Laser–plasma driven green synthesis of size controlled silver nanoparticles in ambient liquid

Abstract

This article explores the expansion behavior of laser produced silver plasma in stationary and stirring liquid media using space resolved optical emission spectroscopy and plasma instigated size controlled synthesis of silver nanoparticles via laser ablation. Second harmonics (532 nm) of an Nd:YAG laser was employed for the ablation of a silver target in ambient liquid for plasma formation. Calculation of plasma parameters — electron temperature and electron number density were done for different laser fluences and in various liquid media at room temperature. The Electron temperature (Te) was measured by exploiting the Boltzmann plot method and the electron number density (ne) was estimated from Stark broadened profiles of isolated lines from optical emission spectra. UV–Vis spectroscopy, fluorescence spectroscopy and high-resolution transmission electron microscopy further substantiated the optical and morphological characteristics of silver nanoparticles. Obtained novel versatile results pave way for a far-reaching understanding in creation and characterization of silver plasma, in ambient liquid; and provides a methodical green approach towards the synthesis of metallic nanoparticles that can be fine tuned for size and morphology, by varying laser parameters.