Twofold Interpenetrated 2D MOF Nanosheets Generated by an Instant In Situ Exfoliation Method: Morphology Control and Fluorescent Sensing

Metal-organic framework (MOF) nanosheets, an emerging family of 2D materials, have gained significant attention due to their thin thickness, large surface areas, abundant exposed accessible active sites, etc. However, it is still a big challenge to fabricate high-quality 2D MOF nanosheets in high yields. Herein, a novel and facile synthetic strategy, named as instant in situ exfoliation method, is developed to prepare 2D MOF nanosheets with large lateral dimension, which combines the characteristics and advantages of the popular top-down and bottom-up approaches. Employing such methodology, the large MOF nanosheets with twofold interpenetrated 2D structure and unique fluorescent properties are massively obtained from the precursors in a high overall yield of 67%, of which the minimum thickness is approximate to 14.0 nm. Owing to their unique interpenetrated structure, lamellar morphology, and high fluorescent emission, the resultant MOF nanosheets are capable of functioning as an efficient fluorescent sensor to selectively and sensitively detect the Fe(3+)and Al(3+)ions, exhibiting much better detection limitation compared with the corresponding bulk MOF.