Synthesis and characterization of copper ions surface-doped titanium dioxide nanotubes

Copper ions surface-doped titanium dioxide nanotubes were prepared via an assembly process based on the reactions between Cu(NH2CH2CH2NH2)(2)(OH)(2) and hydroxide radicals on the surface of TiO2 nanotubes, followed by the heat treatment in air at 723 K. The as-prepared samples were characterized with infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and fluorescence spectroscopy (FL). The photocatalytic activity of the copper ions surface-doped titanium dioxide nanotubes was investigated by photodegradation of Rhodamine B. The results showed that copper ions were successfully introduced onto the surface of TiO2 nanotubes. And two kinds of copper species of Cu(I) and Cu(II) were found on TiO2 surface. Copper ions act as electron trappers facilitating the separation of electrons and holes on the surface of TiO2 nanotubes, which allows more efficiency for the photodegradation of Rhodamine B. (C) 2007 Elsevier Ltd. All rights reserved.