Activation of few layer graphene by μW-assisted oxidation in water via formation of nanoballs - Support for platinum nanoparticles.

The functionalization of carbon nanomaterials in controlled and selective manner and in order to stabilize small metal nanoparticles is of high interest particularly in the catalysis field. We present the μ-waves assisted few layer graphene (FLG) oxidation in water, which results in a partial sheets exfoliation and formation of oxygen functionalized carbon nanoballs, supported on highly graphitized graphene sheets. This double morphology material allows homogenous anchoring of Pt nanoparticles, while the advantages of planar and highly crystallized FLG are preserved. For comparison, acid treated FLG (conventional heating) exhibits highly hydrophobic and inert surface with carboxylic groups as anchoring sides localized at the FLG edges. Despite similar oxygen content, the performed physicochemical analyses depict different nature and localization of the oxygen/defects functionalities introduced in water (in μ-waves) and acid treated FLGs. Finally, the addition of FLG during the preparation of Pt particles-carried out by μ-wave assisted polyol method yields small nanoparticles with average size of 1nm.