Dual Cocatalysts Loaded Type I CdS/ZnS Core/Shell Nanocrystals as Effective and Stable Photocatalysts for H2 Evolution

The photocatalytic activity and stability of nanocrystals (NCs) are two important issues for their application in photocatalysis. In this work, we report a combined method to promote the photocatalytic activity as well as the stability of CdS NCs for photocatalytic H2 evolution. ZnS shell was grown on CdS NCs forming type I core/shell CdS/ZnS nanocrystals (NCs) to restrain the photocorrosion and passivate the trap states on CdS NCs. Thereafter, dual cocatalysts were loaded to promote the separation and transfer of electrons and holes from the core to outer surface for photocatalytic reactions. It is found that Pt and Ni are effective reduction cocatalysts (RCs) while PdS and PbS are effective oxidation cocatalysts (OCs) for promoting the charge separation and transfer. This strategy was also proved to be effective for other type I core/shell NCs, such as CdTe/CdS/ZnS NCs.