Atomically Dispersed Ruthenium on Nickel Hydroxide Ultrathin Nanoribbons for Highly Efficient Hydrogen Evolution Reaction in Alkaline Media

Abstract Achieving highly efficient hydrogen evolution reaction (HER) in alkaline media is a great challenge. Single‐atom catalysts with high‐loading amount have attracted great interest due to their remarkable catalytic properties. Herein, by using nickel foam as the substrate, the authors design and precisely synthesize atomic ruthenium (Ru)‐loaded nickel hydroxide ultrathin nanoribbons (R‐NiRu) with a high atomic Ru loading amount reaching ≈7.7 wt% via a one‐step hydrothermal method. The presence of concentrated Cl⁻ in the synthetic system is beneficial for constructing ultrathin nanoribbons, which, with abundant edge OH groups, make it easy to trap atomic Ru. Taking advantage of the synergy between atomic Ru and the nanoribbon morphology of nickel hydroxide, R‐NiRu exhibit a low overpotential of 16 mV for HER at 10 mA cm⁻² and a Tafel slope of 40 mV dec⁻¹ in aqueous 1.0 m KOH solution, which are superior to those of commercial Pt/C (overpotential of 17 mV at 10 mA cm⁻², Tafel slope of 43 mV dec⁻¹). Density functional theory (DFT) calculation results demonstrate that atomically dispersed Ru can significantly reduce the HER energy barrier. Moreover, R‐NiRu maintains exceptional stability after 5000 cyclic voltammetry cycles. This efficient and facile synthetic strategy provides a new avenue for designing efficient catalysts.