Electronic modulation of Ni2P through anion and cation substitution toward highly efficient oxygen evolution

Rationally designed oxygen evolution reaction (OER) catalysts with structural and compositional superiorities are essential for energy-related electrocatalytic techniques. Transition-metal phosphides have been used as promising electrocatalysts for OER. Incorporating heteroatoms into the lattice can induce lattice distortion and redistribution of electron density, consequently modifying the electronic structure and improving catalytic performance. Herein, Fe- and S-substituted Ni2P uniformly dispersed throughout porous carbon substrate (Ni—Fe—P—S@C) was rationally designed through transformation from the pre-synthesized NiFe-metal organic frameworks (NiFe-MOFs) by partial sulfurization and subsequent phosphorization process. Experimental results and density functional theory calculations showed that Fe and S incorporation could modulate the electronic structure of Ni2P and alter the adsorption free energies of reaction intermediates, contributing to admirable electrocatalytic activity and stability toward OER. Notably, the in-situ formed partially oxidized surface was vital to further improve the local environment. This proposed cation- and anion-substitution strategy will bring new inspiration to boost the electrocatalytic performance of transition-metal-based electrocatalysts for energy conversion applications.