Filamentous Covalent Organic Frameworks with Ultrahigh Iodine Sorption and Dye Selectivity

Covalent organic frameworks (COFs) have received a great deal of attention due to various potential applications. However, facilely synthesizing COFs bearing high sorption capacity and strong selectivity still shows great demand. Herein, a kind of filamentous triazine-containing COF (TATP-COF) was synthesized with a pore diameter of ca. 1.7 nm, a large specific surface area (1487 m2 g–1), and high thermal stability (up to 563 °C). The TATP-COF shows rapid and excellent iodine uptake in both volatile iodine and iodine/cyclohexane solutions with sorption capacities of 5.2 g g–1 and an iodine removal efficiency of 98%. What is more, the removal efficiency of volatile iodine by TATP-COF reached 80% even within 5 h. Such an efficiency exceeds almost 90% of reported COF materials, which makes the present TATP-COF available for the rapid removal of radioactive iodine in emergency situations. Moreover, the TATP-COF could be easily postmodified to sulfonic-functionalized COF (SO3H-TATP-COF), which exhibits outstanding selectivity for dyes based on the charge difference. These behaviors endow the present COFs as candidate vehicles for purification and separation from the perspective of environmental protection and safety.