In Situ Growth of ZIF-8 on PAN Fibrous Filters for Highly Efficient U(VI) Removal

Global environmental challenges especially nuclear pollution pose a great threat to human health and public safety. Metal-organic frameworks (MOFs) with high surface area and excellent stability are potential candidates for the remediation of nuclear pollution. Herein, a ZIF-8-based polyacrylonitrile (PAN) fibrous filter was prepared by an in situ hydrothermal treatment of fibrous filters consisting of PAN, poly(vinylpyrrolidone) (PVP), and zinc ions with an electrospinning method. In the process of hydrothermal treatment, PVP can be extracted from the PAN nanofibers and result in porous structures. Benefiting from these porous structures, the in situ ZIF-8/PAN filters demonstrated a high adsorption capacity of U(VI) (530.3 mg g-1 at pH = 3.0). The extended X-ray absorption fine structure revealed that the adsorption mechanism demonstrated surface complexation between U(VI) and 2-methylimidazole. Furthermore, the adsorption device was fabricated, and the dynamic adsorption shows that in situ ZIF-8/PAN is a promising material for treating the nuclear wastewater. The present work may provide a new strategy to fabricate MOFs into functional devices to remediate the increasing global environmental concerns.