Selective Carbon Dioxide Capture and Ultrahigh Iodine Uptake by Tetraphenylethylene-Functionalized Nitrogen-Rich Porous Organic Polymers

The development of efficient adsorbent materials capable of dual capture of carbon dioxide (CO 2 ) and iodine is of great importance due to the significant contribution of anthropogenic CO 2 to climate change and the potential risks associated with nuclear energy sources, such as the release of radioactive iodine during nuclear waste processing and accidents. In this study, two nitrogen-rich tetraphenylethylene-functionalized porous organic polymers were prepared via a Schiff-base condensation reaction between 4,4′,4″,4‴-tetra(2,4-diamino-1,3,5-triazin-6-yl)tetraphenylethene (TTPE) and 2-carboxaldehydefuran or 2-carboxaldehydethiophene to form aminal-linked triazine-based porous organic polymers, TTPEPOP-O and TTPEPOP-S, having high surface areas of 741 and 999 m 2 g –1, respectively. The synergetic effect of electron-rich nitrogen species, π-conjugated moieties, and microporosity of these polymers makes them promising adsorbents for effective CO 2 sequestration and iodine removal. TTPEPOP-O and TTPEPOP-S exhibit moderate CO 2 uptake of 2.34 and 2.94 mmol g –1, respectively, at 273 K and 1.0 bar, with high selectivity to CO 2 over N 2 and CH 4 under ambient conditions. In addition, the two polymers demonstrate ultrahigh iodine uptake capacity of over 400 wt % from the gas phase and can remove up to 99% of dissolved iodine from iodine-cyclohexane solution. Based on our findings, the ecofriendly (metal-free) nature of TTPEPOPs and their ability to capture both CO 2 and iodine make them promising potential materials for environmental remediation.