Y_2O_3和CeO_2复合掺杂ZrO_2纳米晶的制备与表征

Synthesis and Characterization of Nanocrystalline ZrO_2 Doped with CeO_2 and Y_2O_3

以ZrOCl2.8H2O,Y2O3,Ce（NO3）3.5.5H2O为原料,NH3.H2O作沉淀剂,少量表面活性剂PE作分散剂,采用反向共沉淀-喷雾干燥法,结合物理、化学分散技术,成功地制备了Y2O3,CeO2复合掺杂ZrO2纳米粉末。通过DSC-TG,XRD,XPS,BET和SEM等方法对所制得粉末进行了表征。结果表明：以Ce0.1Y0.1Zr0.8O1.95化学计量比制备的多元氢氧化物胶体经过喷雾干燥处理后,在500℃基本完成水合氧化物的分解,577℃附近完成由非晶相向立方相的转变;经过580-1000℃煅烧后,CeO2和Y2O3已经完全固溶到ZrO2中,形成类质同相体,该粉末系列均属于立方相萤石结构;掺杂进入ZrO2晶格中的Ce呈＋4价形式存在;比表面积由22.0 m^2.g^-1（580℃煅烧）减至4.97 m^2.g^-1（1000℃煅烧）;SEM结果显示800℃煅烧的该粉末颗粒尺寸分布均匀,多呈类球状,且粒径在50-80 nm。

Nanocrystalline zirconia particles, doped with CeO2 and Y203, were successfully prepared by reverse co-precipitation and spray-drying, with the dispersion technique of chemical and physics methods. The hydrate and further thermal treatment samples were characterized in terms of crystalline structure and phase purity, cerium ions valence and specific surface area, particle shape and size distribution using thermal （DTA-TG） analysis, X-ray diffraction, X-ray photoelectron spectroscopy, BET, and scanning electron microscopy. It was found that the hydrate of 0.8Zr（OH）4·0. 1Ce（OH）4·0. 1Y（OH）3 after spray-drying decomposed to ZrO2 over below 500 ℃, and turned to crystal nearly at 580 ℃. After calcination, the XRD and XPS date indicated formation of a solid solution and additional existence of Ce4＋ state near the surface. The specific surface area decreased from 22.0 （be calcined at 580 ℃） to 4.97 m2·g^-1（be calcined at 1000 ℃）. The SEM examination had shown a mierostrueture of particles sizes （1 - 1.5 μm） and grain sizes （50 - 80 nm）.