多孔纳米Ce-M-O(M=Pr,La)粉末的微波诱导燃烧合成及其表征  

Microwave-induced Combustion Synthesis and Characterization of Porous Nanocrystalline Ce-M-O(M=La,Pr) Powders

作　　者：郝仕油[1] 吕天喜[1] 

机构地区：[1]浙江师范大学化学系浙江省固体表面反应化学重点实验室,金华321004

出　　处：《化学学报》2008年第10期1203-1208,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20672101);浙江省教育厅(No.KYZSKY06053)

摘　　要：使用Ce(NO3)3?6H2O,Pr(NO3)3·6H2O,La(NO3)3·6H2O,尿素为原料,利用微波引诱燃烧法合成了多孔纳米Ce-M-O(M=Pr,La)固溶体.使用XRD,X光电子能谱仪(XPS),Raman光谱仪,红外光谱仪(FT-IR),透射电镜(TEM),场发射扫描电镜(FE-SEM)等仪器对纳米粉体进行了表征.XRD分析显示Ce-M-O粉体的粒径在20～50nm之间,且所有样品均具有萤石结构.XPS证明在Ce-Pr-O固溶体中Pr以+3和+4两种形式存在.Raman光谱表明随着M3+的掺杂,在CeO2晶格中产生氧缺陷,且缺陷浓度随掺杂量增加不断提高.红外光谱证明Ce—O键的吸收峰在1400cm-1左右,且由于M3+的掺杂在2346cm-1的吸收峰消失.TEM照片说明样品具有类盘状的网络纳米微晶结构.扫描图像说明产物具有多孔的外貌特征,且孔径分布在2～40nm之间。Porous nanometer Ce-M-O （M=Pr, La） solid solutions were synthesized by a nucrowaveinduced combustion process using cerium nitrate hexahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate and urea as raw materials. The powders were characterized by X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, laser Raman spectrum, FT-IR spectrum, transmission electron micrograph （TEM）, field-emission scanning electron micrograph （FE-SEM） and so on. XRD analysis reveals that the grain size of Ce-M-O varies between 20 and 50 nm and all the samples have the structure of fluorite. XPS concludes that praseodymium has two different forms （pr^3＋and Pr^4＋） in the Ce-Pr-O solid solution. Raman results show that oxygen vacancy has been produced in CeO2 crystal lattices and its concentration is increased with M^3＋ doping. The results of FT-IR exhibit that the absorption band of Ce-O bond rises around 1400 cm^-1 and the IR absorption band of 2346 cm^-1 disappears because of M^3＋doping. The platelike structure of networked nanocrystallites was observed through the TEM images. It can be seen from SEM that the porous appearance has been obtained and the pore size distribution range is 2 to 40 nm.

关 键 词：多孔 纳米 微波引诱燃烧 表征 掺杂 

分 类 号：TB383.1[一般工业技术—材料科学与工程]