First‐principles calculation of Au n @(ZnS) 42 ( n = 6–16) hetero‐nanostructure system

The structure stability and electronic and optical properties of a series of Au@ZnS core–shell nanocomposites with different sizes were investigated theoretically by first‐principle calculation based on density functional theory (DFT). A series of Au n @(ZnS) 42 structures with different n values from 6 to 16 were optimized and obtained. Based on the core–shell interaction energy and second‐order difference of total energy of these structures, it is found that Au 13 @(ZnS) 42 turns out to be the most stable structure. Based on the model of Au 13 @(ZnS) 42 , the density of state and charge density difference were studied and provided a deeper understanding of the electronic structures of Au@ZnS. On the other hand, absorption coefficient and dielectric function were investigated to study the optical properties. It is found that an optical absorption peak appears in visible‐light region, indicating that the photo‐catalytic can be improved prominently due to the optical redshift to visible‐light region when forming core–shell structure from ZnS bulk. And the redshift phenomenon accords well with experiment. Furthermore, the electronic structure further confirms the existence of redshift of optical absorption spectrum.