Preparation and phase transformation of anatase-rutile crystals in metal doped TiO_2/muscovite nanocomposites

摘要

Nanometer titanium dioxide (TiO_2) films were deposited on muscovite flakes and doped with a number of different metal ions (Al~(3+), Sn~(4+), Fe~(3+), Cu~(2+), Co~(2+), Mn~(2+) or Zn~(2+)) using a chemical liquid deposition method. The morphology and the anatase-rutile (A-R) transformation were studied by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. Apart from round particles, SEM micrographs show that euhedral pillar rutile grains are found in the samples doped with Fe~(3+), Mn~(2+) or Zn~(2+) ions. The rutile phase of TiO_2 thin layers on muscovite could be generated at low temperature, 60℃. The XRD results confirm that the addition of metal ions affects the anatase-rutile (A-R) transformation. The Mn~(2+), Sn~(4+), Fe~(3+) and Zn~(2+) ions promote the A-R transformation while the Al~(3+), Cu~(2+) and Co~(2+) ions inhibit the A-R transformation of TiO_2 thin layers on muscovite. The influence of metal ion doping on the A-R transformation of the TiO_2 thin layers on muscovite depends on the substitution of foreign ions for Ti~(4+) ions in TiO_2 thin layers.