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

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 (& eta;(10) = 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.

Automated summary

This study proposes a facile one-stone-two-birds strategy 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, to achieve dual-regulation on geometric and electronic structures of MOF-derived catalysts. The resultant Co2P@NPC catalyst exhibits high bifunctional activity towards oxygen reduction and oxygen evolution reactions, and demonstrates promising power density and long cycling stability when assembled in a quasi-solid-state ZAB.