Seeded growth of gold–silver ultrathin wire–dot hybrid nanostructures

We report the facile synthesis of gold–silver (Au–Ag) nanostructures in a niche hybrid form of ultrathin wire–dots, where the ultrathin nanowires are embedded with quasi-spherical dots along the longitudinal direction. The key to the success of this work relies on the use of seeded growth and the introduction of excessive Ag ions in the growth stage to facilitate the formation of such a unique architecture. Several reaction parameters, including the amount of silver and reductant, seed quantity and size/morphology, are systematically investigated to reveal their role in determining the morphology of the final products. We also recorded their UV-vis extinction spectra and compared them with pure ultrathin wires to investigate the effect of dot regions on the optical properties.