Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, China.
Department of Materials Science and Engineering, Texas A&M University , College Station, Texas 77840, United States.
J Am Chem Soc. 2017 Jul 12;139(27):9136-9139. doi: 10.1021/jacs.7b04829. Epub 2017 Jun 30.
Creating ordered two-dimensional (2D) metal-organic framework (MOF) nanosheets has attracted extensive interest. However, it still remains a great challenge to synthesize ultrathin 2D MOF nanosheets with controlled thickness in high yields. In this work, we demonstrate a novel intercalation and chemical exfoliation approach to obtain MOF nanosheets from intrinsically layered MOF crystals. This approach involves two steps: first, layered porphyrinic MOF crystals are intercalated with 4,4'-dipyridyl disulfide through coordination bonding with the metal nodes; subsequently, selective cleavage of the disulfide bond induces exfoliation of the intercalated MOF crystals, leading to individual freestanding MOF nanosheets. This chemical exfoliation process can proceed efficiently at room temperature to produce ultrathin (∼1 nm) 2D MOF nanosheets in ∼57% overall yield. The obtained ultrathin nanosheets exhibit efficient and far superior heterogeneous photocatalysis performance compared with the corresponding bulk MOF.
制备有序二维（2D）金属有机骨架（MOF）纳米片引起了广泛关注。然而，在高产率下合成具有可控厚度的超薄 2D MOF 纳米片仍然是一个巨大的挑战。在这项工作中，我们展示了一种从本征层状 MOF 晶体中获得 MOF 纳米片的新型插层和化学剥离方法。该方法包括两个步骤：首先，层状卟啉 MOF 晶体通过与金属节点的配位键与 4,4'-联吡啶二硫醚进行插层；随后，选择性地切割二硫键诱导插层 MOF 晶体的剥离，得到独立的自由站立的 MOF 纳米片。这种化学剥离过程可以在室温下高效进行，以约 57%的总产率产生超薄（约 1nm）的 2D MOF 纳米片。与相应的体相 MOF 相比，所得到的超薄纳米片表现出高效和远优异的非均相光催化性能。
