新型多孔复合材料

Due to their potential applications in catalysis, supercapacitor, lithium battery and biosensing, porous materials with high stability, good conductivity and large surface area are attracting intensive attention. Inspired by the formation process of metal-organic frameworks (MOFs), we proposed a new method to form such kind of conductive porous materials with the backbone of layered materials such as graphite and molybdenum disulfide, by applying the coordination chemistry. The method we proposed can be described as follows: Layered materials such as graphite or molybdenum disulfide were used as the mother materials. Through intercalating reactions, metal ions or ligands can be inserted between the layers of the mother materials. With the coordination chemistry between the metal ions and ligands, these intercalated layers can be converted into porous structures. As the carriers such as electrons or holes prefer to transport within the layers and the formed porous materials adapt the layered structures of their mother materials. Thus, the final porous materials may reserve the physical properties from their mother materials like good conductivity, they also show the new properties resulting from the formation of porous MOF-like structures, such as large surface area and chemical activity linked to the diversity kind of function groups introduced during the reaction. MOF materials have high Brunauer-Emmett-Teller (BET) value, but they show low electron conductivity, while layered materials like graphite has good conductivity and low surface area. With the recombination of the properties of layered mother materials and the MOF-like structures, this new kind of material will exhibit broad applications.

具有高稳定性，导电性和比表面积的新型材料由于在化学催化，能源储存、转化以及生物传感等方面的广阔应用，一直吸引着众多研究者。受多孔金属骨架有机聚合物材料(metal-organic frameworks)合成的启发，本研究拟开发一种基于层状导体，半导体（拟以石墨和硫化钼为代表），具有较高的稳定性，优异的导电性能和大比表面积的新型材料。由于层状材料具有各项异性的导电性能，载流子主要在层内运动，层与层间的载流子越迁很少。所以在不破坏层结构的前提下，本研究拟以导电的层状材料为骨架，通过嵌入孔状有机分子-金属离子配合物层来提高其比表面积和相应的化学性能，从而使得到的新型功能型材料不仅具有层状无机材料的优异物理性质，而且也具备了金属骨架有机聚合物的大比表面积和具有化学活性的有机官能团的特性。因为它可能具有的这些特性，这种稳定的，具有导电性和大比表面积的新型材料必将展现出广阔的应用前景。

金属有机骨架材料（metal-organic framework，MOF) 是一类通过金属离子/团簇和有机物配体配位而形成的拥有巨大表面积（BET比表面积1000~8000 m2g–1）的多孔材料，它在催化、储能和分离中都有广泛应用。本项目以开发和制备具有高稳定性ˎ导电性和大比表面积的以二维材料为骨架的多孔层状材料，并探索它的物理化学性质以及在相关领域的应用为研究内容。研究者利用金属有机骨架材料特殊的生长机理，分别设计了通过 “异相成核” 以及 “牺牲模板” 等方法实现了MOF材料在复合物表面的选择性可控生长，成功实现了各种核壳结构以及壳层结构的复合材料的可控制备，这些方法可以使复合材料具有很高的比表面积，而且还可以使材料拥有MOF所不具有的很多性质，将大大提高其应用范围。另外，研究者意识到由于复合材料中的各相分布和结合等原因，会引起材料内部应力的不同，因而以ZIF-8/金纳米粒子为例，对复合过程所引起的MOF晶格性质的变化进行了深入的研究，揭示了复合相分布对于材料物理性质的影响，提出了通过复合过程调节MOF内部应力的一种新思路。这些探索工作的开展都为拓展金属有机骨架化合物在气体吸附、催化以及电学等方面的应用提供了必要的技术支持。