▎ 摘　　要

Searching for highly efficient bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) using nonnoble metal-based catalysts is essential for the development of many energy conversion systems, including rechargeable fuel cells and metal-air batteries. Here, Co9-xFexS8/Co,Fe-N-C hybrids wrapped by reduced graphene oxide (rGO) (abbreviated as S-Co9-xFexS8@rGO) are synthesized through a semivulcanization and calcination method using graphene oxide (GO) wrapped bimetallic zeolite imidazolate framework (ZIF) Co,Fe-ZIF (CoFe-ZIF@GO) as precursors. Benefiting from the synergistic effect of OER active CoFeS and ORR active Co,Fe-N-C in a single component, as well as high dispersity and enhanced conductivity derived from rGO coating and Fe-doping, the obtained S-Co9-xFexS8@rGO-10 catalyst shows an ultrasmall overpotential of approximate to 0.29 V at 10 mA cm(-2) in OER and a half-wave potential of 0.84 V in ORR, combining a superior oxygen electrode activity of approximate to 0.68 V in 0.1 M KOH.