Linares-Moreau Mercedes, Brandner Lea A, Velásquez-Hernández Miriam de J, Fonseca Javier, Benseghir Youven, Chin Jia Min, Maspoch Daniel, Doonan Christian, Falcaro Paolo
Institute of Physical and Theoretical Chemistry, Graz University of Technology, Graz, 8010, Austria.
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
Adv Mater. 2024 Jan;36(1):e2309645. doi: 10.1002/adma.202309645. Epub 2023 Nov 28.
The field of metal-organic frameworks (MOFs) has progressed beyond the design and exploration of powdery and single-crystalline materials. A current challenge is the fabrication of organized superstructures that can harness the directional properties of the individual constituent MOF crystals. To date, the progress in the fabrication methods of polycrystalline MOF superstructures has led to close-packed structures with defined crystalline orientation. By controlling the crystalline orientation, the MOF pore channels of the constituent crystals can be aligned along specific directions: these systems possess anisotropic properties including enhanced diffusion along specific directions, preferential orientation of guest species, and protection of functional guests. In this perspective, we discuss the current status of MOF research in the fabrication of oriented polycrystalline superstructures focusing on the specific crystalline directions of orientation. Three methods are examined in detail: the assembly from colloidal MOF solutions, the use of external fields for the alignment of MOF particles, and the heteroepitaxial ceramic-to-MOF growth. This perspective aims at promoting the progress of this field of research and inspiring the development of new protocols for the preparation of MOF systems with oriented pore channels, to enable advanced MOF-based devices with anisotropic properties.
金属有机框架（MOF）领域的发展已超越了对粉末状和单晶材料的设计与探索。当前的一个挑战是制造能够利用单个组成MOF晶体的定向特性的有序超结构。迄今为止，多晶MOF超结构制造方法的进展已产生了具有确定晶体取向的密堆积结构。通过控制晶体取向，组成晶体的MOF孔道可以沿特定方向排列：这些体系具有各向异性特性，包括沿特定方向增强的扩散、客体物种的优先取向以及对功能性客体的保护。从这个角度出发，我们讨论了MOF在定向多晶超结构制造方面的研究现状，重点关注特定的晶体取向方向。详细研究了三种方法：从胶体MOF溶液进行组装、利用外部场对MOF颗粒进行排列以及从陶瓷到MOF的异质外延生长。本视角旨在推动该研究领域的进展，并激发开发新的制备具有定向孔道的MOF体系的方案，以实现具有各向异性特性的先进MOF基器件。
