Secondary hydrogen spillover enhanced photocatalytic hydrogen evolution activity in Ru/TiO2–GO

Abstract

An effective strategy for enhancing photocatalytic hydrogen evolution reaction (HER) activity is the implementation of the hydrogen spillover effect. Herein, a Ru/TiO₂–GO (graphene oxide) catalyst was fabricated by means of simple hydrothermal and ultrasound-assisted techniques. By using the secondary hydrogen spillover process, which involves the transfer of active hydrogen species from Ru to TiO₂ and then further to GO, the hydrogen evolution activity of Ru/TiO₂–2GO reached 23.9 mmol g⁻¹ h⁻¹, which is 45.2 times and 3.85 times greater than that of TiO₂ (0.53 mmol g⁻¹ h⁻¹) and Ru/TiO₂ (6.2 mmol g⁻¹ h⁻¹), respectively. Controlled experiments and detailed characterization have revealed that the dispersion of GO on the support provides critical desorption sites for H*, thereby promoting the cleavage of Ti–H bonds. H* undergoes secondary spillover onto GO and desorbs to generate H₂, enhancing the photocatalytic HER activity. This study enhances the photocatalytic activity of water splitting for hydrogen production by employing a secondary hydrogen spillover strategy, thereby presenting a novel approach for the design of efficient hydrogen production catalysts.