Photocatalytic properties of TiO2 and TiO2/WO3 films applied as semiconductors in heterogeneous photocatalysis

Abstract

Several semiconductor materials were used in the photodegradation of organic compounds. In this work, the films were obtained by deposition in FTO (Fluorine-Doped Tin Oxide) coated glass plates, solutions containing TiO2 and TiO2/WO3 fibers, synthesized by electrospinning and treated between 650–800 °C, to be used as semiconductors in heterogeneous photocatalysis. The morphology was identified by scanning electron microscopy (SEM), the crystalline structures were identified by X-ray diffraction (XRD) and the photocatalytic properties were analyzed by means of photodegradation analyzes of 125 mL of a 20 ppm solution of methyl orange dye under ultraviolet light. It should be noted that the formation of the crystalline phases is closely linked to the heat treatment temperature. The transition from the anatase phase to rutile is expected for heat treatments above 500 °C. The results indicate that the films based on fibers showed good photoactivity and can be used as photocatalysts, since the doping of TiO2 films with tungstic acid improved the photocatalytic efficiency of the materials by the significant reduction of the band gap range of TiO2.