Rational design of functionalized covalent organic frameworks and their performance towards CO₂ capture

We describe the design and synthesis of two new functionalized covalent organic frameworks, named Cz-COF and Tz-COF, by using monomers containing carbazole and benzobisthiazole as building blocks. The resultant materials possess high crystallinity, permanent porosities as well as abundant heteroatom activated sites in the framework. As solid adsorbents, both COFs exhibit excellent CO₂ uptake (11.0 wt% for Cz-COF and 15.4 wt% for Tz-COF), high adsorption selectivity for CO₂ over N₂ and good recyclability.