Fe₂P/SbZn Heterostructure on N,P-Doped Carbon Scaffolds as Advanced Oxygen Reduction Electrocatalysts for Zinc-Air...

The strategic construction of heterostructures centered around Fe₂P is proven to be effective for improving its performance in the oxygen reduction reaction (ORR) and zinc-air batteries (ZABs). In this study, SbZn is strategically employed to construct a novel Fe₂P/SbZn heterostructure on N,P-doped carbon scaffolds, serving as an efficient electrocatalyst for the ORR in ZABs. Through a one-step pyrolysis of a Fe, Sb, P-incorporated zeolitic imidazolate framework, the Fe₂P/SbZn@PNC catalyst is successfully synthesized. This catalyst demonstrates high ORR activity in alkaline media, achieving a half-wave potential of 0.936 V and a limiting current density of 6.18 mA cm^-2, both significantly surpassing those of commercial 20 wt% Pt/C. When applied in zinc-air batteries, the Fe₂P/SbZn@PNC-based ZABs deliver a higher peak power density and superior long-term cycling stability compared to the Pt/C benchmark. Density functional theory (DFT) calculations reveal that the Fe₂P/SbZn interface drives charge redistribution, optimizing the adsorption/desorption of oxygen intermediates and reducing the rate-determining energy barrier in ORR, thus enhancing catalytic activity. This innovative heterostructure provides new avenues for designing efficient electrocatalysts for energy conversion and storage.