Structural and electronic properties of Mo6S8 clusters deposited on a Au(111) surface investigated with density functional theory

Abstract

The stability and the change of the structural and electronic properties of the molybdenum sulfide cluster Mo6S8 upon adsorption on the Au(111) surface are investigated by density functional band-structure calculations with pseudopotentials and a plane-wave basis set. The nearly cubic cluster preferably adsorbs via a face and maintains its structural integrity. It experiences a strong, mostly nonionic attraction to the surface at several quasi-isoenergetic adsorption positions. The analysis of the electronic structure reveals a negligible electron transfer and S-Au hybridized states, which indicate that the cluster-surface interaction is dominated by S-Au bonds, with minor contributions from the Mo atom in the surface vicinity. All results indicate that Mo6S8 clusters on the Au(111) surface are still redox active and can be employed as surface-active agent in the integration of noble metal and ionic or biological components within nanodevices.