Influence of Poly(Vinylpyrrolidone) Capping Agent on the Synthesis of Silver Structures by Polyol Method

摘要

In this study, silver nano/micro structures were successfully synthesized from silver nitrate via a polyol method at 160 °C. In our synthesis route, ethylene glycol (EG) was used as both as solvent and reducing agent, and polyvinylpyrrolidone (PVP) with different molecular weight was employed as capping agent. When reduced the PVP's molecular weight from 58000 to 8000, the spherical morphology of silver particles changed to rod shape. Moreover, by changing the injection method of PVP and controlling the reaction time, silver nanoparticles with uniform spherical morphology and size was prepared. The obtained silver nanoparticles were characterized by X-ray diffraction (XRD) and ultraviolet-visible spectrophotometry (UV-vis) which indicated the formation of nanoparticles. Scanning electron microscopy (SEM) contributed to the particle morphology and size analysis. The morphology and particle size of the resulting silver nanoparticles were depended on the PVP's molecular weight and the injection method.