Local deposition of anisotropic nanoparticles using scanning electrochemical microscopy (SECM)

Abstract

We demonstrate localized electrodeposition of anisotropic metal nanoobjects, namely Au nanorods (GNR), on indium tin oxide (ITO) using scanning electrochemical microscopy (SECM). A gold microelectrode was the source of the gold ions whereby double pulse chronoamperometry was employed to generate initially Au seeds which were further grown under controlled conditions. The distance between the microelectrode and the ITO surface as well as the different experimental parameters (electrodeposition regime, solution composition and temperature) were optimized to produce faceted gold seeds with the required characteristics (size and distribution). Colloidal chemical synthesis was successfully exploited for better understanding the role of the surfactant and different additives in breaking the crystallographic symmetry and anisotropic growth of GNR. Experiments performed in a conventional three-electrode cell revealed the most appropriate electrochemical conditions allowing high yield synthesis of nanorods with well-defined shape as well as nanocubes and bipyramids.

Electrochemistry of Metal Nanoparticles and Quantum Dots

“…Electrochemical imaging techniques are increasingly used to study nanoparticle films on electrodes. The scanning electrochemical microscopy technique (SECM), developed by Bard et al [24], uses a tip microelectrode as a local probe providing spatially resolved information on the redox reactivity of surfaces and has been used for measurement on electron transfer dynamics [25] and local deposition of nanoparticles [22,26]. Recent developments involve the use of optical signals of the electrode, namely, surface plasmon resonance [27], and combination with AFM in order to probe individual metal nanoparticles [28].…”

Scanning Electrochemical Microscopy for the Electroless Deposition of Gold on Natural Pyrite: Effect of Ferric Ions

“…‐ Particularly, Unwin's group studied from the SECM transients silver adsorption and nucleation on a pyrite surface at a short time scale (<1 s) . The local electrodeposition of cobalt or gold, at various substrates was also studied by SECM with a specific attention to gold deposition on silicon semi conducting substrates and to the electroless deposition of gold . However, these approaches need either the connection of the semiconducting substrate, using a precious metal, or a surface modification step ,.…”

Local Electrodeposition of Metals by Tip Electrode Dissolution Using Scanning Electrochemical Microscopy

“…In SECM, electroactive species are generated from the tip electrode which can approach to the substrate electrode in a close proximity, making a local electrochemical process possible. Local electrochemical depositions of metals using a SECM have been performed in various ways . Generally, to deposit a material within a confined area, a tip generation‐substrate collection (TG‐SC) mode has been used where a tip triggers a certain reaction producing a precursor being reduced or oxidized at a substrate.…”

“…Metal ions generated from a metal tip surface by the anodic dissolution and then reduced on the substrate electrode which is close to the tip electrode. Mandler and coworkers studied localized deposition using this anodic dissolution of Au , Ag and Co . Abad et al .…”