Core-shell Ni2P@CoP nanoarrays supported on NF as a highly efficient electrocatalyst for hydrogen evolution reaction

Low-cost and earth-rich electrocatalysts with excellent catalytic activity in the electrochemical hydrogen evolution reaction (HER) are essential for large-scale renewable energy storage. Herein, we report a new type of core-shell Ni2[email protected] nanoarrays supported on nickel foam (NF) (Ni2[email protected]/NF) with large specific surface area, serving as an efficient cathode for hydrogen evolution reaction (HER). Plenty of tiny Ni2P nanosheets were tightly wrapped on the CoP nanowires, forming a rich heterostructure interface, which can provide more active sites and improve conductivity, thereby increasing their catalytic performance. What's more, the synergistic effect between Ni2P and CoP can promote the rapid electron transfer and improve the catalytic efficiency. The obtained Ni2[email protected]/NF NAs exhibited excellent HER activity with a low overpotential of 61 mV at 10 mA cm−2 and good durability in the alkaline media. The core-shell nanoarray structure of Ni2[email protected]/NF provides a novel method for the preparation of other heterojunction metal phosphides, which can be used to develop high performance HER electrocatalysts.