Interface engineering of Ni2P/MoOx decorated NiFeP nanosheets for enhanced alkaline hydrogen evolution reaction at high current densities.

The rational design of high-performance non-noble metal electrocatalysts at large current densities is important for the development of sustainable energy conversion devices such as alkaline water electrolyzers. However, improving the intrinsic activity of those non-noble metal electrocatalysts remains a great challenge. Therefore, Ni2P/MoOx decorated three-dimensional (3D) NiFeP nanosheets (NiFeP@Ni2P/MoOx) with abundant interfaces were synthesized using facile hydrothermal and phosphorization methods. NiFeP@Ni2P/MoOx exhibits excellent electrocatalytic activity for hydrogen evolution reaction (HER) at a high current density of -1000 mA cm-2 with a low overpotential of 390 mV. Surprisingly, it can operate steadily at a large current density of -500 mA cm-2 for 300 h, indicating its long-term durability under high current densities. The boosted electrocatalytic activity and stability can be ascribed to the as-fabricated heterostructures via interface engineering, leading to modifying the electronic structure, improving the active area, and enhancing the stability. Besides, the 3D nanostructure is also beneficial for exposing abundant accessible active sites. Therefore, this research proposes a considerable route for fabricating non-noble metal electrocatalysts by interface engineering and 3D nanostructure applied in large-scale hydrogen production facilities.