| Abstract: Under hydrothermal condition, nitrate cerium(IV) was used as a cerium source, octadecylamine (C18H37NH2) as the molecular template and urea as a precipitating agent, and the hierarchically well-aligned nanotublar bunches of the cubic fluorite ceria were successfully synthesized. The materials have been characterized by Powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and the selected area electron diffraction (SAED). The products exhibited the hierarchically well-aligned nanotublar bunch which was composed of single nanotube with outer and inner diameter 10～20 and 5～6 nm. The growth process of nanotublar bunches was monitored. Firstly, the separated nanotube appeared in the reaction system. Subsequently, the separated nanotubes integrated into the hierarchically well-aligned nanotublar bunch each other. In addition, the products have different crystalline phase and composition as increasing the final pH value of reaction system; And when the final pH values of reaction system were at 5～6, 6～8 and > 8 respectively, the crystalline phase of the products were respectively cubic fluorite CeO2, mixtures of cubic fluorite CeO2 and hexagonal Ce(OH)CO3, hexagonal Ce(OH)CO3. |
