Facile Fabrication of Platinum Nanodots Assembly Core – Silica Shell Nanosystems

Abstract

Nanosystems using a platinum (Pt) nanodots assembly (multi-Pt nanoparticles, m-Pt) as the core and silica (SiO2) shells were successfully synthesized as m-Pt@SiO2 spherical nanoparticles (NPs) and m-Pt@SiO2 nanochains (NChs) by a reverse microemulsion (water-in-oil)-based method. The kinetically controlled reduction of K2PtCl4 by the Brij35 surfactant within reverse micelles, followed by condensation of tetraethyl orthosilicate, led to the formation of multi-Pt nanodots core–silica shell systems. The reduction kinetics for the growth of core–shell systems was studied in both the presence of reducing agents such as ascorbic acid, glucose, and ethylene glycol and in the absence of supplementary agents, as well as the variation of water-to-surfactant ratio. To assemble Pt NPs within a one-dimensional SiO2 matrix, we attempted to grow Pt NPs in␣situ while the SiO2 materials grew one-dimensionally in a modified microemulsion system. By changing the pH of the reaction media or using highly concentrated ethylene glycol in the synthetic approach, we successfully synthesized m-Pt@SiO2 NChs. © 2015, The Minerals, Metals & Materials Society.