Schematic showing (A) synthesis route of SCU-CPN-1 and its anion-exchange applications [6]; (B) the ⁹⁹TcO₄⁻ removal by iCOPs under different conditions [9]; (C) the synthesis of Ag-TPPE through directly mixing raw materials [12]; (D) the application of NCU-3-X (X = Cl, Br) on ReO₄⁻/TcO₄⁻ removal [13]; (E) the reaction mechanisms for the Ru@HNCC-R catalyzed extraction of ReO₄⁻ during the adsorption-electrocatalysis [14].