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.