Engineering Interfacial Charge Transfer in Fe 2 P/Co 2 P Heterojunctions for Efficient Zn‐Air Batteries

ABSTRACT Single‐phase metal phosphides inherently struggle to simultaneously satisfy the divergent adsorption requirements of oxygen intermediates for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, we report the controllable synthesis of a bimetallic Fe 2 P‐Co 2 P heterojunction to overcome these catalytic limitations. Comprehensive experimental investigations coupled with theoretical calculations and in situ Raman reveal that the tailored hetero‐interface drives significant electronic redistribution, enabling spatial decoupling and the synergistic collaboration of catalytic sites. Benefiting from this synergistic effect, the Fe 2 P‐Co 2 P heterostructure bifunctional electrocatalyst delivers outstanding bifunctional performance, featuring a high ORR half‐wave potential of 0.85 V and a low OER potential of 1.57 V (at 10 mA/cm 2 in 1 M KOH), yielding a narrow potential gap (Δ E ) of 0.72 V. Furthermore, a fabricated recharegable zinc‐air battery equipped with this electrocatalyst achieves a power density of 185.6 mW/cm 2 and demonstrates exceptional cycling stability with an ultra‐long lifespan of 880 h, highlighting its substantial promise for robust energy conversion and storage systems.