An investigation on synthesis and photocatalytic properties of Eu-doped anatase TiO2 coated magnetite

Preparation of Eu-doped anatase titanium dioxide (TiO2) coated magnetite (Fe3O4) photocatalysts (Eu/TiO2/Fe3O4) and their photocatalytic properties under UV and visible light were reported. The composite photocatalysts were prepared by coating photoactive Eu/TiO2 onto magnetic Fe3O4 through the hydrolysis of tetrabutyltitanate (Ti(OC4H9)4) in water/oil (w/o) microemulsion with precursors of Eu(NO3)3 and Ti(OC4H9)4 in the presence of Fe3O4 nanoparticles. The morphological, structural and optical properties of the prepared samples were characterized by BET surface area, transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis absorption spectroscopy. The effect of Eu ion content on the photocatalytic activity was studied, and the result revealed that 0.15 mol% Eu/TiO2/Fe3O4 exhibited the highest photoactivity. The photocatalytic activities of prepared photocatalysts in UV and visible light were estimated by measuring the decomposition rate of phenol (50 mg/L) in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxidation reactions. The photocatalytic performance of Eu/TiO2/Fe3O4 was almost 3.0 times higher than that of single phase TiO2 (either TiO2 prepared by same method or Degussa P25) and TiO2/Fe3O4 for degradation of phenol under visible light. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, the prepared composite exhibits paramagnetic behaviors at room temperature and could be easily recovered from the medium by a simple magnetic process. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants. (author)