Silver Nanoparticles Synthesized by Laser Ablation in Acetone: Influence of Ablation Time and Their Reactivity with Oxygen in the Air

In this work, a method is proposed to control silver nanoparticle dimensions produced by laser ablation varying the ablation time and introducing a sonication phase between ablation and the successive deposition on the substrate. The absorption spectra during laser ablation show a main band, which identifies the dimensions of main particles. The appearance of secondary bands indicates the beginning of an aggregation process with the formation of a small concentration of particles which are spheroid in shape. SEM (secondary electron microscope) images of particle produced with different ablation times confirm the results of absorption measurements. X-ray photoelectron spectroscopy and cathodo-luminescence spectroscopy indicate a high reactivity of the nanoparticles deposited on a substrate. They react with oxygen in the air forming an oxide layer which reveals a luminescence in the blue region.