Abstract: Mesoporous solid spheres were synthesized in water-acetone media using cetyltrimethylammonium bromide as the template agent under condition of water-to-acetone molar ratio lying between 1 and 15.Then SiO₂ nano-hollow spheres with micropore structure were synthesized from the mesoporous solid spheres by hydrothermal treatment with n-butylamine as template agent.Results showed that the solid spheres are converted into hollow spheres in crystallization time of 48 h,and diameter of the hollow spheres lying between 600 and 800 nm in size with shell thickness of ca.70 nm and pore size of ca.0.47 nm.

Key words: cetyltrimethylammonium bromide, nano materials, hydrothermal treatment