Preparation And Property Study Of TiO₂ Nanostructure Materials

Nanostructured materials have become an active research field due to their unique properties different from bulk materials and potential applications. Optical,electronic and mechanical properties of nanostructure materials strongly depend on their morphology and dimensionality. Therefore, it is very significant to develop simple methods to synthesize highly active nanocrystals with controlled morphology, size and crystalline structure, and align nanocrystals to fabricate nanodevices with special functions. In this work, novel approaches to synthesize TiO2 nanostructure materials and films with various morphologies and dimensionalities were proposed, and their properties were also investigated. The main contents are as follows:1. Fabrication of aligned TiO2 nanorod and nanowire arrays. A systematic study on the method to fabricate one-dimensional TiO2 nanostructure arrays was performed. And aligned single-crystalline TiO2 nanorod and nanowire arrays were fabricated directly on conductive glasses coated with SnO2:F film by a simple liquid phase deposition (LPD) method. The one-dimensional nanostructure arrays were characterized by means of X-ray diffraction, scanning electron microscopy, transition electron microscopy and Raman spectrometry. And the effects of various experimental conditions on the morphology of the films were concluded.2. Room temperature synthesis of uniform TiO2 nanocrystals. A systematic study on the low-temperature growth behavior of TiO2 nanocrystals was performed. Uniform TiO2 nanocrystals with controlled morphology and crystalline form were synthesized at room temperature and under atmospheric pressure by a simple method. The as-prepared flowerlike and rodlike rutile TiO2 nanocrystals exhibit excellent photocatalytic performance, and their photocatalytic degradation effeciencies for methyl orange are almost twice that of the commercial photocatalyst P25.3. Fabrication of micrometer-scale hollow TiO2 materials via a bubble-template approach. Micrometer-scale hollow TiO2 materials have been synthesized by a bubble-template method. The as-prepared products were characterized by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. And a possible mechanism was proposed. The bubble-template strategy used in the synthetic process may represent a general approach to fabricate hollow micro- and nanostructures.