CoFe alloy nanoparticles embedded in vertically grown nanosheets on N-doped carbon nanofibers as a trifunctional electrocatalyst for high-performance microbial fuel cells

Herein, a novel MOF-derived trifunctional electrocatalyst with a three-dimensional hierarchical structure of N-doped carbon nanofibers (NCNFs) compounded with vertically grown nanosheets loaded with Co and CoFe alloy nanoparticles is reported. It is found that Co/CoFe NAs@NCNFs has a good half-wave potential of 0.83 V for ORR, the overpotential of 290 mV and 103 mV for OER and HER, respectively. When Co/CoFe NAs@NCNFs catalyst is employed on the cathode of a microbial fuel cell (MFC), the peak power density of the MFC can reach 2139.6 ± 43 mW m−2, which is 1.56 times better than that of commercial Pt/C. Furthermore, the assembled MFCs can also successfully drive the water splitting. The above excellent performance is mainly due to the structure of the interwoven NCNF networks combined with nanosheets which greatly enhances the surface area and mass transfer capacity of the material, and the loaded nanoparticles are constructed into a large number of Fe-Nx-C and Co-Nx-C active sites, further increasing the catalytic performance of Co/CoFe NAs@NCNFs. This work could provide a novel approach to the regeneration and conversion of clean energy.