Size-sorted graphene nanoplatelets are highly desired for fundamental research and technological
applications of graphene. Here we show a facile approach for fabricating size-sorted
graphene oxide (GO) nanoplatelets by a simple centrifugal method using different dispersion
solvents. We found that the small-sized GO nanoplatelets were more effectively separated
when dispersed in water or dimethylformamide (DMF) than in an alkali aqueous solution.
After several iterations of the centrifugation, the sizes of GO in the supernatant solution were
mostly several micrometers. We found that the GO area was not strongly correlated with the
C-O content of the GO dispersed in water. However, the size-sorted GO nanoplatelets in
DMF showed different C-O content, since DMF can reduce GO nanoplatelets during exfoliation
and centrifugation processes.