Synthesis and luminescent properties of TiO2:Eu3+ nanotubes

TiO2 nanotubes doped with Eu3+ ions have been fabricated by a simple hydrothermal process. The formation mechanism of TiO2:Eu3+ nanotubes is proposed in detail. The nanotubes are evolved from the rolling up of the anatase sheets, which was verified by characterizations using the X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). Compared with the TiO2:Eu3+ nanocrystals, TiO2:Eu3+ nanotubes exhibit considerably stronger photoluminescence (PL) under the excitation of 393 nm. Furthermore, the PL intensity increases with the increasing of Eu3+ concentration in TiO2 nanotubes, and concentration quenching occurs when Eu3+ concentration exceeds 2.0 mol%. In addition, the luminescent lifetime of the TiO2:Eu3+ nanotubes is also examined. It is expected that the TiO2:Eu3+ nanotubes can be used as novel semiconductor luminescence materials.