Elucidating the Role of AgCl in the Nucleation and Growth of Silver Nanoparticles in Ethylene Glycol

Silver nanoparticles and nanowires can be efficiently synthesized in high yield using the polyol synthesis method. However, there are many open questions regarding the mechanisms involved, and how the size and morphology can be effectively controlled. In this work, silver nanoparticles were characterized during and after the synthesis procedure. In the early stages, crystalline silver-silver chloride nanoparticles (Ag-AgCl NPs) were the most commonly observed particles. As the reaction progressed, the fraction of Ag-AgCl NPs decreased while the fraction of isolated silver nanoparticles (Ag NPs) increased. We hypothesize that the AgCl in Ag-AgCl NPs dissolves as Ag(I) into the solution and is then reduced to Ag(0), leaving the Ag portion as isolated Ag NPs with similar particle size, morphology, and microstructures. These Ag NPs accounted for the majority of the final product.