Phosphorylation of graphehe oxide to improve adsorption of U(VI) from aquaeous solutions

The graphene oxide (GO) was functionalized with phosphate groups and applied as an effective adsorbent for the removal of uranium from aqueous solutions under various environmental conditions (e.g., solution pH, ions strength, contact time and temperature). Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy have confirmed that the phosphorylate group was successfully introduced on the surface of GO. The adsorption experiments indicated that the monolayer adsorption capacity has been increased from 249.38 mg/g (GO) to 336.70 mg/g [phosphorylated graphene oxide (PGO)] calculated by Langmuir model. Moreover, the adsorptive selectivity coefficients S (U(VI)/M(x)) increase from 42.43 to 51.96% after functionalized with phosphate group. The mechanism of U(VI) absorbed on PGO surface was dominated by surface complexation and electrostatic interaction. The results demonstrate that PGO will be a promising material for the efficient removal of U(VI) in the environment pollution remediation.