【作者】 夏天；

【导师】 曹望和；

【作者基本信息】 大连海事大学 ， 载运工具运用工程， 2005， 硕士

【摘要】 多年来,国内外学者对纳米TiO₂材料的制备及其各种特性作了大量研究,并取得了许多成果。但如何控制微粒组成、大小和粒度分布,以及深入探讨其微观结构,独特的物理、化学和机械性能等内容尚待进一步研究。 基于上述,作者首先对纳米材料的发展、性质、制备的相关技术以及光致发光的有关理论进行了系统的介绍,然后对所开展的研究工作进行了阐述,具体如下: 1.采用溶胶-凝胶法制备了本征TiO₂纳米晶、薄膜以及掺杂稀土离子的TiO₂:Eu³⁺纳米晶。引入动力学理论,分别计算了锐钛矿相和金红石相的晶粒生长的表观活化能,进而对锐钛矿-金红石相转变高温热力学过程进行了理论分析,得出了一些有意义的参考数据。同时利用经验公式计算了样品出现的蓝移量和具有的巨大的表面和界面面积。 2.在室温下,观察到体材料所不具备的光致发光性质,即观察到自由激子、束缚激子、缺陷以及表面态能级的跃迁,同时我们首次发现在818nm附近处呈现半高宽较宽且强度较强的发光峰。此外,Eu³⁺离子的掺杂能有效地抑制TiO₂纳米晶粒的长大以及相转变过程。当对TiO₂:Eu³⁺纳米晶进行激发时,产生一系列Eu³⁺离子的特征发射,并得出新的实验结论,即468nm代替通常的395nm成为最灵敏的激发线;616nm处的纯红色发光为最灵敏的发射线。更多还原

【Abstract】 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.更多还原