Optochemically Responsive 2D Nanosheets of a 3D Metal–Organic Framework Material

Outstanding functional tunability underpinning metal-organic framework (MOF) confers a versatile platform to contrive next-generation chemical sensors, optoelectronics, energy harvesters, and converters. A rare exemplar of a porous 2D nanosheet material constructed from an extended 3D MOF structure is reported. A rapid supramolecular self-assembly methodology at ambient conditions to synthesize readily exfoliatable MOF nanosheets, functionalized in situ by adopting the guest@MOF (host) strategy, is developed. Nanoscale confinement of light-emitting molecules (as functional guest) inside the MOF pores generates unusual combination of optical, electronic, and chemical properties, arising from the strong host-guest coupling effects. Highly promising photonics-based chemical sensing opened up by the new guest@MOF composite systems is shown. By harnessing host-guest optochemical interactions of functionalized MOF nanosheets, detection of an extensive range of volatile organic compounds and small molecules important for many practical applications has been accomplished.