Abstract
The leakage of nuclear pollution highlights the critical importance of effectively separating radioactive pollutants. Radioactive iodine, a high-yield fission product of nuclear reactions, poses serious environmental and health risks. However, the lack of efficient adsorbents makes the management of aqueous radioactive iodine pollution a significant challenge. N-doped materials are among the most recognized adsorbents for iodine removal, but their weak binding affinity and limited number of iodine-binding N-sites hinder their practical application. Herein, a covalent organic framework (COFs) named phen-TPA is synthesized, featuring an increased number and optimized local chemical environment of iodine-binding N-sites. This material demonstrates record-breaking iodine removal kinetics, with a kinetic constant of 14.64 g g(-1) min(-1) for aqueous iodine (I(2)), and the highest-reported iodine adsorption capacity of 11.9 g g(-1) for aqueous triiodide (I(3) (-)). Large-scale flow-through adsorption experiments show that phen-TPA can remove 99.5% aqueous I(2) and I(3) (-) from high-salinity aqueous environments, highlighting its potential for practical applications.