Ultrafast sonochemical synthesis of imine-linked porous organic cages with high surface area for gas adsorption

Porous organic cages (POCs) are promising crystalline porous materials with high porosity, but their conventional solvothermal synthesis is time-consuming and energy-intensive. Herein, we report for the first time an ultrafast sonochemical approach (<5 minutes, ambient temperature) for synthesizing imine-linked POCs (Sono-CC3R-OH, Sono-CC3R, and Sono-NC2R) using methanol as a green solvent. The sonochemically synthesized POCs exhibit exceptional porosity and crystallinity, outperforming their solvothermal counterparts, while achieving a ∼78% reduction in energy consumption. Furthermore, this approach exhibits excellent potential for large-scale production and efficient solvent recyclability. High-surface-area Sono-CC3R-OH demonstrates preferable CO₂ adsorption with a CO₂/N₂ selectivity of up to 77.5. Thus, this work opens a quick and efficient pathway for the synthesis of imine-linked POCs with superior surface area, offering great potential for the scalable production of gas adsorbents.