Hyperbranched Ni x P y /NiCoP Arrays Based on Nickel Foam Electrode for Efficient and Stable Electrocatalytic Hydrogen Evolution

Transition metal phosphides have high catalytic performance and stability among non-precious metal electrocatalysts, particularly exhibiting good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in alkaline solutions, due to the platinum-like electronic structure of transition metal phosphides. In this study, we successfully synthesized nickel phosphide and nickel cobalt phosphate hybrid on the three-dimensional nickel foam by a facile hydrothermal method. It is worth noting that the Ni x P y /NiCoP in 1 M KOH only needs the overpotential of 95 mV to reach the current density of 10 mA∙cm −2 for hydrogen evolution reaction (HER) and the overpotential of 231 mV at 10 mA∙cm −2 for oxygen evolution reaction (OER), which is superior to most electrocatalysts. The obtained results indicate that there is a synergistic effect between the three elements of Ni, Co, and P, facilitating the process of electrocatalysis. Meanwhile, the synthesized electrode not only has a large active surface area, but also good electrical conductivity, effectively facilitating the electrocatalytic reaction kinetics. Thus, this work provides an effective route to a low-cost, high-performance catalyst for electrocatalytic hydrogen production. Graphical abstract