Wheat straw as carbon source to prepare FeCoP2 / N, P Dual-Doped carbon matrix as bifunctional catalyst for application in rechargeable Zinc-air and Aluminum-air batteries.

[Display omitted] • Method of converting cheap wheat straw into bifunctional catalyst is developed. • Catalyst was constructed with FeCoP 2 embedding in N, P dual-doped carbon matrix. • ΔE between ORR and OER achieved 0.84 V suggests excellent bifunctional activity. • Liquid Zinc-air battery achieved 122.5 mW cm−2 and can stably cycle for 110 h. • Solid-state Zinc-air battery achieved 55.6 mW cm−2 and can stably cycle for 35 h. Transformation from crude wheat straw to the efficient bifunctional catalysts was realized to obtain a unique composite structure. The ideal designed construction of bimetallic phosphide nanoparticles embedding in N, P dual-doped carbon matrix exhibited the impressive performances for catalyzing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This catalyst has been used to assemble metal-air batteries. The rechargeable liquid zinc-air battery achieved the power density of 122.5 mW cm−2 and charge–discharge cycled for over 110 h. The rechargeable solid-state zinc-air battery exhibited the power density of 55.6 mW cm−2 and charge–discharge cycled for over 35 h. In addition, it was also investigated in the aluminum-air battery and exhibited excellent performances. This work has paved the way of preparing efficient metal-air battery catalyst from low-cost agricultural by-products. [ABSTRACT FROM AUTHOR]