Zn 0 @ZnS Core‐Shell Nanoparticles via Oxidation of Intermediate Zn 0 Nanoparticles

Zn 0 @ZnS core‐shell nanoparticles were prepared via reduction of ZnCl 2 to Zn 0 nanoparticles and subsequent partial oxidation with elemental sulfur. The intermediate, highly reactive Zn 0 nanoparticles were obtained by sodium naphthalenide ([NaNaph]) reduction of ZnCl 2 in tetrahydrofuran (THF). After centrifugation, the Zn 0 nanoparticles were redispersed in a solution of sulfur in toluene and oxidized by subsequent heating to reflux. According to electron microscopy (HRTEM, HAADF‐STEM), the Zn 0 @ZnS core‐shell nanoparticles exhibit a mean outer diameter of 12 ± 4 nm, consisting of an inner Zn 0 core (8 nm in diameter) and a ZnS shell (2 nm in diameter). HRTEM and XRD confirm the crystallinity of both core and shell. The Zn 0 @ZnS nanostructure shows synergistic properties of core and shell: the ZnS layer efficiently passivates the reactive Zn 0 metal core against oxidation, whereas the optical properties point to dominating metallic behavior of the Zn 0 metal core despite of the ZnS shell.