Preparation of Cr‐doped TiO₂/SiO₂ Photocatalysts and their Photocatalytic Properties

Abstract

Abstract Cr‐doped TiO 2 /SiO 2 nanostructured materials were prepared employing a layer‐by‐layer assemblym technique. TiO 2 colloids were synthesized by a sol‐gel method using TiCl 4 as a precursor. The experimental results showed that sphere‐type TiO 2 particles on SiO 2 exhibited uniform shape and a narrow size distribution. The amount of Ti (wt %) increased as a function of the number of the coating layers. The coatingv layers was composed of anatase titania nanocrystals at 550 °C. The onset of band‐gap transition for Crdoped TiO 2 /SiO 2 showed a red shift compared with that for the undoped TiO 2 /SiO 2 . And the photocatalytic activity of Cr‐doped TiO 2 /SiO 2 was higher than that of undoped sample.