Preparation and photocatalytic performance of a Pr-SiO2-TiO2 nanocomposite for degradation of aqueous dye wastewater

A novel Pr-SiO2-TiO2 nanocomposite catalyst was prepared by a sol gel method and its photocatalytic degradation efficiency on Rhodamine B (RhB) was examined in aqueous dye wastewater. The structure and morphology of the catalyst samples were characterized using by low-temperature N-2 adsorption, thermogravimetry-differential thermal analysis (TG/DTA), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier-Transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The Pr-SiO2-TiO2 nanocomposite was found to exhibit a much higher photocatalytic activity under both UV and visible light irradiation as compared to a commercial TiO2 photocatalyst. The photodegradation efficiency of RhB (5 mg/L) were greater than 95% under UV light irradiation and 91% under visible light irradiation for 90 min, respectively. It is suggested that the synergetic effect between Pr-SiO2 and TiO2 not only inhibit the crystal growth and anatase-to-rutile transformation, but also extend the light response to the visible region. The prepared represents a noteworthy contribution to the study of pollutant degradation in dye wastewaters.