Interface Engineering with the Coupling of a 3D Porous Structure Enables MoP 2 -NiCoP Heterostructure Nanosheets for Enhanced Alkaline Hydrogen Evolution Reaction.

One of the crucial parts of the electrochemically focused energy conversion and storage system is the hydrogen evolution reaction. The further exploration of electrocatalysts made of nonprecious metals could help to bring the technology closer to industrialization. Here, we present an effective hydrogen evolution reaction (HER) electrocatalyst that employs hydrothermal and phosphorization steps to create three-dimensional (3D) porous MoP 2 -NiCoP heterostructure nanosheets on nickel foam (MoP 2 -NiCoP/NF). H 2 O-dissociation and H-adsorption were effectively achieved due to the distinctive interface engineering between NiCoP and MoP 2 , which functions as a channel for immediate electron transfer. Compared to the single-component MoP 2 and NiCoP, the synergistic interaction between the heterogeneous components coupling and the 3D porous structure enables MoP 2 -NiCoP/NF to exhibit satisfactory catalytic activity with an ultralow overpotential of 50 mV at 10 mA cm -2 , which is close to the commercial Pt/C catalyst in alkaline media. More importantly, it exhibits good stability, with the ability to be electrolyzed in 1.0 M KOH electrolyte for 24 h without a significant change in overpotential. This study offers directions for the design of low-cost, high-activity, transition metal phosphides (TMPs)-based HER catalyst alternatives for future practical applications.