Interfacing MnO and FeCo alloy inside N-doped carbon hierarchical porous nanospheres derived from metal–organic framework to boost high-performance oxygen reduction for Zn–air batteries

Abstract

Efficient and strong non-precious metal catalysts are urgently needed for the oxygen reduction reaction (ORR). Here, a facile hydrothermal–pyrolysis process was implemented to engineer CoFe–MnO heterointerfaces encapsulated in N-doped carbon (CFM-NC) nanospheres with a metal–organic framework (MOF) as the precursor. Due to heterointerfaces and hierarchical porosity, CFM-NC-800 exhibited superior ORR activity (half-wave potential of 0.86 V) and durability (30 000 s). Importantly, CFM-NC-800-based Zn–air batteries (ZABs) were capable of extending the outstanding performance, with a high power density of 260 mW cm⁻² and a specific capacity of 812 mA h g⁻¹. Furthermore, the CFM-NC-800-RuO₂-based ZABs showed remarkable stability (480 cycles), outperforming Pt/C-RuO₂ (360 cycles). This work highlights the effects of CoFe–MnO heterointerfaces and hierarchical porosity in ORR electrocatalysis, thereby providing a new avenue for energy conversion and storage.