Hollow Titania Spheres with Movable Silica Spheres\nInside

Abstract

We demonstrate a flexible method for preparing hollow TiO₂ nanospheres with movable silica nanoparticles\ninside (HTNMSNs). In this method, we used monodisperse silica−polystyrene core−shell nanospheres\n(SiO₂-PS-CSNs) sulfonated as templates and prepared the composite shell consisting of TiO₂ and sulfonated\npolystyrene (SPS) through adsorbing or depositing tetrabutyl titanate gel into the SPS shell. Finally the\nHTNMSNs were obtained after removal of all polymers in the composite nanospheres by dissolution or\ncalcinations. We investigated the dependence of the morphologies of HTNMSNs on the thickness of PS\nshells and the size of SiO₂ cores and prepared rare earth doped HTNMSNs by a sol−gel process.