Effect Of External Electric Field On The Formation Of Colloidal Ag-Au Alloy Nanoparticles Through Laser Post-Irradiation

We report the synthesis of Ag-Au alloy nanoparticles (NPs) by post-irradiation of mixed colloidal Ag and Au NPs by a nanosecond pulse laser in the presence of an external electric field (EEF). In our study, size, optical, and plasmonic properties of colloidal Ag-Au alloy NPs were investigated. A colloid of individual Ag and Au NPs were separately prepared by nanosecond pulsed laser ablation in distilled water. An appropriate volume of these colloidal NPs samples was mixed and post-irradiated with the same pulsed laser beam in the presence of a uniform electric field, resulting in the formation of Ag-Au alloy NPs. The synthesized colloidal alloy NPs were characterized using scanning electron microscopy and UV-vis absorption spectroscopy. The results indicate that the EEF can reduce significantly the Ag-Au alloy formation time. The results also show that the wavelength of the localized surface plasmon resonance of alloy NPs decreased by the applied electric field. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)