Formation of Gold−Silver Nanowires in Thin Surfactant Solution Films

Abstract

Thin, long gold/silver nanowires were grown on substrates in thin surfactant solution films. This growth process occurred exclusively in thinning aqueous films as the water evaporated, and elongated surfactant template structures were formed. The nanowire growth depended on the presence of a relatively high concentration of silver ions (typical Ag:Au mole ratio of 1:1). Tuning the pH value to about 5 in the growth solution was crucial for the nanowire growth. Further development of this process may lead to a simple wet chemical technique for the fabrication of relatively uniform arrays of metal nanowires on surfaces.

One-pot hydrothermal synthesis of silver nanowires via citrate reduction

“…synthesis of particles confined within cylindrical membrane pores or synthesized around cylindrical particles) [21][22][23][24][25][26][27][28][29][30][31][32][33], or templateless which uses capping agents to direct growth along specific crystal faces. Template-related approaches have been performed with porous anodic aluminum oxide (AAO) [21][22][23][24][25], carbon nanotubes [26], block copolymers [27,28], and self-assembled surfactants or other amphiphilic species [29][30][31][32][33]. Templateless approaches have been achieved by adding seeds and/or shape-directing capping agents [34][35][36][37][38].…”

Experimental Evidence of Icosahedral and Decahedral Packing in One-Dimensional Nanostructures

“…Krichevski et al . 19 have grown Ag/Au nanowires in a proportion 1/1. These authors do not report any deep structural characterization of the nanowires.…”

Growth of Au/Ag nanowires in thin surfactant solution films: An electron microscopy study

“…1 grew exclusively in the thinning aqueous films, where a relatively high Ag(I) concentration in addition to the Au(III) was required (typical Ag:Au mole ratio of 1:1) [20]. An excess of the reducing agent (ascorbic acid, ∼5 fold excess) was needed in order to obtain almost complete reduction of the metal ions enclosed in the surfactant template within the 15 min period of drying.…”

“…We have recently developed a different approach to form thin, long polycrystalline metal nanowires using the same chemistry [20]. In that case the metal (Au + Ag) reduction occurred in a drying thin growth solution film on a substrate, while the CTAB and metal ion concentrations were gradually increased upon water evaporation.…”