Abstract: Firstly，SiO2 shell precursor was prepared with the sol-gel method using tetraethoxysilane and methyltrimethoxysilane as silica source. Then the emulsion droplets were solidified through the self-templating method with a solidifying agent. After the outer surface of the emulsion droplets was solidified，they could serve as self-templates. Subsequently，the unreacted precursor within the emulsion droplets became solidified onto the templates as shell，producing hollow SiO2 microspheres. The effects of amount of deionized water and stirring rate on the morphology and particle size of hollow silica microspheres were investigated. The morphology，particle size distribution and surface properties were characterized with scanning electron microscopy (SEM)，transmission electron microscopy (TEM)，dynamic light scattering (DLS)，and nitrogen adsorption，respectively. Experiment results indicated that the resulting microspheres with an average particle size of 592 nm were perfectly spherical，and the surface exhibited microporous/mesoporous structure. In addition，the particle size of hollow silica microspheres decreased with increasing amount of deionized water and stirring rate.

Key words: silica, hollow microspheres, sol-gel, self-templating method, particle size distribution