Sonochemical incorporation of nanosized TiO2 inside mesoporous silica with high photocatalytic performance

Highly dispersed of nanosized TiO2 inside mesoporous silica was reported for the first time by using a sonochemical approach. The amount of TiO2 inside the pores of SBA-15 has been controlled through the irradiation time. Characterizations by powder X-ray diffraction, nitrogen adsorption-desoprtion. X-ray photoelectron spectra (XPS), UV-vis spectroscopy and Fourier transform infrared (FT-IR) spectra have been carried out to understand the nature of TiO2 formed inside the pores. At low titania loading of 7-18.5 wt.%, TiO2 is monoatomically dispersed and the pore size of SBA-15 is not altered. With higher titania loading (28 wt.%), the incorporation of TiO2 inside the mesopores of SBA-15 results in a slight reduction of the pore size without blocking the pores. The photocatalytic activities of the resultant nanocomposites with titania loading of 28 wt.% were assessed by measuring the percentage degradation of methyl blue (MB) using UV-vis spectroscopy. The results indicate the sample exhibits an improved photocatalytic performance together with a high adsorption capability as compared with that of the commercial P25. This facile strategy may be extended to other metal oxides, with potential high performance in many applications. (C) 2009 Elsevier Inc. All rights reserved.