In situ synthesis of Ni, Mo bimetallic crystalline-amorphous co-existing heterostructures for efficient hydrogen evolution reaction

Abstract

Electrocatalytic hydrogen production is a green and feasible method for obtaining hydrogen energy. However, the bottlenecks of high cost, low catalytic activity and inferior stability urgently need to be addressed, and constructing advanced catalysts with optimized microscopic morphology and crystal structure is a feasible and effective strategy to overcome this barrier. Herein, an artful strategy of in-situ grown coupled with N doping and C encapsulation was employed to obtain the NC/NiO–Mo/NF with biomimetic cattle stomach-liked porous structure, which can offer shortcut for ion transportation and expose more active sites for H∗ adsorption. Particularly, the constructed NiMoO₄–NiO heterojunction in NC/NiO–Mo/NF can significantly boost the hydrogen evolution activity. Meanwhile, the density functional theory (DFT) confirm that the construction of the crystalline-amorphous heterojunction induces electron transfer from NiMoO₄ to NiO, promoting a downshift in the d-band center, thereby achieving a near-thermoneutral free energy for the hydrogen evolution reaction (HER). The de-signed electrocatalyst exhibits exceptional HER activity, with a small overpotential of 48 mV to achieve a current density of 10 mA cm⁻². It is important that NC/NiO–Mo/NF exhibits exceptional HER stability, with current density of 50 mA cm⁻² for 100 h. The finding provides a feasible strategy for the fabrication of nonprecious-metal-based HER electrocatalysts with high activity and stability toward industrial water electrolysis.