Fully phosphorylated 3D graphene oxide foam for the significantly enhanced U(VI) sequestration.

Efficient sequestration of U(VI) from complex aqueous solution is of vital importance for environmental remediation. In this work, the fully phosphorylated graphene oxide foam (phos-GOF) was synthesized via a facile hydrothermal method and the as-prepared 3D phos-GOF was served as an adsorbent to capture U(VI) from aqueous solution. The introduction of abundant phosphorus-containing groups via phytic acid endows phos-GOF good hydrophilia and excellent affinity for U(VI). The adsorption performance of phos-GOF for U(VI) was carefully evaluated under different environments. phos-GOF shows rapid and high efficiency for U(VI) adsorption. The maximum adsorption capacity of phos-GOF for U(VI) is ∼483 mg/g, which is much higher than that of pristine graphene oxide foam (GOF). In addition, the spent 3D phos-GOF can be easily regenerated by a simple and low-cost desorption process using 0.02 mol/L HNO 3. The interaction mechanism between phos-GOF and U(VI) is mainly attributed to the inner-sphere complexation between phosphoric functional groups and U(VI) based on a series of spectroscopic analyses. The 3D phos-GOF exhibits favorable sequestration performance towards U(VI) which can be used as a potential candidate in uranium-bearing wastewater treatment and disposal. Fully phosphorylated 3D graphene oxide foam for the efficient removal of U(VI). Image 1 • The free-standing 3D phos-GOF was prepared via simple and feasible hydrothermal method. • The maximum adsorption capacity of phos-GOF for U(VI) is ∼483 mg/g. • The adsorption of phos-GOF for U(VI) can be maintained at ∼ 93.5% after five cycles. • Inner-sphere complexation contributes much to the adsorption of phos-GOF towards U(VI). The 3D phos-GOF exhibits rapid and high efficiency for U(VI) sequestration and can be easily separated and regenerated. [ABSTRACT FROM AUTHOR]