engleski

Synthesis and characterization of silver-protected copper nanoparticles

Recently, copper nanoparticles (CuNPs) have attracted wide attention in printing conductive features for application in printed electronics, due to low price of copper precursor material, together with its high conductivity. A major problem in utilizing CuNPs is their instabillity in air and aqueous solutions, therefore, coating the nanoparticles by a proper protective layer is of outmost importance. This study reports the aqueous synthesis of copper core – silver shell nanoparticles. Process was conducted in reduction atmosphere, with addition of poly(acrylic acid) (PAA) as a nanograin stabilizer, nanosilver material for reduction kinetics improvement, and silver(I) nitrate for transmetalation reaction. Characterization of the polymer- and silver- protected nanocopper suspension was performed using cyclic voltammetry (CV) and ultraviolet- visible (UV- Vis) measurements. In alkaline media (ammonium buffer solution, pH = 10.10), addition of Cu(II) and Ag(I) results in ammine-complex formation, which is easily detected by glassy carbon electrode. The increment of anodic current response regarding Cu(II)-complex species with addition of silver(I) salt confirmed transmetalation reaction. Furthermore, absorption maximum of pure CuNPs (λ = 590 nm) has been shifted towards lower values (λ = 418 nm), which is in agreement with silver shell formation. By this method, the obtained bimetallic particles have optical and electric properties of both metals, while the oxidation of the copper core is prevented.

copper nanoparticles synthesis ; transmetalation reaction ; UV-Vis spectroscopy ; cyclic voltammetry

nije evidentirano