Facile Fabrication of Nanofibrillated Chitin/Ag2O Heterostructured Aerogels with High Iodine Capture Efficiency

Nanofibrillated chitin/Ag2O aerogels were fabricated for radioiodine removal. Chitin was first fabricated into nanofibers with abundant acetyl amino groups (-NHCOCH3) on the surface. Then, highly porous chitin nanofiber (ChNF) aerogels were obtained via freeze-drying. The ChNF aerogels exhibited a low bulk density of 2.19 mg/cm(3) and a high specific surface area of 179.71 m(2)/g. Ag2O nanoparticles were evenly anchored on the surfaces of ChNF scaffolds via strong interactions with -NHCOCH3 groups, subsequently yielding Ag2O@ ChNF heterostructured aerogels. The composites were used as efficient absorbents to remove radioiodine anions from water and capture a high amount of I-2 vapor in the forms of AgI and iodine molecules. The adsorption capacity of the composite monoliths can reach up to 2.81 mmol/g of I-anions. The high adsorbability of the composite monolithic aerogel signifies its potential applications in radioactive waste disposal.