Hierarchical Crystalline/Amorphous Heterostructure MoNi/NiMoOx for Electrochemical Hydrogen Evolution with Industry-Level Activity and Stability

The design of cheap, efficient, and durable electrocatalysts for high-throughput H-2 production is critical to give impetus to hydrogen production from fundamental to practical industrial applications. Here, a hierarchical heterostructure hydrogen evolution reaction (HER) electrocatalyst (MoNi/NiMoOx) with 0D MoNi nanoalloys nanoparticles embedded on well-assembled 1D porous NiMoOx microrods in situ grown on 3D nickel foam (NF) is successfully constructed. The synergetic effect of different building units in the unique hierarchical structure endows the MoNi/NiMoOx composites with the highly active heterogeneous interface with low water dissociation energy (Delta G(diss) =-1.2 eV) and optimized hydrogen adsorption ability (Delta G(H)* = -0.01 eV), fast electron/mass transport, and strong catalyst-support binding force. As a result, optimal MoNi/NiMoOx exhibits an ampere-level current density of 1.9 A cm(-2) at an ultralow overpotential of 139 mV in 1.0 (M) KOH and 289 mV in 1.0 (M) PBS solution, respectively. Particularly, scaled-up MoNi/NiMoOx electrodes in a 10 x 10 cm(2) membrane electrode assembly (MEA) electrolyzer reach a high H-2 production rate of 12.12 L h(-1) (12.12 times than that of commercial NF) and exhibit ultralong stability of 1600 h, verifying its huge potential for industrial hydrogen production.