Green synthesis of stable silver nanoparticles using Euphorbia milii latex

Abstract

We report a simple method to create silver nanoparticles that consists in the irradiation of a silver nitrate and Euphorbia milii solution by light from a xenon lamp followed by ultrashort laser pulses. The formation of silver nanoparticles has been confirmed with UV–visible and TEM microscopy, and no additives, such as solvents, surfactants or reducing agents, were used in the procedure. Nanoparticles are present after the xenon lamp illumination, and after the laser irradiation the silver nanoparticles sizes are reduced drastically to the range of 10–50 nm. A concentration variation study of silver nitrate and aqueous latex extract was carried out, as well as with the laser irradiation energy and time. The size reduction can be explained by a multiphoton process that promotes the photoexcitation of the surface plasmon band, breaking the particles due to charge accumulation. The utilization of environmentally friendly solvents is one of the key issues that merits important consideration in a green synthesis strategy.