Improving the adsorption ability of graphene sheets to uranium through chemical oxidation, electrolysis and ball-milling

Three types of graphene sheets (GS) were decorated by chemical oxidation, electrolysis and ball-milling, respectively. These oxidized samples were characterized using SEM, XRD, Raman, FT-IR and XPS, and then were employed to enrich U(VI) from aqueous solutions as a function of pH, contact time and initial concentration of U(VI). These results displayed that the quantities and types of oxygen-functional groups were extremely different through these methods, which highly determined the adsorption capacity of graphene oxide to uranium. This work may provide some helpful information to optimize these fabrication processes and improve the adsorption ability of GS to uranium.