A Nitrogen-Rich Nanoporous Ionic Covalent Organic Framework as Iodine Adsorbent in Gaseous and Aqueous Environments

Adsorbents for iodine capture have shown great potential in the treatment of radioactive nuclear waste. Considering that enriched binding sites and strong binding force are efficient strategies to promote the adsorption capacity of iodine, herein we design and construct a nitrogen-rich ionic nanoporous covalent organic framework (ICOF-TG-DCA) through solvothermal synthesis. ICOF-TG-DCA has been well characterized by various techniques and exhibited long-range order with an ionic skeleton. In addition, the iodine capture of ICOF-TG-DCA was investigated in vapor phase under normal pressure at 350 K and in I2/KI aqueous solution, which the material showed iodine vapor adsorption capacity of 5.15 g g–1 and I3– adsorption capacity of 2.21 g g–1, respectively. The results show that the presence of rich nitrogen groups together with ionic interactions is beneficial to the capture of iodine in ICOF-TG-DCA. The work demonstrates that construction of nitrogen-rich ionic covalent organic frameworks is a good strategy to achieve high iodine capture performance.