Oxygen-deficient TiO2 and carbon coupling synergistically boost the activity of Ru nanoparticles for the alkaline hydrogen evolution reaction

Abstract

The limited reserves and sluggish H₂O dissociation process of Pt necessitate the development of low-cost catalysts with enhanced catalytic performance in the alkaline hydrogen evolution reaction. Here, Ru nanoparticles supported on oxygen-deficient TiO₂@carbon hybrids (Ru/TiO₂-V_O@C) were efficiently fabricated via one-pot carburization of RuCl₃, TiO₂(B) and melamine. The melamine additive assists the formation of oxygen vacancies (V_O) and Ru⁰ and introduces a beneficial carbon dopant. Ru/TiO₂-V_O@C features a remarkably enhanced alkaline HER performance with an overpotential of only 64 mV to attain a current density of 10 mA cm⁻². This satisfactory catalytic performance originates from the strong electronic interaction between Ru and TiO₂-V_O and the synergistic interplay between TiO₂-V_O and the carbon dopant. This synergistic cooperation improves the conductivity, promotes the dissociation of H₂O and optimizes the hydrogen adsorption free energy. This study opens an avenue for the reasonable design of multi-component nanostructures and gives in-depth insights into the alkaline HER mechanism.