Construction of direct Z-Scheme photocatalysts for overall water splitting using two-dimensional van der waals heterojunctions of metal dichalcogenides

Abstract

The direct Z-scheme system constructed by two-dimensional (2D) materials is an efficient route for hydrogen production from photocatalytic water splitting. In the present work, the 2D van der Waals (vdW) heterojunctions of MoSe 2 /SnS 2 , MoSe 2 /SnSe 2 , MoSe 2 /CrS 2 , MoTe 2 /SnS 2 , MoTe 2 /SnSe 2 , and MoTe 2 /CrS 2 are proposed to be promising candidates for direct Z-scheme photocatalysts and verified by first principles calculations. Perpendicular electric field is induced in these 2D vdW heterojunctions, which enhances the efficiency of solar energy utilization. Replacing MoSe 2 with MoTe 2 not only facilitates the interlayer carrier migration, but also improves the optical absorption properties for these heterojunctions. Excitingly, the 2D vdW MoTe 2 /CrS 2 heterojunction is demonstrated, for the first time, to be 2D near-infrared-light driven photocatalyst for direct Z-scheme water splitting. © 2018 Wiley Periodicals, Inc.