Functionalization of two-dimensional 1T′-ReS2 with surface ligands for use as a photocatalyst in the hydrogen evolution reaction: a first-principles calculation study

Abstract

Density functional theory calculations were performed to tune the band edge positions of two-dimensional 1T′-ReS₂ by functionalization with surface ligands. A shift in the band edge was caused by the intrinsic dipole of the ligand and the induced dipole at the ligand/ReS₂ interface. The upward shift in the band edge was tuned over a large range by choosing suitable polar ligands, controlling the surface coverage by the ligand, functionalizing the ligand and building heterostructures. The C₆H₅CN/ReS₂/MoS₂ and C₆H₅CH₂CN/ReS₂/MoS₂ van der Waals heterostructures are ideal candidates for use as photocatalysts in the splitting of water as a result of their strong absorption in the visible region, suitable band edge positions, reduced electron–hole recombination and good stability. Our findings show the potential for creating novel photocatalysts based on van der Waals heterostructures of ReS₂.