Preparation And Properties Of Nano Oxides

Cu2O nanowire has been synthesized under hydrothermal conditions with simplemolecular α-hydroxy carboxylate as both reducing agent and morphology controller.The growth of Cu2O nanowire shows time dependence. Luminescence spectra giveinformation about special reabsorption mode of one dimensional crystal and the actionof excitons at room temperature. Cu2O- Cu core-shell nanocomposite and Cu2O- CuOcomposite were also prepared by further dealing the as-synthesized Cu2O nanowire.UV-visible absorption spectra suggest that the thickness of the copper film on thesurface of Cu2O is about 9nm. The Cu2O-CuO composite shows multiplex conductivityas high as 0.166 S·cm-1.Ⅱ SnO2-TiO2 core-shell nanocrystal SnO2-TiO2 core-shell nanocrystals are synthesized through a homogeneousprecipitation method at 80 ~ 100 °C in an aqueous medium. The great similarity ofSnO2 and TiO2 in crystal structure leads to an epitaxial relationship between these twospecies at the interface of the core-shell composite. The composite has a relatively largeBrunauer-Emmett-Teller (BET) specific surface area for 472.3 m2/g. The surfacecomposition of the composite was revealed by X-ray photoelectron spectrometry (XPS)and powder X-ray diffraction (XRD) to be solely TiO2 with a rutile structure. This newcomposite material exhibits a high ultraviolet absorption capability, and its photocatalytic activity for phenol oxidation and thermal catalytic activity for castor oil aremuch lower than those of commercial titania nanoparticles (P25) and CeO2, respactively.In this context, the SnO2-TiO2 core-shell nanocrystals have enormous potential inapplications as sunscreen materials. 66吉林大学硕士学位论文Ⅲ Cu-SiO2 SiO2 microtube with channel in nanosize has been prepared which will be used astemplate of copper electrolysis.