Tailoring multiple sites of highly elastic nanofiber aerogel for efficient enrichment and separation radioactive iodine

Rational capture of radioactive iodine is of great significance for nuclear energy development and environmental health. However, current nano-adsorbents suffer from limited adsorption capacity and frequent clogging induced by their powder form. In this work, we constructed a highly elastic nanofiber aerogel (MoS 2 @PPH-NFA), which assembled multiple available binding sites (amino-, carboxyl- and sulfide- groups) for synergistically and efficiently capturing molecular and ionic iodine. The aerogel possessed a hierarchically porous structure and exhibited outstanding mechanical integrity even after 20 compression cycles. Thanks to the synergistic effect between multiple adsorption sites, the aerogels could adsorb iodine vapor with a capacity of 4.02 g/g. Both experimental results and theoretical calculations verified that all the amino-, carboxyl- and sulfide- groups in aerogels demonstrated high binding affinity towards iodine species, wherein the amino ones played a predominant role with adsorption energy of −2.33 eV. MoS 2 @PPH-NFA also achieved ionic-iodine capture in aqueous with a maximum adsorption amount of 1.03 g/g, in which chemisorption dominated the adsorption process. In addition, the high flexibility and structural stability endowed MoS 2 @PPH-NFA with potential applicability for molecular/ionic iodine adsorption in mobile phases with more than 50 % removal rate. Overall, this study not only demonstrated the excellent performance of MoS 2 @PPH-NFA working as a promising iodine adsorbent but also provided a vivid prototype of developing novel fiber aerogels for environmental remediation.