Preparation And Catalytic Properties Of Copper Nanoparticles Study

Nanoscience and technology is based on the science of making materials at the level of atoms, molecules. It emerged in the 1980s and has been increasingly developed. It not only includes the basic subjects which are made up of observation, analysis and research, but also the preparation, process and synthesis of nanostructure materials. Metal nanoparticles have been widely exploited for use in many different areas, such as catalysis, photonics, biological labeling, optoelectronics storage, photography and formulation of magnetic ferrofluids. The metal nanoparticles have large apparent surface area and many surface active points. For this reason, it's a good catalyst with high activity and selectivity. Copper is cheap but stable. The copper nanoparticles now is an important raw materials for industry and it will be widely expolited for use in many different areas.Following are the major work of this dissertation:1. Synthesis of copper nanoparticles with different shapesA series of copper nanoparticles with different shapes have been prepared by different methods, including cubes, near-sphericity, plates and branches.2. The influences of sizes and shapes in synthesis of copper nanoparticlesThe influences of sizes and shapes in synthesis of copper nanoparticles have been discussed. Such as the concentration of reactant, the temperature and time of reaction, the kind and concentration of surface active agents. Generally, an uniform sizes and shapes and good dispersity nanoparticles coule be prepared by low concentration of reactant, low system temperture, long reactive time and suitable surface active agents.2. The influences of crystal faces to reactive activity of nanoparticlesThe reactive activity of cubic and near-spherical copper nanoparticles in hydroxylation of benzene have been compared. The cubic copper nanoparticles show the higher reactive activity. The crystal faces of copper nanoparticles play an essential role in determining the catalytic hydroxylation of benzene. The copper nanocubes had the (100) crystal faces with higher surface energy as the basal plane, whereas near-spherical nanoparticles predominantly exposed the most-stable (111) crystal faces with lower surface energy. The planes with higher surface energy are more reactive.