Ultrasound-assisted synthesis and visible-light-driven photocatalytic activity of Fe-incorporated TiO2 nanotube array photocatalysts.

Fe incorporated TiO(2) nanotube arrays (Fe-TiO(2)NTs) were prepared by an ultrasound-assisted impregnating-calcination method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (DRS) indicated that α-Fe(2)O(3) nanoparticles were deposited into the TiO(2) nanotubes, and in the mean time, some Fe(3+) ions were doped into TiO(2) lattice. The absorption of Fe-TiO(2)NTs in the visible light region increased with the increase of Fe content. The photocatalytic activity of Fe-TiO(2)NTs was evaluated by the degradation of methylene blue aqueous solution under visible light irradiation. The results demonstrated that the Fe-TiO(2)NTs exhibited significantly enhanced photocatalytic activity compared with pure TiO(2)NTs. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) analyses further confirmed that the increased photocatalytic activity of the Fe-TiO(2)NTs was attributed to an enhanced separation and transfer of photogenerated charge carriers.