Porous organic cages for radionuclide and heavy metal adsorption: structure–activity relationships

Abstract

Persistent radionuclides and heavy metals pose significant threats to public health and ecological balance. Adsorption methods offer a promising solution by using porous adsorbents. Porous organic cages (POCs) represent a novel subclass of porous materials, distinguished by their modular synthesis and the tunability of their structural and functional properties. This review summarizes the synthesis strategies for POCs and present efforts to harness POCs with specific structures and surface properties as adsorbents for radionuclides and heavy metals. The performance and underlying mechanisms of POCs as adsorbents are critically evaluated, focusing on the structural and electronic features that influence their efficacy. Additionally, the structure–activity relationships (SARs) of POCs in ionic adsorption are explored. These insights will deepen the fundamental understanding of the relationship between POCs' structure and performance, demonstrating their potential as high-performance ion adsorbent materials. Furthermore, we identify the challenges associated with the application of POCs in ion adsorption and outline future research directions. As research progresses, POCs are poised to achieve further breakthroughs in high-performance adsorption, offering viable solutions for environmental remediation and valuable ion recovery.