Abstract:

Covalent organic frameworks (COFs) are a novel class of crystalline porous material made by light elements via strong covalent bonds with periodic structure formed by the polymerization of organic building units. Large specific surface area, tunable porosity and easy chemical modification make COFs an ideal adsorbent material, and it can meet various design requirements. This review thoroughly presents the recent progress and advances of COFs and COF-based materials as superior adsorbents for the efficient removal of radionuclides. The structural advantages are proposed out firstly. Information about the interaction mechanisms between several radionuclides and COFs materials are summarized. The adsorption properties of various COFs with representative radionuclides are evaluated, the mechanism of adsorption was summarized, the reasons for achieving high adsorption capacity and selectivity are also briefly summarized, and the renewability of COFs is also discussed. Finally, a summary and perspective of the development trend of COFs and COF-based materials used to adsorb radionuclides are proposed. As well as on the current limitations (the preparation of COFs, the improvement of its selectivity, the exploration of stability, in-depth adsorption mechanism research, industrial scale application, etc.), some suggestions into future research on designing and researching COFs with better adsorption performance.

Key words: covalent organic frameworks, radionuclides, porous materical, organic compounds, absorption

摘要：

共价有机框架材料（covalent organic frameworks, COFs）是一类由轻质元素通过共价键连接的具有周期性和结晶性的新兴有机多孔聚合物。COFs具有比表面积大、孔隙高度可调及易于化学修饰等特点，使其能满足多样的设计需求，成为吸附剂的理想材料。本文综述了近年来COFs及其复合材料作为高效吸附剂在放射性核素吸附领域的研究进展，首先提出了COFs的结构优势，并对COFs与放射性核素的相互作用机理进行了分类，评估了多种COFs对几种代表性放射性核素的吸附性能，简要总结了吸附的作用方式，并分析了实现高吸附容量以及高选择性的原因，还讨论了COFs材料的可再生性。在文章的最后对用于吸附放射性核素的COFs材料的发展趋势进行了总结和展望，也就目前的局限性（COFs的制备、选择性的提高、稳定性的探究以及深度机理研究、工业规模的应用等）为设计和探究具有更优异吸附性能的COFs材料提供了一些建议。

关键词: 共价有机框架, 放射性核素, 多孔材料, 有机化合物, 吸附