Construction of Tetrathiafulvalene-based Covalent Organic Frameworks for Superior Iodine Capture

The effective capture of radioiodine species during nuclear fuel reprocessing and nuclear accidents is of primary importance but remains challenging for the sustainable development of nuclear energy. Herein, we report two newly designed two-dimensional(2D) and three-dimensional(3D) covalent organic frameworks by introducing tetrathiafulvalene functional groups into the building units for the simultaneous physisorption and chemisorption capture of iodine molecules. Remarkably, the obtained 3D TTF-TAPT-COF material exhibited a superior iodine vapor adsorption capacity of up to 5.02 g/g at 348 K and under ambient pressure and an adsorption kinetics of 0.515 g/(g·h), surpassing most of other materials reported so far. The strong physiochemical interactions between iodine molecules and the frameworks of the obtained COFs were revealed by a set of experimental techniques. This study provides a feasible approach for the rational design and the construction of novel and effective COF-based adsorbents for iodine enrichment and related environmental remediation.