Using γ-irradiation to synthesize Ag nanoparticles

Aqueous dispersions of Ag nanoparticles (NPs) were obtained after γ-irradiation of solutions containing AgNO3, sodium citrate, and ethanol. The dose of γ-irradiation influences the diameter of the Ag NPs, as evidenced from UV-Vis absorption spectra and scanning electron microscopy (SEM) images. When the γ-irradiation dose increased from 60 to 530 Gy, the particle diameters decreased continuously as a result of irradiation-induced Ag NP fragmentation. At a constant γ-irradiation dose (ca. 100 Gy), we obtained Ag NPs that had highly reproducible particle diameters. This study reveals that γ-irradiation-mediated synthesis is a promising method for the preparation of stable Ag NPs when “clean” metal surfaces are required, e.g., for use in sensing devices.