Nitrogen-rich silk fibroin aerogel for effective removal of radioactive iodine

Abstract

Removal of radioactive iodine compounds such as iodomethane and iodine using adsorption methods is a challenge due to the high cost and poor retention capacity of adsorption materials. Herein, a novel silk fibroin composite aerogel containing bipyridine and diethylamine (SBA) was prepared and evaluated for the removal of radioactive iodine. SBA can efficiently remove iodomethane and iodine with an adsorption capacity of 724.3 mg g−1, which is 5.5 times that of a pure silk fibroin aerogel (SFA) (132.5 mg g−1 for SFA), and 347.5 mg g−1 (121.7 mg g−1 for SFA), respectively. X-ray photoelectron and 13C nuclear magnetic resonance spectroscopies reveal that the good adsorption performance of SBA can be attributed to the interaction between the radioactive pollutants and the bipyridine and diethylamine moieties on the SBA backbone. Moreover, after ten adsorption cycles, SBA retains 91.7% of its initial adsorption capacity, demonstrating its potential for environmental remediation.