Preparation of zinc oxide-dispersed silver particles by spray pyrolysis of colloidal solution

ZnO/Ag composite particles for contact, materials were prepared from colloidal solutions by ultrasonic spray pyrolysis. The colloidal solutions were prepared by adding unagglomerated nanometer ZnO particles into the silver nitrate solutions. The composite particles were not hollow, and had spherical morphology with a uniform dispersion of nanometer ZnO particles inside the Ag matrix. The nanometer ZnO particles were completely coated with silver by heterogeneous precipitation onto the preexisting ZnO particles. The weight ratio of ZnO to Ag in the composite particles was varied from 0.08 to 0.33 by changing the amount of nanometer ZnO particles in the colloidal solutions. The mean size of the ZnO/Ag composite particles were increased from 0.85 to 1.24 mu m as the weight ratio of ZnO to Ag increased from 0.08 to 0.33, (C) 1999 Elsevier Science B.V. All rights reserved.