Pore polarity engineering in hydrogen-bonded organic frameworks for enhanced iodine capture

Abstract

Segregation of radioiodine species is critical for nuclear safety, and adsorption-based capture has shown great promise for the remediation of pollutants. In this study, a series of isostructural hydrogen-bonded organic frameworks (HOFs) with various polarities were fabricated. The optimal material, HOF-TAM–BPY, exhibited I₂ uptake capacities of 783 wt% and 112 wt% from the air and aqueous solution, respectively, placing it among the top reported systems. HOF-TAM–BPY also exhibited fast adsorption kinetics, full recyclability, and outstanding moisture tolerance. The promoting effect of the pyridine moieties and the unique pore structure of HOFs on the I₂ adsorption was comprehensively elucidated by spectrally identifying the hosted iodine species and calculating the host–guest interactions. These results demonstrate the essential role of the pore environment of the adsorbent in achieving high iodine capture performance.