Template Prepared By The One-dimensional Coaxial Nano-materials

With the development of research in nanomaterials, there is an increasing interest in one-dimensional nanomaterials. Over these years, as the potential application of nano-coaxial one-dimensional heterostructure (which is called nanocable) on such fields as solar cell, field effect transistor, nano-optical fiber and so on, nanocable has attached special attention. The template method is a common way to make nanomaterials. Porous anodic aluminum oxide (AAO), one kind of the templates, has been widely used to fabricate one-dimensional nanomaterials because of its nanoscale high-density holes array with tunable diameter and length.In this thesis, different porous anodic aluminum oxide (AAO) templates have been prepared by changing the second anodization oxide voltages and it is found that the pore diameter and space between pores get larger with increase of the voltages. The desired templates according to the experiment requirements with both the pore diameter and wall thickness of 100nm are fabricated under the conditions that the first oxide voltage and the second one are 40 V and 80V, respectively. Under the same temperature and phosphate acid concentration, the widen speed of the pores is gained about 2nm/min by control of erode time.The syntheses of copper (Cu) and nickel (Ni) nanaowires are experimental studied by changing the deposition voltage using porous anodic aluminum oxide template combined with direct current (DC) electrochemical deposition method. The optimal deposition voltage of 2.0V is found to fabricate the Cu nanowires out of the electrolyte which is composed of sulfuric acid and copper sulfate while the voltage of 3.0V can lead the production of the nickel nanowire from electrolyte which contains the nickel sulfate, boric acid, sodium chloride. In addition, the optimistic growth processes of the semiconductor CdS, ZnS, ZnO nanowires are studied and obtained.A copper-nickel nanostructure is synthesized by porous anodic aluminum oxide template (AAO) combined with electrochemical deposition according to a new two steps method. First of all, the copper nanowire is deposed in the pores of alumina template by an electrochemical method, and then the pore of the alumina template is widen by the phosphoric acid. After that, the Ni shell is grown in the gap between the deposited copper nanowire and the wall of the template by the electrochemical way and thus the copper-nickel coaxial one-dimensional nanomaterial is synthesized. The core-shell structure is characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and field emission transmission electron microscopy (FETEM) and the results validate that this new method is feasible. Therefore, the new method expanses the field to synthesize the nanotubes and nanocables through the AAO template. The surface-enhanced Raman scattering (SERS) effect of copper-nickel coaxial one-dimensional nanomaterials has explored with Adenine molecule as a probe. The Raman spectrum of copper-nickel coaxial one-dimensional nanomaterial is much stronger than that of single-metal Cu, Ni nanowires, which indicates that this new type of one-dimensional nanomaterial is a potentially active SERS substrate, and also that the transition metal in the application of SERS has been broadened.