Application of Imine-Like Covalent Organic Framework Materials in Separation and Detection of Actinides

Covalent organic frameworks(COFs) are a kind of porous materials with good crystalline and periodic structure formed by covalent bonding of monomers composed of C, H, O and other light elements. This kind of material shows great application potential in separation, energy storage, catalysis and other aspects because of its low density, high thermal stability and good chemical stability. In recent years, COFs materials have developed a variety of bonding bonds with different structures and characteristics from the initial boron-oxygen bonding bonds, and the most widely studied and in-depth class of COFs materials in these fields are composed of imine-like bonds. Imine-like bond is a class of imine bond derived from Schiff base reaction and its similar structure, which not only contains the advantages of imine bond, but also solves some potential application disadvantages. In recent years, the rapid development of nuclear energy has inevitably brought about the shortage of nuclear resources and environmental radioactive pollution, and how to extract and separate radionuclides has become a major problem to be solved urgently. Among the porous materials that have been developed and explored, COFs has its unique advantages compared with other inorganic porous materials, which can effectively avoid many application difficulties in the process of radionuclide extraction. As the most popular research object in the field of this material, imine-like COFs have been applied in the separation of actinides, especially in the adsorption separation of uranyl ions, which is of great significance to the nuclear fuel cycle and the prevention and control of nuclear environmental pollution. In this paper, the recent progress in the separation and detection of actinide elements by imine-like COFs is summarized, and the characteristics of imine-like bonds with different structures are described in detail. The adsorption mechanism and adsorption effect of COFs materials of each structure are summarized and compared in tables, showing how the design ideas affect the adsorption results, which is instructive for the selection of application scenarios to a certain extent. In addition, some new directions and thoughts on the material are proposed in this paper, which are reliable and forward-looking for improving the potential of imine-like COFs in practical applications. At the same time, the major challenges facing the material are summarized. COFs materials still show unfathomable development potential after decades of in-depth research, and fully demonstrate the urgent development space of this kind of materials in the separation of metal ions. Finally, the future development trend of this material is prospected.