钙钛矿复合氧化物中空微纳颗粒的控制合成与气敏性能研究

项目名称： 钙钛矿复合氧化物中空微纳颗粒的控制合成与气敏性能研究

项目编号： No.21271138

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 赵永男

作者单位： 天津工业大学

项目金额： 75万元

中文摘要： 在大量预研基础上，针对多元氧化物以及（异质）多壳层中空微纳颗粒在粒径、单分散性、壳层厚度与层数等可控制备的难点，以钙钛矿型复合氧化物为对象，基于溶胶-凝胶理论中改变电解质浓度可以调节胶体颗粒双电层厚度，使胶体颗粒在不同尺度聚沉，实现聚沉颗粒大小的可调可控，进而在水热、加热回流条件下利用Ostwald熟化作用使聚沉颗粒转变为中空微纳颗粒，通过控制反应时间和温度实现颗粒尺度与壳层厚度的可调可控，搅拌下的加热回流可提高产物的单分散性；以所制备的钙钛矿型复合氧化物中空微纳颗粒为基体，采用层层沉积技术制备（异质）多壳层材料，通过沉积液浓度与沉积次数控制沉积层的层数与厚度，开发出过程可控、具有一定普适性和易于规模化的无模板制备方法。在材料制备的基础上，研究中空微纳颗粒对CO2、水蒸气、乙醇等气体的气敏性能，考查粒径、组成、壳层厚度与层数对气敏性的影响。

中文关键词： 复合氧化物；中空微纳颗粒；熟化；Kirkendall效应；能源材料

英文摘要： This application uses perovskite oxides as the research subject and aims at "Controllable fabrication and gas sensor properties of perovskite oxide hollow micro- and nanoparticles. Sol-gel theory has claimed that the aggregated particles were size-controllable by altering the thickness of the double eletric layer of colloids. The interparticle forces are altered by adjusting the electrolyte concentration of a sol to adjust the sizes of the aggregated particles. Thus, aggregated particles will form with various size. Hydrothermal treatment of these aggregated particles will promote the Ostwald ripening process to hollowing these particles. Hollow particles are then formed with adjustable and controllable size and shell thickness. A hydrothermal route will be developed to synthesize perovskite oxide hollow particles. Furthermore, (heterogeneous) multi-shell hollow micro- or nanoparticles can be readily fabricated by using layer-by-layer deposition method. On the other hand,the addition of electrolyte is well-known to elevate the boiling temperature of a solution for most solutes. We have also found that the boiling temperature of highly concentrated base solutions was over 180 centi degree, which is high enough for most reactions that occur under hydrothermal conditions. From this view, many hydrothermal reactions

英文关键词： complex oxides；hollow micro- and nanoparticles；rippening；Kirkendall effect；energy materials