Study On The Synthesis Of Nano Cerium Oxide Via The Hydrothemal Method And Its Characterization

In this paper, the nano structure or size cerium oxide powders have been synthesized under the hydrothermal conditions with the surface active agent (SDS) adjusting structure, and moreover the technological parameters were studied in detail. The nano particles of cerium oxide with high thermal stability and large specific surface area were synthesized via controlling of technological parameters under the hydrothermal conditions.The experiment results indicate that the main factors influencing on particle size and adsorptive capacity of cerium oxide are: the concentration of Ce (NO3) 3 6H2O and ammonia, the molar ratio of SDS and Ce (NO3) 36H2O, the reaction temperature and time.The optimal technological parameter for synthesis of nano structure of cerium oxide are following that: the concentration of Ce (NO3) 3 6H2O (0.15mol/L), the concentration of ammonia (7mol/L), molar ratio of SDS and Ce (NO3) 3 6H2O (2: 1), the reaction temperature (140 C), reaction time (360minutes). In the results, the particle size of powder is 20nm and the specific surface area of it is 156 m2/g.The connection of reaction time and the particle size was studied in this paper. When other parameters were unchanged, the particle size was increased with the extending of reaction time, and the size of the particle retained on 18nm when the reaction time was extended to 360minutes.In the connection of reaction temperature and the particle size, when other parameters were unchanged, the size of particle was increased from 14nm to 29nm with the temperature increased from 120 C to 200 C, while the size increased little when the reaction temperature was 200 C.XRD pattern and N2 adsorption analysis (BET) show that the nano particle of cerium oxide has high thermal stability and large specific surface area under the hydrothermal condition. The particle size and specific surface area have changed little with the increasing of calcination temperature. The particle size of the cerium oxide calcined at 350 C for 2 hours was 20nm, while calcined at 550 C and 800 C for 2hours was between 30nm and 40nm. The specific surface area of cerium oxide calcined at 350 C for 2 hours was 156 m2/g, while calcined at 550 C for 2 hours was 125 m2/g and calcined at 800 C for 2 hours was 82 m2/g.In this paper, nano structure particle of other rare earth oxide (La and Nd) were also prepared under the hydrothermal condition, which implies that this method has good appliance.