Controllable Synthesis and Photocatalytic Activity of Anatase TiO2 Single Crystals with Exposed {110} Facets

Anatase TiO2 single crystals with a high percentage of the high surface energy {110} facets have been successfully synthesized in a simple and economical way using a modified hydrothermal technique in the presence of hydrogen peroxide and hydrofluoric acid. The morphology and structure of the TiO2 single crystals were characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The photocatalytic activity of the TiO2 crystals for the degradation of methylene blue dye was investigated by ultraviolet light irradiation. The effects of the amounts of HF and H2O2 on the morphology of TiO2 have been studied. The reaction time and temperature have also been investigated. In the TiO2 single crystals, the {001} and {110} facets are present at the same time. The results indicated that a high yield of single crystals with exposed {110} and {110} facets could be obtained by adjusting the reaction time, reaction temperature, and amounts of HF and H2O2. The anatase TiO2 single crystals with exposed {110} facets showed higher photocatalytic activities than those without.