Preparation and characterization of a high-efficiency radon adsorbing material based on activated carbon modified by water immersion and freeze–thaw

In this paper, activated carbon has been modified by water immersion and freeze–thaw cycles to further improve its radon adsorption capacity. Under freezing at − 80 °C and thawing at 50 °C, three cycles of modification were most effective, the radon adsorption coefficient was increased by 24%, and remained stable after five repeated radon adsorption–desorption cycles. The apparent morphology of the modified activated carbon changed significantly. The specific surface area of micropores increased significantly and was positively correlated with the radon adsorption capacity. The new application of this method can provide some references for the modification of material. Graphical abstract Experimental flow process diagram. The activated carbon was modified by water immersion and freeze–thaw cycles under different experimental conditions, and the best modification process was determined by measuring the static adsorption coefficient. The activated carbon with better modification effect was characterized and tested to observe the morphological and structural changes. It was finally concluded that water immersion and freeze-thawing could effectively enhance the microporous volume, specific surface area and radon adsorption capacity of activated carbon.