Efficient and Selective Uranium Extraction From Seawater by Imidazolium-Based Poly (Ionic Liquid)s

Efficient extraction of uranium from seawater supports the development of nuclear energy. To improve the utilization of the adsorbent binding sites, four poly (ionic liquid)s were synthesized using vinylimidazolium-based ionic liquids as binding sites and divinylbenzene to modulate material distance, designated as P-VEIM-Br, P-VEIM-OAc, P-VEIM-C 3 H 7 COO, and P-VEIM-TFA. The results indicate that P-VEIM-OAc exhibits enhanced uranium adsorption at the pH range of 7.0–10.0 with uranium removal efficiency exceeding 90% at an initial concentration of 10 mg L −1 . The test experiments demonstrated that the maximum uranium adsorption capacity of P-VEIM-OAc is 989 mg g −1 (298 K, pH = 8.0). Mechanistic investigations using Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, density functional theory calculations, and zeta potential measurements revealed that the high adsorption performance arises from electrostatic attraction, π–π stacking interactions and hydrogen bonding. In addition, P-VEIM-OAc showed excellent selectivity for uranium in simulated seawater and retained its performance over five cycles. This strategy provides favorable technical support for improving uranium extraction from real seawater.