Solution-Processable Metal–Organic Framework Nanosheets with Variable Functionalities

Metal–organic frameworks (MOFs) intrinsically lack fluidity and thus solution processability. Direct synthesis of MOFs exhibiting solution processability like polymers remains challenging but highly sought-after for multitudinous applications. Herein, a one-pot, surfactant-free, and scalable synthesis of highly stable MOF suspensions composed of exceptionally large (average area > 15 000 µm²) NUS-8 nanosheets with variable functionalities and excellent solution processability is presented. This is achieved by adding capping molecules during the synthesis, and by judicious controls of precursor concentration and MOF nanosheet–solvent interactions. The resulting 2D NUS-8 nanosheets with variable functionalities exhibit excellent solution processability. As such, relevant monoliths, aero- and xerogels, and large-area textured films with a great homogeneity, controllable thickness, and appreciable mechanical properties can be facilely fabricated. Additionally, from both the molecular- and chip-level it is demonstrated that capacitive sensors integrated with NUS-8 films functionalized with different terminal groups exhibit distinguishable sensing behaviors toward acetone due to their disparate host–guest interactions. It is envisioned that this simple approach will greatly facilitate the integration of MOFs in miniaturized electronic devices and benefit their mass production.