Iron-doped nickle cobalt ternary phosphide hyperbranched hierarchical arrays for efficient overall water splitting

Abstract

Transition metal phosphide as an excellent sustainable hydrogen fuel production catalyst can effectively restrain the thermodynamic requirements of electrolysis water reaction. Here, we report a novel Fe-doped NiCoP hyperbranched hierarchical arrays grown on nickel foam (referred as NC1-xFxP HHAs/NF) prepared by a facile hydrothermal method followed by a phosphorization treatment. Compared to traditional nanosheet arrays, the secondary one-dimensional nanowire arrays were grown on primary two-dimensional NC1-xFxP nanosheets arrays supported on the nickel foam to maximum exposed catalytic active sites and provide a large electrolyte contact area and accelerate electrolyte transport, thus greatly improving catalytic activity. Benefit from the synergy of modified electronic structure induced by the Fe-doping and special hyperbranched hierarchical architecture, the optimal NC0.9F0.1P HHAs/NF electrocatalyst show an over potential of 122.5 and 269 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm−2, under 1 M KOH aqueous electrolyte. The material system operates at 1.57 V to reach 10 mA cm−2 in two-electrode measurements. This permits new design principles for highly-efficient multicomponent metal phosphides electrocatalysts with special hierarchical architecture for water splitting.