Nanoparticles of SnS2 within a SiO2 Aerogel for Capture and Storage of Radioiodine Vapor

The efficient capture and storage of radioactive gaseous iodine represents a crucial component in the development of nuclear energy. In this work, an electrospun silica (SiO2) fiber membrane composed of nanofibers with diameters in the range of 200–500 nm was utilized as the substrate. By adopting a construction method reminiscent of “reinforced concrete”, a self-supporting three-dimensional nanofiber aerogel structure with adjustable dimensions was fabricated. Subsequently, ultrathin tin sulfide (SnS2) nanosheets with a thickness of approximately 10 nm were in situ grown on the aerogel. Eventually, a tin sulfide/silica aerogel (SnS2/SiO2 aerogel, SnS2/SiOA) that can be used for the capture of gaseous iodine was obtained. The experimental results suggest that SnS2/SiOA-2 demonstrates high-performance adsorption both under dynamic conditions (1560 mg/g) and static conditions (1760 mg/g). During the capture process, the abundant adsorption active sites conferred by the three-dimensional porous fiber aerogel structure come into play. This allows for full and effective contact between SnS2 and iodine (I2). I2 acquires the electrons released by S2– and is converted into SnI4, which is stably stored within the adsorbent. Notably, the iodine loss of SnS2/SiOA-2 is merely 3% after it has captured iodine and been left standing for 7 days. The construction of this nanofiber aerogel has successfully transformed the nanofiber membrane from a two-dimensional structure into a three-dimensional one, endowing it with excellent iodine capture and storage capabilities. This not only provides an innovative approach to capturing radioactive gaseous iodine but also holds greater application potential under actual working conditions.