Fabrication and anti-oxidation abilities of Cu@Ag core-shell nanoparticles by polyol-assisted method

A simple method was introduced to prepare Cu@Ag core-shell particles at room temperatureby using ethylene glycol (EG) as the reducing agent and AgNO₃ as the source of Ag atom. The effects of types of dispersing agent including gelatin, cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP)on the morphology of Cu@Ag core-shell particles were studied. The results show that gelatin is the best choice as dispersing agent. When the concentration of AgNO₃ is 0.93 mol/L, the copper particles are completely covered with Ag nanoparticles on the surface with gelatin as dispersing agent. Because of the protection of Ag nanoparticles on the surface of Cu particles, the sheet resistance of compacted film based on Cu@Ag core-shell nanoparticles is as low as 1.6 Ω/sq. After being exposed in air for 4 months, the sheet resistance of the Cu@Ag core-shell particles is a little bit higher as 12.6 Ω/sq, which shows an enduring oxidation resistance of Cu@Ag core-shell particles.The silver can be efficiently achieved over the Cu particles under control and shows better anti-oxidation abilities than Cu particles with enduring oxidation resistance. This is a remarkable improvement for the electrical conductivity of Cu particles, which lays the foundations for the application of Cu@Ag core-shell particles in industrial production.