Albolkany Mohamed K, Liu Congyan, Wang Yang, Chen Chun-Hui, Zhu Chaofeng, Chen Xihai, Liu Bo
Hefei National Laboratory for Physical Sciences at the Microscale, Fujian Institute of Innovation of Chinese Academy of Sciences, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Angew Chem Int Ed Engl. 2021 Jun 21;60(26):14601-14608. doi: 10.1002/anie.202103104. Epub 2021 May 17.
Hierarchically porous MOFs (HP-MOFs) present advantageous synergism of micro- and mesopore but challenging in synthetic control at molecular scale. Herein, we present the first example of reversible and controllable mesopore generation and renovation in a microporous MOF of HKUST-1 via synthetic manipulation at molecular scale. An ammonia-gas etching strategy is proposed to create mesopores in carboxylate-based microporous MOFs and thus produce HP-MOFs. Gas-phase etching ensures uniform mesopore formation inside the MOF crystals via plane-oriented cutting the carboxylate-metal bonds off without affecting the crystal size and morphology. The mesopore size is controlled by the etching temperature, while the mesopore volume could be tuned by adjusting etchant pressure. The generated mesopores could be renovated using MOF precursors solutions so that to achieve controllable mesopore generation/closure, and encapsulation of the adsorbed molecules. This work demonstrates a powerful protocol for precisely tailoring and tuning the properties of MOF materials at molecular scale.
分级多孔金属有机框架材料（HP-MOFs）展现出微孔和介孔的有利协同作用，但在分子尺度的合成控制方面具有挑战性。在此，我们展示了通过分子尺度的合成操作在HKUST-1微孔金属有机框架材料中实现介孔可逆可控生成与修复的首个实例。提出了一种氨气蚀刻策略，用于在基于羧酸盐的微孔金属有机框架材料中创建介孔，从而制备HP-MOFs。气相蚀刻通过平面定向切断羧酸盐-金属键确保在MOF晶体内部形成均匀的介孔，而不影响晶体尺寸和形态。介孔尺寸由蚀刻温度控制，介孔体积可通过调节蚀刻剂压力进行调整。生成的介孔可以使用MOF前驱体溶液进行修复，从而实现可控的介孔生成/封闭以及对吸附分子的封装。这项工作展示了一种在分子尺度精确剪裁和调节MOF材料性能的强大方法。
