Record High Iodate Anion Capture by a Redox‐Active Cationic Polymer Network

Abstract As a critical radioactive anionic contaminant, traditional adsorbents primarily remove iodate (IO 3 − ) through ion exchange or hard acid‐hard base interactions, but suffer from limited affinity and capacity. Herein, employing the synergistic effect of ion exchange and redox, we successfully synthesized a redox‐active cationic polymer network (SCU‐CPN‐6, [C 9 H 10 O 2 N 5 ⋅ Cl] n ) by merging guanidino groups with ion‐exchange capability and phenolic groups with redox ability via a Schiff base reaction. SCU‐CPN‐6 exhibits a groundbreaking adsorption capacity of 896 mg/g for IO 3 − . The inferior adsorption capacities of polymeric networks containing only redox (~0 mg/g) or ion exchange (232 mg/g) fragments underscore the synergistic “1+1>2” effect of the two mechanisms. Besides, SCU‐CPN‐6 shows excellent uptake selectivity for IO 3 − in the presence of high concentrations of SO 4 2− , Cl − , and NO 3 − . Meanwhile, a high distribution coefficient indicates its exemplary deep‐removal performance for low IO 3 − concentration. The synergic strategy not only presents a breakthrough solution for the efficient removal of IO 3 − but also establishes a promising avenue for the design of advanced adsorbents for diverse applications.