Investigation of passivated silver nanoparticles

Two-dimension self-assembly superlattices of passivated silver nanoparticles were formed on amorphous carbon films. Transmission electron microscopy (TEM) of the silver nanoparticles indicates that the particle formation involves a dynamic process. In X-ray photoelectron spectroscopy (XPS) spectra, the Ag3d5/2 value decreases first from 368.3 to 367.95 eV, and then to 367.65 eV during the formation, which indicates that the 1-nonanethiol is just physically adsorbed on the surface of the nanoparticles at the beginning of the reaction. Subsequently, the chemical bond was formed between the Ag atoms and S ions, which further demonstrated that the large particles were decomposed into smaller ones in the middle of the particle formation process.