Photocatalytic Reduction of Methyl Orange Using Titania Photocatalyst Codoped with Nitrogen and Gadolinium under Visible Light Illumination
A visible-light-active nitrogen and gadolinium codoped TiO2 catalyst was synthesized by the sol-gel route. For comparison, Gd-doped sample, N-doped sample, and pure titania were prepared through the same method, without adding the corresponding dopants. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD) and Uv-vis spectra. The results showed that the codoped photocatalyst exhibited a smaller size than the undoped titania. The transformation from anatase to rutile was suppressed by doping with N and Gd atoms. Furthermore, the absorbance spectra of N, Gd-codoped TiO2 exhibited a significant red shift to the visible region. The photocatalytic activity of N, Gd-codoped TiO2 was evaluated by photodegradation of methyl orange under visible light irradiation. This codoped sample exhibited enhanced photocatalytic activity compared to N-doped TiO2, Gd-doped TiO2, and pure TiO2. The improvement of the photocatalytic activity was ascribed to the synergistic effects of the N and Gd co-doping.
Yansheng Yin and Xin Wang
S. T. Gu et al., "Photocatalytic Reduction of Methyl Orange Using Titania Photocatalyst Codoped with Nitrogen and Gadolinium under Visible Light Illumination", Advanced Materials Research, Vols. 79-82, pp. 2127-2130, 2009