Bimetallic mutual-doping magnetic aerogels for iodine reduction capture and immobilization.

Adsorption is considered to be one of the most effective methods to remove radioiodine from the solution. However, developing highly efficient adsorbents and the rapid recovery of the used adsorbents is still a challenge. Here, a series of Cu/FeO bimetallic mutual-doping magnetic aerogels (Cu/FeO-BMMA) were synthesized. Based on the in-situ bimetallic co-gelation process, the high dispersion of Cu in the aerogel was realized, providing conditions for the efficient elimination of I. The Fe in the initial gel was reduced to magnetic FeO during the preparation process, allowing for the quick recovery of the adsorbent through the application of a magnetic field. The adsorption experiments showed that Cu/FeO-BMMA has good I adsorption capacity (631.3 mg/g) and fast capture kinetics (equilibrium time < 30 min). In addition, Cu/FeO-BMMA was able to effectively remove trace I in the solution from ppm level (1.0 ppm) down to ppb level (≤30 ppb). The adsorbed I was converted into stable CuI, avoiding secondary pollution due to desorption. Overall, this study provides a potentially efficient iodine capture material for long-term decay storage of radioactive iodine.