TY  - JOUR
AU  - Wandlowski, T.
AU  - Ataka, K.
AU  - Pronkin, S.
AU  - Diesing, D.
TI  - Surface Enhanced Infrared Spectroscopy - Au(111-20nm)/Sulphuric Acid - New Aspects and Challanges
JO  - Electrochimica acta
VL  - 49
SN  - 0013-4686
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - PreJuSER-30246
SP  - 1233 - 1247
PY  - 2004
N1  - Record converted from VDB: 12.11.2012
AB  - 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.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000189226200006
DO  - DOI:10.1016/j.electacta.2003.06.002
UR  - https://juser.fz-juelich.de/record/30246
ER  -