Controlled Synthesis And Property Study Of Low-dimensional Nanostructured Materials

Low-dimensional nanostructured materials have sparked a worldwide interest because oftheir unique electronic, optical, and mechanical properties and their potential applications innanodevices and functional materials. We found by reading a lot of references that structure,dimension, shape and size of dimensional nanomaterials have important effect on theirproperties. Therefore, how to effectively control these factors is our aim. We successfullysynthesized nanostructures of metals and their oxides, fluorides, magnetic materials,phosphates, carbonate and so on. We have realized the control of size and shape ofnanomaterials during the synthesis process, and established new route to synthesize somematerials.1. By means of "soft" template method,we first synthesized PbO2 and Pb3O4 nanorods. Especially, there is no report about the solution-phase synthesis of Pb3O4 up to now. This method is a general approach for the synthesis of other amphoteric metal oxides, by which Cu,Cu2O,CuO and ZnO namorods/nanotubes also were prepared. The formation mechanism has been discussed in detail.2. One-dimensional nanostructures of fluorides were first synthesized by using microemulsion method. BaF2 whiskers with diameters of 40?80 nm and aspect ratio of above 1000 were obtained, and BaF2 whiskers exhibit a single-crystal structure. We also synthesized MgF2 and KMgF3 nanorods.3. By mean of hydrothermal method and the weak dissociation tendency of [Fe(CN)6]3- ions to Fe3+,magnetic Fe2O3 fractals were first synthesized, which showed clear and well-defined dendritic fractal structure. Using Fe2O3 pines as source material, iron nitrides dendrites were obtained by reduction-nitriding, which still retained the shape of source material Fe2O3. Their magnetic properties had been studied. Similarly, by using the single source precursor K3[Co(CN)6], Co3[Co(CN)6]2 nanostructures were successfully prepared. By exactly controlling reaction conditions, Co3[Co(CN)6]2 nanostructures with different shapes can be obtained. This method is a new route to synthesize Co3[Co(CN)6]2.4. Combining solvothermal method and miroemusion, we successfully synthesized low dimensional nanostructures of a series of phosphates, such as hydroxyapatite, lanthanide phosphates, aluminum phosphates and so on. By varying various parameters of miroemulsion system and concentration of reactants, shape and size of products were successfully achieved. The products obtained by this method displayed high crystallization.5. Combining solvothermal method and miroemusion, we synthesized SrCO3 nanostructures with various shapes, such as rodlike, whiskerlike, ellipsoidlike, and spherelike.