Fabrication of Gold Nanoparticles by Pulsed Laser Ablation in Aqueous Media

The growth of Au nanoparticles by laser ablation processes has been systematically investigated. The morphology of Au metal nanoparticles was characterized with respect to laser wavelength, pulse duration, pulse energy, and surfactant concentrations in order to understand the nanoparticle formation process during laser ablation. Three different laser wavelengths including a nanosecond excimer laser operating at 248 nm, femto-second Ti:Sapphire laser operating at 776 nm and nanosecond diode-pumped Nd:YAG laser operating at its second harmonic wavelength of 532 nm were used for Au nanoparticles fabrication in surfactant-free and surfactant-containing aqueous solutions. Field emission SEM, XRD and UV-visible absorption spectrum were used for the characterization of Au nanoparticles. The parameters controlling the morphology of Au nanoparticles during laser ablation in surfactant-free and surfactant-containing aqueous media are discussed. It was found that particle size and size distribution of Au nanoparticles produced by nanosecond Nd:YAG and KrF excimer lasers are less affected by the laser fluence than that of femtosecond Ti:Sapphire laser.