MOF-on-MOF复合纳米薄膜可控制备及其室温气敏性能研究

Nowadays, indoor air pollution is one of the most critical concerns for governments and individuals. Owing to their portability, real-time operability and ease of use, metal oxide (MOX) based gas sensors have attracted consumer's affection. However, MOX gas sensors exhibit long-term bottlenecks of poor selectivity and high operating temperature, which hinder their practical applications in real life. Herein, we suggest a good solution, which is, combining two dimensional (2D) π-conjugated electronic conductive Metal–Organic Frameworks (EC-MOFs, high sensitivity at room temperature) with 2D MOFs nanosheets to make a new type of MOF-on-MOF multilayer thin film. Some research tools, such as crystallography, surfaces/interfaces analysis and sensing properties testing will be used to analyze the relationship between the compositions, structures and properties of the composite semiconductors. Based on it, we will make efforts to summarize and master the law of synthesizing this type composite material and the enhanced sensing mechanism. The conductivity and room temperature activity of EC-MOFs, and the groups and pore size of 2D MOFs nanosheets can be tuned by metal/ligand doping to improve the sensitivity and selectivity, respectively. This study provides a new strategy to solve both the poor selectivity and high operating temperature, and further improve the sensitivity. After conducting this project, 3-5 important papers and 3-4 patents on highly sensitive and selective MOF-on-MOF multilayer thin film devices are planning to be published.

室内空气质量已成为公众关注热点。金属氧化物（MOX）电阻型气敏传感器对居室和工作场所的危险气体检测具有在线、快速且无需专业人员操作的优势。然而，选择性差和工作温度高作为该类传感器的瓶颈问题限制了其大规模应用。本项目拟结合电子导电金属有机框架（EC-MOFs）室温高灵敏度、二维MOFs纳米片的选择性气体分离，构筑MOF-on-MOF复合纳米薄膜。利用晶体学、表/界面分析和性能测试等手段分析材料的组成结构与传感性能之间关系，掌握设计合成MOF-on-MOF复合薄膜的经验规律，研究其性能增强机理。通过调节EC-MOFs导电率和活性，以及二维MOFs纳米片的基团和孔径，既能解决传统MOX气敏传感器选择性差和工作温度高的问题，又能进一步提高灵敏度并扩展检测气体种类，为实际应用打下基础。预期在国际重要学术期刊上发表文章3-5篇，申请专利3-4件。

作为物联网和“中国制造2025”的重要一环，高效半导体器件及其关键材料是21世纪最具影响力和发展前景高新技术。将不同功能的薄膜复合在一起，实现不同功能之间的级联应用，对于拓展材料的应用或提升其器件性能至关重要。在本项目执行期内，我们围绕电子导电和气体选择性金属有机框架复合MOF-on-MOF薄膜这一主题，取得了若干创新成果：例如，我们设计合成了系列级联功能的MOF-on-MOF和MOF-on-MOs薄膜材料，其中印章转印制备的晶格不匹配的MOFs的异质结多层薄膜，通过级联上层二维Cu-TCPP的选择性氨气滤除和下层导电MOF的气敏传感，实现了氨气和苯的选择性反转，利用双层咪唑基薄膜对大尺寸干扰苯系物有效筛除实现中温丙酮气体抗湿度干扰的尺寸选择性检测（选择性S丙酮/苯增强311%）；该复合概念还可扩展至双活性配体有序配位的新型多孔导电MOF（~10-4 S cm-1）和系列导电MOF薄膜的掺杂优化，其室温氨气响应值比原薄膜提升100%以上，含氨基的HITP配体的掺杂实现苯对氨气、三乙胺对氨气的选择性提高220%以上，并探索了导电率与孔隙率对室温气敏性能的影响。该项目发表文章15篇，授权中国发明专利4项。