Controlled Synthesis And Properties Of Micro/nanometer Cu₂O And Cus

In this dissertation, the solution chemical route and sacrificial templates method were developed for the synthesis Cu2O and CuS spheres with different sizes, shell thicknesses and structures, and a novel route was designed to assemble the three- dimensional flowerlike nanostructures. The as-synthesized samples are characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to discuss the influence of fabrication condition on the structure and morphology of hollow microspheres and flowerlike nanostructures. The synthesis mechanism and formation process were also studied. The details are summarized briefly as follows:1. Cu2O mircospheres with controllable sizes, shelled thickness, aggregation degrees and morphologies were successfully synthesized via solution chemical route in the presence of polyvinylpyrrolidone. (a) The size of the mircospheres can be controlled easily by adjusting the concentration of reactant and the amounts of surfactant. (b) A novel"hedgehog-like"Cu2O spherical structure was prepared by changing the solvent ratio. (c) Cu2O products with different sizes and shapes were synthesized with different adding times of N2H4?H2O. (d) The transformation of spherical aggregations to hollow microspheres was observed by prolonging the reduction time. (e) The size and hollow effect of Cu2O mircospheres have significant influences on their photocatalysis properties.2. CuS hollow spheres with different sizes and shelled thicknesses were synthesized under mild conditions with Cu2O mircospheres as sacrificial templates. (a) CuS hollow spheres with different sizes were prepared by changing the sulfide reaction temperatures. (b) CuS hollow spheres with different shelled thicknesses were obtained by using different Cu2O mircospheres as sacrificial templates. (c) Changing the temperatures of sulfide reaction, CuS hollow spheres with different shelled thicknesses were successfully synthesized by using the same Cu2O sacrificial templates.3. A novel route was designed to synthesis the 3D flowerlike CuS nanostructures by using the CuS hollow spheres as a precursor. In this process, the transformation of hollow spheres to 3D flowerlike CuS nanostructures was occurred by the coordinate role of Ostwald ripening, selective etching, and self-assembly process.