Polypyrrole modified Fe-loaded graphene oxide for the enrichment of uranium(vi) from simulated seawater.

Extraction of uranium(vi) from seawater has attracted much attention for its potential use in the nuclear energy field. In this work, we synthesized graphene oxide-polypyrrole (GO-PPy) through pyrrole monomer polymerization on graphene oxide (GO) with an aqueous solution at low temperature and prepared reduced graphene oxide-polypyrrole-zero-valent iron (rGO-PPy-Fe0) composites by chemical deposition. We characterized rGO-PPy-Fe0 using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The rGO-PPy-Fe0 composites were investigated for the removal of uranium from aqueous solution and simulated seawater. The experimental results demonstrated that the rGO-PPy-Fe0 adsorbent possessed a superior capacity for the adsorption of uranium at mg g-1 and μg g-1 at the pH value of seawater. The adsorption process conformed to the pseudo-second-order rate equation and the Langmuir isotherm model. Based on X-ray photoelectron spectroscopy (XPS), we revealed the possible adsorption mechanism of uranium onto rGO-PPy-Fe0, which simulated a prospective potential of the adsorbent in seawater.