PtSe2/SnS2 heterostructure as a direct Z-scheme photocatalyst for water decomposition

Abstract

The direct Z-scheme heterostructure has attracted much attention due to its strong photocatalytic ability. In the present work, we use density functional theory to explore the electronic and optical properties and photocatalytic mechanism of PtSe2/SnS2 heterostructure. Compared with PtSe2 and SnS2 monolayers, PtSe2/SnS2 heterostructure has smaller band gap and better light absorption capacity. The results of band calculation show that the heterostructure form a band arrangement of type-II. Further work function calculations indicate that the direction of the built-in electric field is PtSe2 to SnS2, indicating the charge transfer mechanism is Z-scheme. In the water decomposition reaction, the free energy calculation results show that water decomposition reaction can occur spontaneously under light. Therefore, PtSe2/SnS2 heterostructure can be used as a potential Z-scheme photocatalyst for hydrogen and oxygen production.