Electrodeposition of Well-Adhered Multifarious Au Particles at a Solid|Toluene|Aqueous Electrolyte Three-Phase Junction

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• 作者：Izabela Kaminska ; Martin Jonsson-Niedziolka ; Agnieszka Kaminska ; Marcin Pisarek ; Robert Ho艂yst ; Marcin Opallo ; Joanna Niedziolka-Jonsson
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：October 25, 2012
• 年：2012
• 卷：116
• 期：42
• 页码：22476-22485
• 全文大小：634K
• 年卷期：v.116,no.42(October 25, 2012)
• ISSN：1932-7455

文摘

In order to obtain uniform and reproducible surface enhanced Raman spectroscopy (SERS) platforms, a novel method for deposition of well-adhered multifarious gold particles on a tin-doped indium oxide electrode through electrogeneration at an electrode|gold compound in toluene|aqueous-electrolyte three-phase junction was developed. The electrodeposition was carried out both by double-potential-step chronoamperometry with one pulse for nucleation and one for growth of the particles, and by potentiostatic single-potential-step chronoamperometry. Both procedures give angular, multifarious Au particles with a diameter of 150 卤 40 nm. The size of the particles is independent of deposition time, after an initial growth phase, and controlled by the formation of a microemulsion at the three-phase junction. The particles are likely deposited from the microdroplets and their size is determined by the amount of gold salt in a droplet. The mechanism involves electoreduction of tetraoctylammonium tetrachloroaurate at the tin-doped indium oxide electrode followed by ion transfer across the liquid|liquid interface. The Au particles are strongly adhered to the electrode surface. The Au particle covered electrode enhances Raman scattering on the order of 10⁵鈥?0⁶ times for malachite green isothiocyanate. Surface enhanced Raman spectroscopy studies reveal that the reproducibility of the Au particle deposit is excellent both between samples (<15% RSD) and across a single sample (<12% RSD). The obtained nanoparticulate deposit was also demonstrated to show electrocatalytic activity toward dioxygen reduction.