Nanographene growth from benzene on Pt(111)

Abstract

Graphene growth on a Pt(111) substrate exposed to benzene was studied at substrate temperatures between 800 K and 1100 K. The effects of the substrate temperature during benzene exposure and post-annealing were examined. It was revealed that the substrate temperature during benzene exposure determined the graphene size, which was measured using scanning tunneling microscopy (STM). Nanographenes (NGs) of ~10 nm in size. were obtained by exposing the substrate to benzene at 800 K and post-annealing at 1100 K. The presence of a C–Pt bond, which may fix the carbon atoms on the Pt(111) surface and suppress any further growth of graphene, was confirmed by the carbon K-edge near-edge X-ray absorption fine structure spectroscopy (C K NEXAFS) and X-ray photoelectron spectroscopy (XPS) for the NG. Angle resolved photoemission spectroscopy (ARPES) performed on the NG has a reduced density of states at the Fermi level.