Synthesis of nitrogen-containing covalent organic framework with reversible iodine capture capability

Abstract

The use of covalent organic frameworks (COFs) to cope with environmental issues was promising but making them commercial and practical remains a challenge. In this work, we explored the crystallization of a stable nitrogen-containing covalent organic framework (TAPA-PDA COF) and used it as a porous platform for efficient and reversible volatile iodine capture. The TAPA-PDA COF, prepared by simple, rapid, low temperature reactions, possesses a high BET surface area of over 685 m 2 /g, good crystallinity, high thermal stability and ultrahigh capture of iodine vapor up to 5.09 g/g, which was significantly higher than most reported iodine adsorbents. Although the Raman spectroscopy confirmed the formation of polyiodide compounds through charge transfer between sorbents and iodine molecules, the TAPA-PDA COF still has the ability to be recycled five times while maintaining a high uptake capacity. This study provides promising strategy to solve the difficult problems of commercializing COFs and utilizing them for practical application. • The TAPA-PDA COF was constructed as a porous platform for efficient and reversible volatile iodine capture. • The TAPA-PDA COF demonstrated ultrahigh capture of iodine vapor up to 5.09 g/g. • The TAPA-PDA COF's capture of iodine was a hybrid of physisorption and chemisorption. • The simple, fast and low temperature preparation method provides promising strategy to solve the difficult problems of commercializing COFs.