Room Temperature Growth of Ultrathin Au Nanowires with High Areal Density over Large Areas by in Situ Functionalization of Substrate

Abstract

Although ultrathin Au nanowires (∼2 nm diameter) are expected to demonstrate several interesting properties, their extreme fragility has hampered their use in potential applications. One way to improve the stability is to grow them on substrates; however, there is no general method to grow these wires over large areas. The existing methods suffer from poor coverage and associated formation of larger nanoparticles on the substrate. Herein, we demonstrate a room temperature method for growth of these nanowires with high coverage over large areas by in situ functionalization of the substrate. Using control experiments, we demonstrate that an in situ functionalization of the substrate is the key step in controlling the areal density of the wires on the substrate. We show that this strategy works for a variety of substrates ranging like graphene, borosil glass, Kapton, and oxide supports. We present initial results on catalysis using the wires grown on alumina and silica beads and also extend the method to lithography-free device fabrication. This method is general and may be extended to grow ultrathin Au nanowires on a variety of substrates for other applications.

Directed Assembly of Ultrathin Gold Nanowires over Large Area by Dielectrophoresis

“…In our earlier work on ultrathin gold nanowires, it was proven using AFM measurements that the conduction property can change from a Luttinger liquid mechanism to a hopping mechanism based on the height of the nanowire from the substrate. 15 In this present work Au nanowires have a monolayer of amine as demonstrated by FTIR measurements by Feng et al 6 Nanowires have been cleaned using the nonpolar solvent toluene which cannot remove oleylamine completely, 12 and hence R(T) shows the thermal fluctuation-induced tunneling [FIT] mechanism. Electrical transport properties of assembled ultrathin nanowire bundles are recently reported to be in accordance with the FIT model because of the presence of a monolayer of oleylamine interface formation.…”

Ultrathin Au nanowires supported on rGO/TiO2 as an efficient photoelectrocatalyst

“…2A is a representative transmission electron microscope (TEM) image that reveals a homogeneous dispersion of TiO 2 nanoparticles on the GO sheets as is also evident from the SEM image ( Fig. 38 During this process, the presence of oleylamine (OA) leads to intercalation 39 and functionalization of GO followed by direct nucleophilic attack of the amine on epoxy group that leads to deoxygenation or reduction of GO. High-resolution TEM micrographs from several regions show that the titania particles are interconnected (Fig.…”

“…38 The mixture was sonicated for 1 min and then incubated for 6 h at room temperature. 38 The mixture was sonicated for 1 min and then incubated for 6 h at room temperature.…”

Ultrathin Gold Nanowires and Nanorods

“…The deposition of AuUNWs with high coverage over large areas was achieved by in situ functionalization of various substrates ranging from graphene, borosil glass, Kapton, and metal oxide supports. 50 Highly dense AuUNWs on alumina beads showed catalysis for reduction of 4-nitrophenol to 4aminophenol. The AuUNWs were deposited on Ketjen carbon supports by immersing in acetic acid to remove the OA surfactants, ground together with polyvinylidene fluoride and 1-methyl-2-pyrrolidone, and pasted onto a carbon paper.…”