A facile method to synthesize hierarchical SiO2@CdSe and CdSe hollow spheres

In this paper, a facile method was developed to synthesize SiO₂@CdSe particles by using silica colloidal spheres which efficiently avoided complex prior surface modification. In the experiment, ammonia was introduced to activate silica colloidal spheres with negative charge, which acted as active sites for the nucleation of CdSe nanocrystals around silica colloidal spheres. Then the corresponding CdSe hollow spheres were obtained by dissolving the silica cores. The TEM results exhibited CdSe hollow spheres were consisted of nanorods. On the basis of experimental results, the formation process of the hollow spheres was studied and possible growth mechanism for one-step coating process was proposed.