【作者】 丁倩倩；

【导师】 张莉； 杨良保；

【作者基本信息】 安徽大学 ， 物理化学， 2013， 硕士

【摘要】 表面增强拉曼光谱(SERS)是一种高灵敏度的检测手段。这种检测手段在最近30年里得到迅速发展,特别是在分析化学,药物化学,生命科学领域和环境检测等方面的研究最为广泛。但是从实际应用的角度上看,合成的基底不仅要求能够产生灵敏的SERS信号而且信号必须稳定。本论文中,我们设计了一种新型的磁性基,然后在磁性基表面包裹不同的贵金属纳米材料,研究了不同的形貌的纳米材料对于SERS信号的影响。通过优化条件,选择出最为合适的纳米复合材料用于待测物的SERS检测。这种新型的磁性复合材料,在外加磁场作用下可以实现SERS基底的再生使用。本论文共包括四个章节：第一章,首先对SERS技术做简单的介绍,然后对SERS基底的制备方法和应用领域进行总结。接着对循环SERS的研究做简单的回顾,最后,对于磁性Ni的合成方法进行介绍,并且利用其独特的优点将其引入到SERS检测领域。第二章,以NiCl2·6H2O和85%N2H4作为反应物,控制不同的实验条件,得到了不同形貌的单质Ni纳米材料。通过实验数据,选择最优形貌的单质Ni作为模板,然后通过置换反应在其表面包裹一层Ag纳米颗粒。随后对所制备的材料进行一系列的表征,最后将其应用于SERS研究。由于在材料的制备过程没有加入表面活性剂,基底比较纯净,适于痕量检测。同时利用复合材料的磁性,将所制备材料进行组装和进行SERS信号研究。在第三章,我们选用了另外一种较为稳定的贵金属金作为壳层。通过简单的置换反应,在Ni纳米线的表面包覆一层Au纳米颗粒,合成出Ni@Au核壳纳米材料用于SERS基底。在稳定性研究中,发现放置30天前后,同种材料的SERS信号峰位和峰强没有发生变化。另外,在重复性和循环使用方面也做了研究。在第四章中,基于前面实验的基础上,继续研究一维Ni纳米线在SERS技术中的应用。选取多刺的Ni纳米线作为磁性模板,然后在其表面包裹了一层半导体Ti02纳米颗粒和Ag纳米颗粒,将其用于有机分子光催化降解。所以我们将SERS技术引入光催化领域,用SERS方法对光降解过程进行动态监测,提高了催化研究的精确度。最后,对本论文的工作进行总结。更多还原

【Abstract】 Surface-enhanced Raman scattering (SERS) is a highly sensitive analytical technique. The practical applications of this technique have seen a dramatic increase in the past30years and it is widely applied in a variety of fields, including analytical chemistry, medical science, environmental monitoring, explosive analysis and so on. From an application viewpoint, it is necessary to develop an efficient SERS substrate that can not only provide strong enhancement factors, but also be stable and reproducible. In this paper, we have synthesized a new type of magnetic nanomaterials, and then different noble materials are coated on the surface of the magnetic Ni nanowires. The SERS data are obtained from the nanomaterials of different morphologies.This paper includes four chapters. In the first chapter, we make the simple introduction of SERS, and then summarize the ways of the preparation methods of SERS substrates and the applications. After that, we review the development of renewable substrate. At last, the ways of synthesis Ni nanomaterials are introduced.In chapter2, it is mainly reported the preparation of Ni nanowires using NiCl2·6H2O and85%N2H4as the metal ion precursor and the reducing agent, respectively, without any surfactants. Then the Ni/Ag nanocomposites is used the Ni NWs as the template. It was found that Ag nanomaterials could be coated on the surface of Ni nanowires through a simple and low-cost redox-transmetalation reaction. The approach did not need additional reagents throughout the reduction process, the nanocomposites had a high purity, which would be very helpful in their potential use for SERS detection. SRES measurements showed these nanocomposites were high stable, reproducible and recyclable as the SERS-active substrates. All of these splendid properties used for the SERS substrates open a new opportunity to the recycling SERS measurement.In chapter3, we give a simple, rapid and readily upgraded method to prepare Ni@Au nanocomposites without any surfactants or other linkers. Compared with most of the synthetic strategies available in the literature, this simple and effective method has many advantages. Furthermore, the SERS substrate can be stored long time which is of the great importance in practical application.In the chapter4, we synthesize the Ag-coated Ni@TiO2nanocomposites, with a very good core/shell structure, using the simple vapor-thermal method. We study the dynamics of photo degradation process of the dye molecules using the SERS. Because of the UV-Vis spectrometer with low sensitivity, the low concentration of organic molecules cannot be detected. So the SERS technology is introduced into the catalytic reaction to study the dynamics. This will improve the precision of the catalytic research.At the end of this paper, we give the conclusion of all the work, and then the goal of future research is made.更多还原