Abstract
A convenient chemical conversion method that allows the direct preparation of nanocrystalline ZnE (E=O, S, Se) semiconductor spheres and hollow spheres, as well as their core/shell structures, is reported. By using monodispersed ZnO nanospheres as a starting reactant and in situ template, ZnS, ZnSe solid and hollow nanospheres, and ZnO/ZnS and ZnO/ZnSe core/shell nanostructures have been obtained through an ultrasound-assisted solution-phase conversion process. Another core/shell-type ZnO nanosphere/CdS nanorod and ZnO nanosphere/CdS nanoparticle composites have also been successfully synthesized via a facile sonochemical route. Different sulfur sources used in reaction systems resulted in different surface coating statuses. The photoluminescence and electrogenerated chemiluminescence properties of the as-prepared nanocrystals were investigated. Ultrasonic irradiation has also been used to obtain uniform PbS nanospheres, SrMoO_4 3D spherical superstructure, BaF_2 hollow nest-like nanostructure, and so on. The ultrasound-induced self-assembly growth procedure has been proposed for the possible formation mechanism of above products.
