Achieving efficient alkaline hydrogen evolution reaction on long-range Ni sites in Ru clusters-immobilized Ni3N array catalyst

Hydrogen (H-2) production from alkaline water electrocatalysis is economically appealing yet significantly hindered by the sluggish H2O adsorption and H* binding kinetics on active sites during hydrogen evolution reaction (HER). Herein, we interfacially immobilize Ru clusters on the hierarchical nickel nitride (Ru-Ni3N) nanosheet arrays via the filling of Ru3+ species into the metal vacancies of nickel hydroxide precursors and the subsequent controllable nitridation. The optimized Ru-Ni3N shows the outstanding HER performance, affording a 30-fold rise in the intrinsic activity of Ni sites, a outperforming-Pt/C overpotential at >= 125 mA cm(-2) while remaining a robust stability. We further establish by a combined study of density functional theory (DFT) calculations with experimental analyses that long-range Ni sites around Ru sites act as active sites via the electron delocalization, remarkably weakening the H2O adsorption and H* binding barriers for enhancing the alkaline HER kinetics. Moreover, it also demonstrates an excellent pH-universal HER and overall water splitting performance.

Automated summary

In this study, Ru clusters were immobilized on nickel nitride nanosheet arrays, resulting in improved alkaline water electrocatalytic hydrogen production. The presence of long-range Ni sites around the Ru sites was found to significantly enhance the alkaline HER kinetics, as observed through theoretical calculations and experimental analysis.