Synthesis of Eu-doped photoluminescent titania nanotubes via a two-step hydrothermal treatment

In this work, the synthesis of Eu-doped titania nanotubes was studied via a two-step hydrothermal treatment method. The first hydrothermal treatment was to obtain Eu-doped TiO2 nanopowders with good dispersity. The second treatment was to produce the corresponding nanotubes. X-ray diffraction confirmed that the nanotubes were made of hydrated titania. Scanning electron microscope and transmission electron microscope analyses showed that the multilayered nanotubes had an outer diameter of 12 nm and inner diameter of 4 nm, with length up to a few microns. The Eu-doped nanotubes exhibited strong emission lines associated with the D-5(0)-> F-7(j) transition of Eu3+. The nanotubes prepared by the two-step hydrothermal treatment exhibited better photoluminescence properties than the corresponding nanopowders and nanotubes prepared directly by the one-step hydrothermal treatment. The effect of the heat treatment of nanotubes was also studied.