Title : LiAlO2-Melamine for efficient and rapid iodine capture
Inadequate accessible resources and uncontrolled population growth have provided the opportunity to identify and use uncustomary resources for industrial application. Nuclear power is potential to fulfill the global energy demand, and iodine is an essential input for such energy production. However, it produces wastes that can severely affect ecological inhabitants’ life cycles and human health. Having commendable nuclear waste management, including separation of pollutants and safe storage, is crucial to tackle such problems. As a result, the search for efficient material to capture iodine from off-gas streams continues. Herein, a novel composite of lithium aluminate and melamine, abbreviated as LiAlO2-Mel, was synthesized and exhibited high vapor iodine capture capacity accompanied by good regeneration ability. The LiAlO2-Mel showed an enormous capture capacity of 1281 mg/g within 4 h towards I2 (g) at 150 °C. The kinetics study showed that the dominant process (at 150 °C) was chemisorption via N???I and C–NH???I bonding mechanisms. Also, LiAlO2-Mel has a low surface area (14.6157 m2/g) yet produced high capacity, suggesting chemisorption played a critical role. However, physisorption was the dominant process at lower temperature values, as proved by kinetics fittings and activation energy (Ea = 23.19 KJ/mol) studies. The kinetics models were validated by statistical error validity models (sum of square error, Chi-square test, and normalized standard deviation). Thermogravimetric analysis and adsorption-desorption experiments showed that the LiAlO2-Mel can be recovered by heat treatment (25–800 °C) in an N2 atmosphere and ethanol washout (24 h, 25 °C) of the LiAlO2-Mel-I. The high capture capacity, along with eco-friendly and cost-effectiveness, highlights the promising potential of LiAlO2-Mel for iodine capture.