Ellagic acid-based MOFs/polyethersulfone composite membrane with hierarchical porous structure for rapid uranium...

The extraction of uranium from contaminated wastewater to mitigate radioactive contamination risks is crucial for the sustainable development of nuclear energy. Herein, zirconium ellagate metal-organic frameworks (denoted SU-102) were hybridized with polyethersulfone (PES) and polyvinylpyrrolidone (PVP) to construct SU-102 integrated PES/PVP (denoted PP-SU) membrane. This membrane featured with hierarchical porous structure for uranium extraction. Among the additions of the SU-102 ranging from 1% to 4%, the membrane prepared with a 3% SU-102 (PP-SU3) exhibited the highest adsorption capacities for UO₂²⁺ ions. Moreover, the incorporation of the SU-102 significantly enhanced the hydrophilicity of the PP-SU3 membrane, which showed complete wetting within 125 s, outperforming both the PES membrane and PES/PVP (denoted PP) membrane. Notably, the PP-SU3 membrane exhibited high adsorption capacities for UO₂²⁺ ions, up to 37.39 mg g^-1 at 47 °C, accompanied by a rapid adsorption rate with equilibrium attained in approximately 120 min. Importantly, the PP-SU3 membrane exhibited excellent UO₂²⁺ ions removal ability in the simulated uranium wastewater. Its uranium adsorption efficiency remained remarkably high at 74.11% after four consecutive adsorption-desorption cycles. This straightforward approach opens up new avenues for developing membrane materials with hierarchical porous structures for uranium extraction, demonstrating significant potential for providing low-carbon clean energy.