MOF derived Co–Mo2C heterojunctions with interfacial electronic modulation for oxygen reduction reaction and zinc–air batteries

Zinc-air batteries (ZABs) have emerged as promising candidates for next-generation energy storage systems due to their high energy density, safety, and environmental benignity. However, their efficiency is hindered by sluggish oxygen reduction reaction (ORR) kinetics. Constructing heterojunction with optimized interfacial electronic structure has emerged as a promising approach to enhance ORR activity. Herein, we report a Co–Mo 2 C heterojunction encapsulated within nitrogen-doped carbon (Co–Mo 2 C@NC) derived from a ZnCoMo-based metal–organic framework (ZnCoMo–HZIF). The intimate interface between Co and Mo 2 C enables the strong electronic coupling, which induces the interfacial charge redistribution and optimizes the d-band center of Co active sites. This electronic modulation significantly enhances the oxygen intermediate adsorption and lowers the energy barrier. As a result, Co–Mo 2 C@NC delivers outstanding ORR performance with a high half-wave potential (E 1/2 ) of 0.85 V, a low Tafel slope of 94.7 mV dec -1 , and a good long-term stability. Additionally, Co–Mo 2 C@NC as the air cathode in a zinc-air battery exhibits superior power performance and outstanding cycling stability.