel cells

Manganese dioxide–graphene nanosheet (MnO2/GNS) hybrid is used as an alternative cathode catalyst for oxygen reduction reaction in air-cathode microbial fuel cell (MFC). The results show that the nanostructured MnO2/GNS composite exhibit an excellent catalytic activity for oxygen reduction reaction due to MnO2 nanoparticles closely anchored on the excellent conductive graphene nanosheets. As a result, MFC with MnO2/GNS as air cathode catalyst generates a maximum power density of 2083 mW m−2, which is higher than that of MFC with pure manganese dioxide catalyst (1470 mW m−2). Therefore, MnO2/GNS nanocomposite is an efficient and cost-effective cathode catalyst for practical MFC applications. ► MnO2–graphene nanosheet (MnO2/GNS) hybrid is prepared under microwave irradiation. ► The electrode modified by MnO2/GNS exhibits high catalytic activity for ORR. ► Microbial fuel cells with MnO2/GNS generates a maximum power density of 2083 mW m−2.