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

摘要

The surfactant-assisted hydrothermal route was used to prepare fractal dendrite cerium carbonate hydroxide (CeOHCO_3) microstructures. After annealing at 600 ℃ for 4 h, the products were transformed to CeO_2. 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 photo-luminescence (PL) showed that a strong ultraviolet emission at 336 nm was observed for CeOHCO_3, and that centered at 415 nm for CeO_2 microstructures. Both of these emission peaks are different from those reported for CeOHCO_3 and CeO_2 with other shapes. In addition, the possible growth mechanism of dendrite CeOHCO_3 microstructures and the role of surfactant polyvinyl pyrrolidone (PVP) were also investigated in this paper.