Boosting solar driven hydrogen production rate of Cu2S@CdS p-n heterostructures and CuxCd1-xS nanorods.

To improve CdS photocatalytic activity, both Cu x Cd 1- x S nanorods and Cu 2 S@CdS p-n heterostructures have been prepared with a simple solvothermal method. The results showed that the maximum H 2 generation rate is equal to 10 mmol h−1 g−1 and 12.1 mmol h−1 g−1 for samples 0.3-Cu 2 S@CdS and Cu 0.1 Cd 0.9 S, respectively, which are nearly 9 and 12 times larger than that of CdS (1.2 mmol h−1 g−1) without using Pt as the co-catalyst. The measurements of the light absorption revealed that the samples Cu 2 S@CdS p-n heterostructures and Cu x Cd 1- x S nanorods have an increased visible light absorption. Band structure revealed that Cu 2 S@CdS p-n composite is a type-II heterostructure, which facilitates the separation of photoexcited charge carriers. Furthermore, as the Cu-doping CdS introduced a defect level, which induced the increase of carrier density, and the defect energy level in Cu 0.1 Cd 0.9 S and the band energy in CdS form a type-II heterostructure. Due to the appropriate band structure and stronger light absorption, Cu 2 S@CdS p-n heterostructures and Cu+-doping CdS demonstrated an improved photocatalytic activity and stability. Schematic illustration of band structure diagram and photogenerated carriers' transfer of Cu 2 S@CdS and Cu 0.1 Cd 0.9 S/CdS under visible light irradiation. [Display omitted] • Type-II p-Cu 2 S@n-CdS heterostructures and Cu x Cd 1- x S composites were prepared. • The optimized Cu 2 S@CdS copmposites have a H 2 evolution rate of 10 mmol h−1 g−1. • The optimized Cu x Cd 1-x S composites have a hydrogen rate of 12.1 mmol h−1 g−1. [ABSTRACT FROM AUTHOR]