Synthesis of Single Crystal Hollow Silver Nanoparticles in a Fast Reaction-Diffusion Process

Colloidal hollow silver nanoparticles were produced by a fast chemical reduction of silver oxide nanoparticles capped with glutathione. These hollow silver particles were surprisingly single crystalline and had almost perfect spherical shells. The reaction was further tested for the transformation of silver oxide nanoparticles to hollow silver sulfide nanopartides by a reaction with sulfide ions. Analysis of the dimensions of the precursor Ag2O nanopartides and product hollow Ag nanoparticles as well as the sensitivity of the reduction process to the nature of reducing agent and its concentration hints that the reaction had to proceed through inward diffusion of reducing agent versus fast outward diffusion/dissolution of silver ions. We believe that this type of reactions resembles transformation reactions that have been associated with the nanoscale Kirkendall effect in its broader sense.