Quantum-Chemical Study of Adsorption of Tl+ Ions on Au(111)

Resumo

A density-functional study of the interaction of Tl⁺ ions with the gold surface is carried out based on the cluster model of the metal surface. The geometry and energy characteristics are assessed. Ion Tl⁺ exists on the surface in its ad-ionic form. The electronic state of the Au–\({\text{Tl}}_{{{\text{ads}}}}^{ + }\) system is analyzed. The involvement of the adsorbed thallium ion and the neighboring gold atoms in the formation of molecular orbitals of this system is assessed. Their formation is preferentially contributed by s-orbitals of thallium and d-orbitals of gold. It is found that in alkaline media, Tl⁺ ions coadsorb with OH^– ions to form TlOH on the surface. The possible geometrical configuration of their associate with OH^– ions is determined for the low and high surface coverages by OH^– ions.