Size contrast of Pt nanoparticles formed on neighboring domains within suspended and supported graphene

The relatively small size of thin (one or few layers) graphene flakes makes it extremely difficult to study the behavior of suspended graphene by characterization techniques other than the electron microscopies. Herein, we exploited the capability of spatially resolved photoemission in combination with high resolution transmission electron microscopy to investigate the interaction of thermally evaporated Pt atoms on suspended and supported graphene. Spectroscopic and microscopic analyses reveal that the nucleation of nanometersized Pt particles in these two regions exhibit different trends. While only small nanometer-sized islands are present on the supported graphene, relatively larger clusters of islands were also found on the suspended flakes. The X-ray photoemission C 1s core levels acquired after the Pt deposition show an increase in the number of vacancies in the graphene sheets.