Preparation of Dispersed Spherical Platinum Particles with Controlled Size and Internal Structure

Abstract

Center for Advanced Materials Processing, Clarkson University, Potsdam, New York 13699, USA *Email: goiadanv@clarkson.edu Uniform dispersed spherical platinum particles were precipitated by reducing Pt(IV) hexaammine ([Pt(NH3)6] ) complex ions with L-ascorbic acid in the presence of polymeric dispersants. By varying the nature and the amount of dispersing agent the average diameter of the Pt spheres could be adjusted between 200 nm and 800 nm. Electron microscopy and X-ray diffraction (XRD) evaluations revealed that the fi nal Pt particles were the result of an irreversible aggregation of small (~6 nm) nanoparticles. The size of the constituent crystallites was controllably increased through a subsequent heat treatment process without affecting the shape or the dispersion of the Pt spheres. The method described represents a versatile and cost-effective route for producing Pt powders at the sub-micrometre or micrometre scale with controlled crystallinity for thick fi lm electronic applications.