Graphene as electronic structure modifier of nanostructured Pt film for enhanced methanol oxidation reaction electrocatalysis

We report a novel, nanostructured Pt-graphene (Pt-G) hybrid, which is composed of Pt nanowires (NWs) grown directly on intrinsic graphene by using a mesoporous silica thin film as a nanotemplate. The direct junction between the Pt NWs and graphene, as well as the defect-free nature of the graphene grown via chemical vapor deposition, enables the charge transfer from graphene to Pt in Pt-G. The Raman, ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) data on Pt-G show clear evidence for the charge transfer from graphene to Pt. Through the interaction, the Fermi level of Pt is raised by 0.3 eV. With the electronic structure altered, Pt-G shows an increased tolerance to CO-poisoning and, hence, enhanced methanol oxidation reaction (MOR) performance with increased If/Ib ratio and cycle stability. The present data demonstrate a novel way to exploit the unusual characteristics of graphene for useful applications.