Constructing imine and amine-based hydrogen-bonded organic frameworks in aqueous media and selective CO2 adsorption

Hydrogen-bonded organic frameworks (HOFs) have become a unique class of crystalline porous materials with potential applications in the field of gas adsorption and separation. However, the synthesis of HOFs with multifunctional groups is challenging. Herein, we synthesized two HOFs containing both imines and primary amines using the ethanol/water/KOH method. These two HOFs exhibited superior water and chemical stability. Moreover, both HOFs demonstrated excellent CO2 adsorption capacity and CO2/N2 separation performance, with HOF-HZ displaying a high CO2/N2 selectivity up to 494 at 273 K and 0.1 bar. Our findings are expected to contribute to the synthesis and design of multifunctional HOF structures.