Implanting HxYO2−x sites into Ru-doped graphene and oxygen vacancies for low-overpotential alkaline hydrogen evolution

Abstract

Abstract Highly efficient electrocatalysts for the hydrogen evolution reaction (HER) are essential for sustainable hydrogen energy. The controllable production of hydrogen energy by water decomposition depends heavily on the catalyst, and it is extremely important to seek sustainable and highly efficient water-splitting electrocatalysts for energy applications. Herein, bimetallic RuYO 2 − x nanoparticles (Ru: 8.84 at.% and Y: 13 at.%) with high densities and low loadings were synthesized and anchored on graphene through a simple solvothermal strategy by synthesizing hydrogen yttrium ketone (H x YO 2 − x ) serving as an inserted medium. Electron microscopy demonstrated that the RuYO 2 − x /C was composed of densely arranged particles and graphene flakes. Electrochemical results showed that the RuYO 2 − x /C had a remarkably low overpotential of η 10 = 56 mV at a current density of 10 mA cm −2 in alkaline media, a Tafel slope of 63.18 mV dec −1 , and 24 h of stability. The oxygen vacancies of RuYO 2 − x /C provided a large proton storage capacity and a strong tendency to bind hydrogen atoms. DFT calculations showed that RuYO 2 − x/ C catalysts with more Ru-O-Y bonds and V O dramatically decreased the energy barrier for breaking H-OH bonds. Moreover, the robust metal-support interactions provided optimized energies for hydrogen adsorption and desorption, which explained the high activity and favorable kinetics for RuYO 2 − x /C catalytic hydrogen precipitation in alkaline electrolyte reactions. This work presents a hydrogen insertion method for the preparation of low-loading, high-density, high-performance and stable water decomposition catalysts for hydrogen production.