The Interaction of Water with Solid Surfaces: Fundamental Aspects Revisited

Surface science studies of model fuel cell electrocatalysts

Structure and nanostructure in ionic liquids.

Reference LPI-ARTICLE-1999-017View record in Web of Science Record created on 2006-02-21, modified on 2017-05-12

/pdf/metal-oxide-surfaces-and-their-interactions-with-aqueous-22jt31pax0.pdf

Metal Oxide Surfaces and Their Interactions with Aqueous Solutions and Microbial Organisms.

Sum-Frequency Vibrational Spectroscopy on Water Interfaces: Polar Orientation of Water Molecules at Interfaces

THE arrangement of water molecules at charged, aqueous interfaces is an important question in electrochemistry, geochemistry and biology. Theoretical studies1–11 suggest that the molecules become arranged in several layers adjacent to a solid interface, with densities similar to that in the bulk, and that the molecules in the first layer are reoriented from oxygen-up to oxygen-down as the electrode charge changes from negative to positive. Few of these predictions have been verified experimentally12–16, however. Using X-ray scattering, we have measured the water density profile perpendicular to a silver (111) surface at two applied voltages. We find that the water molecules are ordered in layers extending about three molecular diameters from the electrode, and that the spacing between the electrode and first water layer indicates an oxygen-up (oxygen-down) average orientation for negative (positive) charge. Contrary to current models, however, we find that the first layer has a far greater density than that in bulk water. This implies that the hydrogen-bonding network is disrupted in this layer, and that the properties of the water in the layer are likely to be very different from those in the bulk.

Voltage-dependent ordering of water molecules at an electrode–electrolyte interface

Electrochemical deposition of copper on a gold electrode in sulfuric acid: resolution of the interfacial structure.

Distribution of water molecules at Ag(111)/electrolyte interface as studied with surface X-ray scattering

: Using grazing incidence geometry and a thin layer cell, x-ray scattering has been used to study the structure of electrochemically deposited monolayers of lead on silver (111) and gold (111) electrodes in-situ. For the lead monolayer deposited on sliver, the lead was found to order in a hexagonoal closed packed (hcp) geometry with the lead lattice compresssed 1.2% relative to bulk lead. A rotational epitaxy angle of 4.4 deg was observed. From the width of the first order diffraction peak, the domain size of the lead was determined to be 300 A indicating that even when deposited from a solution, the lead forms a well ordered two-dimensional solid. On a gold (111) substrate, the lead monolayer was again found to order into a hcp layer, incommensurate with the gold. The lead was compressed 0.7% relative to bulk lead, with a domain size 200 A. Keywords: X-ray electrode; Lead(Metal); Gold electrode; Interface structure; Electrodeposition.

Grazing incidence X-ray diffraction of lead monolayers at a silver (111) and gold (111) electrode/electrolyte interface

Presentation des spectres de SEXAFS en incidence rasante de la couche de Cu deposee de facon electrochimique sur une electrode Au(111) immergee en solution sous potentiel controle. Les rayons X sont polarises parallelement a la surface d'or. Analyse de la fonction de distribution radiale

Gary L. Borges

Papers

Voltage-dependent ordering of water molecules at an electrode–electrolyte interface

Electrochemical deposition of copper on a gold electrode in sulfuric acid: resolution of the interfacial structure.

Distribution of water molecules at Ag(111)/electrolyte interface as studied with surface X-ray scattering

Grazing incidence X-ray diffraction of lead monolayers at a silver (111) and gold (111) electrode/electrolyte interface

In-plane structure of underpotentially deposited copper on gold(111) determined by surface EXAFS