Synthesis of Platinum Nanoparticles on Two-Dimensional Carbon Nanostructures with an Ultrahigh Aspect Ratio Employing Supercritical Fluid Chemical Vapor Deposition Process

Carbon nanowalls (CNWs), two-dimensional carbon nanostructures comprising plane graphene layers standing vertically on a substrate, have attracted considerable attention for several applications, because of their ultrahigh aspect ratio and large surface area. We developed a formation method of platinum (Pt) nanoparticles using the supercritical fluid-chemical vapor deposition (SCF-CVD), and demonstrate the synthesis of dispersed Pt nanoparticles of 2 nm diameter on the entire surface of CNWs, by using SCF-CVD employing metal–organic compound. The SCF-CVD process has proved quite effective for the synthesis of Pt nanoparticles on the intricate surface of carbon nanostructures with narrow interspaces.