Regulating the Electronic Structure of Tungsten Carbide‐Induced Co(OH) 2 for Efficient Water and Urea Electrolysis in Hydrogen Production from Urea‐Containing Water

Abstract Urea oxidation reaction (UOR) is considered a capable method for simultaneously producing hydrogen and treating urea‐rich wastewater. The development of well‐designed, high‐performance electrocatalysts is crucial for efficient urea oxidation. In this study, a tungsten carbide (WC) and Co(OH) 2 nanocomposite (WC@Co(OH) 2 ) is synthesized through a simple hydrothermal process for electrocatalytic UOR performance. X‐ray absorption spectroscopy revealed that WC@Co(OH) 2 ‐2 exhibited higher levels of high‐spin Co 3+ electronic states compared to pristine Co(OH) 2 . The optimized WC@Co(OH) 2 electrocatalysts showed remarkable activity in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and UOR, with potentials of 0.152, 1.475, and 1.38 V, @ 10 mA cm −2 , respectively. The WC@Co(OH) 2 ‐2 catalyst also exhibited a high turnover frequency of 31.2 s −1 . Moreover, an overall urea electrolysis system constructed with the prepared WC@Co(OH) 2 , attained 1.55 V at 10 mA cm −2 , which is 0.21 V lower than the potential required for overall water splitting. In situ Raman result revealed the quick reconstruction of WC 1‐x @Co(OH) 2 , where tungsten species infiltrate into CoOOH, forming a restored WC 1‐x @CoOOH layer that serves as the active species for water splitting. Furthermore, the WC@Co(OH) 2 ‐2 exhibited a high Faradaic efficiency of 92.18% and exceptional durability. This work broadens the UOR electrocatalyst and contributes the advancement of energy‐efficient hydrogen production technologies.