Preparation of Ag Nanoparticles Colloid by Pulsed Laser Ablation in Distilled Water

The Ag nanoparticles colloid was prepared by pulsed laser ablation for different time in 10 ml distilled water without any surface active agent, and it was analysed by means of UV-visible spectrophotometer and transmission electron microscopy (TEM). The results showed that the ablation efficiency and absorbance increased fast and shift to higher energies with increasing ablation time from 5 to 10 min, then increased slowly from 10 to 20 min, and increased fast again from 20 to 25 min. The morphologies of most Ag nanoparticles were nearly spherical. The average diameter and its distribution decreased from 5 to 7.5 min, then increased from 7.5 to 15 min, and decreased from 15 to 25 min.