Generally for the synthesis of Fe3O4@GO-Pr-SO3H, we started
from conversion of graphite to GO. Supporting Fe3O4 nanoparticles
on the surface GO was accomplished by coprecipitation of Fe2+ and
Fe3+ under alkaline solution over addition of ammonia at 80 C.
Functionalization of Fe3O4@GO with MPTMS caused to form thiol
functions. These thiols were subsequently oxidized to sulfonic acid
groups in the presence of hydrogen peroxide at room temperature.
A schematic synthetic route for the synthesis of Fe3O4@GO-PrSO3H
is depicted in Scheme 1.