Synthetic route to the nano-sized titania with high photocatalytic activity using a mixed structure-directing agent

The nanocrystalline titania was synthesized, using a cetyltrimethylammonium bromide and nonsurfactant glycerol as a mixed structure-directing agent, by hydrothermal method. Combination of the mixed structure-directing agent and hydrothermal method resulted in the formation of nanocrystalline titania (HT2) with smaller size, higher crystallinity and much larger surface area. The samples were characterized by XRD, TEM and N2 adsorption-desorption techniques. The relationship between the photocatalytic activity of the samples in the degradation of methyl orange and surface area, crystallinity and particle size was investigated. HT2 shows similar photocatalytic activity to P25. It was found that the surface area (ca. 285.3 m2 g−1) and pore diameter (4-6 nm) of HT2 was higher and its photocatalytic activity was best among the synthesized samples. This approach can be extended to synthesize different oxide nanocrystals with novel structures and properties.