Biomass derived Fe,N-doped carbon material as bifunctional electrocatalysts for rechargeable Zn-air batteries

• A high-performance ORR/OER catalyst is prepared by using corn stalks as precursor. • FeN x and FeC x originated from Fe, N-dual doped improve catalytic performance. • The Fe-MNC catalyst achieves an excellent performance for Zn-air batteries. The development of affordable and perdurable electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) has been considered as an alternative to address the global energy crisis and grievous environmental pollution. Therefore, exhaustively developing low-cost bifunctional electrocatalysts is of significance especially derived from the ubiquitous carbonous biomass materials. Here, an advanced catalyst of Fe, N-dual doped mesoporous and microporous carbon nanosheets (Fe-MNC) is synthesized by using Fe-pyridine coordination complex as the sources of Fe, N and corn stalk soot as the support. The Fe-MNC possesses vigorous electrocatalytic performance for ORR with an E 1/2 of 0.85 V. Moreover, for OER, the overpotential is as low as 309 mV at the current density ( j ) of 10 mA cm −2 and the Tafel slope is 127 mV dec −1 . What's more, a rechargeable Zn-Air battery is constructed based on Fe-MNC as the air cathode. This work not only establishes an easy access and sustainable way to produce a cost-cutting and highly efficient ORR/OER catalyst, but also paves a new way for a greater value-added utilization of biomass carbon for sustainable energy conversation.