High surface area “3D Graphene Oxide” for enhanced sorption of radionuclides

Earlier studies demonstrated that graphene oxide (GO)
with large number of defects is favorable for the sorption of
radionuclides. Here we report oxidation treatment which converts high
surface area activated reduced graphene oxide (arGO) into a 3D
analogue of defect-rich GO (dGO). Oxidation of arGO using
ammonium persulfate results in oxidation corresponding to carbon to
oxygen ratio C/O=3.3, similar to the oxidation state of graphene oxide
while preserving high BET surface area of about 880 m2/g. Analysis
of surface oxidized arGO shows high abundance of oxygen functional
groups very similar to dGO and hydrophilic properties. The “3D
graphene oxide” showed high sorption capacity for U(VI) removal in
an extraordinary broad interval of pH. Notably, the surface oxidized
carbon material has a rigid 3D structure with micropores accessible
for penetration of radionuclide ions. Therefore, the bulk “3D GO” can
be used as a sorbent directly without dispersing, the step required for
GO to make its surface area accessible for pollutants