UV/ozone-assisted low temperature preparation of mesoporous TiO2 with tunable phase composition and enhanced solar light photocatalytic activity

In this paper, we report a UV/ozone-assisted method for low temperature preparation of mesoporous TiO2 with controlled crystalline phase. The results showed that the crystallization of mesoporous TiO2 can occur at temperatures as low as 100 degrees C under UV/ozone irradiation. Highly crystalline mesoporous anatase TiO2 was obtained after UV/ozone treatment at 200 degrees C. The phase transformation from anatase to rutile occurred during the UV/ozone treatment at 300 degrees C and mesoporous bicrystalline TiO2 with a controlled mixture of anatase and rutile phases was prepared by adjusting the exposure time. The photocatalytic performance of the mesoporous TiO2 strongly depends on the crystal structures and the bicrystalline mesoporous TiO2 exhibits remarkably enhanced solar light photocatalytic activity. This technique can be useful for low temperature preparation of crystalline mesoporous titania on various substrates and may be generalized to the synthesis of other materials.