A one-step facile synthesis of fcc Ru–RuO2 activates superior bifunctionality toward overall alkaline water splitting

Abstract

A simple synthesis of face-centered cubic (fcc) Ru and RuO₂ co-existing electrocatalysts for excellent overall water splitting through reasonable design and assembly protocols remains a formidable challenge. Herein, an fcc Ru–RuO₂/C electrocatalyst was successfully synthesized by the wet impregnation method with the help of an alkaline solvent for the first time by one-step annealing. As expected, the overpotential of fcc Ru–RuO₂/C at 10 mA cm⁻² is 30 mV and 283 mV for the HER and OER, respectively, which is better than the 44 mV and 331 mV of commercial Pt/C and RuO₂. Theoretical calculations reveal that the superior performance is mainly attributed to the synergistic effect of fcc Ru and RuO₂ nanoparticles in changing the electronic structure and making the adsorption behavior of reaction intermediates reach the desirable level, thus greatly accelerating the hydrogen evolution kinetics and reducing the energy barrier of oxygen evolution. This work not only highlights the importance of phase engineering, but also elucidates the necessity for obtaining bifunctional catalysts in which a metal and an oxide co-exist.