Deng Wei-Hua, Li Qiao-Hong, Chen Jie, Wang Chuan-Zhe, Fu Zhi-Hua, Ye Xiao-Liang, Wang Guan-E, Xu Gang
State Key Laboratory of Structural Chemistry, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, <350117, Fuzhou, China.
Angew Chem Int Ed Engl. 2023 Aug 1;62(31):e202305977. doi: 10.1002/anie.202305977. Epub 2023 Jun 26.
The electronic conductivity (EC) of metal-organic frameworks (MOFs) is sensitive to strongly oxidizing guest molecules. Water is a relatively mild species, however, the effect of H O on the EC of MOFs is rarely reported. We explored the effect of H O on the EC in the MOFs (NH ) -MIL-125 and its derivatives with experimental and theoretical investigations. Unexpectedly, a large EC increase of 10 on H SO @(NH ) -MIL-125 by H O was observed. Brønsted acid-base pairs formed with the -NH groups, and H SO played an important role in promoting the charge transfer from H O to the MOF. Based on H SO @(NH ) -MIL-125, a high-performance chemiresistive humidity sensor was developed with the highest sensitivity, broadest detection range, and lowest limit of detection amongst all reported sensing materials to date. This work not only demonstrated that H O can remarkably influence the EC of MOFs, but it also revealed that post-modification of the structure of MOFs could enhance the influence of the guest molecule on their EC to design high-performance sensing materials.
金属有机框架材料（MOFs）的电子电导率（EC）对强氧化性客体分子敏感。水是一种相对温和的物质，然而，水对MOFs电导率的影响鲜有报道。我们通过实验和理论研究探索了水对MOFs（NH₄）₂-MIL-125及其衍生物电导率的影响。出乎意料的是，观察到水使H₂SO₄@（NH₄）₂-MIL-125的电导率大幅增加了10倍。与-NH基团形成的布朗斯特酸碱对，且H₂SO₄在促进电荷从水转移到MOF中起重要作用。基于H₂SO₄@（NH₄）₂-MIL-125，开发了一种高性能化学电阻式湿度传感器，在所有已报道的传感材料中具有最高的灵敏度、最宽的检测范围和最低的检测限。这项工作不仅证明了水可显著影响MOFs的电导率，还揭示了MOF结构的后修饰可以增强客体分子对其电导率的影响，从而设计出高性能传感材料。
