Scalable and Precise Synthesis of Two-Dimensional Metal Organic Framework Nanosheets in a High Shear Annular Microreactor

Despite their promise as next generation materials for adsorbents, membranes and sensors, two-dimensional metal organic frameworks (2D MOFs) are far from commercial adoption. Current synthesis methods are neither scalable nor precise enough to use at industrial scales. Furthermore, the characterization of 2D MOF nanostructure is problematic due to aggregation in post-processing. By accelerating precipitation kinetics and using the recently developed annular flow microreactor, we synthesized copper benzene-dicarboxylic acid nanosheets with significantly higher efficiency and precision than conventional batch methods. The reactor space-time yield was five orders of magnitude higher than the previously published batch methods. We used liquid cell transmission electron microscopy to reduce drying-induced aggregation and revealed a monodisperse particle size distribution. These developments are step-changes in the synthesis and analysis of 2D MOF structures, and may accelerate the commercialization of innovative 2D MOF technologies.