GeSe/MoS2 van der Waal heterostructure a potential photocatalyst candidate for overall water splitting: A DFT study

In the present work, GeSe/MoS2 van der Waals heterostructure (vdWH) is investigated using density functional theory for photocatalytic water splitting application. The structural stability, electronic properties and optical absorption of GeSe, MoS2 and vdWH are determined to check their suitability for water splitting through photocatalysis. The results of band structure and density of states confirmed application of designed vdWH as photocatalyst for water splitting as it satisfies the redox potential of the water. Since, the type-II heterostructure charge transfer has been observed between monolayers which further prohibited the recombination rate of photogenerated electrons and holes, hence increased the lifetime of the carriers. Furthermore, the strong optical absorption of the designed vdWH, in both visible spectrum and ultraviolet has also been observed. The results indicated that in the presence of built-in electric field, the Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) can be triggered spontaneously. The findings show that GeSe/MoS2 vdWH may be used as photocatalyst for water splitting.