MOF-derived Co single atoms anchored on Fe3C-decorated carbon nanosheets for stable zinc–air batteries

Abstract

Developing non-precious metal electrocatalysts with high activity and stability is crucial for enhancing the efficiency of zinc–air batteries (ZABs). Herein, we anchor MOF-derived porous carbon embedded with Co single atoms (SAs) into graphene-like nanosheets decorated with Fe₃C nanoparticles (NPs) to construct a bifunctional oxygen electrocatalyst (Co_SA/Fe₃C_NP/N–C). The synergistic effects between Fe₃C NPs and Co single atoms enhance oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics. Additionally, the introduction of graphene-like nanosheets enhances the dispersion of MOF-derived carbon, thus facilitating the exposure of active sites. The resulting catalyst delivers a peak power density of 182.8 mW cm⁻² and exhibits ultrahigh stability over 1100 h when assembled in a ZAB. The excellent performance can be attributed to enhanced active site accessibility, the low Fenton effect of Fe₃C NPs and Co SAs, and their synergistic interactions. This work integrates synergistic design in both composition and structure, providing a novel strategy for developing efficient and durable non-precious metal catalysts.