Hydrothermal preparation of fractal dendrites: Cerium carbonate hydroxide and cerium oxide

The surfactant-assisted hydrothermal route was used to prepare fractal dendrite cerium carbonate hydroxide (CeOHCO3) microstructures. After annealing at 600 degrees C for 4 h, the products were transformed to CeO2. The crystal structures of the two compounds were determined by X-ray diffraction (XRD). The morphologies and microstructures were characterized by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). Room temperature photoluminescence (PL) showed that a strong ultraviolet emission at 336 nm was observed for CeOHCO3, and that centered at 415 nm for CeO2 microstructures. Both of these emission peaks are different from those reported for CeOHCO3 and CeO2 with other shapes. In addition, the possible growth mechanism of dendrite CeOHCO3 microstructures and the role of surfactant polyvinyl pyrrolidone (PVP) were also investigated in this paper. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.