This title appears in the Scientific Report :
2004
Please use the identifier:
http://dx.doi.org/10.1016/j.electacta.2003.06.002 in citations.
Surface Enhanced Infrared Spectroscopy - Au(111-20nm)/Sulphuric Acid - New Aspects and Challanges
Surface Enhanced Infrared Spectroscopy - Au(111-20nm)/Sulphuric Acid - New Aspects and Challanges
The structure and orientation of water molecules on Au(1 1 1-20nm) film electrodes in contact with aqueous sulphuric acid solution was studied by surface enhanced infrared reflection-absorption spectroscopy (SEIRAS) employing an attenuated total reflection (ATR) configuration (ATR-SEIRAS) with a ver...
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Personal Name(s): | Wandlowski, T. |
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Ataka, K. / Pronkin, S. / Diesing, D. | |
Contributing Institute: |
Institut für Grenzflächen und Vakuumtechnologien; ISG-3 |
Published in: | Electrochimica acta, 49 (2004) S. 1233 - 1247 |
Imprint: |
New York, NY [u.a.]
Elsevier
2004
|
Physical Description: |
1233 - 1247 |
DOI: |
10.1016/j.electacta.2003.06.002 |
Document Type: |
Journal Article |
Research Program: |
Materialien, Prozesse und Bauelemente für die Mikro- und Nanoelektronik |
Series Title: |
Electrochimica Acta
49 |
Subject (ZB): | |
Publikationsportal JuSER |
The structure and orientation of water molecules on Au(1 1 1-20nm) film electrodes in contact with aqueous sulphuric acid solution was studied by surface enhanced infrared reflection-absorption spectroscopy (SEIRAS) employing an attenuated total reflection (ATR) configuration (ATR-SEIRAS) with a vertical spectroelectrochemical cell. The spectrum of interfacial water is strongly dependent on electrode potential, ionic strength and pH. Coadsorption of hydronium ions with weakly hydrogen-bonded water molecules was found at E < E-pzc. At E > E-pzc strong hydrogen-bonding among water molecules and to coadsorbed sulphate species exists. Based on pH-dependent electrochemical, spectroscopic and in situ STM investigations, a new model is suggested to represent the ordered (root3 x root7) adlayer at maximum sulphate coverage theta = 0.2: a Zundel or hydrated hydronium ion H5O2+, in which one proton is shared between two water molecules, bridges adjacent sulphate species via hydrogen-bonds along the main diagonal of the (root3 x root7) unit cell. This alternating arrangement gives rise to a long-range ordered, 2D network of sulphate and water species interconnected by hydrogen-bonds, and capable to form hydrogen-bonds with second-layer water species. The suggested model is consistent with all experimental observations as well as predictions from quantum-chemical and molecular dynamic simulations. (C) 2003 Elsevier Ltd. All rights reserved. |