Ag NPs-coated polyurethane sponge as a water filter for removal of toxic metal ions at high concentrations.

Heavy metal ions are toxic to humans, plants, and marine life, making it crucial to eliminate them from water. This study reports the development of a new nanocomposite material (Alg@Ag/PU) that involves modifying silver nanoparticles (Ag NPs) with alginate (Alg) and coating them onto a polyurethane sponge (PU) for removing heavy metal ions. The successful coating of Alg@Ag NPs onto PU due to their strong chemical binding was confirmed by morphology and size characterization. Batch experiments were conducted to evaluate the removal efficiency of heavy metal ions at high concentrations (∼100 mg/L). The maximum adsorption amount was achieved within 6 h, and the highest removal efficiency was obtained at pH values between 6 and 7. Furthermore, the Alg@Ag/PU nanocomposite demonstrated excellent recyclability for metal ion removal even after 5 cycles. In summary, this work developed a simple and cost-effective method for producing an environmentally-friendly nanocomposite material for the efficient removal of heavy metal ions.