Study On Preparations Of Nanocopper And Cuprous Oxide Nano-wire

The synthesis and research on nanocopper have become a hot point of nanoscience and nanotechnology for it not only have quantum size effect, surface effect and the small size effect which usually nanomaterials possess, but also have its unique electrical, optical, magnetic and other properties. As a result, nanocopper has applications in a wide variety of fields. Compared to other noble metals, such as Ag and Au, Cu is 1000 times more abundant and 100 times less expensive and its higher conductivity, better electromigration resistance which lead it to be used as electronic wire in the traditional electronic circuits and also be used as high-performance transparent electrodes, transparent conductive film and magnetic biosensor and so on.To find preparation routes with higher yield, lower cost, and perfect technology which could prevent nano Cu from aggregation and oxidation is the key problem in the research on the preparation of nano Cu. Currently, there are various methods for preparing nanocopper, among which the chemical reduction is used mostly. Ascorbic acid (Vc) used as reducing agent in chemical reduction is a new and green method. Among it the Vc is not only used as reducing agent and also used as capping agent. The chemical reduction has many advantages. Such as simple, convenient, economical, effective. Diethanolamine is used as solvent and reductant without addition of other reductant. This technology has many merits such as easy operation, simple process, cheaper equipment which is a novel methods. With diethanolamine as solvent we can obtain antioxidant nanocopper with perfect morphology. In recent years, hard-template methods have become an important method for producing nanowires. By using this method we can control the thickness and growth direction of the nanowire effectively and prevent nanowires from aggregation. Thereby, we can synthesize nanowires with uniform structure successfully.In present work, firstly, the optimum reaction temperature of CuCl2·2H2O react in diethanolamine and the effects of amount of hexadecylamine(HDA) was investigated. Secondly, we present a facile hydrothermal process using Cu(NO3)2·3H2O as copper source and Vc as reducing agent and capping agent to synthesis of Cu submicron wires. Some influencing factors of amount of hexadecylamine and Vc, kind of solvents, reaction time were investigated. Thirdly, we also describe a approach by using SBA-15 as a host, Cu(NO3)2·3H2O as copper source to prepare nano-line Cu2O by ultrasonic-assisted impregnation and thermal treatment in liquid paraffin. The effects of the solution concentration, the heat treatment solvent, the manner of dispersion, washed the precursor or not and impregnation time were investigated. The obtained products has been characterized by nitrogen adsorption-desorption isotherms, small-angle and wide-angle X-ray diffraction (XRD) and transmission electron microscope (TEM). The following conclusions can be drawn by the results:In diethanolamine system, with CuCl2·2H2O as copper source,200℃, we can obtained the cubic nanocopper with exposed surface of (111) plane. The particle size of nanocopper tends to increase with the increase amount of HDA.With HDA in the system has some influence on morphology of product, but we did not get the ideal nanowire.In solvothermal system, without HDA, Cu:Vc=1:1, EtOH-H2O (2:1 v/v) solution as the solvent for reaction at 80℃for 3.0 h is benefit for the formation of a small amount of Cu submicron wires and reaction for 9.0 h is benefit for the generation of Cu submicron cube. With distilled water as solvent reation at 80℃for 6.0-12.0 h are better for getting large amount of Cu submicron wires and reation for less or more time cannot obtain the perfect morphology. The product does not appear perfect morphology with ethanol as solvent. With the reaction time extending, the green product obtained and there have coverage on surface of product.In SBA-15 system, to wash precursor samples or not is a key factor to obtain product with loading copper species. The precursor samples should not be washed with distilled water. Because it woule be resulted in the loss of copper species. It can obtain extensive homogeneous Cu2O nano-line in the channels of SBA-15 after the unwashed precursor samples heat treatment in liquid paraffin. Prolonged immersion time is benefit for more Cu2+ into the channels of SBA-15. The unwashed precursor for repeatedly impregnation and heat treatment in liquid paraffin in favor to get uniform Cu2O nanowires distribution outside the channels of SBA-15. By using SBA-15 as a template is not suitable with alkaline solvent and polar solvent as solvent for heat treatment. SBA-15 framework would collapse with basic solvent as solvent, The Cu2+ which have entered the channels of SBA-15 during the impregnation process would migrate to the outside with polar solvent as solvent.