【作者】 王勇；

【导师】 唐东升；

【作者基本信息】 湖南师范大学 ， 凝聚态物理， 2009， 硕士

【摘要】 二氧化钛是一种宽禁带半导体化合物,在太阳能、微电子、锂离子电池、光催化以及气体传感器等应用领域内所起到的作用正日渐突出。其低维结构以其更为优异的物理化学性质而吸引越来越多的注意力和研究热情。本论文中,我们采用化学气相沉积法和水热法成功地制备了TiO₂一维纳米结构,并通过控制宏观实验条件从而实现对二氧化钛一维纳米结构微结构精确控制。在这基础上,通过对水热法所制备的二氧化钛一维纳米结构进行高温退火,改善了一维纳米结构的结晶度和电子结构,以及实现其晶格由锐钛矿结构向金红石结构转变。水热法中,通过在溶液中引入三价铁离子,实现二氧化钛一维纳米结构磁性搀杂。X射线衍射分析显示二氧化钛一维纳米结构的晶格常数增大。紫外光漫反射谱显示二氧化钛一维纳米结构的禁带宽度由3.22eV减少到了3.03 eV。磁性掺杂的二氧化钛一维纳米结构的电学和磁学性质正在深入研究中。更多还原

【Abstract】 Titanium dioxide （TiO₂）, which is a typical wide forbidden gap semiconductor material, plays an outstanding part in applied fields such as photo catalysis, lithium ion batteries, photovoltaic cells, nanoelectronics and gas sensors. Furthermore, more and more researchers, excited by the wonderful physical and chemical properties when we come to low-dimensional nanostructures of this semiconductor, begin to keep an eye on TiO₂ nanostructures, including nanowires and quantum dots, which may offer promising future for electronics and phototronics.Adopting two different methods （CVD and hydrothermal synthesis）, we have successfully achieved TiO₂ nanowires. And then by optimizing the growth conditions, we have also successfully controlled the nanostructures of TiO₂ nanowires during growth process. Furthermore, by thermal annealing, the anatase-type TiO₂ nanowires obtained by hydrothermal synthesis method can be transformed into rutile-type structure. The crystallinity of TiO₂ nanowires has also been improved simultaneity.Based on hydrothermal synthesis method, Fe-doped TiO₂ nanowires have been successfully synthesized by introducing Fe³⁺ ions into the solvent. The morphologies, microstructures and electronic structures have been characterized carefully by scanning electron microscopy, X-ray diffraction technique, and ultraviolet/visible/near infrared diffusive reflectance spectroscopy. The most important feature is that the optical band gap reduces from 3.22 eV to 3.02 eV with the increase of the doping concentration. Moreover, research on electrical transport and magnetic properties of Magnetic doping TiO₂ nanowires is still going on.更多还原