Efficient Zr-doped FS–TiO2/SiO2 photocatalyst and its performance in acrylonitrile removal under simulated sunlight

Abstract

The aim of this research is to develop an efficient photocatalyst for the degradation of acrylonitrile under simulated sunlight. In this work, Zr-doped FS–TiO2/SiO2 photocatalyst was reported for the degradation of acrylonitrile. Sol–gel method were used for the preparation of Zr-doped FS–TiO2/SiO2 with the molar ratio of Ti:Zr varied from 1:0.07. The prepared photocatalyst was calcined at 450 °C for 2 h. The characteristics of Zr-doped FS–TiO2/SiO2 were examined by X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS). XRD results confirmed the presence of anatase phase of TiO2, and it also reveals that the Zr doping did not change the crystal phase of TiO2. The absorbance of Zr-doped FS–TiO2/SiO2 was significantly enhanced, as confirmed by the red shift in UV–Vis DRS spectra. Zr doping inhibits the recombination of electron–hole pairs and enhanced the photocatalytic activity. The UV–Vis DRS spectra show stronger absorption in Zr-doped FS–TiO2/SiO2 photocatalysts compared to FS–TiO2/SiO2. XPS analysis illustrated the presence of Zr4+, Ti3+, Ti4+, O2− and OH groups in Zr-doped FS–TiO2/SiO2. Then, the photocatalytic activity of the prepared photocatalyst was tested for the photocatalytic degradation of acrylonitrile under simulated sunlight. Zr doping, together with F and S would enhance the surface area and charge separation, making it serve as a more effectual photocatalyst than TiO2 and FS–TiO2/SiO2. The degradation ratio of acrylonitrile reached 79.2% within 6 min of simulated sunlight due to the doping effect of Zr into FS–TiO2/SiO2 photocatalyst. Zr doping could enhance the thermal stability of anatase phase of TiO2 and improve its surface properties.