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

TLDR: This poster presents a probabilistic procedure to constrain the number of particles in the response of the immune system to the presence of Tau.

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

Figures

Figure 34. TPD spectra corresponding to the desorption of phosphate as mass 47 (PO) as a function of exposure of an Fe2O3 surface to a solution containing 3 µg/mL P, pH 6.7, and 0.01 M NaCl.

Figure 61. Example of the theoretically expected dependence of the logarithm of an electrolytic ion surface equilibrium constant on the inverse of the dielectric constant for a variety of different solids.

Figure 35. Integrated TPD spectra for mass 31 (P) from titania and alumina surfaces as a function of exposure to a calcium phosphate solution containing 119 µg/mL P.

Figure 33. Phosphorus-to-metal AES peak ratios as a function of exposure to a phosphate-containing solution for the phosphate 110-eV peak to (a) the iron 651-eV peak, (b) the aluminum 60-eV peak, and (c) the titanium 387-eV peak. The iron oxide surface was exposed to a solution containing 3 µg/mL P, and the titania and alumina surfaces were exposed to a solution containing 119 µg/mL P.

Figure 27. Electric field strength (from the square root of the SHG signal) at the amorphous silica-aqueous solution interface as a function of pH. This signal stems from an “electric field-induced second harmonic” (EFISH). As the pH rises, surface silanol sites deprotonate to produce negative surface charge; the resulting electric field near the interface gives rise to an increasing EFISH signal with rising pH. The results suggest two different surface sites and are consistent with a pH of zero net proton charge of pH ) 2-3 (adapted from ref 407).

Figure 26. Interaction forces (repulsion or attraction) between a hematite (R-Fe2O3) tip over a hematite (0001) surface in 0.01 M NaCl, measured as a function of pH using an AFM. Labeled curves are calculations of EDL repulsion forces from DLVO theory, for which pKa1 and pKa2 for surface deprotonation reactions were taken from ref 405. Disagreement between calculation and experiment at low pH can be accounted for by assuming that Cl- from HCl adsorbs specifically to the surface, limiting the buildup of positive charge: >FeOH2+ + Cl- ) >FeOH2Cl, log K ) 2.45. Typical tip-sample approach rates were 6 or 12 nm s-1; faster rates can lead to hydrodynamic damping and artifactual curvature.400 Ionic strength is 0.01 M except where noted.404

Full text

University of Nebraska - Lincoln University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln
US Department of Energy Publications U.S. Department of Energy
1999
Metal Oxide Surfaces and Their Interactions with Aqueous Metal Oxide Surfaces and Their Interactions with Aqueous
Solutions and Microbial Organisms Solutions and Microbial Organisms
Gordon E. Brown Jr.
Stanford University
Victor Henrich
Yale University
William Casey
University of California
David Clark
Los Alamos National Laboratory
Carrick Eggleston
University of Wyoming
See next page for additional authors
Follow this and additional works at: https://digitalcommons.unl.edu/usdoepub
Part of the Bioresource and Agricultural Engineering Commons
Brown, Gordon E. Jr.; Henrich, Victor; Casey, William; Clark, David; Eggleston, Carrick; Andrew Felmy,
Andrew Felmy; Goodman, D. Wayne; Gratzel, Michael; Maciel, Gary; McCarthy, Maureen I.; Nealson,
Kenneth H.; Sverjensky, Dimitri; Toney, Michael; and Zachara, John M., "Metal Oxide Surfaces and Their
Interactions with Aqueous Solutions and Microbial Organisms" (1999).
US Department of Energy
Publications
. 197.
https://digitalcommons.unl.edu/usdoepub/197
This Article is brought to you for free and open access by the U.S. Department of Energy at
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in US Department of Energy
Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln.

Authors Authors
Gordon E. Brown Jr., Victor Henrich, William Casey, David Clark, Carrick Eggleston, Andrew Felmy Andrew
Felmy, D. Wayne Goodman, Michael Gratzel, Gary Maciel, Maureen I. McCarthy, Kenneth H. Nealson,
Dimitri Sverjensky, Michael Toney, and John M. Zachara
This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/
usdoepub/197

Metal Oxide Surfaces and Their Interactions with Aqueous Solutions and
Microbial Organisms
Gordon E. Brown, Jr.*
Surface and Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University,
Stanford, California 94305-2115
Victor E. Henrich*
Surface Science Laboratory, Department of Applied Physics, Yale University, New Haven, Connecticut 06520
William H. Casey
Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616
David L. Clark
G.T. Seaborg Institute for Transactinium Science, Nuclear Materials Technology Division, Los Alamos National Laboratory,
Los Alamos, New Mexico 87545
Carrick Eggleston
Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071-3006
Andrew Felmy
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352
D. Wayne Goodman
Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255
Michael Gra¨tzel
Institute of Chemical Physics, EÄ cole Polytechnique Fe´de´rale de Lausanne, CH-1015 Lausanne, Switzerland
Gary Maciel
Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523
Maureen I. McCarthy
Theory, Modeling and Simulation Group, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory,
Richland, Washington 99352
Kenneth H. Nealson
Jet Propulsion Laboratory-183-301, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099
Dimitri A. Sverjensky
Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218
Michael F. Toney
IBM Almaden Research Center, San Jose, California 95120
John M. Zachara
Environmental Molecular Sciences, Laboratory Pacific Northwest National Laboratory, Richland, Washington 99352
Received February 27, 1998 (Revised Manuscript Received November 9, 1998)
77Chem. Rev. 1999, 99, 77−174
10.1021/cr980011z CCC: $35.00 © 1999 American Chemical Society
Published on Web 12/24/1998
This article is a U.S. government work, and is not subject to copyright in the United States.

Contents
1. Introduction 78
2. Characterization of Clean Metal Oxide Surfaces 83
2.1. The Nature of Defects on Metal Oxide
Surfaces
83
2.2. Overview of UHV Surface Science Methods
Used To Study Clean Metal Oxide Surfaces
84
2.3. Geometric and Electronic Structure of Clean,
Well-Ordered Surfaces
86
2.3.1. Atomic Geometry 86
2.3.2. Electronic Structure 89
2.4. Imperfections on Oxide Surfaces 91
2.4.1. Bulk Point Defects 91
2.4.2. Steps, Kinks, and Point Defects 92
3. Water Vapor−Metal Oxide Interactions 92
3.1. Experimental Studies on Single-Crystal Metal
Oxides
93
3.1.1. MgO and CaO 93
3.1.2. R-Al
2
O
3
95
3.1.3. TiO
2
(Rutile) 95
3.1.4. TiO
2
(Anatase) 97
3.1.5. R-Fe
2
O
3
97
3.2. NMR Studies of Amorphous and
Polycrystalline Samples under Ambient
Conditions
98
3.2.1. NMR Methods 98
3.2.2. Cross-Polarization NMR as a
Surface-Selective Technique
100
3.2.3. NMR Applied to Metal Oxide Surfaces 100
4. Aqueous Solution−Metal Oxide Interfaces 103
4.1. Metal Ions in Aqueous Solutions 103
4.1.1. Complexation 104
4.1.2. Speciation 106
4.2. Solubility and Thermodynamics of Metal
Oxide Surfaces in Contact with Aqueous
Solutions
108
4.2.1. Metal Oxide Dissolution/Solubility 108
4.2.2. Thermodynamics of Surfaces in Contact
with Aqueous Solution
110
4.3. Experimental Studies of the Electrical Double
Layer
111
4.3.1. Experimental Issues Concerning the
Aqueous Solution−Metal Oxide Interface
111
4.3.2. Experimental Techniques 112
4.3.3. The Electrical Double Layer 115
4.3.4. Geometric Structure of Metal Oxide
Surfaces in Contact with Bulk Water
119
4.4. Chemical Reactions at Aqueous
Solution−Metal Oxide Interfaces
120
4.4.1. Conceptual Models of Sorption of
Aqueous Inorganic and Organic Species
at Metal Oxide Surfaces
120
4.4.2. Experimental Studies of Metal Cation and
Oxoanion Sorption at Metal
Oxide−Aqueous Solution Interfaces
122
4.4.3. Heterogeneous Redox Reactions at Metal
Oxide−Aqueous Solution Interfaces
131
4.4.4. Precipitation Reactions in the Interfacial
Region
138
4.4.5. Catalysis and Photocatalysis 139
4.4.6. Photocatalytic Effects of Oxides in the
Atmosphere
141
5. Dissolution and Growth of Metal (Hydr)oxides 141
5.1. Reactivities of Metal (Hydr)oxide Oligomers:
Models for Surface Complexes
141
5.2. Structural Similarities between Aqueous Oxo
and Hydroxo Oligomers and Simple Surfaces
141
5.3. Dissolution Rates of Metal (Hydr)oxides and
Depolymerization of Surface (Hydr)oxide
Polymers
142
6. Biotic Processes in Metal Oxide Surface
Chemistry
144
6.1. Surface Attachment and Biofilm Formation 144
6.2. Metal Oxide Dissolution (Reductive and
Nonreductive)
145
6.2.1. Nonreductive Dissolution of Metal Oxides 145
6.2.2. Reductive Dissolution of Metal Oxides 146
6.3. Metal Oxide Formation 149
6.3.1. Manganese Oxide Formation 149
6.3.2. Anaerobic Iron Oxide Formation 149
6.3.3. Magnetite Formation 150
7. Theory 150
7.1. Background 150
7.1.1. Thermodynamic Approaches 150
7.1.2. Molecular-Based Approaches 152
7.2. Example Applications 154
7.2.1. Hydroxylation of MgO (100) and CaO
(100)
154
7.2.2. Transferring Molecular Modeling Results
to Thermodynamic Models
156
7.2.3. Thermodynamic Modeling 157
8. Challenges and Future Directions 160
8.1. Surface Complexation Modeling Challenges 160
8.2. Experimental Challenges 161
8.2.1. Atomic-Scale Geometric and Electronic
Structure
161
8.2.2. Future Prospects for Experimental
Studies of Interfacial Layers
162
8.2.3. Reaction Kinetics 163
8.2.4. Particles, Colloids, and Nanostructured
Materials
163
8.2.5. Geomicrobiology 164
8.3. Theoretical Challenges 165
9. Acknowledgments 166
10. References 166
1. Introduction
During the past decade, interest in chemical reac-
tions occurring at metal oxide-aqueous solution
interfaces has increased significantly because of their
importance in a variety of fields, including atmo-
spheric chemistry, heterogeneous catalysis and pho-
tocatalysis, chemical sensing, corrosion science, en-
vironmental chemistry and geochemistry, metallurgy
and ore beneficiation, metal oxide crystal growth, soil
science, semiconductor manufacturing and cleaning,
and tribology. The metal oxide-aqueous solution
interface is reactive due to acid-base, ligand-
exchange, and/or redox chemistry involving protons
(hydronium ions), hydroxyl groups, aqueous metal
ions, and aqueous organic species and also complexes
among these species. Interfacial localization of those
species (adsorption) may result from electrostatic,
chemical complexation, and hydrophobic interactions
78 Chemical Reviews, 1999, Vol. 99, No. 1 Brown et al.

between surface and sorbate. One very important,
but only partly understood, aspect of oxide-aqueous
solution interfaces is the nature of the interfacial
solvent, in which the structure and properties of
interfacial water are perturbed relative to bulk water
(Figure 1). Oxide surface reactivity is exploited in
many industrial processes involving catalysis and
photolysis and is fundamental to environmental
Gordon E. Brown, Jr., received his B.S. in chemistry and geology in 1965
from Millsaps College, Jackson, MS, and his M.S. and Ph.D. in mineralogy
and crystallography from Virginia Polytechnic Institute & State University in
1968 and 1970, respectively. He is currently the D. W. Kirby Professor of
Earth Sciences at Stanford University and Professor and Chair of the Stanford
Synchrotron Radiation Laboratory Faculty at SLAC.
Victor E. Henrich received his Ph.D. in physics from the University of Michigan
in 1967. He is currently the Eugene Higgins Professor of Applied Science at
Yale, and a Professor in the Departments of Applied Physics and of Physics.
He is the co-author, with P. A. Cox of Oxford University, of The Surface Science
of Metal Oxides (Cambridge University Press, 1994).
William H. Casey has appointments in the Department of Land, Air and Water
Resources and in the Department of Geology at University of California, Davis;
previously he was at Sandia National Laboratories. His research concerns
the energetics and kinetics of the reactions between minerals and aqueous
solutions, and in recent work, he has determined rate coefficients for
dissociation of Al−O bonds in various dissolved aluminum complexes.
David L. Clark received a B.S. in chemistry in 1982 from the University of
Washington and a Ph.D. in inorganic chemistry in 1986 from Indiana University
under the direction of distinguished Prof. Malcolm H. Chisholm. He is presently
the Director of the Glenn T. Seaborg Institute for Transactinium Science at
Los Alamos National Laboratory.
Carrick Eggleston graduated from Dartmouth College in 1983. He worked in
the oil field and at a ski area before graduate school, received a National
Science Foundation graduate fellowship, and received a Ph.D. from Stanford
University in 1991. He is presently an Assistant Professor at the University of
Wyoming.
Andrew R. Felmy is a Staff Scientist in the Environmental Dynamics and
Simulation Directorate in the Environmental Molecular Sciences Laboratory
at PNNL. He obtained his Ph.D. in 1968 under Professor John H. Weare
from the Department of Chemistry at the University of California, San Diego
in the theoretical physical chemistry group.
D. Wayne Goodman received his Ph.D. in physical chemistry from the
University of Texas in 1974 and the following year, as a NATO Fellow, did
postdoctoral study at the Technische Hochschule, Darmstadt, Germany. He
is Professor of Chemistry at Texas A&M University and currently holds the
Robert A. Welch Chair.
Michael Gra¨tzel has been a Professor at the Institute of Physical Chemistry
at the Swiss Federal Institute of Technology in Lausanne, Switzerland since
1977. He served as Head of the Chemistry Department from 1983 to 1985
and from 1991 to 1993.
Metal Oxide Surfaces and Their Interactions Chemical Reviews, 1999, Vol. 99, No. 1 79

Frequently asked questions

Q1. What was long thought to affect the solubility of metal oxide minerals near deformed rocks?

It was long hypothesized that extended defect structures, such as dislocations and crystallographic shear planes, affected the solubility of metal oxide minerals near deformed rocks and in areas of high radiation fluxes. 

Q2. What surface materials are coated with a veneer of sorbed organic molecules?

Fe and Al oxide surfaces show high affinity for naturalorganic molecules containing carboxylate functional groups,436 and these surfaces may be coated with a veneer of sorbed organic molecules in surface soils and aquatic sediments. 

Q3. What is the direct means of studying short-range order on the surface of materials?

44,45Scanning probe microscopies (SPM) offer the most direct means of studying short-range order on the surface of materials since they can achieve (or nearly achieve) atomic resolution. 

Q4. What methods have been used to probe the aqueous solution-metal oxide interface?

In addition, a number of more conventional methods have been used to probe the aqueous solution-metal oxide interface, including NMR and EPR spectroscopies. 

Q5. What is the way to study adsorption at defect sites?

On oxides, whose stoichiometric surfaces are often relatively chemically inert, it has been possible to study adsorption at defect sites in some detail. 

Q6. What is the role of coordination chemistry in determining the mode of sorption of metal ?

the coordination chemistry of aqueous metal ions can be important in determining their mode of sorption and the reactive sites to which they can bind. 

Q7. What is the importance of characterization of defect populations before performing reactivity experiments?

It is particularly important to characterize defect populations before performing reactivity experiments, since chemical reactivity of metal oxide surfaces is very often dominated by defect sites. 

Q8. What is the threshold pressure for dissociative chemisorption of water on terrace sites?

A similar photoemission study of the interaction of water vapor with CaO (100)93 showed that the experimental threshold pressure for dissociative chemisorption of water is ≈10-9 Torr, whereas the predicted threshold pressure for dissociative chemisorption of water on terrace sites, based on a thermodynamic analysis of the reaction CaO + H2O ) Ca(OH)2, is 2.2 × 10-9 Torr.93 

Q9. What is the point of failure of transfer of information from the solution state to surfaces?

It is clear that, at some point, transfer of information from the solution state to surfaces will fail, as structures differ and as unique solvent properties near the surface become important, but this point of failure is not known.