Preparation of nanostructured CeCO3OH particles from aqueous solutions and gels containing biological polymers and their thermal conversion to CeO2†
Abstract
Nanostructured CeCO3OH particles were prepared from aqueous solutions and gels containing CeCl3 and biological polymers (gelatin and agar) by the addition of (NH4)2CO3 solutions. The morphologies of the CeCO3OH products depended on the kind and concentration of the biological polymers. Sheaf- and cocoon-like CeCO3OH particles of ca. 2 μm in size consisting of fine particles of ca.10 nm in diameter were obtained from the precursor solutions containing gelatin. On the other hand, CeCO3OH precipitates with inhomogeneous size and shape were obtained from the precursor solutions and gels containing agar. Such morphological variation of CeCO3OH particles was thought to be due to the suppression of nucleation and growth of CeCO3OH crystals by the biological polymers. The CeCO3OH particles thus obtained were converted to CeO2 particles by the heat treatment at 600 °C, and the morphology as well as nanostructure remained during the heat treatment.