矿化剂溶液在水热合成钆掺杂（10%摩尔钆）二氧化铈纳米粉末中的作用。

Effect of the mineralizer solution in the hydrothermal synthesis of gadolinium-doped (10% mol Gd) ceria nanopowders.

作者信息

Dell'Agli Gianfranco, Spiridigliozzi Luca, Marocco Antonello, Accardo Grazia, Ferone Claudio, Cioffi Raffaele

机构信息

Department of Civil and Mechanical Engineering and INSTM Research Unit, University of Cassino and Southern Lazio, Cassino, Frosinone - Italy.

Department of Engineering and INSTM Research Unit, University Parthenope of Naples, Naples - Italy.

出版信息

J Appl Biomater Funct Mater. 2016 May 18;14(2):e189-96. doi: 10.5301/jabfm.5000282.

DOI:10.5301/jabfm.5000282

PMID:27149940

Abstract

BACKGROUND

Gadolinium-doped ceria is an attractive electrolyte material for potential application in solid oxide fuel cells (SOFCs) operating at intermediate temperatures typically with 10%-20% substitution of Ce+4 by Gd+3. In particular, 10% gadolinium-doped ceria seems to have the highest values of conductivities among the other dopant compositions.

METHODS

Nanosized powders of gadolinium-doped ceria were prepared by hydrothermal treatment using coprecipitate as a precursor and in the presence of 3 different mineralizer solutions. The powders obtained were characterized by X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy and thermal analysis, while the electrical behavior of the corresponding pellets were ascertained by AC impedance spectroscopy.

RESULTS

Nanocrystalline gadolinium-doped ceria powders with fluorite cubic crystal structure were obtained by hydrothermal treatment. Independent of the mineralizer used, these powders were able to produce very dense ceramics, especially when selecting an optimized sintering cycle. In contrast, the electrical behavior of the samples was influenced by the mineralizer solution, and the samples synthesized in the neutral and alkaline solutions showed higher values of electrical conductivity, in the range of temperatures of interest.

CONCLUSIONS

By the coprecipitation method, it has been possible to synthesize nanosized gadolinium-doped cerium oxide in a fluorite structure, stable in a wide range of temperatures. Hydrothermal treatment directly on the as-synthesized coprecipitates, without any drying step, had a very positive effect on the powders, which can be sintered with a high degree of densification, especially with an optimized sintering cycle. Furthermore, the electrical behavior of these samples was very interesting, especially for the samples synthesized using neutral mineralizer solution and basic mineralizer solution.

摘要

背景

钆掺杂二氧化铈是一种有吸引力的电解质材料，有望应用于中温运行的固体氧化物燃料电池（SOFC），通常Ce⁺⁴被Gd⁺³替代10%-20%。特别是，10%钆掺杂二氧化铈似乎在其他掺杂剂组成中具有最高的电导率值。

方法

以共沉淀物为前驱体，在3种不同矿化剂溶液存在下，通过水热处理制备了钆掺杂二氧化铈纳米粉末。通过X射线衍射分析、扫描电子显微镜、透射电子显微镜和热分析对所得粉末进行表征，同时通过交流阻抗谱确定相应颗粒的电学行为。

结果

通过水热处理获得了具有萤石立方晶体结构的纳米晶钆掺杂二氧化铈粉末。无论使用何种矿化剂，这些粉末都能够制备出非常致密的陶瓷，特别是在选择优化的烧结周期时。相比之下，样品的电学行为受矿化剂溶液影响，在感兴趣的温度范围内，在中性和碱性溶液中合成的样品显示出更高的电导率值。

结论

通过共沉淀法，有可能合成具有萤石结构、在很宽温度范围内稳定的纳米级钆掺杂氧化铈。直接对合成的共沉淀物进行水热处理，无需任何干燥步骤，对粉末有非常积极的影响，这些粉末可以高度致密化烧结，特别是采用优化的烧结周期。此外，这些样品的电学行为非常有趣，特别是对于使用中性矿化剂溶液和碱性矿化剂溶液合成的样品。