Facile Dispersion of Nanosized NiFeP for Highly Effective Catalysis of Oxygen Evolution Reaction

Abstract

Transition metal phosphides (TMPs) are commonly attributed to efficient oxygen-evolving catalysts but are limited by insufficient exposure of active sites. Homogeneous dispersion and reducing size to nanoscale by modulating the combinations of metal and nonmetal P would benefit to explore their intrinsic activities. Based on size-confined synthesis strategy, nanostructured bimetallic phosphide NiFeP with dimensions of several nanometers has been synthesized via controlled pyrolysis of a green organophosphorus source. The highly dispersed Ni0.65Fe0.35P electrocatalyst exhibited relatively low oxygen evolution reaction overpotential of 270 mV while supporting the current density of 10 mA/cm2 (without iR-drop corrections). Additionally, current density of 200 mA/cm2 at overpotential of 500 mV was achieved in alkaline solutions, which was 4-fold and 5-fold OER activity higher (η = 500 mV) than their single-metal counterparts Ni2P and FeP, respectively, and even better than a conventional method compound and n...