Ni Nanoparticle-Embedded MoN Nanosheet Heterojunction on Delignified Wood Carbon as a Highly Active and Durable Electrocatalyst for Hydrogen Production

It remains a significant challenge to develop highly efficient, low-cost electrocatalysts for sustainable, scalable, and industrial-level hydrogen (H2) production. Herein, a heterostructured electrocatalyst composed of Ni nanoparticle-embedded MoN nanosheets grown on delignified wood carbon (denoted Ni/MoN@DWC) is successfully constructed by interfacial engineering. Experimental results indicate that the stable heterointerface, asymmetric charge dispersion, and low-tortuous hierarchically porous structure accelerate electron transfer and enhance adsorption/desorption of reaction intermediates. When utilized as a self-supporting electrode in an alkaline electrolyte, the Ni/MoN@DWC delivers low potentials of 36 and 149 mV vs RHE at 10 and 100 mA cm–2, respectively, for hydrogen evolution reaction. Meanwhile, it also exhibits excellent durability with a negligible activity decline after 100 h continuous electrolysis at 10 mA cm–2. Utilizing the Ni/MoN@DWC bifunctional catalyst, a two-electrode electrolyzer shows an ultrasmall cell voltage of 1.34 V at 10 mA cm–2 for urea-assisted water splitting, which is about 220 mV lower than that of conventional water splitting, and displays long-term durability of >35 h in continuous electrolysis, indicating its great promise for industrial applications in hydrogen production from water splitting.