Green synthesis of Pt nanoparticles using Keggin and Dawson heteropolyacids and preparation of their composites with carbon nanotubes

Abstract

In this paper, a facile green chemistry method was applied to synthesize platinum nanoparitcles (Pt NPs) using two types of heteropolyacids, Keggin and Dawson. Heteropolyacids play a crucial role, acting as reducing agent and also an efficient stabilizer under UV irradiation in this procedure. The main goal of our project was to control the shape and minimizing the size of Pt NPs by changing parameters such as time and concentration ratio of heteropolyacids to platinum ions. In both cases, the uniform sphere shape of Pt NPs with narrow size distribution was achieved. The smallest size of Pt NPs obtained by using Keggin was 2nm, while the minimum size of particles using Dawson was about 18nm. Then, Pt NPs with 2 nm average size was decorated on the functionalized multiwall carbon nanotubes and characterized by XRD, FTIR and TEM. The synthesized nanocomposite is promising to show high electrocatalytic activity in methanol oxidation which is expected due to the unique properties of Pt NPs, heteropolyacids and multiwall carbon nanotubes.