Electrocrystallization of Tetrathiafulvalene Charge-Transfer Salt Nanorods on Gold Nanoparticle Seeds

Abstract

This paper describes electrochemical synthesis of nanorods of tetrathiafulvalene (TTF) charge-transfer salt on gold nanoparticle (GNP) seeds. The seed-mediated process was monitored by cyclic voltammetry, AFM, and field-emission SEM. The electrodeposition of GNPs (nucleation seeds) on highly oriented pyrolytic graphite (HOPG) electrodes was studied as a function of the electrolytic conditions. The GNP size increases with increasing HAuCl 4 concentration and decreasing applied overpotential. A morphological transition from quasi-spherical particles to dendritic aggregates occurs when the HAuCl 4 concentration increases from 0.5 to 1 mM. The electrocrystallization of (TTF)Br 0.76 on the GNP-decorated HOPG was investigated as a function of TTF concentration and GNP morphology. We observed a preferential nucleation of (TTF)Br 0.76 on the GNP seed. The seed-mediated (TTF)Br 0.76 crystals display a confined crystal morphology in comparison to those nucleated on bare HOPG. (TTF)Br 0.76 nanorods as small as 7 nm in height were nucleated on GNPs of 20 nm in height. We also observed preferential nucleation of (TTF)Br 0.76 on high-energy facets rather than on the most prominent face of the GNP. The nanoconfinement effect is attributed to the local curvature of the GNP seed that imposes an interfacial strain, thus limiting the cross-sectional dimension of the ensuing (TTF)Br 0.76 crystal. This study contributes to the understanding of electrocrystallization at the nanoscale and a solution-based method to incorporate nanorods on nanopatterns and nanodevices.

Electrodeposition of partially oxidized tetracyanoplatinate nanowires on seeds and patterns for gas sensing

“…The seed-mediated electrocrystallization of K(def )TCP was studied using AuNPs as nucleation seeds. The electrodeposition of AuNPs on HOPG electrodes was described in our previous work [20]. We found that the AuNP morphology was primarily controlled by the HAuCl 4 concentration.…”

“…In our case, the small size (or highly curved nanoparticle surface) is hypothesized to directly cause the size and shape confinement of the 1-D nanostructures [18,19]. More recently, we applied the seed-mediated mechanism for the electrocrystallization of tetrathiafulvalene (TTF) charge-transfer salt nanowires [20]. TTF nanowires with diameter as small as 7 nm were synthesized by the seedmediated mechanism.…”

Biomimetic Hydroxyapatite Composite Coatings with a Variable Morphology Mediated by Silk Fibroin and Its Derived Peptides Enhance the Bioactivity on Titanium

“…On the contrary, a high current density expedites the movement of ions near the cathode, and the nucleation and growth of HA crystals are enhanced accordingly . In addition, a high current density may give rise to a relatively high overpotential, yielding a high deposition resistance, thus promoting the growth of new crystal nuclei and inhibiting the growth of crystal particles. − Consequently, crystals tend to grow perpendicular to the surface of the cathode and form a needle-like or rod-like morphology …”

Recent Advances in Integrating 1D Nanomaterials into Chemiresistive Gas Sensor Devices

“…To overcome the manufacturing challenge, our group applies seed-mediated crystallization for precision integration of NW sensors, utilizing unique features of CTC electrochemistry. [75] Au nanoparticles (AuNPs) with well-defined size and shape were used for fundamental understanding of seed-mediated electrocrystallization of CTCs. [75a] Figure 10a,b shows AuNPs with different sizes and shapes that can be used as nucleation seeds for CTC crystallization.…”