Formation and Stabilization of Anisotropic Palladium and Platinum Nanoparticles in Aqueous Polymer Solution Using Microwave Irradiation

Anisotropic palladium and platinum nanoparticles were synthesized by reduction of the corresponding metal ions with hydrazine using polyacrylamide as a stabilizing agent in aqueous medium under microwave irradiation. The formation of particles was confirmed by UV-visible spectroscopy. The size and shape of the particles were determined using transmission electron microscopy. Rapid microwave heating resulted in 'star-shaped' palladium nanoparticles, but platinum nanoparticles were observed to be spherical with a distinctly visible 3-4 nm coating of polyacrylamide on their surface, which was not observed for the palladium particles. The Pt nanoparticles were used as a catalyst in the redox reaction.