Alginate-Based Ionic Polymer Composite Derived from Seaweeds for Efficient Iodine Capture

Materials capable of separating and removing iodine vapor from nuclear fuel reprocessing off-gases are significant to our environment, especially for human health. Adsorption is an effective and widely used separation method. In this work, a novel biomass alginate-based composite [N1111][Alg]@MF was fabricated by modifying biomass polymers from seaweeds and used for effective iodine capture. Starting materials such as [N1111][Alg]@MF are accessible and low-cost. Benefiting from abundant functional groups in alginate and the high porosity provided by MF, the iodine adsorption capacity of [N1111][Alg]@MF was as high as 5.82 g g-1, and the adsorption equilibrium could reach within 9 h. The combined experimental characterization and theoretical density functional theory calculations clearly reveal the I2 capture mechanism. The abundant hydroxyl and carboxyl functional groups in [Alg]- played an important role in the accumulation of iodine. In addition, the high physicochemical stability makes [N1111][Alg]@MF exhibit very excellent I2 adsorption recyclability, which highlights their great potential in practical applications. Given the worldwide abundance and renewability of seaweeds, [N1111][Alg]@MF can easily be employed as low-cost, large-scale applied green adsorbents for effective iodine capture.