Developing Pulsed Laser Ablation in Liquid for the Synthesis of Gold Colloids

This report presents the design, development, and optimization of a setup for the synthesis of gold nanoparticles (Au NPs) via Pulsed Laser Ablation in Liquid, using a KrF excimer laser (of 248 nm wavelength). The setup was entirely assembled during the internship, with particular attention to beam alignment, target positioning, and system reproducibility. Using pure water as the initial liquid medium, the work investigates the role of laser parameters such as fluence and irradiation time, as well as the influence of ligands on the morphology and stability of the resulting colloids. After observing significant aggregation in water, trisodium citrate dihydrate was introduced to improve colloidal stability.A detailed analysis of concentration effects revealed that a TCD concentration between 10−4 and 10−3 M not only minimized aggregation but also influenced the overall synthesis dynamics. UV-Vis spectroscopy and TEM were employed to characterize the optical and structural features of the nanoparticles. This work provides a reproducible framework to produce Au NPs with tunable properties and offers insights into the interplay between ablation and irradiation processes.