Densely assembled single-phase rutile-TiO2 nanorods with diameters of 150-200 nm and lengths of 2-7 μm have been successfully synthesized for the first time by a heating-sol-gel template method. It was found that the heating process of TiO2 sol was beneficial to the single-phase formation of rutile-TiO2 nanorods. Transmission electron microscopic observations reveal that these rutile-TiO2 nanorods are the aggregates of nanocrystallites grown preferentially to the  axis with diameters of 10-30 nm. Selected area electron diffraction and energy dispersive X-ray spectroscopy measurements confirm that the obtained nanorods are rutile-TiO2 nanorods with good compositional uniformity and a relatively distinct crystallite shape over the entire length. The photoluminescence result shows a broad band confined in the wavelength range of 400-600 nm. This broad band is thought to originate from bound excitations emission due to the trapping of free excitons by TiO6 octahedra near defects which are possibly oxygen vacancies and/or the color center of Al 3+ impurities.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版ステータス||Published - 2004 10月|
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