Thiophene-based mesoporous covalent organic framework for efficient iodine vapor capture

Abstract

The development of adsorbent materials for highly efficient iodine capture is in high demand from the perspective of ecological environment and human health. Herein, two covalent organic frameworks (COFs), JLNU-312 and JLNU-313, were successfully synthesized for iodine adsorption. The obtained JLNU-COFs possess high crystallinity and one-dimensional mesoporous channels. Iodine adsorption experiments demonstrated that both COF materials exhibit effective performance for iodine adsorption, with a maximum amount of up to 4.67 g g⁻¹ for JLNU-312 and 2.47 g g⁻¹ for JLNU-313. Moreover, both JLNU-COFs have good stability, reusability and iodine retention capacity. Theoretical calculations clearly show that the higher adsorption performance of JLNU-312 is also due to the strong interaction between the adsorbed iodine and the abundant triazine nitrogen-rich adsorption sites uniformly distributed in the pore. This work shows that effective iodine adsorbents can be achieved by introducing nitrogen-rich sites into the framework of COF materials.