Photodegradation of Rhodamine B on Sulfur Doped ZnO/TiO₂ Nanocomposite Photocatalyst under Visible‐light Irradiation

Abstract

Abstract Sulfur doped ZnO/TiO 2 nanocomposite photocatalysts were synthesized by a facile sol‐gel method. The structure and properties of catalysts were characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), UV‐vis diffusive reflectance spectroscopy (DRS) and N 2 desorption‐adsorption isotherm. The XRD study showed that TiO 2 was anatase phase and there was no obvious difference in crystal composition of various S‐ZnO/TiO 2 . The XPS study showed that the Zn element exists as ZnO and S atoms form SO 2− 4 . The prepared samples had mesoporosity revealed by N 2 desorption‐adsorption isotherm result. The degradation of Rhodamine B dye under visible light irradiation was chosen as probe reaction to evaluate the photocatalytic activity of the ZnO/TiO 2 nanocomposite. The commercial TiO 2 photocatalyst (Degussa P25) was taken as standard photocatalyst to contrast the prepared different photocatalyst in current work. The improvement of the photocatalytic activity of S‐ZnO/TiO 2 composite photocatalyst can be attributed to the suitable energetic positions between ZnO and TiO 2 , the acidity site caused by sulfur doping and the enlargement of the specific area. S‐3.0ZnO/TiO 2 exhibited the highest photocatalytic activity under visible light irradiation after Zn amount was optimized, which was 2.6 times higher than P25.