Decoration of the Interior Surface of Hollow Spherical Silica Colloids with Pt Nanoparticles

This paper describes the generation of Pt nanoparticles inside hollow silica colloids. Solvent etching of a -Se core in a -Se@Pt@silica double-shelled colloids transformed the thin Pt layer into a number of Pt nanoparticles, decorating the interior surface of hollow silica colloids. The release rate of a -Se was directly related to the formation of Pt nanoparticles. Fast dissolution of the core in solvents such as carbon disulfide (CS 2 ) and hydrazine (N 2 H 4 ) produced Pt nanoparticles with diameters less than 15 nm, while slow release of a -Se in alcohols or in a mixture of CS 2 and water did not make any change in the Pt thin layer. At elevated temperatures (65 °C) in alcohols, the nanoparticles were aggregated and rearranged into large nanoparticles. The nanoparticles obtained in these processes were characterized single crystallites with HR-TEM analysis and electron diffraction patterns.