Tuning d-Band Center in Tungsten-Incorporated Ni(OH) Nanosheets with Nickel/Carbon Nanofibers for Promoted Urea Electrooxidation and Its-Assisted Efficient Hydrogen Production.

The urea oxidation reaction (UOR), recognized as an energy-efficient alternative to the oxygen evolution reaction (OER), has garnered considerable scientific interest due to its dual functionality in energy-saving hydrogen (H) production and environmental remediation. In this study, tungsten-incorporated nickel hydroxide anchored on nickel-carbon nanofibers (denoted as W-Ni(OH)@Ni-CNFs) has been developed through a synergistic electrospinning-carbonization-electrodeposition strategy for high-performance UOR catalysis. Systematic characterizations demonstrate that W incorporation induces favorable surface reconstruction of Ni(OH) and modulates its electronic structure, collectively leading to exceptional electrocatalytic enhancement. The optimized catalyst exhibits remarkable UOR activity with ultralow potentials of 1.351 and 1.547 V versus reversible hydrogen electrode (RHE) at the current densities of 10 and 300 mA cm, respectively, outperforming most benchmark catalysts to date. Density functional theory (DFT) simulations elucidate that W incorporation strategically modulates the d-band center position, strengthening key intermediates adsorption and reducing the reaction energy barrier for the rate-determining step. Furthermore, a urea-assisted water electrolyzer constructed with W-Ni(OH)@Ni-CNFs anode and Pt/C cathode achieves a low cell voltage of 1.376 V at 10 mA cm. This configuration exhibits a 6.4-fold enhancement in H evolution rate compared to conventional alkaline water electrolysis, highlighting its substantial energy-saving advantages.