The dual functional roles of Ru as co-catalyst and stabilizer of dye for photocatalytic hydrogen evolution

• A high-efficient stable EY-Ru system was built for photocatalytic H2 evolution.
• The hydrogen evolution amount in 3 h over Ru was 4.9 times higher than that of Pt.
• The interaction of Ru and EY promoted electron transfer and reduced EY decomposition.

In this work, a highly efficient and relatively stable photocatalyst, Eosin Y (EY)-sensitized metal Ru for hydrogen generation under visible light irradiation, was developed. Ru-EY photcatalyst showed 4.9 times higher hydrogen generation activity than Pt-EY under the same conditions. The highest apparent quantum efficiency (AQE) of Ru-EY photocatalyst was found to be 46.3% at the wavelength of 520 nm. XPS and TEM characterization results and fluorescence decay experiments indicated that there was a strong interaction between Ru and EY. This interaction could enhance the utilization of photogenerated electron and reduce the degradation rate of EY under visible light irradiation, thereby enhancing the photocatalytic performance of Ru-EY system.