Hydrothermal synthesis and characterization of nanocrystalline ceria powders

Nanocrystalline ceria powders were prepared by hydrothermal treatment of cerium(IV) ammonium nitrate solutions at 120-200 °C in the absence of a precipitating agent. We have conducted a systematic investigation of the effects that the hydrothermal temperature and reaction time have on the physical properties of the product powders. When the hydrothermal temperature was increased, the product ceria powders exhibited larger crystallite sizes and higher yields. Increasing the reaction time produced a greater yield of crystalline ceria powder as a result of further hydrothermal reactions and structural rearrangement. The physical properties of these ceria powders can be controlled by adjusting the hydrothermal conditions.