The Chemical Physics of Surfaces

1. Introduction.- 1.1. Surface States and Surface Sites.- 1.1.1. The Chemical Versus Electronic Representation of the Surface.- 1.1.2. The Surface State on the Band Diagram.- 1.1.3. The Fermi Energy in the Surface State Model.- 1.1.4. Need for Both Surface Site and Surface State Models.- 1.2. Bonding of Foreign Species to the Solid Surface.- 1.2.1. Types of Interaction.- 1.2.2. The Chemical Bond.- 1.2.3. Acid and Basic Surface Sites on Solids.- 1.2.4. Adsorbate Bonding on Various Solid Types.- 1.2.5. Movement of Surface Atoms: Relaxation, Reconstruction, and Relocation.- 1.2.6. The Electronic Energy Level (Surface State) of a Sorbate/Solid Complex.- 1.3. Surface Hydration on Ionic Solids.- 1.4. Surface Heterogeneity.- 2. Space Charge Effects.- 2.1. General.- 2.1.1. The Double Layer Involving Two Planar Sheets of Charge.- 2.1.2. The Space Charge due to Immobile Ions: The Depletion Layer.- 2.1.3. The Double Layer in the Band Diagram, Fermi Energy Pinning.- 2.2. Space Charge Effects with Reactive Surface Species.- 2.2.1. The Accumulation Layer.- 2.2.2. The Inversion Layer.- 2.3. Electron and Hole Transfer between the Solid and Its Surface.- 2.3.1. Basic Physical Model of Electron and Hole Capture or Injection.- 2.3.2. Electron and Hole Transfer with Large Changes in the Surface Barrier.- 2.3.3. Charge Transfer to a Surface Species in a Polar Medium: The Fluctuating Energy Level Mechanism.- 3. Experimental Methods.- 3.1. Surface Measurements Based on Electrical and Optical Techniques.- 3.1.1. Work Function.- 3.1.2. Surface Conductivity.- 3.1.3. Electroreflectance.- 3.1.4. Field Effect.- 3.1.5. Surface Photovoltage.- 3.1.6. Capacity of the Double Layer.- 3.1.7. Channel Measurements.- 3.1.8. Powder Conductance.- 3.1.9. Ellipsometry.- 3.1.10. Other Electrical and Optical Measurements.- 3.2. The Surface Spectroscopies.- 3.2.1. Ultraviolet Photoelectron Spectroscopy (UPS).- 3.2.2. Energy Loss Spectroscopy (ELS).- 3.2.3. Soft X-Ray Appearance Potential Spectroscopy (SXAPS).- 3.2.4. Field Emission (FEM).- 3.2.5. Field Ion Microscopy (FIM).- 3.2.6. Ion Neutralization Spectroscopy (INS).- 3.2.7. Low-Energy Electron Diffraction (LEED).- 3.2.8. Methods of Chemical Composition Determination for the Surface.- 3.2.9. Studies of Chemical Reactions due to the Impinging Beam.- 3.3. Chemical Measurements.- 3.3.1. Infrared Absorption.- 3.3.2. Temperature-Programmed Desorption.- 3.3.3. Adsorption of Gaseous Acids and Bases or of Indicators.- 4. The Adsorbate-Free Surface.- 4.1. Introduction.- 4.1.1. The Classification of Solids.- 4.1.2. Preparation of a Clean Surface.- 4.2. Theoretical Models.- 4.2.1. Quantum Models.- 4.2.2. Semiclassical Models: The Madelung Model for Ionic Solids.- 4.2.3. Models for Electron Pair Sharing: Lewis and Bronsted Sites.- 4.2.4. Comparison of the Various Surface States and Sites.- 4.3. Measurements on Adsorbate-Free Ionic Solids.- 4.3.1. Reconstruction on Ionic Solids.- 4.3.2. Physical Measurements on Ionic Solids.- 4.3.3. Chemical Measurements on Ionic Solids.- 4.4. Measurements on Adsorbate-Free Covalent or Metallic Solids.- 4.4.1. Reconstruction on Covalent and Metallic Solids.- 4.4.2. Electrical Measurements of Intrinsic Surface States on Covalent Solids.- 4.4.3. Measurement by the Surface Spectroscopies.- 5. Bonding of Foreign Species at the Solid Surface.- 5.1. Reconstruction and Relocation in Bonding.- 5.2. The Semiclassical Model of Bonding: The Surface Molecule.- 5.2.1. Surface Molecule Versus Rigid Band Model.- 5.2.2. Adsorbate Bonding to Covalent or Metallic Solids.- 5.2.3. Adsorbate Bonding to Ionic Solids.- 5.2.4. Multilayer Adsorption: The Development of a New Phase.- 5.3. Quantum Models of the Adsorbate/Solid Bond.- 5.3.1. Solid State Theories: The Semi-infinite Crystal.- 5.3.2. Cluster Models.- 5.3.3. The Interacting Surface Molecule (the Model Hamiltonian Analysis).- 5.3.4. Other Quantum Models.- 5.3.5. Remarks.- 5.4. Measurement of Adsorbate Surface States on Covalent or Metallic Solids.- 5.4.1. Screening Shifts and Other Inaccuracies in Measurement.- 5.4.2. Bond Angles.- 5.4.3. Surface State Energy Levels of Sorbate/Sorbent Bonds.- 5.5. The Chemistry of Surface States.- 5.5.1. Change of Surface State Energy Associated with Bonding.- 5.5.2. The Influence of a Polar Medium or Coadsorbate on the Surface State Energy.- 5.5.3. Surface States due to Multiequivalent Foreign Adsorbates.- 5.6. The Formation of Surface State Bands.- 6. Nonvolatile Foreign Additives on the Solid Surface.- 6.1. General.- 6.2. Dispersion of Additives.- 6.2.1. Techniques for Dispersing Additives.- 6.2.2. Measurement of Dispersion.- 6.2.3. Sintering of Dispersed Particles: Surface Diffusion of Adsorbates.- 6.3. The Cluster, the Transition between a Molecule and a Solid.- 6.4. The Control of Surface Properties with Additives.- 6.4.1. Theoretical Discussion.- 6.4.2. Observations of Additive Effects.- 6.5. The Real Surface.- 7. Adsorption.- 7.1. Adsorption Isotherms and Isobars.- 7.1.1. Physical Adsorption.- 7.1.2. Heat and Activation Energy of Adsorption, Irreversible Chemisorption.- 7.1.3. The Adsorbate Superstructure.- 7.2. Ionosorption on Semiconductors.- 7.2.1. The Surface State Representation of Adsorbed Species.- 7.2.2. Observations of Ionosorption.- 7.3. Adsorption with Local Bonding.- 7.3.1. Adsorption on Ionic Solids.- 7.3.2. Adsorption on Platinum.- 8. The Solid/Liquid Interface.- 8.1. Introduction.- 8.2. Theory.- 8.2.1. Double Layers and Potentials in Electrochemical Measurements.- 8.2.2. Charge Transfer between the Solid and Ions in Solution.- 8.2.3. Energy Levels of Surface Species Relative to Band Edges.- 8.3. Observations with Semiconductor Electrodes.- 8.3.1. Measurement Methods.- 8.3.2. Radical Generation (Current Doubling).- 8.3.3. Measurements of Energy Levels and Band Edges.- 8.3.4. Other Charge Transfer Measurements, Capture Cross Section.- 8.4. Comparison of the Solid/Liquid with the Solid/Gas Interface.- 9. Photoeffects at Semiconductor Surfaces.- 9.1. General.- 9.2. Simple Hole/Electron Recombination.- 9.2.1. Theory.- 9.2.2. Experimental Results.- 9.3. Photoadsorption and Photodesorption.- 9.3.1. Theory.- 9.3.2. Experimental Observations of Photoadsorption and Photodesorption.- 9.4. Photocatalysis.- 9.4.1. Photodecomposition of Adsorbed Species.- 9.4.2. Photostimulated Catalytic Reactions.- 9.5. Direct Excitation of Surface States by Photons.- 10. Surface Sites in Heterogeneous Catalysis.- 10.1. General Concepts.- 10.1.1. The Role of the Catalyst.- 10.1.2. Some Correlations in Heterogeneous Catalysis.- 10.2. Surface Sites Associated with Steps and Other Geometrical Factors.- 10.3. The Role of Acid and Basic Sites in Catalytic Reactions.- 10.4. Covalent Bonding to Coordinatively Unsaturated Metal and Cationic Sites.- 10.5. Sites in Oxidation Catalysis.- 10.5.1. Introduction.- 10.5.2. Oxygen Exchange Sites in Oxidation Catalysis.- 10.5.3. Dangling Bonds as Active Sites for Adsorption and Electron Exchange.- 10.5.4. Wide Bands as Electron Sources and Sinks: n-Type and p-Type Semiconductors.- 10.6. Examples of Oxidation Catalysis.- 10.6.1. Platinum.- 10.6.2. Partial Oxidation Catalysts: Bismuth and Iron Molybdate.- References.- Author Index.