Synthesis of aluminananosheetsvia supercritical fluid technology with high uranyl adsorptive capacity

Supercritical carbon dioxide is beneficial to the synthesis of superior ultrafine and uniform materials due to its high chemical stability, low viscosity, high diffusivity, and “zero” surface tension. γ-Alumina nanosheets were obtained by a simple hydrothermal route in the presence of supercritical carbon dioxide. XRD, FTIR, SEM, TEM and nitrogen sorption isotherm were employed to characterize the samples. Alumina as-prepared has a high specific surface area of up to 200 ± 6 m2 g−1, which presents a high adsorption capacity (4.66 ± 0.02 mg g−1) for uranyl ions from aqueous solution. Furthermore, the adsorption process was found to be endothermic and spontaneous in nature.