Ni Nanoparticle-Embedded MoN Nanosheet Heterojunction\non Delignified Wood Carbon as a Highly Active and Durable Electrocatalyst\nfor Hydrogen Production

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