Exploration of 1D channels in stable and high-surface-area covalent triazine polymers for effective iodine removal

摘要

Developing stable open-pore sorbents with high porosity to efficiently capture radiotoxic iodine from the waste streams of nuclear is highly desirable in addressing the environmental issues. Here, we report three highly stable covalent triazine polymers with the same chemical composition while bearing different degree of crystallinity and pore structures toward iodine capture. The best adsorption capacity of 4.31 g g(-1) towards iodine vapor is achieved by CTF-1@ZnCl2 composed of ordered skeletons and uniform 1D open channels. In comparison, the amorphous samples, i. e. CTF-1@ZnCl2 center dot H2O and CTF-1@TFMS, display moderate uptakes of iodine up to 2.41 and 1.18 g g(-1), respectively. Similar trend is also demonstrated in the case of iodine retaining in hexane, where the open pore array in the crystalline CTF-1@ZnCl2 contributes significantly to its high adsorption capacity when compared to those interpenetrated and/or low-degree-crosslinked networks. The CTF-1@ZnCl2 after treating by organic solvent/dilute base/acid still maintain the capacities in iodine adsorptions with good recyclability, demonstrating their excellent structural stability. This study illustrates the importance of ordered skeletons and uniform 1D open channels in the adsorption process, which may provide a potential platform targeting for solving key environmental issues.