Sun Yonghe, Song Sanan, Xiao Dehai, Gan Linfeng, Wang Yuanrui
School of Chemical Engineering, Changchun University of Technology, Changchun, Jilin 130012, China.
College of Chemistry, Jilin University, Changchun, Jilin 130012, China.
ACS Omega. 2020 Sep 16;5(38):24262-24271. doi: 10.1021/acsomega.0c02382. eCollection 2020 Sep 29.
Volatile radionuclides generated during the nuclear fission process, such as iodine, pose risks to public safety and cause the threat of environmental pollution. Covalent organic framework (COF) materials have a controlled pore structure and a large specific surface area and thus demonstrate great opportunities in the field of radioactive iodine adsorption. However, the harsh synthetic conditions and the weak binding capability toward iodine have significantly restricted the applications of COFs in iodine adsorption. Here, we demonstrate a facile way to prepare a series of stable C-N-linked COFs with high efficiency to capture radioactive iodine species. Large-scale synthesis can be conducted by the aldol condensation reaction at room temperature. The resulting COFs have a large surface area and a strong resistance to acid, base, and water. Moreover, all types of COFs show high iodine adsorption, up to 2.6 g/g (260% in mass), owing to the large surface area and the functional groups in COFs. They not only absorb conventional I molecular but also ionic state (I and I) iodine species. Theoretical calculations are further performed to understand the relationship between different iodine species and the functional groups of all COFs, offering the mechanisms underlying the potent adsorption abilities of COFs.
核裂变过程中产生的挥发性放射性核素，如碘，会对公众安全构成风险并造成环境污染威胁。共价有机框架（COF）材料具有可控的孔隙结构和大比表面积，因此在放射性碘吸附领域展现出巨大机遇。然而，苛刻的合成条件以及对碘的弱结合能力显著限制了COF在碘吸附方面的应用。在此，我们展示了一种简便的方法来高效制备一系列稳定的C-N连接的COF，用于捕获放射性碘物种。可通过室温下的羟醛缩合反应进行大规模合成。所得的COF具有大表面积以及对酸、碱和水的强耐受性。此外，由于COF的大表面积和官能团，所有类型的COF都表现出高碘吸附量，高达2.6 g/g（质量比为260%）。它们不仅能吸收传统的I分子，还能吸收离子态（I⁻和I₃⁻）碘物种。进一步进行理论计算以了解不同碘物种与所有COF官能团之间的关系，揭示了COF强大吸附能力背后的机制。
