In situ x-ray-diffraction and -reflectivity studies of the Au(111)/electrolyte interface: Reconstruction and anion adsorption

Journal Article · Thu Oct 15 04:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.10321· OSTI ID:7163618

Wang, J; Ocko, B M ^[1]; Davenport, A J; Isaacs, H S ^[2]

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1. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. Department of Applied Science, Brookhaven National Laboratory, Upton, New York 11973 (United States)

{ital In} {ital situ} x-ray-scattering studies of the Au(111) electrode surface have been carried out in NaF, NaCl, LiCl, CsCl, KCl, and NaBr solutions using grazing-incident-angle diffraction and reflectivity techniques. The top layer of gold atoms undergoes a reversible phase transition between the (1{times}1) bulk termination and a ({ital p}{times} {radical}3 ) uniaxial discommensuration (striped) phase on changing the electrode potential. Below the critical potential, in all solutions, {ital p}=23, which is identical to that obtained in vacuum. An ordered array of discommensuration kinks is not observed. Above the critical potential, 23{lt}{ital p}{lt}30. At sufficiently positive potentials, the surface forms an ideally terminated (111) surface. In the negative potential sweep, the reconstruction starts to reform at the critical potential. Analysis of the potential dependence of the scattered x-ray intensity with differing anions in NaF, NaCl, and NaBr solutions supports a unifying model that depends on the induced surface charge density. The transition to the (1{times}1) phase is much faster than the formation of the reconstructed phase. Cycling the potential in the reconstructed region improves the reconstructed surface order. The adsorption of anions and surface water'' at the gold interface has been investigated using specular x-ray reflectivity.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7163618
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:16; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ADSORPTION
CATALYSTS
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ELECTROCATALYSTS
ELEMENTS
GOLD
INTERFACES
METALS
MIXTURES
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
REFLECTIVITY
SCATTERING
SOLUTIONS
SORPTION
STRUCTURE FACTORS
SURFACE PROPERTIES
TRANSITION ELEMENTS
X-RAY DIFFRACTION