A study of graphene decorated with metal nanoparticles

Interaction of nanoparticles of metals such as Ag, Au, Pt and Pd with graphene has been examined by employing Raman spectroscopy and first-principles calculations. There is a significant shift of the G-band as well as of the other bands, in addition to variation in the relative intensities of D- and 2D-bands when the metal nanoparticles are deposited on graphene. The shifts in the G- and D-bands show meaningful trends with the ionization energies of the metals as well as the charge-transfer energies. Results from the calculations underscore the importance of charge-transfer between the metal particles and graphene.