/Cu(111) Decorated with Au Nanoparticles for Photocatalytic Applications

Nanostructured materials composed of two dimensional (2D) semiconductors decorated with metal nanoparticles are predicted to be efficient photocatalysts for water splitting and CO₂ reduction. In this research, 2D-MoS₂ is prepared on various substrates such as Cu(111), Au(111), Si(111) using a multistep procedure based on Mo evaporation in an H₂S environment under ultrahigh vacuum conditions. Subsequently, the 2D material is decorated with Au nanoparticles via physical vapor deposition. The composition and crystallinity of the 2D-MoS₂ are investigated by Auger electron spectroscopy and low energy electron diffraction, while the electronic structure of the Au particles as well as the band alignment at the Au-MoS₂ junction is investigated by XUV photoemission spectroscopy. Besides the preparation and characterization of Au/2D-MoS₂, this contribution will also provide details about the interaction of CO₂ and H₂O molecules with the Au/2D-MoS₂ photocatalyst, which is investigated via temperature programmed desorption/reaction in the presence and absence of light irradiation and will correlate the catalytic and photocatalytic activity with the Au particle size and 2D-MoS₂ morphology.