Colyliform Crystalline 2D Covalent Organic Frameworks with Quasi-3D Topologies for Rapid I2 Adsorption.

Constructing three-dimensional (3D) structural characteristics on two-dimensional (2D) covalent organic frameworks (COFs) is a smart approach to effectively improve the pore permeability and mass transfer rate of the materials and realize the rapid adsorption for guest molecules, while avoiding the high cost and monomer scarcity in preparing 3D COFs. Herein, we report for the first time a series of colyliform crystalline 2D COFs with quasi-three-dimensional (Q-3D) topologies, consisting of unique "stereoscopic" triangular pores, large interlayer spacings and flexible constitutional units which makes the pores elastic and self-adaptable for the object transmission. The as-prepared QTD-COFs have fairly faster adsorption rate (2.51 g/h) for iodine than traditional 2D COFs, with an unprecedented maximum adsorption capacity of 6.29 g/g. The excellent adsorption performance, as well as the prominent irradiation stability enable the QTD-COFs to be reliably applied to the rapid removal of radioactive iodine under special circumstances of emergency response to nuclear accidents.