多级结构纳米氧化物基敏感材料的可控构筑及其气敏器件的研究

In this project,the novel hierachical structure of nano-oxides, constructed by two or more than two kinds of low dimensional building blocks, will be synthesized by a simple, economical solution-based route and/or further modified by noble metal and/or carbon materials to obtain gas sensing materials with high conductivity, ultrahigh sensitivity, high selectivity and good stability. The formation mechanism of hierachical structure of oxides will be also studied in detail. The above hierachical structure of oxides will be assembled to form gas sensors by in-situ chemistry bath deposition method which will keep the hierachical structure well. Furthermore, the deep investigation will be performed on the low temperature gas sensor structural design and optimimization. The mechanism for gas adsorption and desorption will be studied by combining theoretical caculation with characterizations of dynamic gas sorption apparatus, infrared spectra, electricity properties, etc., to illustrate the relationship between hierachical structure of oxides and their gas sensing properties..This project will help us to understand the mechanism of the formation of hierarchical structures, improve the assembly technique of the gas sensors,enhance the gas sensing properties and widen the application fields of these new sensing materials. These results may provide theoretical guides for further investigation of the relationship between the micro-structures of the oxides and their gas sensing properties and practical application of the gas sensors.

本课题拟采用简单的软化学合成体系，制备具有两种或两种以上由低维结构单元构筑的多级结构纳米氧化物基材料，或通过贵金属、碳素材料复合调控氧化物基多级结构，获得高导电性、超灵敏度、高选择性和稳定性的气体敏感材料，并研究多级结构氧化物基材料的构建机制。利用化学浴沉积实现多级结构氧化物基材料在不同元件基体表面的原位组装，力争保持其多级结构的形貌完整，并进行低温气体敏感器件的结构设计与性能优化研究。采用动态气体吸附仪、红外光谱、材料电学性质等实验测定和理论计算相结合研究气体吸脱附机理，揭示纳米氧化物基材料的多级结构与气敏性能之间的关系。.多级结构纳米氧化物基气体敏感材料及其气敏器件的研究可阐明氧化物基多级结构的构建机制，完善多级结构纳米氧化物基材料的敏感器件组装技术，提高其传感器性能，拓展新型敏感材料的应用领域，进而为深入探究氧化物基材料显微结构与气敏性之间的关系和器件的实际应用奠定理论基础。

金属氧化物多级结构气敏材料是近年来敏感材料科学领域的研究热点之一。本项目采用简单的溶液化学法制备出了10余种由低维度纳米结构单元构筑的多级结构氧化物材料，在UV、IR、XRD、SEM、TEM和AFM等结构和形貌表征的基础上，研究了材料的制备方法、组装形式、构筑单元、复合材料等对材料显微结构与气敏性能的影响规律，同时采用XPS和质谱色谱联机技术研究了材料的敏感机理。研究发现，相对较高的表面吸附氧含量、较薄的组装膜、原位组装、小尺寸构筑单元和多孔结构有利于气敏性能的提高。该研究结果对今后该类气敏材料的进一步开发和实用化提供了重要的理论依据。