A one-stone-two-birds strategy to construct metal–organic framework-derived cobalt phosphide as an efficient bifunctional electrocatalyst for oxygen electrode reactions

Abstract

Materials derived from metal–organic frameworks (MOFs) are promising oxygen electrocatalysts for zinc–air batteries (ZABs). Rational design of precursors and introduction of heteroatoms are effective strategies for optimizing the performance of MOF-derived catalysts. Herein, a facile one-stone-two-birds strategy is proposed to achieve dual-regulation on geometric and electronic structures by constructing a phytic acid cross-linked metal ion (M-PA) network film on the surface of 2D Zn/Co ZIF-L, followed by an annealing procedure. The resultant catalyst composed of cobalt phosphide nanoparticles and N, P co-doped carbon substrates (denoted as Co₂P@NPC) exhibits high bifunctional activity towards the oxygen reduction reaction (E_1/2 = 0.852 V) and oxygen evolution reaction (η₁₀ = 336 mV). Moreover, the quasi-solid-state ZAB assembled with Co₂P@NPC also delivers a promising power density and long cycling stability. The present work demonstrates an effective strategy to develop MOF-derived materials with a protected morphology and optimized electronic structures.