Construction of a multidimensional CdS@MoS2 heterojunction for enhancing the activity and transfer efficiency of photogenerated carriers

Abstract

Developing semiconductor catalysts with high catalytic activity and good economic benefits is an important and challenging task in the field of photocatalysis. In this study, CdS nanosheets with a three-dimensional hollow structure were grown on MoS₂ nanosheets by a hydrothermal method. The hydrogen production of the CdS@MoS₂-25 wt% composites is 8.2 mmol in 3 h, which is 43.71 times that of pure CdS and 4.7 times that of Pt. Density functional theory (DFT) was used to further study the band structure of the composites. The experimental and calculation results show that the addition of co-catalyst MoS₂ reduces the band gap of CdS and accelerates the transfer rate of photogenerated electrons. The construction of a n–n homogeneous structure reduces the interface transmission resistance of the carriers, and the photocatalytic performance of the composite material has been significantly improved. Therefore, the composite material is an excellent semiconductor photocatalyst that can replace precious metals in the reaction. In addition, after adding the promoter MoS₂ to participate in the photocatalytic reaction for 12 h, the composite material still maintains high photocatalytic activity, and the recombination rate of photogenerated carriers is greatly reduced, which proves that the photocatalyst has good stability.