The graphene was synthesized with oil soluble food antioxidants
as reducing agent (See supporting information). The
magnetite (Fe3O4) magnetic nanoparticles were synthesized via
a solvothermal process [28]. As shown in Fig. 1, the magnetic
graphene was fabricated via a simple method by co-mixing according
to our previous studies with some modifications [25,28,38].
Briefly, Fe3O4 (2500 mg), PSA (1250 mg) and graphene (1000 mg)
were placed in a 100 mL vial. After adding 30 mL acetonitrile, the
magnetic graphene dispersive solution was obtained by vortexing
vigorously for 1 min, and then an external magnet was attached to
the outside bottom ofthe vial and the magnetic graphene was gathered
to the bottom of the vial. The supernatant was discarded. The
product was washed with toluene for several times. The washed
product was then vacuum-dried at 60 ◦C overnight. The yield of
magnetic graphene was approximately 100%, which was attributed
to the complete retrieval of components during the mild co-mixing
method.