Optical Properties and Formation Mechanism of Gold Nanoparticles Fabricated by Sono-electrochemical Method

Gold nanoparticles (Au NPs) were synthesized rapidly using the Sono-electrochemical method, employing gold electrodes and hexadecyltrimethylammonium bromide (CTAB) as the reducing agent. This method offers high productivity, utilizes simple equipment, and is cost-effective. The resulting Au NPs exhibited sizes ranging from 20 to 60 nm. The UV-vis absorption spectra of the synthesized Au NPs show a peak due to surface plasmon resonance absorption at around 530–548 nm, corresponding to transverse electronic oscillation. The relationship between the size of the Au NPs and their absorption spectrum was also investigated. Additionally, the impact of current density, CTAB surfactant concentration, and acetone volume on the size and characteristic plasmon properties of the Au NPs was examined. The formation mechanism of the Au NPs was also discussed.