Study on the growth mechanism of silver nanorods in the nanowire-seeding polyol process

Uniform silver nanorods have been successfully synthesized through a nanowire-seeding, multisteps polyol process in the high concentration reaction system. In this developed three-step polyol process, ethylene glycol is used as the solvent and reductant while poly(vinylpyrrolidone) (PVP) is used as the capper agent. The silver nanowires are used as the seeds in step 3 to radial grow into nanorods with larger diameter but similar length. Desorption of PVP from the surface of silver is presumed as the critical factor to cause the dominant regrowth of wire-like seeds towards radial direction, rather than axial direction. More details of the radial growth mechanism have also been discussed. This synthesis strategy will be significant in the large scaled preparation of nanomaterials.