Advanced porous adsorbents for radionuclides elimination

With the rapid development of nuclear industry, effective management of nuclear waste and oversight of nuclear fuel cycle are critical. Radionuclides such as uranium (U), plutonium (Pu), neptunium (Np), americium (Am), curium (Cm), technetium (Tc), rhenium (Re), iodine (I), selenium (Se), thorium (Th), cesium (Cs), and strontium (Sr) transferred into environment are dangerous. It is crucial to design the corresponding materials to exhibit high adsorption capacity and selectivity among competing species in nuclear waste. Herein, this review comprehensively summarizes the application of advanced porous materials, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and amorphous porous organic polymers (POPs) as porous adsorbents for radionuclides removal. These porous materials feature uniform composition, large porosity, and good stability, which lay a good foundation for various applications. The tunable pore sizes, high specific surface areas, exchangeable sites, and functional groups are designed as accessible platforms for nuclides diffusion and adsorption. Specific binding mechanisms toward various radionuclides, such as complexation, electrostatic interaction, and ion exchange are presented. Beyond traditional adsorbents, the superior capacity, kinetics, selectivity, and reusability of COFs, MOFs, and POPs make them broad application prospects in radionuclides removal, providing a way for effective applications in environmental remediation.