【作者】 吴侠；

【导师】 吴玉程；

【作者基本信息】 合肥工业大学 ， 材料学， 2005， 硕士

【摘要】 众所周知,根据需要设计新的纳米材料体系,特别是纳米复合体系的设计和研究,已成为当前纳米科学技术和凝聚态物理研究的前沿和热点,这方面的研究更强调按人们的意愿设计新的体系,更有目的地使该体系具有人们所希望的特性,因此,纳米复合体系越来越受到人们的关注,在这其中,纳米复合薄膜是一类具有广泛应用前景的纳米复合材料,由于纳米粒子的性能、工艺条件等参量的变化都对纳米复合薄膜的性能有着显著的影响,因此,可以在较多的条件下实现对其功能特性的调制。本文以溶胶凝胶法制备银、氧化铜/二氧化硅纳米复合薄膜,采用X射线衍射仪对样品的相组成进行分析,比表面及孔隙分析仪表征介孔SiO2基体以及复合样品的的孔结构与孔径分布,扫描电子显微镜观察薄膜的表面形态,紫外-近红外光谱仪进行复合体系的光吸收测试,透射电子显微镜观察样品的组织形貌。针对溶胶凝胶法制备纳米复合薄膜的影响因素做了详细而全面的讨论,系统地研究了各种因素对薄膜成膜质量和溶胶稳定性的影响,确定了每种因素对获得理想结果的重要程度及每种因素的最佳取值范围,并给出了优选方案和推荐最优方案。对于银/二氧化硅样品,随着处理温度的升高和银含量的增加,金属银颗粒尺寸逐渐增大,其等离子共振吸收峰强度升高,峰位向低能方向有明显红移,吸收峰的半高宽变窄,样品的带边吸收随着复合体系银含量的增加和处理温度的上升也会发生红移。对于氧化铜/二氧化硅样品,0. 05CuO/SiO2在300℃,400℃,500℃处理后的光吸收谱的吸收边,其光吸收数值可以用间接带隙半导体光吸收边公式来很好的拟合,而对样品0. 02CuO/SiO2、 0. 05CuO/SiO2、 0. 1 CuO/SiO2在大气气氛下800℃处理一小时后的光吸收谱的吸收边,其光吸收却可以用直接带隙半导体光吸收公式来拟合。因此可以用较为简单的手段实现对复合体系光学性能的调制。更多还原

【Abstract】 It was well known that the research of new nanomaterial system, especially the design of nanocomposite system, has become the focus of nanomaterial science and technology. Nanocomposite film is one of nanocomposite materials that have a widely applying future. Because the changes of nanoparticles have evidently effects on the properties of nanocomposite film, it is easy to realize the tailoring of its functional properties. In this paper, the Ag, CuO/SiO2 nanocomposite films were prepared through sol-gel method and reduced under hydrogen atmosphere. The microstructure and properties of the composites were characterized by X-ray diffractometer （XRD）, specific surface area and porosity instrument, transmission electron microscopy （TEM）, scanning electron microscopy （SEM） and UV-VisNir spectrophotometer. The most important factors of sol-gel processing that affect the resulting nanocomposite films’ qualities were discussed sufficiently and the most reasonable ratio of every component was recommended. The optical absorption properties of every sample were discussed in detail. About the Ag/SiO₂ film, its optical absorption peak remarkably red-shifted （lower energy） and the full width at half maximum decreased with increasing the doped composition and reducing temperature. About the CuO/SiO₂ films, the optical absorption edge of 0.05CuO/SiO₂ treated at 300℃, 400℃, 500℃ in atmosphere can well followed the expression of semiconductor with indirect-band gap those of 0.02CuO/SiO₂ 0.05CuO/SiO₂ 0.1CuO/SiO₂ treated at 800℃ in atmosphere can well followed the expression of semiconductor with direct-band gap. The reasons of these phenomena were discussed by Mie theory.更多还原