Large-Scale Synthesis of Monodisperse UiO-66 Crystals with Tunable Sizes and Missing Linker Defects via Acid/Base Co-Modulation.

Beyond their pore structures and surface chemistry, precise controls over other attributes of metal-organic frameworks (MOFs) such as shapes, sizes, and defects are also favorable to their fundamental studies and applications but still remain challenging. Herein, we reported an acid/base co-modulation strategy to the large-scale synthesis of monodisperse UiO-66 crystals with acetic acid for modulating crystal shape and with triethylamine (TEA) as a base for controlling the nucleation of crystallization and tuning the formation of missing linker defects via promoting presumably the singe deprotonation of terephthalic acid linkers. The obtained monodisperse MOF crystals have a well-defined octahedral shape, tunable sizes ranging from ∼500 nm to ∼2 μm, and high thermal stability. Their assembled-monolayers are responsive to methanol vapor with the crystal size-dependent and defect-relevant sensing performances.