The Preparation And Characteristics Of Titania Nanocrystals And Thin Films By Sol-Gel Process

For many years, the scholars at home and abroad have carried out a lot of researches for the preparation and various characteristics of nanometer titania materials, and have gained much production. However, how to control the component, size and particle distribution, and investigate their microstructures in detail, especially, their physical, chemical and mechanical characteristics all need the further study.As mentioned above, author firstly carried out the systematic introduction for the development of nanometer materials, properties, the relevant technologies of preparation and the relevant theories of photoluminescence, and then reported the research work carried out. The contents are as follows.1. Titania nanocrystals, thin films and TiO₂:Eu³+ nanocrystals were prepared by sol-gel process using Ti(0-BU)4 as the precursor. The kinetic theories were introduced, and the crystalline particles growth apparent activity energy of anatase and rutile phases were calculated, and then the high-temperature thermodynamics processes of anatase-rutile phase transitions were theoretically analyzed, and some excellent reference data were gained. Meanwhile, the huge surface and interface areas were calculated using several experiential formulas.2. At room temperature, the optical properties which mass materials didn't take on were observed in nanometer titania materials, that is to say, the energy transitions of free excitons, bound excitons, defects and surface states could be seen, at the same time, we firstly observed the wider FWHM and stronger emission peaks at round 818nm. In addition, the Eu³+ ions could effectively restrain the growth of titania nanocrystals and phase transitions. When the TiO₂:Eu³+ nanocrystals were excited, a series of characteristic emission could be seen, therefore the new experimental conclusions were reached, namely, the 468nm was the most sensitive excitation linerather than the general 395nm and the pure red luminescence at 616nm was the most sensitive emission line.