Photocatalytic decomposition of methylene orange using nitrogen-doped titania prepared by ultrasonic technique

Nitrogen-doped titania (TiO₂) photocatalysts were prepared by sol-gel process coupled with ultrasonic irradiation at room temperature. The photocatalytic decomposition of methyl orange (MO) solution under ultraviolet and visible light irradiation was used as a probe reaction to estimate their photocatalytic activities. The physico-chemical properties of the samples were investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). A more uniform nanoparticle dispersion, marginally higher surface area, smaller grain size, and higher phase purity are some advantages of preparing TiO₂ by the ultrasonic technique. The nitrogen-doped titania prepared by ultrasonic technique were more effective than the samples prepared by conventional stirring method. Its UV–Vis diffuse reflectance spectra was red shifted compared to the un-doped sample and it showed high decomposition of MO under ultraviolet as well as visible light irradiation. (paper)