Metal-organic framework-derived Fe/Fe3C embedded in N-doped carbon as a highly efficient oxygen reduction catalyst for microbial fuel cells

Microbial fuel cells (MFCs) have become new energy approach for sustainable development. The exploitation of economic and efficient electrocatalysts for the oxygen reduction reaction (ORR) is essential for obtaining remarkable MFCs performance. Herein, metal–organic framework (MOF)-derived Fe/Fe3C embedded in nitrogen-doped carbon hybrids, prepared through a simple solvothermal and pyrolysis approach, are highly efficient ORR catalysts. The unique mixed dimension (1D/2D) and mesoporous structure provide abundant active sites and build transfer channels for improvement. Additionally, the presence of nitrogen doping played an important role to accelerate electron diffusion and transport. A maximum power density of 1974.75 ± 26.16 mW m−2 is earned by Fe/Fe3C/NC-800, and is 1.45 times of 20% Pt/C (1366.45 ± 28.65 mW m−2). Therefore, the Fe/Fe3C/NC catalyst is a prospective ORR catalyst in MFCs and in future renewable energy storage and conversion technologies.