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

Abstract: Outstanding functional tunability underpinning metal-organic framework (MOF) confers a versatile platform to contrive next-generation chemical sensors, optoelectronics, energy harvesters and converters. We report a rare exemplar of a porous 2D nanosheet material, constructed from an extended 3D MOF structure. We develop 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. 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. We show highly promising photonics based chemical sensing opened up by the new Guest@MOF composite systems. By harnessing host-guest optochemical interactions of functionalized MOF nanosheets, we have accomplished detection of an extensive range of volatile organic compounds (VOCs) and small molecules important for many practical applications.