Preparation, characterization and visible-light-driven photocatalytic activity of Fe-incorporated TiO2 microspheres photocatalysts

Fe incorporated TiO2 microspheres (Fe-TiO2) were prepared by integrating the sol–gel method and impregnating–calcination method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis diffuse reflectance spectroscopy indicated that α-Fe2O3 nanoparticles were deposited onto the TiO2 microspheres, and in the mean time, some Fe3+ ions were doped into TiO2 lattice. The absorption of Fe-TiO2 microspheres in the visible light region increased with the increasing of Fe content. Photoluminescence (PL) analyses further confirmed that Fe-incorporation effectively promoted the separation and transfer of photogenerated charge carriers, which can improve the photocatalytic activity of the samples. The photocatalytic activity of Fe-TiO2 microspheres was evaluated by the degradation of methylene blue aqueous solution under visible light irradiation. The results demonstrated that the Fe-TiO2 microspheres exhibited significantly enhanced photocatalytic activity compared with pure TiO2 microspheres. What is more, the charge-transfer processes in Fe-TiO2 were also discussed.