Polyol Synthesis of Silver Nanowires: An Extensive Parametric Study

Silver nanowires have been synthesized by a polyol process. A detailed parametric study determining the relationship between final morphology of the products and temperature, injection rate, molar ratio of poly(vinylpyrrolidone) to silver nitrate, sodium chloride amount, and stirring rate is presented. The as-synthesized silver nanowires are analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The dependency of nanowire morphology and aspect ratio on synthesis parameters is shown via SEM images. Furthermore, the nanowire diameter is found to decrease with stirring rate, poly(vinylpyrrolidone) to silver nitrate molar ratio, and temperature and to increase with injection rate. The lack of sodium chloride and its presence in excess amounts resulted in the formation of particles with different sizes in addition to nanowires. In addition, poly(vinylpyrrolidone) to silver nitrate molar ratio is found to affect the morphology of the resulting nanostructure, leading to formation of particles at high and low ends. The results reported in this paper provide a basis for optimizing silver nanowire growth through the self-seeding polyol method.