A nitrogen-rich covalent organic framework for simultaneous dynamic capture of iodine and methyl iodide

Abstract

The efficient capture of gaseous radioiodine species during the used nuclear fuel reprocessing and nuclear accident event has attracted much attention but remains challenging owing to the low concentration of iodine combined with harsh operational conditions including elevated temperatures, high humidity, and strong acidity. Previously reported emerging materials for iodine uptake cannot outperform commercial zeolites and active carbon under the practical dynamic scenario. We overcome the challenges by introducing a bipyridine group into the COF structure and maximization of its density to significantly enhance the interactions between the COF host and iodine species, affording the first COF showing capabilities of simultaneous capture of iodine and organic iodide under dynamic conditions and representing clear advances over commercial materials. This design philosophy can be extended to the remediation of pollutants and extraction of strategic resources in low concentrations.