Preparation, characterization and activity evaluation of heterojunction ZrTi 2O 6/TiO 2 photocatalyst

Abstract

A new heterojunction photocatalyst ZrTi 2O 6/TiO 2 was synthesized by a sol–gel method using ZrOCl 2·8H 2O and tetrabutyl titanate [Ti(OC 4H 9) 4] as the raw materials. The structure and optical properties of the ZrTi 2O 6/TiO 2 photocatalyst were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), and UV–Vis diffuse reflection spectrum (DRS). The photocatalytic activity of the photocatalyst was evaluated by photocatalytic reduction of Cr 2O 7 2− and photocatalytic oxidation of methyl orange (MO). The production of hydroxyl radicals ( OH) during the photocatalytic process was detected by a photoluminescence (PL) technique using terephthalic acid as a probe molecule. The results showed that photocatalytic activity of the ZrTi 2O 6/TiO 2 photocatalyst (mole ratio of Zr/Ti is 1:1, heat treatment at 600 °C for 2 h) was higher than that of other samples and pure-TiO 2. The heterojunction between ZrTi 2O 6 and TiO 2 was confirmed by HR-TEM. And the mechanism of the increased photocatalytic activity was also discussed.