Synthesis and Electrochemistry of 6 nm Ferrocenated Indium–Tin Oxide Nanoparticles

Abstract

Indium-tin oxide (ITO) nanoparticles, 6.1 ± 0.8 nm in diameter, were synthesized using a hot injection method. After reaction with 3-aminopropyldimethylethoxysilane to replace the initial oleylamine and oleic acid capping ligands, the aminated nanoparticles were rendered electroactive by functionalization with ferrocenoyl chloride. The nanoparticle color changed from blue-green to light brown, and the nanoparticles became more soluble in polar solvents, notably acetonitrile. The nanoparticle diffusion coefficient (D = 1.0 × 10(-6) cm(2)/s) and effective ferrocene concentration (C = 0.60 mM) in acetonitrile solutions were determined using ratios of DC and D(1/2)C data measured by microdisk voltammetry and chronoamperometry. The D result compares favorably to an Einstein-Stokes estimate (2.1 × 10(-6) cm(2)/s), assuming an 8 nm hydrodynamic diameter in acetonitrile (6 nm for the ITO core plus 2 nm for the ligand shell). The ferrocene concentration result is lower than anticipated (ca. 1.60 mM) based on a potentiometric titration of the ferrocene sites with Cu(II) in acetonitrile. Cyclic voltammetric data indicate tendency of the ferrocenated nanoparticles to adsorb on the Pt working electrode.

Photophysical and Redox Properties of Molecule-like CdSe Nanoclusters

“…Considering that a nanocluster donates a single electron, the D value is calculated to be 5.4 × 10 –4 cm 2 /s for the Cd 34 Se 20 (SPh) 28 nanocluster. The diffusion coefficient is significantly higher for a 1.2 nm diameter nanocluster . This experimental result suggests that the nanoclusters behave as multielectron donors or acceptors, which could originate from the electrons or hole trapping inside the Cd 34 Se 20 (SPh) 28 .…”

“…The diffusion coefficient is significantly higher for a 1.2 nm diameter nanocluster. 56 This experimental result suggests that the nanoclusters behave as multielectron donors or acceptors, which could originate from the electrons or hole trapping inside the Cd 34 Se 20 (SPh) 28 . 25 This multielectron transfer process of nanoclusters could potentially trigger their decomposition upon charging during the electrochemical measurements, which we have mentioned previously.…”

A transparent flexible z-axis sensitive multi-touch panel based on colloidal ITO nanocrystals

“…This has triggered significant research efforts to develop alternatives for sputtered ITO films. 25 Resistivities of the as-prepared ITO NC films are as such very high owing to a high electron tunnel barrier imposed by the long oleate ligands surrounding the ITO NCs, and the films required post-thermal annealing treatment to be used as electrodes. Materials that are being actively developed as alternatives for sputtered ITO include graphene, 19 carbon nanotubes, 5,8,13 metal nanowires 3,4,6,7 and TCO nanoparticles 22 such as doped In 2 O 3 , ZnO, Ga 2 O 3 , CdO, etc.…”

“…2 Recent reports proposed chemically synthesized ITO nanocrystals (NCs) dispersed in organic solvents for ITO electrode fabrication, 23,24 and their surface functionalization for electrochemical applications. 25 Resistivities of the as-prepared ITO NC films are as such very high owing to a high electron tunnel barrier imposed by the long oleate ligands surrounding the ITO NCs, and the films required post-thermal annealing treatment to be used as electrodes. We, on the other hand ventured to exploit the potential of solution processed ITO NC films for transparent, flexible resistive sensor application.…”

Stepwise Solid‐Phase Synthesis and Solid‐State Electrochemistry of Redox‐Active Viologen Core/Shell‐Structured Modified Silica Materials

“…As a general strategy for the bottom‐up synthesis of functionalized materials, the immobilization of redox‐active compounds on particles, resulting in a core/shell‐structured system, combines high accessibility and simple separation of the modified material 32. The preparation of ferrocene‐terminated indium tin oxide,33 gold,34 and silica35–37 particles was reported recently. In particular, monodisperse and nonporous spherical Stöber silica particles are well established as solid supports38–42 and provide a defined geometry and surface environment.…”