▎ 摘　　要

In this study, we report a new approach for Mn3O4-graphene nanocomposite by ex situ method. This nanocomposite shows two-dimensional aggregation of nanoparticle, and doping effect by decorated manganese oxide (Mn3O4), as well. The graphene film was made through micromechanical cleavage of graphite on the SiO2/Si wafer. Manganese oxide (Mn3O4) nanoparticle with uniform cubic shape and size (about 5.47 +/- 0.61 nm sized) was synthesized through the thermal decomposition of manganese(II) acetate, in the presence of oleic acid and oleylamine. The nanocomposite was obtained by self-assembly of nanoparticles on graphene film, using hydrophobic interaction. After heat treatment, the decorated nanoparticles have island structure, with one-layer thickness by two-dimensional aggregations of particles, to minimize the surface potential of each particle. The doping effect of Mn3O4 nanoparticle was investigated with Raman spectra. Given the upshift in positions of G and 2D in raman peaks, we suggest that Mn3O4 nanoparticles induce p-doping of graphene film.