Transition-metal dichalcogenides/Mg(OH)2 van der Waals heterostructures as promising water-splitting photocatalysts: A first-principles study
Journal
Physical Chemistry Chemical Physics
Journal Volume
21
Journal Issue
4
Start Page
1791
End Page
1796
ISSN
14639076
Date Issued
2019
Author(s)
Abstract
We performed first-principles calculations of the structural, electronic, and optical properties of heterostructures which consist of transition metal dichalcogenides MX2 (M = Mo, W; X = S) stacked with Mg(OH)2. All the heterostructures are formed by van der Waals forces. The MoS2/Mg(OH)2 and WS2/Mg(OH)2 vdW heterostructures were found to be semiconductors with indirect bandgaps and possess intrinsic type-II band alignment. In particular, a comparison of the band edge positions with the redox potential of water indicates that the heterostructures are potential photocatalysts for water splitting, enabling water reduction on the MX2 layer and water oxidation on the Mg(OH)2 layer. Moreover, the photogenerated charges will be effectively separated in the presence of a large built-in electric field across the interface. In addition, all of the MX2/Mg(OH)2 heterostructures show strong optical absorption in the visible and infrared regions, indicating their promise for application in photocatalytic water splitting. © 2019 the Owner Societies.
SDGs
Publisher
Royal Society of Chemistry
Type
journal article