Facile synthesis of a nitrogen-rich covalent organic framework for the efficient capture of iodine

Abstract

The successful capture and storage of iodine is significant, serving the dual purpose of nuclear waste management and safe medical use of radioactive isotopes. Hence, there is an urgent need to develop adsorbents through effective methods, ensuring the efficient capture of iodine from various media. Therefore, we designed and synthesized a nitrogen-rich porous covalent organic framework via Schiff base polycondensation reaction using triazine core trialdehyde and diamine as monomers. The covalently linked nitrogen-rich covalent organic framework NR_COF-C1 developed in this study exhibited remarkable thermal and chemical stability. The presence of ample pi-electron-rich arenes and nitrogen centers in this polymer facilitates its efficient interaction with iodine. NR_COF-C1 showed its promise as an adsorbent material for the efficient capture of iodine in the vapor phase at elevated temperatures (75 °C: 5.45 g g⁻¹) and at room temperature (25 °C: 2.15 g g⁻¹) as well as from aqueous solutions at room temperature (25 °C: 4850.75 mg g⁻¹). Moreover, NR_COF-C1 serves as a recyclable adsorbent with minimal loss in capture efficiency. The exceptional performance of NR_COF-C1 in capturing iodine and its robust retention ability make it an outstanding material for the steady capture and safe containment of iodine.