Effects of the confining solvent on the size distribution of silver NPs by laser ablation

Laser ablation of a silver target confined in acetone, ethanol, methanol, propanol, and distilled water allowed us to obtain silver nanoparticles with different size distributions. We employed a pulsed Nd:YAG laser (λ = 532 nm, 0.5 J/pulse) with a high fluence of 64 J/cm2 with a scanning density of 2,500 pulses/cm2, having overlapping of consecutive pulses. The analysis of transmission electron micrographs showed that the smaller particle sizes were obtained confining the target in propanol, while the larger ones were obtained employing ethanol. Nanoparticle size distributions were fitted with two Gaussian peaks in all five cases, being the smaller sizes the most frequent. Predominant peaks were centered at 4.8 and 13.9 nm in propanol and ethanol, respectively, having a broader distribution for the nanoparticles obtained in ethanol. Furthermore, comparison of electron micrographs taken the day of synthesis and 4 and 9 months later in the case of water and propanol, respectively, shows that nanoparticle suspension is more stable in propanol.