Theoretical investigation of Ag_n@(ZnS)_(42)(n=6-16) using first principles:Structural,electronic and optical properties

Ag@ZnS nanoparticles display enhanced photocatalytic efficiency and good photoelectric properties compared to their single-component counterparts in the process of forming a core-shell structure using an Ag cluster as the inner core of a ZnS outer shell. In this study, first-principles calculations were used to investigate the structural, electronic, and optical properties of Ag_n@(ZnS)₄₂ (n = 6-16) core-shell nanocomposites. The calculated results show significant even-odd oscillations in the structural stability, that is, Ag@ZnS nanostructures with an even number of Ag_n core atoms are relatively more stable than those with an odd number of core atoms. The second-order differences in the total energies (Δ₂E) and the core-shell interaction energy E_cs indicate that a Ag₁₂@(ZnS)₄₂ nanostructure is the most stable configuration. A significant red shift was found in Ag_n@(ZnS)₄₂ nanoparticles in the absorption spectrum compared with a (ZnS)₄₈ nanostructure, which is likely attributed to the strong electron interactions between the Ag core and the ZnS shell.