Armored MOFs: Enforcing Soft Microporous MOF Nanocrystals with Hard Mesoporous Silica
Armored MOFs: Enforcing Soft Microporous MOF Nanocrystals with Hard Mesoporous Silica
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DOI：
10.1021/ja409675j
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发表时间：
2014-04-16
影响因子：
15
通讯作者：
Zeng, Hua Chun
中科院分区：
文献类型：
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作者：
Li, Zheng;Zeng, Hua Chun
金属有机骨架（MOFs）是一类非常有吸引力的超分子软质材料，但其机械强度相对较弱。为了加强MOF材料的实际应用，一种可能的方法似乎是将它们转化为具有更强第二相的更硬的复合材料。显然，这种增强相必须具有更大的孔隙率，以使离子或分子物质进入或离开MOF而不改变其原始的物理化学性质。本文报道了一种用介孔二氧化硅（mSiO（2））增强壳包覆微孔MOFs及其衍生物的一般合成方法。四种著名的MOFs（ZIF-8、ZIF-7、UiO-66和HKUST-1）代表了MOFs的两个重要家族，在纳米复合材料产品中充当核心相。我们表明，机械性能（硬度和韧性）的显着增强，确实可以实现这种“铠装方法”。mSiO（2）包裹的MOFs及其含金属的纳米复合材料的优异的可接近性也已经通过催化还原4-硝基苯酚而被证明。
Metal organic frameworks (MOFs) are a class of fascinating supramolecular soft matters but with relatively weak mechanical strength. To enforce MOF materials for practical applications, one possible way seems to be transforming them into harder composites with a stronger secondary phase. Apparently, such a reinforcing phase must possess larger porosity for ionic or molecular species to travel into or out of MOFs without altering their pristine physicochemical properties. Herein we report a general synthetic approach to coat microporous MOFs and their derivatives with an enforcing shell of mesoporous silica (mSiO(2)). Four well-known MOFs (ZIF-8, ZIF-7, UiO-66, and HKUST-1), representing two important families of MOFs, have served as a core phase in nanocomposite products. We show that significant enhancement in mechanical properties (hardness and toughness) can indeed be achieved with this "armoring approach". Excellent accessibility of the mSiO(2)-wrapped MOFs and their metal-containing nanocomposites has also been demonstrated with catalytic reduction of 4-nitrophenol.