A First Principles Study of 2D-2D CdS/MoS2 van der Waals Heterostructure

Recently 2D heterostructures have attracted much attention in the field of photocatalytic water splitting. Here, we demonstrate 2D-2D van der Waals heterostructure CdS/MoS2 with improved efficiency for the water splitting hydrogen production. We designed and explored the structural properties of CdS and MoS2 monolayers and observed similar hexagonal atomic arrangement for both monolayers. By constructing the heterostructure, we aim to introduce interfacial dipoles inside the material, which will separate the charge carriers efficiently. For the analysis of electronic properties, band structure and density of states calculations were performed for the CdS/MoS2 heterostructure and compared with those of isolated CdS and MoS2 monolayers. The band gap of the heterostructure is indirect and obtained to be 1.19 eV. This Reduced band gap of the heterostructure indicates good visible light absorption, which is favorable for photocatalysis.