Rational manipulation of interfacial-water supply and photothermal effect in Ru-CoP/Co₂P nanoneedle arrays for...

Tailoring the dissociative water‑hydrogen bonding network at catalyst-electrolyte interface and introducing favorable photothermal effect are pivotal for propelling diverse electrocatalytic reactions. Herein, we developed an advanced Ru-CoP/Co₂P/NF nanoarray catalyst, achieving the rational modulation interfacial-water and photothermal effect. In-situ Raman and electrochemical analyses show that Ru doping modifies the electronic structure of CoP/Co₂P/NF, promoting the directional evolution of interfacial-water and accelerating hydrogen evolution reaction (HER) kinetics. Moreover, Ru doping enhances the photothermal effect of CoP/Co₂P/NF, which counteracts the enthalpy change of urea oxidation reaction (UOR), strengthens the adsorption of urea molecules, accelerates interfacial electron transfer and activates inert reaction sites. The symbiotic photoelectric effect diminishes UOR activation energy from 27.0 to 14.2 kJ mol^-1. Under the synergistic promotion of these effects, the Ru-CoP/Co₂P/NF requires only 1.26, 1.32, 1.36 V (for UOR) and 64, 126, 161 mV (for HER) to reach 100, 500 and 1000 mA cm^-2, respectively. Further constructed HER||UOR electrolyser can deliver 100 and 500 mA cm^-2 at only 1.32 and 1.59 V, and can operate stably at a high current density of 500 mA cm^-2 for 100 h without obvious degradation. This innovative strategy of integrating interfacial-water modulation with near-infrared light excitation provides new impetus for advanced electrocatalytic system.