Heterointerface-engineered electron-bridge in hollow carbon nanotube-anchored Fe 2 P/FeCoP electrocatalyst for highly stable Zn–air batteries

Transition metal phosphides (TMPs) hold promise as effective bifunctional oxygen electrocatalysts for rechargeable Zn-air batteries (RZABs), yet their practical application is hindered by inadequate durability and sluggish kinetics. Herein, we design a heterophosphate composite comprising Fe₂P-FeCoP heterojunctions anchored on 1D hollow N, P-doped carbon nanotubes (Fe₂P-FeCoP@HNPC) through controlled metal modulation of an aniline-phytate nanorods. Critically, the interfacial electronic coupling between Fe₂P and FeCoP induces a cross-interfacial electron-bridge network, which drives charge redistribution to accelerate interfacial electron transfer and refines the d band adsorption energetics for optimized oxygen intermediate binding. Coupled with its hollow architecture, Fe₂P-FeCoP@HNPC enables synergistic mass/charge transfer enhancement. The synergistic electronic-structural effects endow Fe₂P-FeCoP@HNPC with exceptional bifunctional activity, achieving a high ORR half-wave potential (0.83 V vs. RHE) and low OER overpotential (1.53 V @10 mA cm⁻²), attributed to the stabilized electron-bridge effect and hierarchical mass/charge transfer dynamics. Fe₂P-FeCoP@HNPC assembled RZAB achieves a peak power density of 145 mW cm⁻² and ultralong cycling stability (>1240 h) with negligible decay. This work demonstrates a universal strategy to harmonize electronic and structural engineering in TMPs for high-performance electrochemical energy systems.