Platinum nanoparticles on HOPG surface modified by 380 keV Ar+ irradiation: TEM and Raman studies

The ion beam-induced defects in carbon supports for platinum (Pt) nanoparticles have been found to enhance the catalytic activity. Highly oriented pyrolytic graphite (HOPG) was irradiated with 380 keV argon ions (Ar), and Pt nanoparticles were then deposited on it by a radio frequency (rf) magnetron sputtering method. The Pt nanoparticle size on Ar-irradiated HOPG and the carbon structure at the interface were investigated by transmission electron microscope (TEM) and Raman spectroscopy, respectively. The observed size of Pt nanoparticles on the irradiated HOPG was larger than that on the non-irradiated HOPG. Raman spectra indicated that vacancy-like defects were formed on the HOPG surface by Ar-irradiation at the fluences between and ions/cm, and sp defects were induced by irradiation more than ions/cm. These defective structures on the HOPG would promote the Pt particle growth.