Ionic liquid-assisted synthesis of silver nanorods by polyol reduction

Silver nanorods have been successfully synthesized in large scale by the ethylene glycol (EG) reduction in the presence of ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) and polyvinyl-pyrrolidone (PVP). The silver nanorods were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), electron energy disperse spectroscopy (EDS) and UV–vis spectroscopy. The results showed that the uniform silver nanorods have an average diameter of about 100 nm and the aspect ratio from 15 to 20. IL, bmimBF4 may play a role of capping agent together with PVP in the formation of silver nanorods. On the other hand, bmimBF4 may accelerate nucleation and improve the stability of the resulting Ag nanorods due to the low interface tension of IL.