A general and rapid synthesis of metal sulphides hollow spheres that have properties enhanced by salt-assisted aerosol decomposition: a case of ZnS and other multicomponent solid solutions

Abstract

Synthesis of hollow structures of metal sulphides generally involves various templates and complex chemical processing. In the present study, a general and rapid method of salt-assisted aerosol decomposition (SAD) is presented for the synthesis of hollow spheres of various metal sulfides, including ZnS, ternary sulfides, and solid solutions. The NaCl salt plays a critical role in the formation of hollow spheres of metal sulfides. The hollow spherical microstructure was formed from solid by using a small amount of water soluble NaCl salt. The formation of metal sulphide hollow spheres differs from previous mechanisms and is referred to as molten salt heterogeneous nucleation (MSHN). The present method offers the most promising advantage for controlling the multicomponent composition of hollow spheres. Furthermore, hollow spheres of sulphides have much enhanced properties such as photoluminescence of ZnS:Mn²⁺ and photocatalytic dye degradation of ZnIn₂S₄ due to the role of molten salt in the promotion of crystallization, The present method could be explored further by applying the process to other compounds such as sulfides, oxides, and nitrides.