Fabrication of a 3D Sr-based metal–organic framework bearing ant topology for highly efficient iodine capture in solution and vapor phases

Abstract

The most widespread pollutant, radioactive iodine (I₂), has caused major harm to human health due to its radiotoxicity, which has become a global issue. Therefore, designing novel adsorbents for the effective removal of iodine from nuclear waste is of great significance. In this study, we successfully synthesized a strontium-based metal–organic framework (MOF) [Sr₂(pydc)₂]_n (UH-1) under solvothermal conditions by employing ligand 2,5-pyridine dicarboxylic acid (2,5-pydc). UH-1 was thoroughly characterized by using advanced analytical techniques such as single-crystal X-ray diffraction, FT-IR, thermal gravimetric analysis, powder-X-ray diffraction, elemental analysis, SEM-EDX and Raman techniques. Topological analysis reveals that UH-1 presents ant topology. UH-1 exhibits good thermal and chemical stability, enabling it to function in harsh environments. The presence of abundant aromatic rings and O-donor sites in UH-1 makes it a potential adsorbent for iodine. The adsorption kinetics were investigated by employing the pseudo-second order rate equation. The interaction mechanism between iodine and MOF was also examined in detail. UH-1 demonstrated exceptional adsorption capabilities, indicating its remarkable potential for the sustainable removal of iodine in vapor and solution phases.