Synthesis And Property Investment Of Noble Metal/Semiconductor Nanocomposites

In this thesis, we mainly studied the synthesis and application of noble metal/semiconductor nanocomposites, such as M/Cu₂O (M = Ag, Au) nanoparticles, Au/CdS nanorods, and Ag/ZnO nanoarrays. The major contents can be summarized as follows:1. Cu₂O octahedron nanoparticles were firstly prepared through a met-chemical reduction method, and then, the prepared Cu₂O octahedron nanoparticles were added into a solution containing rare-metal ions at room temperature. Under the illumination of visible light, M/Cu₂O (M = Ag, Au) nanocomposites were obtained. The influence of light source and solution temperature on the deposition of noble metal (take Ag as an example) nanoparticles has been studied. The experimental results show that visible light is more favorable for the deposition of Ag nanoparticles onto Cu₂O nanocrystals, and a solution temperature of more than 30°C can prevent the erosion of Cu₂O. The photocatalytic properties of the prepared M/Cu₂O nanocomposites were studied, which show that the M/Cu₂O nanocomposites have higher photocatalytic activities than the original Cu₂O nanocrystals.2. CdS nanorods with diameters of about 30 nm and lengths of 200³00 nm were firstly prepared through a hydrothermal method. Then gold nanoparticles were deposited onto the surfaces of CdS nanorods through a simple photocatalytic reduction route. The structure and morphology of the prepared products were characterized. Further study revealed that the Au/CdS nanocomposites not only have very good adsorption efficiency toward organic dyes such as rhodamine 6G, crystal violet and methylene blue, but also can efficiently degrade the dyes under the illuminiation of UV light.3. Vertically aligned ZnO nanorod arrays were grown from zinc foil through a simple wet-chemical method. Then, under the illumination of visible light, Ag nanoparticles were grown onto the surfaces of ZnO nanorods through the photocatalytic reduction of ZnO, and Ag/ZnO nanocmposite arrays were obtained. The Ag/ZnO nanoarrays can be applied as substrates for surface enhanced Raman scatting (SERS) detection.