Homogeneous Crystalline/Amorphous Interface in Ni(OH)₂ Nanosheets for Enhanced Urea Oxidation Reaction

Urea oxidation reaction (UOR) plays a vital role in photoelectrochemical urea splitting and electrochemical degradation of wastewater containing urea. Nonetheless, complex reaction processes, slow kinetics, and high energy barriers continue to be obstacles for UOR. Herein, we report nickel hydroxide nanosheets with abundant homogeneous crystalline/amorphous interfaces. In this work, abundant homogeneous crystalline/amorphous interfaces decorated nickel hydroxide nanosheets (C/A-Ni­(OH)₂ NSs) are rationally constructed via a rapid in situ surface reconstruction of Ni_0.85Se NSs precursor. Impressively, C/A-Ni­(OH)₂ NSs demonstrate remarkable UOR performance, demonstrating a low Tafel slope of 19.4 mV dec^–1, an ultralow working potential of 1.32 V vs reversible hydrogen electrode (RHE) at 100 mA cm^–2, and remarkable stability for more than 500 h. The combination of experimental analysis and characterization results indicates that the formation of the homogeneous crystalline/amorphous interface greatly facilitates the generation of corresponding hydroxyl oxide (*OOH) active substances. This research contributes to our understanding of surface reconstruction and interface engineering, providing broad prospects for the design of advanced UOR catalysts.