Nanocrystalline anatase TiO2 limited within the mesoporous channels of SBA-15 has been prepared by in-situ hydrolysis precipitation of Ti(SO4)2 solution and subsequent calcination. The as-synthesized samples were characterized by TEM, BET, XRD, SAXD, Raman, UV-Vis, XPS and XRF techniques, and the results indicated that the nano-TiO2 particles were restricted within the channels and dispersed uniformly without blocking the pores. The Raman and XPS data indicated that most TiO2 particles were deposited on the support without forming a Ti—O—Si bond. The activities of the samples were evaluated by the photo degradation of methyl orange under UV light. The results showed that the TiO2 contents and the size of the particles on the support of SBA-15 affected the catalytic activity obviously, and the samples with TiO2 particle sizes of about 6～7 nm showed the best catalytic activity. Little difference of the activity was observed between the fresh sample and the sample used for 5 times.

Key words: SBA-15, space-restriction, nano-TiO2, photocatalytic activity