IMPROVEMENT OF PHOTOCATALYTIC ACTIVITY OF TiO2 VIA COMBINED ROUTE OF METAL DOPING AND SURFACE ACIDIFICATION

In the present work, a combined route involving first doping of iron or neodymium ions via sol–gel method followed by acidification of the metal-doped TiO2 particles for the improvement of the photocatalytic capability of TiO2 was reported. The obtained metal-doped/acidified TiO2 photocatalysts were thoroughly characterized by X-ray diffraction, Fourier transform infrared analysis, and photoluminescence emission spectra. At the same time, their photocatalytic activities were evaluated in simulant photodegradation of methylene blue (MB). The results based on these characterizations showed that not only a rutile layer formed on the surface of original TiO2 particles after surface cladding, but also the doped Fe or Nd ion had a favorable effect on suppression of the electron–hole recombination in the titania under ultraviolet light irradiation. Furthermore, the photocatalytic activity of the material obtained by Fe doping and acidification was substantially improved in comparison to the untreated TiO2. However, the sample prepared from Nd-doping and acidification of TiO2 showed decreased capability relative to the untreated TiO2 in degradation of MB under similar conditions. Finally, the reason why the photocatalytic activities of the obtained catalysts are sensitive to the metal-doping was discussed in details.