CdS quantum dots and tungsten carbide supported on anatase-rutile composite TiO2 for highly efficient visible-light-driven photocatalytic H2 evolution from water

Developing efficient photocatalysts with noble-metal-free co-catalysts for visible-light-driven photocatalytic H-2 evolution from water is appealing yet remains challenging. Herein, by supporting CdS QDs with diameters smaller than 5 nm and tungsten carbide (WC) on TiO2, a CdS/WC/TiO2 photocatalyst was fabricated for visible-light-driven photocatalytic H2 evolution from aqueous solution containing lactic acid as an electron donor. The optimal H-2 evolution rate on CdS/WC/TiO2 (624.9 mu mol h(-1)) is comparable to the H-2 evolution rate on CdS/Pt/TiO2 (636.2 mu mol h(-1)), indicating that WC is a good candidate to substitute Pt as the co-catalyst. Formation of an anatase-rutile composite TiO2 with a rutile content of 68.7% makes great contribution to the efficient H-2 evolution on CdS/WC/TiO2. The rutile-anatase composite TiO2 promotes the separation of the photogenerated electron-hole pairs and thereby benefits the efficient H-2 evolution reaction. The present work is expected to be helpful in designing efficient noble-metal-free photocatalysts for H-2 evolution from visible-light-driven photocatalytic water splitting.