Effect of MoS₂ thickness on properties of adsorbed Au nanoparticles

Transition metal nanoparticles supported by MoS₂ is a system of interest in catalytic applications. The question whether the thickness of MoS₂ plays any critical role in determining the chemical activity of the supported nanoparticle is still debated. In this work, using density functional theory based calculations, we study the electronic density of states of Au nanoparticles of varying size supported by single layer, bilayer, and trilayer MoS₂. We find that thickness of MoS₂ support has only a minor effect on the d states (frontier orbitals) of Au nanoparticles. This effect is most notable on Au atoms located at the perimeter of the nanoparticles, which are in contact with the MoS₂ basal plane. Using CO oxidation as a prototype, we comment on the implication of these findings on catalytic properties of MoS₂-supported Au nanoparticles and compare with available experimental data.