Preparation of micro-nano-sized Cu-Ag core-shell particles by a quick-making method and their conductivity

Micro-and nano-sized Cu and Ag core-shell particles were fabricated by a simple and quick-making method with copper micro-particles, gelatin and silver sulfate (Ag₂SO₄) as raw materials, and citric acid trisodium (SC) as reducing-and chelating-agent. The influence of SC and Ag₂SO₄ on the morphologies and oxidation resistance of Cu-Ag particles were investigated. The results showed that the dosage of SC directly affected the uniformity and morphology of the Ag coated Cu particles. The more the Ag₂SO₄ was used, the lower the conductive resistance was for the prepared particles. With dosages of 1.5 g and 8.0 g for SC and Ag₂SO₄respectively, the Cu-particles could be covered by Ag nanoparticles completely to form core-shell structured Cu-Ag particles, thereafter, the electrical resistance of sheets made of which can reach as low as 1.1Ω.