MOFs基ZnO多孔空心球阵列薄膜及其紫外光驱动下气敏特性研究

The semiconductor gas sensor driven by UV light has the advantages of safety, reliability and low working temperature etc., and developing a room temperature gas sensor with excellent gas sensitivity under UV light, such as high sensitivity, fast response/ recovery and good stability is one of the goals pursued in this field. Base on the features of metal-organic frameworks (MOFs) which can obtain porous materials with high porosity, the MOFs arrays are firstly prepared with two-dimensional colloidal crystal template method in liquid phase. Combined with the specific heat treatment, the ZnO porous hollow array film is constructed in situ on the sensor substrate, and the properties and regulation methods are studied under UV light. The main research contents in this project include: regulation of thin film structure parameters and growth mechanism; the intrinsic correlation between UV wavelength/intensity, the modification of noble metal and the gas-sensing properties; the construction and application of gas sensor with high performance. This project focuses on solving two scientific problems: the controllable construction of sensitive thin films under the effect of surface induction and space limit of template and the modulation effect of array film to UV light field. This project aims to obtain gas sensor with high sensitivity under UV light and investigates the related mechanism. This project will not only reveal the mechanism and regulation methods of gas sensor under UV light, but also realize preliminary application for the highly sensitive detection of nitrogen dioxide and ozone.

紫外光激发型半导体气体传感器具有安全可靠、工作温度低等优点，发展具有灵敏度高、响应/恢复快、稳定性好等优异性能的紫外光驱动型室温气体传感器是本领域追求的目标之一。本项目利用金属有机框架化合物（MOFs）可以获得高孔隙率多孔材料的特征，发展二维胶体晶体模板液相生长MOFs阵列的方法，并结合热处理控制在传感器基底上原位构筑ZnO多孔空心球阵列敏感薄膜，研究紫外光驱动下气敏特性与调控方法。主要内容包括：薄膜结构参数调控与生长机理；紫外光波长/强度以及贵金属修饰与气敏特性之间的内在关联；高气敏性能气体传感器构筑与应用初探。项目注重解决模板表面诱导和空间限域效应下敏感薄膜的可控构筑以及阵列薄膜对紫外光场的调制效应两个科学问题；旨在获得紫外光驱动下具有优异气敏性能的气体传感器，并研究相关机理。本项目研究将揭示阵列精细结构对气敏性能的影响机制，也为二氧化氮、臭氧等气体的高性能传感器研究提供基础。

半导体式气体传感器由于体积小、重量轻、便于集成化等优点，现已在工业危险气体泄露、有毒有害气体检测、易燃易爆气体预警等领域得到广泛应用。然而，其仍然存在响应时间较长（长达几十秒至数分钟）、灵敏度低、工作温度高等缺点。因此，本项目基于有机框架化合物材料（MOFs）探索出较为规则的球形ZIF-8材料的合成条件，研究不同退火温度下材料表面粗糙程度的变化情况，探究了不同退火温度和紫外光驱动下材料的气敏特性；结果表明当退火温度为400℃，紫外光功率为3.60 mW/cm2时，制备的器件对甲醛气体表现出较好的气敏特性。进一步在合成过程中利用CuCl2刻蚀ZIF-8前驱物，制备了不同修饰比例的ZnO-CuO空心纳米笼异质结构复合材料，探究了不同比例下气敏材料的敏感特性，结果表明当CuO的质量比达到1 wt%时，对硫化氢气体表现出高响应、低工作温度，低检测下限、高选择、一致性和重复性等气敏特性。而研制的α-Fe2O3多孔空心球阵列薄膜、ZnO@CuO多孔空心球有序阵列、聚苯胺类有机半导体材料、Au修饰的ZnFe2O4卵黄状球壳结构和AuPd合金修饰的SnO2中空纳米球材料，不仅是本项目研究内容和目标的进一步补充，更扩展了目标气体的检测种类，实现对不同气体的高性能检测。同时基于这些气体传感器，开发了在线测试系统，对氨气、硫化氢等多种目标气体进行实时在线检测。通过本项目的顺利实施，将为高性能传感器的研制及对有毒有害气体的检测提供数据和物质支持，也将为传感器的实际应用提供理论基础和借鉴作用。