In-situ separation study of radiation-prepared reduced graphene oxide gel

Reduced graphene oxide (rGO) gel has a large specific surface area and has great application potential in the separation and recovery of radionuclides such as U (VI) and Th (IV). In this study, γ-ray irradiation was used to irradiate the aqueous solutions containing U (VI) and graphene oxide (GO), Th (IV) and GO, Eu(III) and GO, respectively. U (VI), Th (IV), Eu (III) ions could be loaded simultaneously as the rGO gel was self-assembled. After the load is completed, the block gel could be taken out directly from the solution to separate metal ions in the solution. The effects of initial ion concentration and pH on the in-situ separation of U (VI), Th (IV) and Eu (III) were investigated. The results show that this method can effectively separate metal ions from aqueous solution. The load capacities of U (VI) and Th (IV) are up to 1001.8 and 577.8 mg/g, respectively. In addition, the effect of the presence of metal ions on the formation of rGO gel was also investigated. The results show that when U (VI) and Eu (III) ions are present, the gel can be formed in a wider pH range (1 ∼ 6). Meanwhile, Th (IV) and Eu (III) ions can greatly reduce the absorbed dose required for rGO gel formation. This method can be used to separate radionuclides in aqueous solutions. (authors)