3D Network nanostructured NiCoP nanosheets supported on N-doped carbon coated Ni foam as a highly active bifunctional electrocatalyst for hydrogen and oxygen evolution reactions

A highly active bi-functional electrocatalyst towards both hydrogen and oxygen evolution reactions is critical for the water splitting. Herein, a self-supported electrode composed of 3D network nanostructured NiCoP nanosheets grown on N-doped carbon coated Ni foam (NiCoP/NF@NC) has been synthesized by a hydrothermal route and a subsequent phosphorization process. As a bifunctional electrocatalyst, the NiCoP/NF@NC electrode needs overpotentials of 31.8 mV for hydrogen evolution reaction and 308.2 mV for oxygen evolution reaction to achieve the current density of 10 mA·cm⁻² in 1 mol·L⁻¹ KOH electrolyte. This is much better than the corresponding monometal catalysts of CoP/NF@NC and NiP/NF@NC owing to the synergistic effect. NiCoP/NF@NC also exhibits low Tafel slope, and excellent long-term stability, which are comparable to the commercial noble catalysts of Pt/C and RuO₂.