Two-dimensional CdO/PtSSe heterojunctions used for Z-scheme photocatalytic water-splitting

Two-dimensional (2D) Z-scheme photocatalytic systems can usually achieve high catalytic efficiencies by separating the photoinduced carriers attend water redox reaction at different positions and providing much stronger overpotentials to drive water redox reaction. However, it is filled with challenges to develop Z-scheme photocatalysts (PCs) due to the strict requirement of proper band edge alignment and built-in electric field. Based on hybrid density functional, the photocatalytic properties of CdO/PtSSe heterojunctions (HJs) including CdO/SPtSe and CdO/SePtS HJs are investigated. The analysis of electronic structures, work functions, and charge transfer suggest the proper band alignments and the existence of built-in electric field from CdO to PtSSe, confirming the Z-scheme photocatalytic mechanism of CdO/SPtSe and CdO/SePtS HJs. The light absorption curves show that CdO/SPtSe and CdO/SePtS HJs could harvest sufficient solar light. Furthermore, both CdO/SPtSe and CdO/SePtS HJs can provide sufficient overpotentials to finish water redox reaction. These findings indicate that CdO/SPtSe and CdO/SePtS HJs are promising water-splitting PCs.