Nano zero valent iron encapsulated in graphene oxide for reducing uranium

Nano zero-valent iron (Fe-0) has been widely used to remove Uranium (U(VI)). In order to enhance the performance of Fe-0 toward U(VI) removal, the Fe-0 was assembled into graphene oxide (GO) sheets via 3-aminopropyl triethoxysilane (APTES) as Fe-0/APTES-GO composites. The Fe-0/APTES-GO composites were triumphantly prepared, characterized and analyzed by means of Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) together with Energy Dispersive Spectrometer (EDS), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Photoelectron Spectroscopy (XPS). SEM and TEM-EDS results manifested that Fe-0 particles were encapsulated into rolled-up GO, which greatly improved the stability of Fe-0. Batch experiment showed that only a small amount of Fe2+ was leached in the first two leaching cycles of Fe-0/APTES-GO composites. The removal capacity of Fe-0/ APTES-GO composites was up to 1357.99 mg/g at pH = 4.1 and T = 50 degrees C, which was mainly attributed to the reducing activity of Fe-0 and an abundance of functional groups (i.e., -COOH, C-OH and -OH) on the Fe-0/APTES-GO composites. The electrostatic potential (ESP) from the calculation also supported that U(VI) tended to be reduced at the back side of the GO-Fe-0 cluster. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Fe-0/APTES-GO composites show promising results in removing U(VI) due to the reducing activity of Fe-0 and abundant functional groups on the composites. Batch experiments demonstrate the effective removal of uranium by Fe-0/APTES-GO composites.