High efficient adsorption and storage of iodine on S, N co-doped graphene aerogel

Highlights: • S, N co-doped graphene aerogel (SN-GA) was synthesized by one-step method. • SN-GA exhibits a 3D porous architecture with a high surface area of 179.91 m²/g. • SN-GA shows the maximum iodine adsorption capacity up to 999 mg/g at 298 K. • After iodine adsorption, iodine@SN-GA shows relatively high thermostability. • DFT method was used to the theoretical simulate on iodine adsorption process. -- Abstract: High efficient adsorption of radioiodine in nuclear waste has attracted extensive attentions all over the world. In this work, we fabricated sulfur and nitrogen co-doped graphene aerogels (SN-GA) through one-step hydrothermal method, and investigated its iodine adsorption behavior including adsorption kinetics and isotherms in water. Our results reveal that SN-GA exhibits a 3D porous architecture with thiophene-S, oxidized-S, pyridine-N, pyrrole-N and graphite-N co-doped into the sp² carbon frameworks. The adsorption experiment showed SN-GA has a maximum iodine adsorption capacity of 999 mg g⁻¹ determined by Langmuir isotherm, and the adsorption process could be better described by the pseudo-second-order model.