skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer

Abstract

The growth of crystalline water films on Pt(111) and Pd(111) is investigated using temperature programmed desorption of the water films and of rare gases adsorbed on the water films. The water monolayer wets both Pt(111) and Pd(111) at all temperatures investigated (e.g. 20-155 K, for Pt(111)). However, crystalline ice films grown at higher temperatures (e.g. T>135 K) do not wet the monolayer. Similar results are obtained for crystalline ice films of D2O and H2O. Amorphous water films, which initially wet the surface, crystallize and dewet exposing the water monlayer when they are annealed at higher temperatures. Thinner films crystallize and dewet at lower temperatures than thicker films. For samples sputtered with energetic Xe atoms to prepare ice crystallites surrounded by bare Pt(111), subsequent annealing of the films causes water molecules to diffuse off the ice crystallites to reform the water monolayer. A simple model suggests that, for crystalline films grown at high temperatures, the ice crystallites are initially widely separated with typical distances between crystallites of ~14 nm or more. The experimental results are consistent with recent theory and experiments suggesting that the molecules in the water monolayer form a surface with no dangling OH bonds or lone pair electrons,more » giving rise to a hydrophobic water monolayer on both Pt(111) and Pd(111).« less

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
908944
Report Number(s):
PNNL-SA-51889
Journal ID: ISSN 0021-9606; JCPSA6; 18397; 21797; 21891; KC0301020; TRN: US200722%%826
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics, 126(11):Art. No. 114702; Journal Volume: 126; Journal Issue: 11
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; PLATINUM; PALLADIUM; SUBSTRATES; ICE; CRYSTAL GROWTH; FILMS; WETTABILITY; Environmental Molecular Sciences Laboratory

Citation Formats

Kimmel, Greg A., Petrik, Nikolay G., Dohnalek, Zdenek, and Kay, Bruce D.. Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer. United States: N. p., 2007. Web. doi:10.1063/1.2672869.
Kimmel, Greg A., Petrik, Nikolay G., Dohnalek, Zdenek, & Kay, Bruce D.. Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer. United States. doi:10.1063/1.2672869.
Kimmel, Greg A., Petrik, Nikolay G., Dohnalek, Zdenek, and Kay, Bruce D.. Wed . "Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer". United States. doi:10.1063/1.2672869.
@article{osti_908944,
title = {Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer},
author = {Kimmel, Greg A. and Petrik, Nikolay G. and Dohnalek, Zdenek and Kay, Bruce D.},
abstractNote = {The growth of crystalline water films on Pt(111) and Pd(111) is investigated using temperature programmed desorption of the water films and of rare gases adsorbed on the water films. The water monolayer wets both Pt(111) and Pd(111) at all temperatures investigated (e.g. 20-155 K, for Pt(111)). However, crystalline ice films grown at higher temperatures (e.g. T>135 K) do not wet the monolayer. Similar results are obtained for crystalline ice films of D2O and H2O. Amorphous water films, which initially wet the surface, crystallize and dewet exposing the water monlayer when they are annealed at higher temperatures. Thinner films crystallize and dewet at lower temperatures than thicker films. For samples sputtered with energetic Xe atoms to prepare ice crystallites surrounded by bare Pt(111), subsequent annealing of the films causes water molecules to diffuse off the ice crystallites to reform the water monolayer. A simple model suggests that, for crystalline films grown at high temperatures, the ice crystallites are initially widely separated with typical distances between crystallites of ~14 nm or more. The experimental results are consistent with recent theory and experiments suggesting that the molecules in the water monolayer form a surface with no dangling OH bonds or lone pair electrons, giving rise to a hydrophobic water monolayer on both Pt(111) and Pd(111).},
doi = {10.1063/1.2672869},
journal = {Journal of Chemical Physics, 126(11):Art. No. 114702},
number = 11,
volume = 126,
place = {United States},
year = {Wed Mar 21 00:00:00 EDT 2007},
month = {Wed Mar 21 00:00:00 EDT 2007}
}
  • The growth of crystalline water films on Pt(111) is investigated using rare gas physisorption. The water monolayer wets Pt(111) at all temperatures investigated (20-155 K). At low temperatures (T ≤ 120 K) where the water mobility is limited, additional water layers kinetically wet the monolayer surface. However, crystalline ice films grown at higher temperatures (T > 135 K) do not wet the water monolayer. These results are consistent with recent theory and experiments suggesting that the molecules in the water monolayer form a surface with no dangling OH bonds or lone pair electrons, giving rise to a hydrophobic water monolayermore » on Pt(111).« less
  • No abstract prepared.
  • The growth of amorphous solid water (ASW) films on Pt(111) is investigated using rare gas (e.g. Kr) physisorption. Temperature programmed desorption of Kr is sensitive to the structure of thin water films and can be used to assess the growth modes of these films. At all temperatures that are experimentally accessible (20 – 155 K), the first layer of water wets Pt(111). Over a wide temperature range (20 – 120 K), ASW films wet the substrate and grow approximately layer-by-layer for at least the first 3 layers. In contrast to the ASW films, crystalline ice films do not wet themore » water monolayer on Pt(111). Virtually identical results were obtained on epitaxial Pd(111) films grown on Pt(111). The desorption rates of thin ASW and crystalline ice films suggest that the relative free energies of the films are responsible for the different growth modes. However at low temperatures, surface relaxation or “transient mobility” is primarily responsible for the relative smoothness of the films.« less
  • The growth of amorphous solid water films on Pt (111) is investigated using rare gas physioabsorption.
  • We have used a new low-energy electron diffraction (LEED) detector, that features a low beam current electron gun, to investigate for the first time the LEED intensities arising from a water-surface adsorption system. H{sub 2}O adsorption structures are very sensitive to electron radiation damage. A disordered monolayer of H{sub 2}O molecules is formed on Pt(111) at 160 K. Upon further exposure an ordered multilayer film is grown that yields new diffraction spots. The periodicity of the diffraction pattern of the multilayer structure is compatible with the model of a molecular ice crystal. Preliminary intensity versus energy spectra of the icemore » crystal'' are presented. The film thickness is estimated to be well above 10 A.« less