一维氧化铟基复合核壳纳米纤维的制备及其室温气敏传感性质研究

In mine environment, hydrogen sulfide is a common, flammable, explosive, and toxic gas. To detect hydrogen sulfide in an effective and safe way is very important for protecting the security of mine workers and underground resources. At present, how to quickly and accurately identify dilute hydrogen sulfide gas at room working temperature in the mine environment is still a difficulty of the current research. This project intends to fabricate a series of one-dimensional noble metals (Au, Pt)/porous rare earth doped indium oxide core-shell nanofibers by electrospinning and build the corresponding gas sensors. In-depth study the sensitizing effect of noble metal core on indium oxide shell and the interaction mechanism between core-shell materials, realize the modulation laws of band gap, electronic and gas sensing properties due to the introduction of rare earth elements with different kinds and concentrations, investigate the influence of metal core and rare earth on sensing mechanism, clear the mutual constraint and dependency relationship between the sensitivity and response and recovery time at room operating temperature, through controlling the thermodynamic of the reaction mechanism to get the gas sensor with high sensitivity, and short response and recovery time to dilute hydrogen sulfide at room working temperature. This project will obtain a new series of high-performance indium oxide nanocomposite gas sensors and provide the theoretical guidance and experimental evidence for the practical application of hydrogen sulfide detection in complex mine environment.

硫化氢是矿井环境中常见的一种易燃易爆毒性气体，对其进行安全有效探测是保护矿工安全和井下资源的重要手段。目前，针对矿井环境特点获得可在室温下准确快速地探测出稀薄硫化氢气体的传感器件仍然是研究的难点。本项目拟采用静电纺丝法制备一系列一维贵金属(Au, Pt)/多孔稀土掺杂氧化铟核壳纳米纤维并构筑传感器件。研究贵金属内核对氧化铟壳层的敏化作用和核壳间的相互作用机理；研究稀土元素的掺杂种类和浓度对氧化铟带隙、电学性质与传感特性的调控规律；研究金属内核和稀土的引入对气敏传感机制的影响；研究室温下灵敏度与响应时间之间相互制约和依赖的内在原因；通过反应机制的热力学控制获得对稀薄硫化氢具有高灵敏度快速响应的器件。本项目将获得新一类的高性能复合纳米氧化铟传感器，并为其在矿井等封闭复杂环境内对硫化氢气体检测的实际应用提供重要的理论基础与实验依据。

矿井环境封闭且复杂，其中常见的硫化氢（H2S）气体具有易燃易爆毒性大等特点，对人体具有不可逆转的伤害，对其进行安全有效探测是保护矿工安全和井下资源的重要手段。目前，针对矿井环境特点获得可准确快速地探测出稀薄H2S气体的传感器件仍然是研究的难点。针对目前的问题，本项目从构筑一维贵金属@多孔稀土掺杂氧化铟核壳纳米纤维出发，深入研究了利用静电纺丝法制备同轴多孔核壳纳米纤维复合材料及其在H2S气敏传感方面的应用。主要工作包括静电纺丝法制备同轴核壳纳米复合纤维、半导体（尤其是In2O3）与贵金属及稀土掺杂之间的相互作用及相关材料的气敏传感特性和机制解释等方面。所获得的Pt@多孔稀土掺杂In2O3核壳纳米纤维形貌均匀，稀土掺杂种类和内外壳层各自可调且接触良好，通过参数调控成功得到核壳纳米纤维的形成机制，并明确在核壳界面形成一定的阻挡层对形成良好核壳结构非常必要。深入认识了稀土掺杂、贵金属引入与In2O3的相互作用机理，明确贵金属的引入有利于In2O3表面氧缺陷浓度的提高，并可以改变其局域微环境；稀土离子掺杂可增大In2O3的带隙、短路电流密度、开路电压及空气中电阻值。通过对反应的热力学控制实现对H2S进行高灵敏度快速探测，所获得的器件对H2S气体的响应值与In2O3纳米纤维相比有2个数量级的提高，可以有效对稀薄H2S气体进行高选择性探测。基于以上研究成果，我们在Nanoscale、J. Mater. Chem. C、ACS Appl. Inter. Mater., Sensor. Actuat. B-Chem.等杂志上发表SCI论文32篇，其中影响因子大于3的30篇，影响因子大于6的11篇，在短时间内被引用共达180余次，申请专利1项、做国内分会报告2次。本项目为获得新一类高性能复合纳米材料及其在气敏传感，尤其是矿井等封闭复杂环境下气体检测提供了更具实用价值的功能材料，为实际应用奠定理论基础与实验依据。