A Nitrogen-Rich Nanoporous\nIonic Covalent Organic\nFramework as Iodine Adsorbent in Gaseous and Aqueous Environments

Adsorbents for iodine capture have shown great potential\nin the\ntreatment of radioactive nuclear waste. Considering that enriched\nbinding sites and strong binding force are efficient strategies to\npromote the adsorption capacity of iodine, herein we design and construct\na nitrogen-rich ionic nanoporous covalent organic framework (ICOF-TG-DCA)\n through solvothermal synthesis. ICOF-TG-DCA has been well characterized\nby various techniques and exhibited long-range order with an ionic\nskeleton. In addition, the iodine capture of ICOF-TG-DCA was investigated\nin vapor phase under normal pressure at 350 K and in I<sub>2</sub>/KI aqueous solution, which the material showed iodine vapor adsorption\ncapacity of 5.15 g g<sup>–1</sup> and I<sub>3</sub><sup>–</sup> adsorption capacity of 2.21 g g<sup>–1</sup>, respectively.\nThe results show that the presence of rich nitrogen groups together\nwith ionic interactions is beneficial to the capture of iodine in\nICOF-TG-DCA. The work demonstrates that construction of nitrogen-rich\nionic covalent organic frameworks is a good strategy to achieve high\niodine capture performance.