A study of graphene decorated with metal nanoparticles

► Graphene-metal nanoparticle (Ag, Au, Pt and Pd) composites, prepared by glycol reduction under microwave irradiation were studied by Raman spectroscopy. ► There is a significant charge-transfer interaction between graphene and the metal nanoparticles. ► First-principles calculations also underscore the importance of charge-transfer between the metal nanoparticles and graphene.