Chemically Robust Cationic Porous Organic Polymer (POP) for Selective Detection and Removal of ReO4‐ as a Surrogate of Radioactive 99TcO4‐

The efficient removal of 99TcO4‐ from alkaline nuclear waste is vital for optimizing nuclear waste management and safeguarding the environment. However, current state‐of‐the‐art sorbent materials are constrained by their inability to simultaneously achieve high alkali resistance, rapid adsorption kinetics, large adsorption capacity, and selectivity. In this study, we synthesized a urea‐rich cationic porous organic polymer, IPM‐403, which demonstrates exceptional chemical stability, ultrafast kinetics (~92% removal within 30 seconds), high adsorption capacity (664 mg/g), excellent selectivity, along with multiple‐cycle recyclability (up to 7 cycles), making it highly promising for the removal of ReO4‐ (surrogate of 99TcO4‐) from nuclear wastewater. Notably, after exposure to 1 M NaOH solution for 24 hours, IPM‐403 maintained a high adsorption capacity of 421.3 mg/g for ReO4‐. Furthermore, IPM‐403 acts as an efficient sensor for ReO4‐, exhibiting a turn‐on response and a detection limit as low as 78.8 ppb.