High yield synthesis of pure alkanethiolate-capped silver nanoparticles.

One-phase, one-pot synthesis of Ag(0) nanoparticles capped with alkanethiolate molecules has been optimized to easily achieve a pure product in quantitative yield. We report the synthesis of dodecanethiolate-capped silver particles and the chemophysical, structural, and morphologic characterization performed by way of UV-vis, (1)H NMR, and X-ray photoelectron (XPS) spectroscopies, X-ray powder diffraction (XRD) and X-ray absorption fine structure analysis (XFAS), electron diffraction and high-resolution transmission electron microscopy (HR-TEM), and scanning and transmission electron microscopy (SEM and TEM). Depending on the molar ratio of the reagents (dodecylthiosulphate/Ag(+)), the mean Ag(0) particle size D(XRD) is tuned from 4 to 3 nm with a narrow size distribution. The particles are highly soluble, very stable in organic solvents (hexane, toluene, dichloromethane, etc.), and resistant to oxidation; the hexane solution after one year at room temperature does not show any precipitation or formation of oxidation byproducts.