Biomass-Derived Fe2N@NCNTs from Bioaccumulation as an Efficient Electrocatalyst for Oxygen Reduction and Zn–Air Battery

Metal compounds encapsulated in carbon materials exhibit promising properties as potential oxygen electrocatalysts. Herein, we first report Fe2N@C derived from the biomass bioaccumulation doping method, which offers a new perspective for exploring oxygen reduction reaction (ORR) electrocatalysts with low cost and high performance. The Fe2N@NCNTs prepared with our biodoping method display excellent ORR activity with a low half-wave potential (E1/2) and long-term stability in a broad pH range. More importantly, a zinc–air battery (ZAB) constructed with Fe2N@NCNTs’ catalysts exhibits a high open-circuit voltage (1.53 V), high peak power density (135 mW cm–2), and excellent stability (over 200 h). The significantly improved ORR performance can be attributed to the high N-doping level and its hierarchically porous structure. This work offers a path for the development of ORR catalysts for environmental governance and efficient energy conversion.