Hydrothermal synthesis of single-crystalline CeCO3OH flower-like nanostructures and their thermal conversion to CeO2

Orthorhombic single-crystal CeCO3OH flower-like nanostructures have been successfully synthesized on a large scale by the hydrothermal method at 120 degrees C using Ce(NO3)(3)center dot 6H(2)O as the cerium source, aqueous urea as both an alkaline and carbon source and polyvinyl alcohol as surfactant. Polycrystalline CeO2 nanostructures have been obtained by thermal decomposition-oxidation of single-crystalline CeCO3OH flower-like nanostructures at 500 degrees C in flowing air. CeCO3OH flower-like nanostructures and CeO2 nanostructures were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), room temperature UV/vis absorption spectrum, differential scanning calorimetric analysis (DSC), and thermogravimetric analysis (TG). The high absorption in the UV region for CeO2 nanostructures indicated that this material was suitable as UV-blocking material. (C) 2008 Elsevier B.V. All rights reserved.