State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, P.R. China.
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, P.R. China.
Angew Chem Int Ed Engl. 2017 May 8;56(20):5512-5516. doi: 10.1002/anie.201701604. Epub 2017 Mar 23.
Hollow metal-organic frameworks (MOFs) are promising materials with sophisticated structures, such as multiple shells, that cannot only enhance the properties of MOFs but also endow them with new functions. Herein, we show a rational strategy to fabricate multi-shelled hollow chromium (III) terephthalate MOFs (MIL-101) with single-crystalline shells through step-by-step crystal growth and subsequent etching processes. This strategy relies on the creation of inhomogeneous MOF crystals in which the outer layer is chemically more robust than the inner layer and can be selectively etched by acetic acid. The regulation of MOF nucleation and crystallization allows the tailoring of the cavity size and shell thickness of each layer. The resultant multi-shelled hollow MIL-101 crystals show significantly enhanced catalytic activity during styrene oxidation. The insight gained from this systematic study will aid in the rational design and synthesis of other multi-shelled hollow structures and the further expansion of their applications.
中空金属-有机骨架（MOFs）是具有复杂结构的有前途的材料，例如多层壳，不仅可以增强 MOFs 的性能，还可以赋予它们新的功能。在此，我们展示了一种通过分步晶体生长和随后的蚀刻工艺来制造具有单晶壳的多壳中空铬（III）对苯二甲酸 MOFs（MIL-101）的合理策略。该策略依赖于不均匀 MOF 晶体的形成，其中外层比内层具有更强的化学稳定性，并且可以被乙酸选择性地蚀刻。MOF 成核和结晶的调节允许定制每个层的腔室大小和壳厚度。所得的多壳中空 MIL-101 晶体在苯乙烯氧化过程中表现出显著增强的催化活性。从这项系统研究中获得的见解将有助于合理设计和合成其他多壳中空结构，并进一步扩展它们的应用。
