Silver nanoparticles: New synthesis, characterization and photophysical properties

In this paper. we report a new solution phase synthetic route to prepare silver(0) nanoparticles and their optical properties. The Ag(0) nanoparticles were prepared by reduction of AgNO3 using t-BuONa-activated NaH in tetrahydrofuran at low temperature. The resulting t-BuONa-stabilized silver nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and UV-vis spectroscopy. The cubic face centered Ag(0) particles produced present a tight size distribution with an average radius of 3.3 +/- 0.7 unit. The silver nanoparticles dispersed in tetrahydrofuran exhibit a broad and structured fluorescence band when exposed to oxygen. This result is corrolated with a red shift of the surface plasmon absorption band. This process has been attributed to production of charged nanoclusters, Ag-m(2+), produced by consecutive oxidation then chemisorption of Ag+ onto metal surface. (c) 2007 Elsevier B.V. All rights reserved.