Mesoporous titania with high crystallinity during synthesis by dual template system as an efficient photocatalyst

Abstract

The mesoporous titania, designated MS-TiO 2 was successfully prepared via a new combination of pluronic P123 and poly ethylene glycol templates and acetic acid as the hydrolytic retardant with extremely high crystallinity achieved during synthesis process. MS-TiO 2 has remarkable thermal stability, biporous mesostructure and superior photocatalytical activity for phenol degradation and mineralization as compared to mesoporous TiO 2 prepared using single template systems. The anatase–rutile phase transformation of the MS-TiO 2 was not observed up to 800 °C. The mesoscale order of MS-TiO 2 was retained after thermal treatment up to 450 °C as confirmed by low angle X-ray diffraction and transmission electron microscopy analyses. It maintained its pore properties at high temperature of 700 °C with a significant pore size 10.4 nm and pore volume 0.11 cm 3/g. MS-TiO 2 has biporous mesostructure with the small mesopore of 5.5 nm and the large mesopore of 8.7 nm in mean pore diameters. The MS-TiO 2 showed higher photocatalytic activity for phenol degradation than mesoporous titania prepared using single templates and standard system of Degussa P25. The remarkably high catalytic activity of the MS-TiO 2 is attributed to its high crystallinity and biporous mesostructure. The phenol mineralization was confirmed using high performance liquid chromatography and total organic carbon analyses.