Metallic CoS2 nanosheets promote photocatalytic hydrogen production of CdS nanoparticles

In this paper, CdS nanopaticles were first prepared by a simple hydrothermal method, and then CoS 2 nanosheet was grown in situ on CdS, thereby successfully constructing CdS/CoS 2 binary heterojunction photocatalyst. The prepared CdS/CoS 2 -15 % nano-heterojunction exhibited the highest hydrogen yield in photocatalytic water decomposition (45.89 mmol h −1  g −1 ), which was 112 times higher than that of single CdS. The high photocatalytic activity and relatively high stability of the CdS/CoS 2 -15 % nano heterojunction could be mainly attributed to the loading of the co-catalyst CoS 2 . Density functional theory (DFT) calculations show that CoS 2 has properties similar to metals, and the Fermi level of CoS 2 are lower than that of CdS. The sheet-like CoS 2 and its higher binding energy provide favorable conditions for the adsorption of hydrogen ions, and its metallic like properties and lower Fermi level help CoS 2 effectively obtain photo generated electrons from CdS, which effectively promotes the production of hydrogen gas. This study provides a useful idea for the development of cost-effective co-catalysts to assist other semiconductor materials in improving the hydrogen production efficiency of visible-light-driven photolysis of water.