Porphyrin-Based Hyper-Cross-Linked Polymers as Adsorbents for Reversible Capture of Iodine

Designing a novel adsorbent with high selectivity and absorptive capacity to remove I 2 remains a challenging task. In this work, a series of porphyrin-based hyper-cross-linked porous organic polymers (PHCPs) with a dual hydroxy-rich structure were synthesized by the Friedel–Crafts reaction. PHCPs exhibit excellent thermal stability. The incorporation of abundant π-electrons and heteroatoms (N/O) in the PHCPs framework leads to substantial charge transfer interactions with iodine, resulting in a high adsorption capacity (469 mg g –1 ) and rapid adsorption. Moreover, the adsorption dynamics of PHCPs for iodine in both aqueous and cyclohexane solutions follow a pseudo-second-order kinetic model, and the adsorption isotherm model complies with the Freundlich model. Importantly, PHCPs selectively capture I 3 – in the presence of anionic competition and effectively capture iodine at different pH values. Additionally, the volatile iodine capture performance of PHCPs reached 623 wt %. This study highlights the extensive application prospects of PHCPs in the removal of iodine from both the gas and liquid phases.