Abstract

Copper nanoparticles were synthesized and the effect of the operating conditions via both chemical and electrochemical synthesis methods was investigated in this paper. In the chemical reduction method, copper nanoparticles were prepared in a copper sulfate solution using NaBH₄ as reducing agent and then stabilized in the presence of polyvinylpyrrolidone under nitrogen atmosphere. Temperature and concentration ratio of reducing agent to precursor influenced the synthetic progress and size of the copper nanoparticles. Copper nanoparticles with average particle size 30 nm were formed when the concentration ratio is greater than 2 in the temperatures range from 60 to 75°C. In the electrochemical deposition method, copper nanoparticles were prepared using a bath containing homogeneously acidified copper sulfate solution. The nanoparticles were formed as spongy layers on the plating electrode which is easily separated. Average particle size 10 nm of copper nanoparticles is obtained with controlling of the electrolyte concentration and current density. The comparison shows that electrochemical deposition gives finer particle of copper but size controlling of the nanoparticles are more controllable than the chemical reduction method.

Key words: Copper nanoparticles, operating conditions, electrochemical deposition, chemical reduction.

Abbreviation

TEM, Transmission Electron Microscope; MLCC, multilayer ceramic capacitor; PSD, particle size distribution; EDS, energy dispersive X-ray spectroscopy;XRD, X-ray diffraction.