Efficient Capture of ReO4‐ from Water by Imidazolium‐Based Cationic Polymeric Nanotraps

Rhenium represents an irreplaceable metal resource, which finds extensive applications in diverse fields, particularly in the aerospace and petrochemical industry. However, its remarkably low natural abundance and the lack of independent ore deposits pose significant challenges to its extraction and recovery processes. In this study, we present the highly efficient adsorption of perrhenate by a cationic polymeric nanotrap material, namely CPN-3VIm. The maximum adsorption capacity of CPN-3VIm-Cl for ReO4- attains an impressive value of 1220 mg·g-1. Notably, even in the low-concentration ReO4- solution of 8.5 ppm, the removal rate could still exceed 99%. The recycling performance of CPN-3VIm-Cl also shows exceptional results, with both ReO4- removal and recovery rates surpassing 90% throughout five adsorption-desorption cycles. Furthermore, CPN-3VIm-Cl exhibits nearly 100% extraction efficiency for ReO4- within a broad pH range of 4-10 and demonstrates remarkable structural stability under extreme conditions, such as 3M sulfuric acid or 3M nitric acid. Additionally, a comprehensive investigation into the interaction mechanism between CPN-3VIm-Cl and perrhenate was carried out using SEM-EDS mapping, Raman, FT-IR, and XPS analysis.