Potentiostatic Electrodeposition of Binder‐Free Ni–W Electrodes for Coupled Energy‐Saving Hydrogen Production and Urea Remediation

ABSTRACT Substituting the kinetically sluggish oxygen evolution reaction with the thermodynamically favorable urea oxidation reaction (UOR) offers a compelling strategy for simultaneously achieving energy‐efficient hydrogen production and wastewater remediation. Nevertheless, the design of UOR catalysts that combine high activity with long‐term durability remains a significant challenge. Herein, we report the scalable fabrication of binder‐free Ni–W nanostructures directly grown on carbon paper through a controlled potentiostatic electrodeposition approach. Electrochemical kinetic analysis confirms that the electrocrystallization follows a diffusion‐controlled pathway characterized by instantaneous nucleation and subsequent three‐dimensional growth. The optimized Ni–W electrode delivers outstanding UOR activity, reaching a current density of 100 mA cm ⁻² at a potential of just 1.77 V versus the reversible hydrogen electrode. In a two‐electrode urea electrolyzer configuration, the system achieves 10 mA cm ⁻² at only 1.54 V, markedly lower than the voltage required for conventional water splitting. Beyond the energy‐efficient hydrogen generation, the system demonstrates meaningful environmental remediation capability, degrading 47% of urea over 30 h of continuous electrolysis. By integrating pollutant removal with electrolytic H ₂ production within a single platform, this work establishes a scalable, binder‐free catalyst architecture aligned with circular economy principles and advances the frontier of sustainable energy conversion. image