Iron- and nitrogen-functionalized graphene as a non-precious metal catalyst for enhanced oxygen reduction in an air-cathode microbial fuel cell

► It is the first time to use Fe-N functionalized graphene as a cost-effective catalyst in microbial fuel cells. ► Fe-N-G exhibited excellent electrocatalytic activity toward oxygen reduction in neutral medium. ► Fe-N-G significantly enhanced the performance of MFC as compared to that of Pt/C cathode. ► Fe-N-G is a promising alternative to costly Pt catalyst for practical MFC application.