Controlled assembly and single electron charging of monolayer protected Au144 clusters: an electrochemistry and scanning tunneling spectroscopy study
| Autor: | Marcel Mayor, H. Siegenthaler, Pavel Moreno-García, Yongchun Fu, Ulrike Fluch, Nataraju Bodappa, Thomas Wandlowski |
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| Rok vydání: | 2014 |
| Předmět: |
Aqueous solution
Chemistry Scanning tunneling spectroscopy Dispersity Analytical chemistry 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences 0104 chemical sciences 3. Good health chemistry.chemical_compound Monolayer Ionic liquid General Materials Science Differential pulse voltammetry 0210 nano-technology |
| Zdroj: | Nanoscale |
| ISSN: | 2040-3372 |
| Popis: | Single gold particles may serve as room temperature single electron memory units because of their size dependent electronic level spacing. Here, we present a proof-of-concept study by electrochemically controlled scanning probe experiments performed on tailor-made Au particles of narrow dispersity. In particular, the charge transport characteristics through chemically synthesized hexane-1-thiol and 4-pyridylbenzene-1-thiol mixed monolayer protected Au(144) clusters (MPCs) by differential pulse voltammetry (DPV) and electrochemical scanning tunneling spectroscopy (EC-STS) are reported. The pyridyl groups exposed by the Au-MPCs enable their immobilization on Pt(111) substrates. By varying the humidity during their deposition, samples coated by stacks of compact monolayers of Au-MPCs or decorated with individual, laterally separated Au-MPCs are obtained. DPV experiments with stacked monolayers of Au(144)-MPCs and EC-STS experiments with laterally separated individual Au(144)-MPCs are performed both in aqueous and ionic liquid electrolytes. Lower capacitance values were observed for individual clusters compared to ensemble clusters. This trend remains the same irrespective of the composition of the electrolyte surrounding the Au(144)-MPC. However, the resolution of the energy level spacing of the single clusters is strongly affected by the proximity of neighboring particles. |
| Databáze: | OpenAIRE |
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