Underwater laser ablation approach to fabricating monodisperse metallic nanoparticles

Pulsed laser ablation of Ag bulk in distilled water is investigated to synthesize metallic nanoparticles. Formation of Ag colloids abundant with fine particles no more than 4 nm has been achieved by introducing a new experimental scheme. Subsequent colloid aging led to significant narrowing of size distribution and refining of particle shape (from ellipsoidal or irregular to spherical). Morphology modification of the particles is attributed to a selective sedimentation of the suspensions during the aging. We demonstrate here a possibility of producing monodisperse metallic nanoparticles using the laser approach in a simple scheme.