Preparation of Platinum Nanoparticles by Sonochemical Reduction of the Pt(II) Ion

• Published in: Langmuir Vol. 15; no. 8; pp. 2733 - 2737
• Main Authors: Mizukoshi, Yoshiteru, Oshima, Ryuichiro, Maeda, Yasuaki, Nagata, Yoshio
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.04.1999
• Subjects: Chemistry; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Sonochemical reaction; Chemical reduction; Anionic surfactant; Platinum ion; Nanostructure; Sodium compound; Aqueous solution; Experimental study; Metal particle; Lauryl sulfate
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la9812121

Platinum nanoparticles were prepared in an aqueous system using high-intensity ultrasound (200 kHz, 6 W cm-2). The particles formed in the presence of a surfactant (sodium dodecyl sulfate, SDS) were stable, homogeneously spherical, and relatively monodispersed with an average 2.6 nm diameter. The rate of formation of the platinum nanoparticles was 26.7 μM min-1 in the Pt(II)−SDS system. Reducing species generated near and/or in the hot bubbles, which were sonochemically induced in the media, would react with the PtCl4 2- complexes to form the platinum nanoparticles. Three kinds of the reducing species were proposed to be formed in the sonicated system:  (a) radicals formed from the thermal decomposition of SDS at the interfacial region between the cavitation bubbles and bulk solution; (b) radicals formed via reactions of the hydroxyl radicals or hydrogen atoms with SDS; (c) hydrogen atoms. During the reduction of the Pt(II) ion, (b) and (c) ((b) > (c)) may be effective while (a) is only slightly effective, whereas in the cases of gold and palladium nanoparticles (a) was the main reductive species.