▎ 摘　　要

A detailed understanding of synergetic catalytic effect of graphene-metallic nanoparticles composite is challenging and the heart of the graphene-based catalyst. On the basis of density functional theory, we have theoretically studied the confinement of Pt/graphene composite by using the conversion from the ozone decomposition to the hydroxyl radical generation as the probe reactions, finding that graphene plays a direct role in regulating the electronic structure of the Pt nanoparticles during every step of reactions. Furthermore, an electric field was introduced to guide the charge transfer direction between the Pt nanoparticles and the graphene sheet and to change the electronic state of the Pt/graphene composite. We attribute the presenting synergetic catalytic effect to the transfer of electrons between the pi orbitals of graphene and the d orbitals of metal atoms. We believe that our discovery may be of a quite general nature and could lead to new advances and development of a new class of graphene-based catalyst.