Raman spectroscopy of Ar+-irradiated graphite surfaces supporting platinum nanoparticles

Abstract

Ion irradiation is well-known as a versatile tool for manipulating the physical, chemical and magnetic properties of carbon materials. Recently, the ion-beam-induced defects in carbon supports for platinum (Pt) nanoparticles have been found to enhance catalytic activity during the oxygen reduction reaction. This finding suggests that the electronic structure of the Pt nanoparticles would be affected by the ion-beam-irradiated carbon support. Raman spectroscopy was performed on the highly oriented pyrolytic graphite (HOPG) following the irradiated with 380 keV argon ions (Ar+) and the deposition of Pt nanoparticles using radio frequency (rf) magnetron sputtering. In this paper, we obtained the phonon correlation length from Raman spectrum, and estimated that approximately three point defects were present at the interface between each 5 nm Pt nanoparticle and the HOPG irradiated with Ar+ at the fluence of 1.0 × 1013 ions/cm2.