【摘要】 用碳酸氢铵作沉淀剂通过添加NH4NO3 和(NH4)2CO4 两种不同的试剂制备了超细CeO2 粉体。采用X射线衍射、BET和激光散射的方法研究了不同灼烧温度下粉体粒径的变化规律, 并研究了粉体粒径对紫外线吸收的影响。结果表明: NH4NO3 和(NH4)2CO4 作为添加剂可以制得一次粒径在10~100 nm的纳米粉体, 团聚粒径在200~300 nm分散性好的超细CeO2 粉体。X射线衍射和BET测得的一次粒径随灼烧温度升高呈明显增大的趋势, 激光散射测得的团聚粒径随灼烧温度变化不明显。CeO2 粉体分散在去离子水中的吸收光谱研究表明, 粉体一次粒径大小对光的吸收效果有明显影响, 粒径小, 紫外线吸收效果好, 可见光穿透性强, 粒径增大, 粉体将失去紫外线吸收效果, 紫外吸收受粉体的团聚粒径影响不大。更多还原

【Abstract】 Ultra-fine CeO₂ particle-sized powders were prepared by precipitation method with bicarbonate as precipitant while NH₄NO₃ and （NH₄）₂CO₄ serve as additives, respectively. The variant regularity of particle size with calcinations temperatures was studied by XRD, BET and Lazer Scattering methods. The results show that nano-particle sized CeO₂ with primary particle size of 10100nm and aggregated particle size of 200300nm can be obtained while NH₄NO₃ and （NH₄）₂CO₄ serves as additive. The primary particle size determined by XRD and BET method increases significantly with temperature, however the secondary particle size dose not change appreciably analyzed by laser scattering method. As CeO₂ dispersed in de-ionized water, ultra violet（UV）-visible absorbance spectrum was applied to study its absorbance characters. The study finds that it has good UV absorbance and visible light transparency as CeO₂ powder with an ultra-fine particle size. UV absorbance is greatly influenced by the primary particle size. With the primary particle size increase, the UV absorbance weakens markedly. The secondary particle size has little influence on its UV absorbance.更多还原