Fe, N dual doped graphitic carbon derived from straw as efficient electrochemical catalysts for oxygen reduction reaction and Zn-air batteries

In this paper, we present a facile and one-step way for synthesizing Fe, N dual doped highly porous graphitic biomass carbon (FeNC) by using K2FeO4 to fulfill the activated process and catalytic graphitization of straws. The FeNC demonstrates hierarchically porous structure with large surface area of 1034 m2 g−1, Fe, N dual doping with certain amount of Fe-Nx, and graphitic structure. With these favorable features, the electrocatalytic activity for oxygen reduction reaction (ORR) reveals that the FeNC exhibits positively onset potential with highly comparable limiting current density when comparing with the sample using conventional KOH activated agent. In additional, the assembled Zn-air battery using FeNC as air-cathode catalyst delivers a maximal power density of 128.4 mW cm−2. Considering the abundance of straws on the earth and the low-cost and green prepared process, the present FeNC materials are highly promising in application in ORR catalysts for Zn-air battery and other energy-related fields. The Fe, N dual doped highly porous graphitic carbon was prepared from carbonization of straws fibers. As a cathode catalyst, the Zn-air battery delivered a maximal power density of 128.4 mW/cm2 and was used as power source for lighting up LEDs. [Display omitted] •The K2FeO4 acts as activating agent and graphitization catalyst for FeNC.•Fe, N codoping and graphitic structure in FeNC increase active sites and conductivity.•The FeNC exhibits an enhanced electrocatalytic activity for ORR.•The Zn-air battery using FeNC as cathode delivers a power density of 128.4 mW/cm2.