Interface cooperative Pt-CoNi LDH for urea-assisted energy-saving hydrogen production under ampere-level current density

Engineering bifunctional electrocatalysts featuring promoted adsorption for multiple intermediates and reactants via interface modulation strategies is critical for urea-assisted water splitting toward sustainable energy conversion. However, exploring efficient bifunctional electrocatalysts capable of driving both the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) at high current densities remains challenging. Herein, a self-supported bifunctional electrode is constructed on nickel foam, where the cooperative CoNi LDH is decorated with low-content Pt nanospheres (Pt-CoNi LDH/NF) for urea-assisted H 2 production. The strong metal-support interaction (SMSI) and multi-metal synergy collectively regulate the adsorption/desorption behavior of key reaction species, thereby lowering the energy barrier for the rate-determining step and improving overall catalytic efficiency. The optimized catalyst exhibits substantially reduced potentials of 1.32 V (UOR) and -30 mV (HER) to reach 10 mA cm -2 . A urea-assisted electrolytic cell merely requires 1.36 V to afford 10 mA cm -2 . Notably, in a practical anion-exchange membrane (AEM) electrolyzer configuration, the Pt-CoNi LDH/NF electrode maintains stable at 2 A cm -2 , while preserving high UOR/HER bifunctional activity. This study develops an integrated approach that couples urea-containing wastewater remediation with energy-efficient hydrogen production. The Pt-CoNi LDH/NF nanospheres catalyst fabricated via a corrosion-drop-anchoring approach shows superior activity and stability toward HER, UOR, and urea-assisted OWS. • The superhydrophilic/aerophobic nanostructure and interface engineering boost reaction kinetics. • Pt sites optimize H* adsorption for HER and Ni 2+ /Ni 3+ cycle for UOR, enabling bifunctional activity. • The assembled electrolyzer requires only 1.73 V to reach 1 A cm -2 .