a-Fe2O3纳米晶高能晶面的可控制备及气敏性能的研究

The important foundation of reducing disaster and ensuring the safety of human life is real-time monitoring the atmospheric pollutants and flammable gases of the gas sensors. These needs are inseparable with the reliability and selectivity study of high-performance gas sensor. The gas sensing material is the key point to develop high performance gas sensors. One of the biggest characteristics of metal-oxide semiconductor as a sensitive material is the surface structure of controllability, because gas-sensing process is a typical surface reaction. In the project, the a-Fe2O3 nanocrystals materials with high-energy face would be obtained by introducing suitable protecting groups-assistance the liquid phase synthetic technologies, made into a resistance-type semiconductor gas sensor. The different crystal faces structure of a-Fe2O3 nanocrystals would be regulated to improve the the quantity and relative positions of the surface active atoms and leading to the adsorption capacity and recognition capability of the target gases. The goal of the present project is reveal the structure-property relationship of a-Fe2O3 nanocrystals materials from the way of molecules and atoms, Establish the sensing mechanism model of sensing material in microstructure and sensing properties, realization the selective identification feature of the crystal face of material to the target gas, and provide a scientific basis for high-efficient and reliable gas sensing materials and gas sensors.

气体传感器对污染物质时空分布的准确测量和易燃易爆气体实时监控的正确把握，是减小灾难发生和确保人类生命安全的重要基础。这些需求均与高性能气体传感器的可靠性和选择性研究密不可分。发展新型高性能敏感元件的关键是敏感材料。金属氧化物半导体作为气敏材料的最大特色之一是在于表面结构的可控性，而气敏反应过程是一种典型的表面反应。本项目将采用液相合成方法，引入合适的保护基团，获得具有高能晶面的a-Fe2O3纳米晶体材料，制作成电阻型半导体式气体传感器。重点研究通过调控a-Fe2O3纳米晶体不同晶面的表面结构，改善a-Fe2O3纳米晶体表面活性位点的数量和位置，从而影响其对靶向气体分子的吸附能力和识别能力，其目标是从分子-原子角度揭示a-Fe2O3纳米晶材料的构-效关系，建立敏感材料微观结构和性能的感知机理模型，实现材料表面对靶向气体的选择性识别特性。为发展高效可靠敏感材料和气体传感器提供科学依据。

金属氧化物半导体气体传感器面临的主要问题是在选择性差及其选择机制不明确等问题，本项目针对气体传感器的选择性提出利用金属氧化物高能晶面的暴露来提高气体传感器的性能，采用液相合成方法，引入合适的保护基团，制备了一系列具有高能晶面的金属氧化物纳米晶体材料。开拓了一类制备高能晶面的方法，并将上述具有高能晶面的金属氧化物纳米晶体材料作为敏感材料制作成电阻型半导体式气体传感器。重点研究通过金属氧化物纳米晶的表面调控，改善金属氧化物纳米晶表面活性位点的数量和位置，系统研究了不同类型的金属氧化物基的气体传感器的传感器性能，建立敏感材料微观结构和性能的感知机理模型等。并整理、发表了一系列学术论文。