Properties of Nanocomposite Ag-Cu Colloids Prepared by Electrical Spark Discharge Method

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Colloidal nanoparticles are crucial in various scientific and industrial applications.
• Developing efficient and controlled synthesis methods for bimetallic nanoparticles like Ag-Cu is essential.
• Electrical spark discharge offers a promising, scalable technique for nanoparticle production.

Purpose of the Study:

• To synthesize nano silver-copper (Ag-Cu) colloids using electrical spark discharge.
• To investigate the effect of electrode composition (pure Ag-Cu vs. composite wires) on colloid properties.
• To determine optimal synthesis parameters for Ag-Cu colloid production.

Main Methods:

• Utilized an electrical discharge machine with deionized water as the dielectric fluid.
• Employed pure Ag, pure Cu, and Ag-Cu composite wires (92.5:7.5 and 72:28 ratios) as electrodes.
• Analyzed colloid characteristics including absorbance, wavelength, particle size, suspension stability, lattice widths, and crystal orientation using techniques like transmission electron microscopy and X-ray diffraction.

Main Results:

• Identified optimal parameters: 30-30 µs T_on-T_off, 5 min process time, and ~11 A current.
• The 72:28 composite wire produced colloids with the smallest particle size (85.27 nm) and highest absorbance (1.479), alongside good stability (14.8 mV).
• Composite-produced colloids showed shifted diffraction peaks and altered lattice widths, attributed to internal structural defects.

Conclusions:

• Electrical spark discharge is an effective method for synthesizing nano Ag-Cu colloids.
• Electrode composition significantly influences colloid properties, with the 72:28 composite yielding superior results in terms of particle size and stability.
• The study provides insights into controlling Ag-Cu nanoparticle characteristics for potential applications.