Study Of Ni-noble Metal Nanomaterials Act As The Surface Enhanced Raman Spectra Substrate

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.