Seed Concentration Control of Metal Nanowire Diameter

Abstract

Gold/silver nanowires (NWs) of controlled diameters were synthesized from catalytic metal seed particles at the substrate/solution interface. Small seed nanoparticles of three different sizes: ~1 nm (11 gold atoms), ~1.4 nm (~55 gold atoms), and homemade nanoparticles of ~2 nm were used. By varying a single type of seed particle concentration in the growth solution, the NW diameters and morphology could be controlled, between bundles of ultrathin NWs of ~2-3 nm diameter to thicker isolated single NWs with a mean diameter of ~16 nm. In addition, the catalytic reduction rate leading to NW growth was found to be seed size dependent at small seed sizes (<2 nm). The two types of metallic NW films were tested for their performance as transparent electrodes after additional metal deposition for their stabilization and conductivity enhancement. The thin NW bundles exhibit superior transparent conductor properties.

Efficient Synthesis of MCu (M = Pd, Pt, and Au) Aerogels with Accelerated Gelation Kinetics and their High Electrocatalytic Activity

“…Based on this phenomenon, this hydrogel formation follows spontaneous assembly involving the transient formation of NPs, short nanowires, nanowire networks, and the resultant hydrogels. It is well known that the formation of nanowires is usually ascribed to two mechanisms, i.e., oriented growth from nuclei and orientation attachment between NPs . According to the result mentioned above, orientation attachment plays a significant role in hydrogel formation instead of oriented growth.…”

Development of Au-Ag nanowire mesh fabrication by UV-induced approach

“…Prominent examples of hard templates include polycarbonate membranes [24], alumina template membranes [25], mesoporous silica membranes [26], single-walled carbon nanotubes [27], and poly(vinylpyrolidone) (or, PVP) [28,29]. Soft templates based surfactants such as cetyltrimethylammonium bromide (CTAB) have become popular in the preparation of metal nanorods and nanowires, because of their multitude of possible phases at various concentrations in water as well as possible formation of flexible pore space [30].…”

“…Addition of the mild reducing agent, reduces these ions to Au 1+ colorless solution, thus forming Au-complexes, and Ag-complexes from Ag 1+ ions [30,34]. Further reduction to the neutral metallic state involves the addition of the metal seeds acting as the catalysis for the nanowire-growth initiation [35] -the gold seeds serve as the nucleation centers that catalyze the reduction of the metal ions by the ascorbate ions [30]. The adsorption of CTAB on seed particles causes the formation of a liquid crystalline CTAB tubular phase, which shall act as template for the formation of the nanowires [30].…”

Large-scale controllable preparation and performance of hierarchical nickel microstructures by a seed-mediated solution hydrogen reduction route

“…[15][16][17][18] When small nanoparticles as seeds are added into a solution including a metal salt and mild reducing agent, the catalytic reduction of the metal salt on the surface of the metal particles is faster than that in the bulk solution. [15][16][17][18] When small nanoparticles as seeds are added into a solution including a metal salt and mild reducing agent, the catalytic reduction of the metal salt on the surface of the metal particles is faster than that in the bulk solution.…”