Springer Handbook of Inorganic Photochemistry (Springer Handbooks)

Foreword Contents About the Editors About the Section Editors Contributors Part I: Background and Fundamentals 1 Historical Development of Inorganic Photochemistry 1.1 Introduction: The Beginnings of Photochemistry 1.2 The Advent of Quantum Theory and Its Applications on Photochemistry 1.3 Instrumental Developments 1.4 The Photochemistry of Inorganic Compounds 1.5 Concluding Remarks References 2 Fundamentals of Photochemistry: Excited State Formation/Deactivation and Energy Transfer Processes 2.1 Introduction 2.2 Reaching the Excited State - Light Absorption 2.3 Deactivating the Excited State - Jablonski Diagram 2.4 Using the Energy of the Excited State - Chemical Reactions 2.4.1 Photolabilization/Photoisomerization Reactions 2.4.2 Photoredox Reactions 2.4.3 Prompt Reactions 2.5 Using the Energy of the Excited State - Energy Transfer Processes 2.5.1 Energy Transfer from Organic Molecules to Coordination Compounds 2.5.2 Energy Transfer from Coordination Compounds to Organic Molecules 2.5.3 Energy Transfer from Coordination Compounds to Coordination Compounds 2.5.4 Energy Transfer from Coordination Compounds to Other Species 2.6 Final Remarks References 3 Fundaments of Photoinduced Electron Transfer in Inorganic Molecular Systems 3.1 Brief Chronology 3.2 Comments About the Thermodynamics of Electrochemical Reactions 3.3 Electron Transfer Theory 3.4 How Does Adiabaticity Affect Electron Transfer Rates? 3.5 Thermodynamics and Marcus Inverted Region 3.6 Comprehensiveness of the Electron Transfer Field 3.7 Photoinduced Electron Transfer 3.7.1 Why (and How) Does an Excited State is Different from Its Ground State? 3.7.2 Exchange Reactions in PET 3.7.3 Role of the Excited State in Exergonic and Endergonic ET 3.7.4 How Does Adiabaticity Affect Photoinduced Electron Transfer? 3.7.5 Role of Diffusion and a Simplified Overall PET Scheme 3.8 Applications 3.8.1 Understanding Natural Photosynthesis 3.8.2 Photoinduced Proton-Coupled Electron Transfer 3.8.3 H2O Oxidation 3.8.4 CO2 Reduction 3.8.5 Photoinduced Electron Transfer in DSSC 3.9 Final Remarks References 4 Electron Transfer Processes in Heterostructured Photocatalysts 4.1 Introduction 4.2 Key Photoprocesses in Single Component Photoactive Materials 4.2.1 Absorption of Light by Solid Photocatalysts. Quantities Describing Light Absorption Used in Heterogeneous Photocatalysis Absorbance, Reflectance, Transmittance, Linear Absorption Coefficient Absorbance and Reflectance of Powders Used in Heterogeneous Photocatalysis Intrinsic (Fundamental) Absorption of Solids 4.2.2 Photogeneration, Recombination, and Trapping of Charge Carriers in Photoactive Solids Diffusion and Drift of Charge Carriers Trapping of Carriers by Defects Stationary Concentration of Photocarriers and Band-to-Band Recombination Recombination of Carriers via Defects Trapping of Carriers with Formation of Centers Similar to Color Centers Lifetimes and Concentrations of Free Charge Carriers 4.3 Heterostructured Materials: Semiconductor-Semiconductor 4.4 Heterostructured Materials: Metal-Semiconductor 4.5 Concluding Remarks References Part II: Experimental Techniques (From Steady-State to Ultrafast Methods) 5 Transient Absorption Spectroscopy in Inorganic Systems 5.1 General Introduction 5.2 Experimental Techniques: Basics 5.2.1 Nanosecond Transient Absorption Technique 5.2.2 Femtosecond Transient Absorption Technique 5.3 Latest Instrumental Developments 5.3.1 Pump-Pump-Probe 5.3.2 Basic Principles of Time-Resolved Electronic Circular Dichroism 5.3.3 Transient Absorption Spectroelectrochemistry 5.4 Applications 5.4.1 Pump-Probe Experiments 5.4.2 Multiple-Charge Photo-Accumulation by Pump-Pump-Probe Experiments 5.4.3 Combination of Transient Absorption and Electrochemistry 5.4.4 Ruthenium Complexes as Chiral Paradigms for TR-CD Spectroscopy 5.5 Concluding Remarks References 6 An Introduction to Steady-State and Time-Resolved Photoluminescence 6.1 Introduction 6.2 Molecular States: Adiabatic Approximation and the Born-Oppenheimer Expansion 6.3 Light Absorption: A Pertubative Effect 6.4 The Light-Matter Interaction: A Phenomenological Approach 6.5 The Pathways for the Relaxation 6.6 Reverse Intersystem Crossing and the Delayed Fluorescence 6.7 Emission Quantum Yields 6.8 Steady-State Photoluminescence: Measuring Emission Spectra and Emission Quantum Yield 6.9 Time-Resolved Photoluminescence: Measuring Lifetimes and the Relaxation Rates References 7 IR Absorption (Time-Resolved Infrared Spectroscopy, Raman): Tracking Vibrational Signatures of the Metal-Containing ... 7.1 Introduction 7.2 Time-Resolved Infrared Spectroscopy (TRIR) 7.2.1 Rapid-Scan and Step-Scan FTIR 7.2.2 Synchrotron Source 7.2.3 Ultrafast Transient IR 7.2.4 Transient 2DIR 7.3 Time-Resolved Raman Spectroscopy 7.3.1 Resonance Raman (RR), Transient Resonance Raman (TR2), and Time-Resolved Resonance Raman Spectroscopy (TR3) 7.3.2 Femtosecond Stimulated Raman Spectroscopy (FSRS) and its Analogs 7.4 Conclusion and Outlooks References 8 Spectroelectrochemistry 8.1 What Is Spectroelectrochemistry? 8.2 Spectroelectrochemistry Techniques 8.2.1 UV/VIS/NIR Absorption Spectroelectrochemistry 8.2.2 Infrared Absorption Spectroelectrochemistry 8.2.3 Photoluminescence Spectroelectrochemistry 8.2.4 Raman Spectroelectrochemistry 8.3 How to Perform Spectroelectrochemistry Experiments 8.3.1 UV/VIS/NIR Absorption Spectroelectrochemistry 8.3.2 IR Absorption Spectroelectrochemistry 8.3.3 Photoluminescence Spectroelectrochemistry 8.3.4 Raman Spectroelectrochemistry 8.4 Applications of Spectroelectrochemistry in Inorganic Chemistry 8.4.1 UV/VIS/NIR Absorption Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Properties of Biological and Metalloenzymatic Complexes Catalysis, Energy, Redox-Switchable Platforms, and Electrochromics 8.4.2 IR Absorption Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Catalytic Reduction of CO2 Metalloproteins 8.4.3 Photoluminescence Spectroelectrochemistry Electro-Triggered Luminescent Materials Detection and Quantification of Luminescent Compounds Fluorescent Bioprobes to Monitor Cellular Uptake Processes 8.4.4 Raman Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Properties of Biological Complexes Catalysis and Energy 8.5 Future of Spectroelectrochemistry in Inorganic Chemistry References 9 Inorganic Photoelectrochemistry from Illumination Techniques to Energy Applications 9.1 A Brief Overview and Historical Background on Photoelectrochemistry 9.2 Semiconductors: Electron Energy Levels and Energy Band Model 9.3 Photoelectrochemistry Experiences, the Quantities Measured Habitually 9.3.1 Conversion of Light to Chemical and Electrical Energy Efficiency 9.3.2 Flat-Band Potential 9.3.3 Surface States Sub-Band-Gap Illumination Approach Impedance Spectra Approach The Approach via Scanning Tunnelling Microscopy 9.4 Photoelectron Emission into Electrolytic Solution 9.4.1 From Metals into Solution 9.4.2 From Semiconductors into Solutions 9.5 Equilibrium and Interface Electrode-Electrolyte 9.6 The Traditional Theory and Calculation of the Photocurrent 9.7 Dark and Photocurrent 9.8 Illumination and Photocurrent 9.9 Semiconductor Electrodes 9.9.1 Single Crystal Electrodes 9.9.2 Polycrystalline Electrodes Electrochemical Deposition of Semiconductor Films Electroless Deposition of Semiconductor Films 9.9.3 Nanocrystalline Semiconductor Films 9.10 (Semiconductor Electrodes) Applications 9.10.1 Sensor Applications 9.10.2 Solar Cells 9.11 Photoelectrocatalysis 9.12 Photoelectrochemical Reduction of CO2 9.13 The Hydrogen Sulfide Photoelectrolysis 9.14 The Photosplitting of Water 9.15 Wastes and Photoelectrochemistry 9.16 Photoelectrochemical Devices References 10 X-Ray Photoelectron Spectroscopy (XPS): Principles and Application for the Analysis of Photoactive Materials 10.1 Introduction 10.2 X-ray Photoelectron Spectroscopy (XPS) 10.3 Surface Analysis 10.3.1 Surface Sensitivity 10.3.2 Initial State Effects 10.3.3 Final Sate Effects 10.3.4 Background Selection for Quantification 10.3.5 Limit of the Detection of the Technique 10.3.6 Influence of Adsorbed Contaminants on the Surface 10.3.7 Particle Size Determination from XPS 10.3.8 Photon Sources 10.4 XPS Analysis of Photoactive Materials 10.4.1 Titanium Oxide (TiO2) 10.4.2 Tantalum (V) Oxide (Ta2O5) 10.4.3 Cadmium Sulfide (CdS) 10.5 Conclusion References 11 X-Ray Absorption Spectroscopy (XAS) 11.1 Introduction 11.2 Interactions of X-Rays with Matter 11.2.1 X-Rays 11.2.2 Electronic Levels-Transitions 11.2.3 Interactions 11.3 X-Ray Absorption Spectroscopy 11.3.1 Introduction 11.3.2 XANES 11.3.3 EXAFS 11.3.4 Experimental Setup for XAS 11.3.5 Operando Experiments-Damages 11.4 Conclusion 11.5 Summary References 12 Photoacoustic Spectroscopy 12.1 Photoacoustic Spectroscopy: Its Principle and Characteristics 12.2 Instrumental Setups and Conditions for Photoacoustic Spectroscopy 12.3 Single-Beam Photoacoustic Spectroscopic Measurement of Titania Photocatalyst Samples 12.4 Double-Beam Photoacoustic Spectroscopy for Titania Photocatalyst Samples 12.5 Reversed Double-Beam Photoacoustic Spectroscopy for Titania Photocatalyst Samples 12.6 ERDT/CBB Patterns as a Fingerprint of Metal-Oxide Samples 12.7 Photoacoustic Spectroscopy as Useful Tool for Solid Materials: Conclusive Remarks References 13 Time Resolved Microwave Conductivity: Studying Mobile Charge-Carriers in TiO2 Photoactive Particles 13.1 Introduction 13.2 The TRMC Principle 13.3 The Experimental Setup 13.4 The TRMC Signal 13.5 Studies on Pure TiO2 13.6 Studies on Modified TiO2 13.6.1 Metal Particles Modification 13.6.2 Dye Modification 13.7 Conclusion References 14 Near Infrared Light Active Lanthanide-Doped Upconversion Nanoparticles: Recent Advances and Applications 14.1 Introduction 14.2 Basic Concepts of Upconversion in Lanthanides 14.2.1 Dopants: Sensitizers and Activators 14.2.2 Host Materials 14.2.3 Mechanisms Excited-State Absorption Energy Transfer Upconversion Cooperative Sensitization Upconversion Cross Relaxation Photon Avalanche Energy Migration-Mediated Upconversion 14.3 Synthesis Strategies and Surface Modification of UCNP 14.3.1 Synthesis of Hydrophobic UCNP 14.3.2 Direct Synthesis of Hydrophilic UCNP 14.3.3 Conversion of Hydrophobic UCNP to Hydrophilic UCNP 14.4 UCNP for Various Applications 14.4.1 Advanced Lighting, Display and Security Applications 14.4.2 Contrast Agents for Bioimaging 14.4.3 Drug Delivery Applications 14.4.4 Photocatalytic Applications 14.4.5 Sensing Applications 14.5 Summary and Future Perspective References Part III: Theoretical Modeling 15 Charge Carrier Management in Semiconductors: Modeling Charge Transport and Recombination 15.1 Introduction 15.2 Overview of Photocatalysis 15.3 Relevant Electronic Structure Methods 15.4 Modeling Charge Transport 15.4.1 Polaron Transport Polaron Electronic Structure Polaron Hopping Pathways Polaron Localization and Other Computational Considerations Polaron Examples and Applications 15.4.2 Mesoscale Modeling of Polaron Transport 15.4.3 Modeling Band Transport 15.5 Modeling Charge Recombination 15.5.1 Non-Trap-Assisted Charge Recombination 15.5.2 Trap-Assisted Recombination 15.6 Engineering Charge Transport and Recombination 15.6.1 Facet Engineering 15.6.2 Heterojunctions 15.6.3 Homojunctions 15.6.4 Defect Engineering 15.7 Conclusions and Outlook References 16 Ab Initio Modeling of Semiconductor-Water Interfaces 16.1 Introduction 16.2 Band Alignment at Interfaces 16.2.1 Introduction 16.2.2 Free Energy Perturbation Method 16.2.2.1 Thermodynamic Integration 16.2.2.2 Acidity Constants 16.2.2.3 Redox Potentials 16.2.3 Band Alignment with Computational SHE 16.2.4 Some Examples of Band Alignment at Semiconductor-Water Interfaces 16.3 Acidity of Aqueous Metal Oxide Surfaces 16.3.1 Introduction 16.3.2 DFTMD Methods for Computation of Surface Acidities 16.3.3 Surface Acidity Calculation of Aqueous Metal Oxide Surfaces 16.3.3.1 Acidity of Aqueous Rutile TiO2 Interface 16.3.3.2 Acidity of Mineral-Liquid Interface 16.3.3.3 Acidity of (α-Fe2O3)-Liquid Interface 16.4 Electric Double Layers at Semiconductor-Water Interfaces 16.4.1 Electric Double Layer Model 16.4.2 Ab Initio Modeling of Electric Double Layer 16.4.3 Calculation of Interfacial Double Layer Capacitance 16.5 Electron and Hole Localization at Semiconductor-Water Interfaces 16.5.1 Introduction 16.5.2 The Injection of Hole/Electron 16.5.3 The State of Hole/Electron and the Choice of Functional 16.5.4 Identify the State of Hole/Electron 16.5.5 Trapping Energy and Redox Ability 16.5.6 Insight into Redox Ability 16.5.7 Summary 16.6 Proton-Coupled Electron Transfer 16.6.1 Nørskov-Rossmeisl Model 16.6.2 Koper Model 16.6.3 Thermodynamics and Kinetics of PCET 16.7 Conclusions References 17 Plasmon-Coupled Resonance Energy Transfer and Photocatalysis: Theory and Application 17.1 Introduction 17.2 Plasmonic Photocatalysis: Experiments 17.2.1 Photocatalysis by Plasmonic Metals 17.2.2 Photocatalysis by Composite Metal-Semiconductor Structures 17.3 Theoretical Studies of Plasmon-Enhanced Chemistry 17.4 Plasmon-Coupled Resonance Energy Transfer: Experiments 17.5 Theoretical Studies of Plasmon-Coupled Resonance Energy Transfer 17.5.1 Rate Expressions for Electric Dipole-Electric Dipole Resonance Energy Transfer 17.5.2 Analysis of Plasmon-Coupled Resonance Energy Transfer 17.6 Conclusion Appendix A: Derivation of Quasistatic Expression of Electric Field from an Electric Dipole Appendix B: Dipole and Quadrupole Polarizability of a Sphere with a Dipole Source Appendix C: Analysis of Plasmon-Coupled Resonance Energy Transfer Using Scalar Green´s Function References Part IV: Homogeneous Systems 18 Dissociative Ligand Field-Based Photochemistry in Organometallic Compounds 18.1 Introduction 18.2 Small Molecule as Ligands 18.2.1 Amine Complexes Rh(III) Complexes Co(III) Complexes 18.2.2 Metal-Carbonyl Complexes 18.2.3 Arene and Cyclopentadienyl Complexes 18.3 Conclusions References 19 Ligand-to-Metal Charge Transfer Excited States in Organometallic Compounds 19.1 Introduction 19.2 Classification and Characterization of Electronic Transitions and Related Excited States 19.2.1 Transitions Between Molecular Orbitals, Predominantly Localized on a Metal Ion 19.2.2 Transitions Between Molecular Orbitals, Predominantly Centered on Ligands 19.2.3 Transitions Between Molecular Orbitals of Different Localization: On the Metal Ion and Ligands 19.2.4 Electron Density Transfer Between a Molecule and Environmental Species 19.3 Fundamental Properties and Applications of LMCT Excited States 19.3.1 Electric Dipole Moments and Solvatochromism A Brief Theoretical Background Positive Solvatochromism and Determination of μg, μe, and Δμ 19.3.2 Relation Between Emission Quantum Yield and Lifetime 19.3.3 Frontier Molecular Orbitals and the Paradigm Ehν ΔEredox 19.3.4 Triplet LMCT States and Triplet Energy Transfer Coordination of α-olefins by d0 Metallocenes: Computational Evidence 19.4 LMCT Excited States Based on Group III Metal Complexes 19.5 LMCT Excited States Based on Group IV Metal Complexes 19.5.1 Frontier Molecular Orbitals and (Non-)Localized Triplet LMCT States Optically Detected Magnetic Resonance (ODMR) Data Nonlocalized LMCT Excited States 19.5.2 Titanium Complexes 19.5.3 Zirconium Complexes 19.5.4 Hafnium Complexes 19.6 LMCT Excited States Based on Group V Metal Complexes 19.7 LMCT Excited States Based on Other Metallocenes: Some Cases 19.8 Closing Remarks References 20 Photoinduced Electron-Transfer in First-Row Transition Metal Complexes 20.1 Introduction 20.1.1 Basic Photophysical and Photochemical Concepts Types of Electronic Transitions 20.1.2 General Photoredox Catalytic Cycle 20.1.3 Quantification of Excited-State Processes in Photocatalysis 20.2 First-Row Transition Metal Complexes: Fundaments and Catalytic Applications 20.2.1 Scandium, Titanium, and Vanadium 20.2.2 Chromium 20.2.3 Manganese 20.2.4 Iron 20.2.5 Cobalt 20.2.6 Nickel 20.2.7 Copper 20.2.8 Zinc 20.2.9 Summary of the Properties of Selected First-Row Transition Metal Photoredox Catalysts (Fig. 20.52) 20.3 Perspectives and Conclusions References 21 Photochromic Reactions in Coordination Compounds 21.1 Introduction 21.2 Photochromic Linkage Isomerization of Coordination Compounds 21.3 Photochromic Ligands and Their Coordination Compounds 21.3.1 Photosensitized Photochromism Ligands with Photochromic Azo- or Stilbene-Like Moiety Spiropyran- or Spirooxazine-Containing Ligands Diarylethene-Containing Ligands 21.3.2 Multi-addressable and Gated Photochromism 21.4 Applications of Photochromic Coordination Compounds 21.4.1 Photoswitchable Luminescent and NLO Properties 21.4.2 Photoswitchable Catalysis 21.4.3 Photochromic Gel 21.5 Conclusion References Part V: Supramolecular Systems 22 Mechanically Interlocked Systems: Photoactive Rotaxanes and Catenanes 22.1 Introduction 22.1.1 Mechanically Interlocked Molecules 22.1.2 The Role of Inorganic Chemistry 22.2 Photoactive Interlocked Systems 22.2.1 Charge-Separation Devices 22.2.2 Antenna Systems and Switches 22.3 Photoactivated Interlocked Systems 22.3.1 Photoinduced Electron Transfer: Metal Complexes as Stations 22.3.2 Photoinduced Electron Transfer: Metal Complexes as Triggers 22.3.3 Photodissociation of Metal Complexes 22.4 Conclusion References 23 Lanthanide Supramolecular Systems 23.1 Introduction to Lanthanides 23.1.1 Electronic Properties Electronic Configuration Lanthanide Contraction Calculation of Ground State Energy Level Magnetism of Ln(III) 23.1.2 Coordination Properties 23.1.3 Optical Properties Absorption Emission 23.1.4 Antenna Effect Energy Transfer Pathways Energy Transfer Mechanisms 23.2 Photophysical Properties of Ln(III) 23.2.1 Nonradiative Quenching by Proximal Oscillators 23.2.2 Hydration State of Ln(III) 23.2.3 Luminescence Quantum Yield Relative Quantum Yield Absolute Quantum Yield Intrinsic Quantum Yield 23.2.4 Diagnosing Poor Energy Transfer 23.2.5 Interpretation of Luminescence Spectrum of Eu(III) 5D0 7F0 Transition 5D0 7F1 Transition .5D0 7F2 Transition 5D0 7F4 Transition Point Group Symmetry Assignment 23.2.6 Circularly Polarized Luminescence 23.3 Self-Assembly of Ln(III) Systems 23.3.1 Monometallic Systems β-Diketonates Pyridine-Based Ligands s-Triazine-Based Ligands 23.3.2 Polymetallic Systems Triple-Stranded Helicates Tetrahedral Cages and Cubes Wheels Metallacrowns Trefoil Knot 23.4 Applications of Ln(III) Luminescence 23.4.1 Sensors Ion Sensing Protein Sensing 23.4.2 Medical Imaging Optical Imaging Magnetic Resonance Imaging 23.4.3 OLED 23.4.4 Stimuli-Responsive Luminescence 23.4.5 Single-Molecule Magnets 23.4.6 Anti-counterfeit Tags 23.5 Conclusion References 24 Multinuclear Metal Complexes: Coordination Dendrimers, Polymers, and Coordination Cages 24.1 Dendrimers 24.1.1 Synthetic Strategies Divergent Synthesis Convergent Synthesis Comparison of Divergent and Convergent Approaches 24.1.2 Photochemical and Photophysical Properties Properties of Selected Examples 24.1.3 Dendrimers Built Around a Metal Complex as a Core Dendrimer Made of Porphyrins 24.1.4 Chemistry on the Complex 24.2 Coordination Polymers 24.2.1 Zn(II) Polymers (Type-II Polymers) Zinc (II) Polymers Based on Schiff-Bases Zn(II) Polymers Based on Polypyridine 24.2.2 Ru(II) Polymers (Type-I Polymers) Iridium (III) Polymers (Type-I and Type-II Polymers) Polymers Conjugated with Ir(III) Complexes on the Main Chain Polymers Conjugated with an CN or NN or NN Ligand of Ir Complexes on the Main Chain (Type-II Polymer) Polymers Conjugated with Ir(III) Complexes in the Side Chain (Type -I Polymers) 24.2.3 Pt (II) Containing Polymers Platinum(II)-Containing Metallopolyynes (Type-II Polymers) 24.3 Coordination Cages 24.3.1 Coordination Cages Based on Lanthanoids 24.3.2 Coordination Cages Based on Luminescent Ligands 24.3.3 Luminescent Cages Based on Metallo-Porphyrin Components 24.3.4 Photochromic Coordination Cages 24.4 Conclusions References 25 Photochemistry of Metal-Organic Frameworks 25.1 Photoactive Metal-Organic Frameworks 25.1.1 Context and Background 25.1.2 Advantages of MOFs Over Other Photoactive Materials Multicomponent Crystalline Porous 25.1.3 MOFs as Semiconductors or Molecular Crystals? 25.1.4 Absorption and Energy Transfer within MOFs 25.2 Synthesis and Structures of Photoactive MOFs 25.2.1 General Synthetic Concerns 25.2.2 Photoactive Metal Nodes The {Zn4O} Node The {Zr6} Node Titanium Nodes The {Fe3} Node Lanthanide Nodes Iridium and Ruthenium Nodes 25.2.3 Photoactive Organic Linkers Purely-Organic Linkers Metalloligand Linkers 25.2.4 Photoactive Guests 25.3 Applications of Photoactive Metal-Organic Frameworks 25.3.1 Photocatalytic Metal-Organic Frameworks 25.3.2 Luminescent Metal-Organic Frameworks 25.3.3 Upconversion and Non-linear Optics in Metal-Organic Frameworks 25.3.4 Photoresponsive MOFs 25.4 Conclusion References 26 Other Photoactive Inorganic Supramolecular Systems: Self-Assembly and Intercomponent Processes 26.1 Introduction 26.2 Intermolecular Recognition and Assemblies 26.2.1 Molecular Recognition Between Discrete Molecules 26.2.2 Soft Matter/Gels 26.2.3 Mechanochromism and Aggregation-Induced Emission 26.3 Intercomponent Electronic Energy and Electron Transfer Processes 26.3.1 Electronic Energy Transfer in Supramolecular Systems 26.3.2 Reversible Electronic Energy Transfer 26.3.3 Photoinduced Electron Transfer 26.4 Other Photoactive Multicomponent Systems and Approaches 26.5 Conclusion References Part VI: Heterogeneous Systems 27 Fundamental Principles of Semiconductor/Electrolyte Junctions 27.1 Introduction 27.2 Operation of a Semiconductor Electrode 27.2.1 Description of the Equilibrium State of a Semiconductor Immersed in Liquid Solution 27.2.2 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by an Applied Pot... Energy Band Diagrams Governing Equations 27.2.3 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by Suprabandgap I... 27.2.4 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by an Applied Pot... 27.2.5 Effect of Surface States on the Operation of a Semiconductor Electrode 27.3 Rate Constants for Heterogeneous Charge Transfer at Semiconductor/Solution Interfaces 27.3.1 Historical Context 27.3.2 Reorganization Energy 27.3.3 Fluctuating Energies of Redox Molecules in Solution and Models for Heterogeneous Charge Transfer at Semiconductor/Solut... 27.3.4 Explicit Expressions for Electron and Hole Transfer at Semiconductor/Solution Interfaces 27.3.5 Franck-Condon Factor and the Inverted Region 27.3.6 Upper Bounds on Rate Constant Values 27.4 Summary References 28 Discovery and Development of Semiconductors and Structures for Photoelectrochemical Energy Conversion 28.1 Background 28.1.1 Introduction 28.1.2 Physical Foundations: Semiconductor Physics and Photoelectrochemistry Early Discoveries and Fundamental Mechanisms The Semiconductor-Liquid Junction Charge Transport and Transfer to the Electrolyte Multijunction Photoelectrochemical Cells Performance Metrics of Semiconductor Photoelectrodes 28.1.3 Structural Principles: Roles of Electronic and Crystalline Structures Structural Origins of Bands in Solids: Relationships to Bandgaps, Band Energies, and Band Dispersion Crystal Structure to Electronic Structure Relationships of Semiconductors Interactions of Charge Carriers with the Crystal Lattice 28.2 State of the Field: Current Semiconductors and Their Properties 28.2.1 Metal Oxides Photoanodes Photocathodes 28.2.2 Metal Chalcogenides Photocathodes 28.2.3 Metal Nitrides and Oxynitrides 28.2.4 Main Group Compounds: Silicon and III-V Compounds 28.3 Concluding Thoughts: Current Challenges and Promising Pathways References 29 Advanced Understanding of Kinetics and Reaction Mechanisms on Semiconductor Surfaces 29.1 Introduction 29.2 Reaction Pathways Photogenerated Charge Carrier on Semiconductor Surface 29.2.1 Direct Charge Transfer Versus Surface Charge Trapping 29.2.2 Surface Electron-Hole Recombination 29.2.3 Surface State Charge Transfer 29.3 Some Chemically Valuable Reactions 29.3.1 Oxygen Evolution Reaction 29.3.2 Hydrogen Evolution Reactions 29.3.3 Carbon Dioxide Reduction Reaction 29.4 Key Factors Controlling the Dynamics of Charge Carriers on Semiconductor Surface 29.4.1 Surface States 29.4.2 Crystal Orientation at the Surface 29.5 Modification of Semiconductor Surfaces for Enhanced PEC Performance 29.5.1 Noncatalytic Modification 29.5.2 Catalyst Modification 29.6 Operando Characterization of Kinetics and Mechanism of Reactions on Semiconductor Surface 29.6.1 Photoelectrochemical Characterization Cyclic Voltammetry Photoelectrochemical Impedance Spectroscopy (EIS) Intensity Modulated Photocurrent Spectroscopy Dual Working Electrode Photoelectrochemistry 29.6.2 Spectroelectrochemistry UV-Vis Spectroelectrochemistry Attenuated Total Reflection Infrared Spectroscopy Ambient Pressure X-Ray Photoelectron Spectroscopy In-Situ X-Ray Absorption Spectroscopy 29.7 Summary References 30 Solid-Solid Interfaces in Photoelectrochemistry: Co-catalysts, Surface Passivation, and Corrosion Protection 30.1 Introduction 30.2 Semiconductor Corrosion and Photo-Corrosion 30.2.1 Thermodynamics of Dark Corrosion for Photoelectrochemical Materials 30.2.2 Pourbaix Diagrams, Cathodic, and Anodic Corrosion Potentials 30.2.3 Energetics of Photocorrosion 30.2.4 Surface Pourbaix Diagram and Local Corrosion 30.2.5 Kinetics for Photocorrosion 30.2.6 Effect of Defects on Local Photocorrosion 30.2.7 Passivation and Stabilization: Strategies Moving Forward 30.3 Solid-Solid Interfaces of Photocathodes 30.3.1 Co-catalysts for Photocathodes: Improving Kinetics, Charge Separation, and Surface Passivation 30.3.2 Co-catalysts as Coatings: Multifunctional Protective Coatings 30.3.3 Multifunctional Passivation Layer and Coatings 30.3.4 Protective Coatings for Materials TiO2/Catalyst Coating CdS/Catalyst Coating Solid-Solid Interface with 2D Layered Materials TiO2 and Co-catalysts with Organic Photoabsorbers 30.3.5 Co-optimization of Interfacial Layers and Co-catalysts for Photocathodes 30.4 Methods to Characterize Charge Separation, Surface-State Passivation, and Charge-Transfer Kinetics 30.4.1 Quantification of Photocurrent Carrier-Separation Efficiency (Fig. 30.4) 30.4.2 Quantification of Charge-Injection Efficiency 30.4.3 Effect of Co-catalyst Surface Layers 30.4.4 Quantifying Electron-Hole Recombination 30.4.5 Modification of Band Edge Alignment by Surface Layers 30.4.6 Photocathode/Co-catalyst Interfaces: Adaptive Junctions and Pinch-off Effect 30.5 Solid-Solid Interfaces for Photoanodes 30.5.1 Challenges of Photoanodic Corrosion Mitigation 30.5.2 Hybrid Semiconductor/Liquid Junctions: 2D Materials as Interfacial Layers 30.5.3 Metal-Coating-Semiconductor Photoanodes Oxide Coatings Tunnel Interfacial Layer as Coatings 30.5.4 Protective Coatings for Buried Heterojunction Interfaces Heterojunctions of Absorbers and Intermediate-Band Transport Coatings Catalyst on Photoanodes Without Explicit Coating 30.5.5 Photoanode/Back Contact Interfaces and Graded Compositional Doping 30.5.6 Wide Bandgap Photoanode/Co-catalyst Solid-Solid Interfaces Methods of Co-catalyst Deposition Contacts of Porous Co-catalysts and Liquids with Oxides Oxide/Coating or Oxide/Oxide Heterojunctions for Photoanodes Heterojunction or Homojunction of n-Type Photoanode Absorber and p-Type Overlayer Type II Heterojunction with n-Type Photoanode Band Edge Position Manipulation by Overlayers Heterojunction of Nitrides and Ternary Oxynitride Photoanodes 30.6 Other Cases of Solid-Solid Interfaces on Photoanodes 30.6.1 Co-optimization of Multiple Element Alloy Co-catalysts on Absorbers 30.6.2 Hybrid Composite Absorber/Coating Interface 30.7 Summary References 31 Molecular Functionalization of Semiconductor Surfaces 31.1 Introduction 31.2 Surface-Bound Molecules and the Contacting Phase 31.2.1 Surfaces Under Vacuum 31.2.2 Metallic Contacts/Schottky Junctions 31.2.3 Interfaces with Solution 31.3 Metal Chalcogenides 31.3.1 Dipole Modulation of Metal Chalcogenides 31.4 Metal Oxide Semiconductors 31.4.1 Molecular Control of Band Edge Positions on Oxide Semiconductors 31.4.2 Photoelectrosynthesis Cells 31.5 Silicon 31.5.1 Synthetic Surface Chemistry on Silicon Surfaces Silicon-Carbon Bond Formation Noncarbon Linkages 31.5.2 Dipole Tuning on Silicon 31.5.3 Catalyst Attachment on Silicon 31.6 III-V Semiconductors (GaP, GaAs, and GaInP2) 31.6.1 Dipole Manipulation on III-V Semiconductors 31.6.2 Molecular Catalyst Incorporation on III-V Semiconductors 31.7 Conclusions and Future Outlook References 32 Solar Fuels Devices: Multi-Scale Modeling and Device Design Guidelines 32.1 Introduction 32.2 Modeling on Multiple Scales 32.2.1 Macroscale Device Modeling Device Description Methodology and Governing Equations Application to H2O Splitting via Practical Photoelectrochemical Devices Component Choice Results Application to Concurrent CO2 and H2O Splitting via Practical Photoelectrochemical Devices Component Choice Results 32.2.2 Mesoscale Digitalization of the Exact Morphology Methodology and Governing Equations Application to an Anode in a Water Splitting Device Application to a Cathode in CO2 Reduction Device 32.3 Non Continuum-Scale and Coupling of Multiple Scales 32.4 Conclusions References 33 Exciton Transport and Interfacial Charge Transfer in Semiconductor Nanocrystals and Heterostructures 33.1 Introduction 33.2 Electronic Structures of NCs and Band Alignment of NC Heterostructures 33.2.1 Electronic Structures of 0D, 1D, and 2D NCs 33.2.2 Band Alignments and Examples of NC Heterostructures 33.3 Exciton Transport in 1D NRs and 2D NPLs 33.4 Single-Electron Transfer from NCs 33.4.1 Dependence on Electronic Coupling 33.4.2 Dependence on Driving Force 33.4.3 Dependence on NC Lateral Dimension 33.4.4 Hot Electron Transfer 33.5 Multi-electron Transfer from NCs 33.5.1 Lifetime of Multi-excito Foreword Contents About the Editors About the Section Editors Contributors Part I: Background and Fundamentals 1 Historical Development of Inorganic Photochemistry 1.1 Introduction: The Beginnings of Photochemistry 1.2 The Advent of Quantum Theory and Its Applications on Photochemistry 1.3 Instrumental Developments 1.4 The Photochemistry of Inorganic Compounds 1.5 Concluding Remarks References 2 Fundamentals of Photochemistry: Excited State Formation/Deactivation and Energy Transfer Processes 2.1 Introduction 2.2 Reaching the Excited State - Light Absorption 2.3 Deactivating the Excited State - Jablonski Diagram 2.4 Using the Energy of the Excited State - Chemical Reactions 2.4.1 Photolabilization/Photoisomerization Reactions 2.4.2 Photoredox Reactions 2.4.3 Prompt Reactions 2.5 Using the Energy of the Excited State - Energy Transfer Processes 2.5.1 Energy Transfer from Organic Molecules to Coordination Compounds 2.5.2 Energy Transfer from Coordination Compounds to Organic Molecules 2.5.3 Energy Transfer from Coordination Compounds to Coordination Compounds 2.5.4 Energy Transfer from Coordination Compounds to Other Species 2.6 Final Remarks References 3 Fundaments of Photoinduced Electron Transfer in Inorganic Molecular Systems 3.1 Brief Chronology 3.2 Comments About the Thermodynamics of Electrochemical Reactions 3.3 Electron Transfer Theory 3.4 How Does Adiabaticity Affect Electron Transfer Rates? 3.5 Thermodynamics and Marcus Inverted Region 3.6 Comprehensiveness of the Electron Transfer Field 3.7 Photoinduced Electron Transfer 3.7.1 Why (and How) Does an Excited State is Different from Its Ground State? 3.7.2 Exchange Reactions in PET 3.7.3 Role of the Excited State in Exergonic and Endergonic ET 3.7.4 How Does Adiabaticity Affect Photoinduced Electron Transfer? 3.7.5 Role of Diffusion and a Simplified Overall PET Scheme 3.8 Applications 3.8.1 Understanding Natural Photosynthesis 3.8.2 Photoinduced Proton-Coupled Electron Transfer 3.8.3 H2O Oxidation 3.8.4 CO2 Reduction 3.8.5 Photoinduced Electron Transfer in DSSC 3.9 Final Remarks References 4 Electron Transfer Processes in Heterostructured Photocatalysts 4.1 Introduction 4.2 Key Photoprocesses in Single Component Photoactive Materials 4.2.1 Absorption of Light by Solid Photocatalysts. Quantities Describing Light Absorption Used in Heterogeneous Photocatalysis Absorbance, Reflectance, Transmittance, Linear Absorption Coefficient Absorbance and Reflectance of Powders Used in Heterogeneous Photocatalysis Intrinsic (Fundamental) Absorption of Solids 4.2.2 Photogeneration, Recombination, and Trapping of Charge Carriers in Photoactive Solids Diffusion and Drift of Charge Carriers Trapping of Carriers by Defects Stationary Concentration of Photocarriers and Band-to-Band Recombination Recombination of Carriers via Defects Trapping of Carriers with Formation of Centers Similar to Color Centers Lifetimes and Concentrations of Free Charge Carriers 4.3 Heterostructured Materials: Semiconductor-Semiconductor 4.4 Heterostructured Materials: Metal-Semiconductor 4.5 Concluding Remarks References Part II: Experimental Techniques (From Steady-State to Ultrafast Methods) 5 Transient Absorption Spectroscopy in Inorganic Systems 5.1 General Introduction 5.2 Experimental Techniques: Basics 5.2.1 Nanosecond Transient Absorption Technique 5.2.2 Femtosecond Transient Absorption Technique 5.3 Latest Instrumental Developments 5.3.1 Pump-Pump-Probe 5.3.2 Basic Principles of Time-Resolved Electronic Circular Dichroism 5.3.3 Transient Absorption Spectroelectrochemistry 5.4 Applications 5.4.1 Pump-Probe Experiments 5.4.2 Multiple-Charge Photo-Accumulation by Pump-Pump-Probe Experiments 5.4.3 Combination of Transient Absorption and Electrochemistry 5.4.4 Ruthenium Complexes as Chiral Paradigms for TR-CD Spectroscopy 5.5 Concluding Remarks References 6 An Introduction to Steady-State and Time-Resolved Photoluminescence 6.1 Introduction 6.2 Molecular States: Adiabatic Approximation and the Born-Oppenheimer Expansion 6.3 Light Absorption: A Pertubative Effect 6.4 The Light-Matter Interaction: A Phenomenological Approach 6.5 The Pathways for the Relaxation 6.6 Reverse Intersystem Crossing and the Delayed Fluorescence 6.7 Emission Quantum Yields 6.8 Steady-State Photoluminescence: Measuring Emission Spectra and Emission Quantum Yield 6.9 Time-Resolved Photoluminescence: Measuring Lifetimes and the Relaxation Rates References 7 IR Absorption (Time-Resolved Infrared Spectroscopy, Raman): Tracking Vibrational Signatures of the Metal-Containing ... 7.1 Introduction 7.2 Time-Resolved Infrared Spectroscopy (TRIR) 7.2.1 Rapid-Scan and Step-Scan FTIR 7.2.2 Synchrotron Source 7.2.3 Ultrafast Transient IR 7.2.4 Transient 2DIR 7.3 Time-Resolved Raman Spectroscopy 7.3.1 Resonance Raman (RR), Transient Resonance Raman (TR2), and Time-Resolved Resonance Raman Spectroscopy (TR3) 7.3.2 Femtosecond Stimulated Raman Spectroscopy (FSRS) and its Analogs 7.4 Conclusion and Outlooks References 8 Spectroelectrochemistry 8.1 What Is Spectroelectrochemistry? 8.2 Spectroelectrochemistry Techniques 8.2.1 UV/VIS/NIR Absorption Spectroelectrochemistry 8.2.2 Infrared Absorption Spectroelectrochemistry 8.2.3 Photoluminescence Spectroelectrochemistry 8.2.4 Raman Spectroelectrochemistry 8.3 How to Perform Spectroelectrochemistry Experiments 8.3.1 UV/VIS/NIR Absorption Spectroelectrochemistry 8.3.2 IR Absorption Spectroelectrochemistry 8.3.3 Photoluminescence Spectroelectrochemistry 8.3.4 Raman Spectroelectrochemistry 8.4 Applications of Spectroelectrochemistry in Inorganic Chemistry 8.4.1 UV/VIS/NIR Absorption Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Properties of Biological and Metalloenzymatic Complexes Catalysis, Energy, Redox-Switchable Platforms, and Electrochromics 8.4.2 IR Absorption Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Catalytic Reduction of CO2 Metalloproteins 8.4.3 Photoluminescence Spectroelectrochemistry Electro-Triggered Luminescent Materials Detection and Quantification of Luminescent Compounds Fluorescent Bioprobes to Monitor Cellular Uptake Processes 8.4.4 Raman Spectroelectrochemistry Properties of Organometallic and Coordination Complexes Properties of Biological Complexes Catalysis and Energy 8.5 Future of Spectroelectrochemistry in Inorganic Chemistry References 9 Inorganic Photoelectrochemistry from Illumination Techniques to Energy Applications 9.1 A Brief Overview and Historical Background on Photoelectrochemistry 9.2 Semiconductors: Electron Energy Levels and Energy Band Model 9.3 Photoelectrochemistry Experiences, the Quantities Measured Habitually 9.3.1 Conversion of Light to Chemical and Electrical Energy Efficiency 9.3.2 Flat-Band Potential 9.3.3 Surface States Sub-Band-Gap Illumination Approach Impedance Spectra Approach The Approach via Scanning Tunnelling Microscopy 9.4 Photoelectron Emission into Electrolytic Solution 9.4.1 From Metals into Solution 9.4.2 From Semiconductors into Solutions 9.5 Equilibrium and Interface Electrode-Electrolyte 9.6 The Traditional Theory and Calculation of the Photocurrent 9.7 Dark and Photocurrent 9.8 Illumination and Photocurrent 9.9 Semiconductor Electrodes 9.9.1 Single Crystal Electrodes 9.9.2 Polycrystalline Electrodes Electrochemical Deposition of Semiconductor Films Electroless Deposition of Semiconductor Films 9.9.3 Nanocrystalline Semiconductor Films 9.10 (Semiconductor Electrodes) Applications 9.10.1 Sensor Applications 9.10.2 Solar Cells 9.11 Photoelectrocatalysis 9.12 Photoelectrochemical Reduction of CO2 9.13 The Hydrogen Sulfide Photoelectrolysis 9.14 The Photosplitting of Water 9.15 Wastes and Photoelectrochemistry 9.16 Photoelectrochemical Devices References 10 X-Ray Photoelectron Spectroscopy (XPS): Principles and Application for the Analysis of Photoactive Materials 10.1 Introduction 10.2 X-ray Photoelectron Spectroscopy (XPS) 10.3 Surface Analysis 10.3.1 Surface Sensitivity 10.3.2 Initial State Effects 10.3.3 Final Sate Effects 10.3.4 Background Selection for Quantification 10.3.5 Limit of the Detection of the Technique 10.3.6 Influence of Adsorbed Contaminants on the Surface 10.3.7 Particle Size Determination from XPS 10.3.8 Photon Sources 10.4 XPS Analysis of Photoactive Materials 10.4.1 Titanium Oxide (TiO2) 10.4.2 Tantalum (V) Oxide (Ta2O5) 10.4.3 Cadmium Sulfide (CdS) 10.5 Conclusion References 11 X-Ray Absorption Spectroscopy (XAS) 11.1 Introduction 11.2 Interactions of X-Rays with Matter 11.2.1 X-Rays 11.2.2 Electronic Levels-Transitions 11.2.3 Interactions 11.3 X-Ray Absorption Spectroscopy 11.3.1 Introduction 11.3.2 XANES 11.3.3 EXAFS 11.3.4 Experimental Setup for XAS 11.3.5 Operando Experiments-Damages 11.4 Conclusion 11.5 Summary References 12 Photoacoustic Spectroscopy 12.1 Photoacoustic Spectroscopy: Its Principle and Characteristics 12.2 Instrumental Setups and Conditions for Photoacoustic Spectroscopy 12.3 Single-Beam Photoacoustic Spectroscopic Measurement of Titania Photocatalyst Samples 12.4 Double-Beam Photoacoustic Spectroscopy for Titania Photocatalyst Samples 12.5 Reversed Double-Beam Photoacoustic Spectroscopy for Titania Photocatalyst Samples 12.6 ERDT/CBB Patterns as a Fingerprint of Metal-Oxide Samples 12.7 Photoacoustic Spectroscopy as Useful Tool for Solid Materials: Conclusive Remarks References 13 Time Resolved Microwave Conductivity: Studying Mobile Charge-Carriers in TiO2 Photoactive Particles 13.1 Introduction 13.2 The TRMC Principle 13.3 The Experimental Setup 13.4 The TRMC Signal 13.5 Studies on Pure TiO2 13.6 Studies on Modified TiO2 13.6.1 Metal Particles Modification 13.6.2 Dye Modification 13.7 Conclusion References 14 Near Infrared Light Active Lanthanide-Doped Upconversion Nanoparticles: Recent Advances and Applications 14.1 Introduction 14.2 Basic Concepts of Upconversion in Lanthanides 14.2.1 Dopants: Sensitizers and Activators 14.2.2 Host Materials 14.2.3 Mechanisms Excited-State Absorption Energy Transfer Upconversion Cooperative Sensitization Upconversion Cross Relaxation Photon Avalanche Energy Migration-Mediated Upconversion 14.3 Synthesis Strategies and Surface Modification of UCNP 14.3.1 Synthesis of Hydrophobic UCNP 14.3.2 Direct Synthesis of Hydrophilic UCNP 14.3.3 Conversion of Hydrophobic UCNP to Hydrophilic UCNP 14.4 UCNP for Various Applications 14.4.1 Advanced Lighting, Display and Security Applications 14.4.2 Contrast Agents for Bioimaging 14.4.3 Drug Delivery Applications 14.4.4 Photocatalytic Applications 14.4.5 Sensing Applications 14.5 Summary and Future Perspective References Part III: Theoretical Modeling 15 Charge Carrier Management in Semiconductors: Modeling Charge Transport and Recombination 15.1 Introduction 15.2 Overview of Photocatalysis 15.3 Relevant Electronic Structure Methods 15.4 Modeling Charge Transport 15.4.1 Polaron Transport Polaron Electronic Structure Polaron Hopping Pathways Polaron Localization and Other Computational Considerations Polaron Examples and Applications 15.4.2 Mesoscale Modeling of Polaron Transport 15.4.3 Modeling Band Transport 15.5 Modeling Charge Recombination 15.5.1 Non-Trap-Assisted Charge Recombination 15.5.2 Trap-Assisted Recombination 15.6 Engineering Charge Transport and Recombination 15.6.1 Facet Engineering 15.6.2 Heterojunctions 15.6.3 Homojunctions 15.6.4 Defect Engineering 15.7 Conclusions and Outlook References 16 Ab Initio Modeling of Semiconductor-Water Interfaces 16.1 Introduction 16.2 Band Alignment at Interfaces 16.2.1 Introduction 16.2.2 Free Energy Perturbation Method 16.2.2.1 Thermodynamic Integration 16.2.2.2 Acidity Constants 16.2.2.3 Redox Potentials 16.2.3 Band Alignment with Computational SHE 16.2.4 Some Examples of Band Alignment at Semiconductor-Water Interfaces 16.3 Acidity of Aqueous Metal Oxide Surfaces 16.3.1 Introduction 16.3.2 DFTMD Methods for Computation of Surface Acidities 16.3.3 Surface Acidity Calculation of Aqueous Metal Oxide Surfaces 16.3.3.1 Acidity of Aqueous Rutile TiO2 Interface 16.3.3.2 Acidity of Mineral-Liquid Interface 16.3.3.3 Acidity of (α-Fe2O3)-Liquid Interface 16.4 Electric Double Layers at Semiconductor-Water Interfaces 16.4.1 Electric Double Layer Model 16.4.2 Ab Initio Modeling of Electric Double Layer 16.4.3 Calculation of Interfacial Double Layer Capacitance 16.5 Electron and Hole Localization at Semiconductor-Water Interfaces 16.5.1 Introduction 16.5.2 The Injection of Hole/Electron 16.5.3 The State of Hole/Electron and the Choice of Functional 16.5.4 Identify the State of Hole/Electron 16.5.5 Trapping Energy and Redox Ability 16.5.6 Insight into Redox Ability 16.5.7 Summary 16.6 Proton-Coupled Electron Transfer 16.6.1 Nørskov-Rossmeisl Model 16.6.2 Koper Model 16.6.3 Thermodynamics and Kinetics of PCET 16.7 Conclusions References 17 Plasmon-Coupled Resonance Energy Transfer and Photocatalysis: Theory and Application 17.1 Introduction 17.2 Plasmonic Photocatalysis: Experiments 17.2.1 Photocatalysis by Plasmonic Metals 17.2.2 Photocatalysis by Composite Metal-Semiconductor Structures 17.3 Theoretical Studies of Plasmon-Enhanced Chemistry 17.4 Plasmon-Coupled Resonance Energy Transfer: Experiments 17.5 Theoretical Studies of Plasmon-Coupled Resonance Energy Transfer 17.5.1 Rate Expressions for Electric Dipole-Electric Dipole Resonance Energy Transfer 17.5.2 Analysis of Plasmon-Coupled Resonance Energy Transfer 17.6 Conclusion Appendix A: Derivation of Quasistatic Expression of Electric Field from an Electric Dipole Appendix B: Dipole and Quadrupole Polarizability of a Sphere with a Dipole Source Appendix C: Analysis of Plasmon-Coupled Resonance Energy Transfer Using Scalar Green ́s Function References Part IV: Homogeneous Systems 18 Dissociative Ligand Field-Based Photochemistry in Organometallic Compounds 18.1 Introduction 18.2 Small Molecule as Ligands 18.2.1 Amine Complexes Rh(III) Complexes Co(III) Complexes 18.2.2 Metal-Carbonyl Complexes 18.2.3 Arene and Cyclopentadienyl Complexes 18.3 Conclusions References 19 Ligand-to-Metal Charge Transfer Excited States in Organometallic Compounds 19.1 Introduction 19.2 Classification and Characterization of Electronic Transitions and Related Excited States 19.2.1 Transitions Between Molecular Orbitals, Predominantly Localized on a Metal Ion 19.2.2 Transitions Between Molecular Orbitals, Predominantly Centered on Ligands 19.2.3 Transitions Between Molecular Orbitals of Different Localization: On the Metal Ion and Ligands 19.2.4 Electron Density Transfer Between a Molecule and Environmental Species 19.3 Fundamental Properties and Applications of LMCT Excited States 19.3.1 Electric Dipole Moments and Solvatochromism A Brief Theoretical Background Positive Solvatochromism and Determination of μg, μe, and Δμ 19.3.2 Relation Between Emission Quantum Yield and Lifetime 19.3.3 Frontier Molecular Orbitals and the Paradigm Ehν ΔEredox 19.3.4 Triplet LMCT States and Triplet Energy Transfer Coordination of α-olefins by d0 Metallocenes: Computational Evidence 19.4 LMCT Excited States Based on Group III Metal Complexes 19.5 LMCT Excited States Based on Group IV Metal Complexes 19.5.1 Frontier Molecular Orbitals and (Non-)Localized Triplet LMCT States Optically Detected Magnetic Resonance (ODMR) Data Nonlocalized LMCT Excited States 19.5.2 Titanium Complexes 19.5.3 Zirconium Complexes 19.5.4 Hafnium Complexes 19.6 LMCT Excited States Based on Group V Metal Complexes 19.7 LMCT Excited States Based on Other Metallocenes: Some Cases 19.8 Closing Remarks References 20 Photoinduced Electron-Transfer in First-Row Transition Metal Complexes 20.1 Introduction 20.1.1 Basic Photophysical and Photochemical Concepts Types of Electronic Transitions 20.1.2 General Photoredox Catalytic Cycle 20.1.3 Quantification of Excited-State Processes in Photocatalysis 20.2 First-Row Transition Metal Complexes: Fundaments and Catalytic Applications 20.2.1 Scandium, Titanium, and Vanadium 20.2.2 Chromium 20.2.3 Manganese 20.2.4 Iron 20.2.5 Cobalt 20.2.6 Nickel 20.2.7 Copper 20.2.8 Zinc 20.2.9 Summary of the Properties of Selected First-Row Transition Metal Photoredox Catalysts (Fig. 20.52) 20.3 Perspectives and Conclusions References 21 Photochromic Reactions in Coordination Compounds 21.1 Introduction 21.2 Photochromic Linkage Isomerization of Coordination Compounds 21.3 Photochromic Ligands and Their Coordination Compounds 21.3.1 Photosensitized Photochromism Ligands with Photochromic Azo- or Stilbene-Like Moiety Spiropyran- or Spirooxazine-Containing Ligands Diarylethene-Containing Ligands 21.3.2 Multi-addressable and Gated Photochromism 21.4 Applications of Photochromic Coordination Compounds 21.4.1 Photoswitchable Luminescent and NLO Properties 21.4.2 Photoswitchable Catalysis 21.4.3 Photochromic Gel 21.5 Conclusion References Part V: Supramolecular Systems 22 Mechanically Interlocked Systems: Photoactive Rotaxanes and Catenanes 22.1 Introduction 22.1.1 Mechanically Interlocked Molecules 22.1.2 The Role of Inorganic Chemistry 22.2 Photoactive Interlocked Systems 22.2.1 Charge-Separation Devices 22.2.2 Antenna Systems and Switches 22.3 Photoactivated Interlocked Systems 22.3.1 Photoinduced Electron Transfer: Metal Complexes as Stations 22.3.2 Photoinduced Electron Transfer: Metal Complexes as Triggers 22.3.3 Photodissociation of Metal Complexes 22.4 Conclusion References 23 Lanthanide Supramolecular Systems 23.1 Introduction to Lanthanides 23.1.1 Electronic Properties Electronic Configuration Lanthanide Contraction Calculation of Ground State Energy Level Magnetism of Ln(III) 23.1.2 Coordination Properties 23.1.3 Optical Properties Absorption Emission 23.1.4 Antenna Effect Energy Transfer Pathways Energy Transfer Mechanisms 23.2 Photophysical Properties of Ln(III) 23.2.1 Nonradiative Quenching by Proximal Oscillators 23.2.2 Hydration State of Ln(III) 23.2.3 Luminescence Quantum Yield Relative Quantum Yield Absolute Quantum Yield Intrinsic Quantum Yield 23.2.4 Diagnosing Poor Energy Transfer 23.2.5 Interpretation of Luminescence Spectrum of Eu(III) 5D0 7F0 Transition 5D0 7F1 Transition .5D0 7F2 Transition 5D0 7F4 Transition Point Group Symmetry Assignment 23.2.6 Circularly Polarized Luminescence 23.3 Self-Assembly of Ln(III) Systems 23.3.1 Monometallic Systems β-Diketonates Pyridine-Based Ligands s-Triazine-Based Ligands 23.3.2 Polymetallic Systems Triple-Stranded Helicates Tetrahedral Cages and Cubes Wheels Metallacrowns Trefoil Knot 23.4 Applications of Ln(III) Luminescence 23.4.1 Sensors Ion Sensing Protein Sensing 23.4.2 Medical Imaging Optical Imaging Magnetic Resonance Imaging 23.4.3 OLED 23.4.4 Stimuli-Responsive Luminescence 23.4.5 Single-Molecule Magnets 23.4.6 Anti-counterfeit Tags 23.5 Conclusion References 24 Multinuclear Metal Complexes: Coordination Dendrimers, Polymers, and Coordination Cages 24.1 Dendrimers 24.1.1 Synthetic Strategies Divergent Synthesis Convergent Synthesis Comparison of Divergent and Convergent Approaches 24.1.2 Photochemical and Photophysical Properties Properties of Selected Examples 24.1.3 Dendrimers Built Around a Metal Complex as a Core Dendrimer Made of Porphyrins 24.1.4 Chemistry on the Complex 24.2 Coordination Polymers 24.2.1 Zn(II) Polymers (Type-II Polymers) Zinc (II) Polymers Based on Schiff-Bases Zn(II) Polymers Based on Polypyridine 24.2.2 Ru(II) Polymers (Type-I Polymers) Iridium (III) Polymers (Type-I and Type-II Polymers) Polymers Conjugated with Ir(III) Complexes on the Main Chain Polymers Conjugated with an CN or NN or NN Ligand of Ir Complexes on the Main Chain (Type-II Polymer) Polymers Conjugated with Ir(III) Complexes in the Side Chain (Type -I Polymers) 24.2.3 Pt (II) Containing Polymers Platinum(II)-Containing Metallopolyynes (Type-II Polymers) 24.3 Coordination Cages 24.3.1 Coordination Cages Based on Lanthanoids 24.3.2 Coordination Cages Based on Luminescent Ligands 24.3.3 Luminescent Cages Based on Metallo-Porphyrin Components 24.3.4 Photochromic Coordination Cages 24.4 Conclusions References 25 Photochemistry of Metal-Organic Frameworks 25.1 Photoactive Metal-Organic Frameworks 25.1.1 Context and Background 25.1.2 Advantages of MOFs Over Other Photoactive Materials Multicomponent Crystalline Porous 25.1.3 MOFs as Semiconductors or Molecular Crystals? 25.1.4 Absorption and Energy Transfer within MOFs 25.2 Synthesis and Structures of Photoactive MOFs 25.2.1 General Synthetic Concerns 25.2.2 Photoactive Metal Nodes The {Zn4O} Node The {Zr6} Node Titanium Nodes The {Fe3} Node Lanthanide Nodes Iridium and Ruthenium Nodes 25.2.3 Photoactive Organic Linkers Purely-Organic Linkers Metalloligand Linkers 25.2.4 Photoactive Guests 25.3 Applications of Photoactive Metal-Organic Frameworks 25.3.1 Photocatalytic Metal-Organic Frameworks 25.3.2 Luminescent Metal-Organic Frameworks 25.3.3 Upconversion and Non-linear Optics in Metal-Organic Frameworks 25.3.4 Photoresponsive MOFs 25.4 Conclusion References 26 Other Photoactive Inorganic Supramolecular Systems: Self-Assembly and Intercomponent Processes 26.1 Introduction 26.2 Intermolecular Recognition and Assemblies 26.2.1 Molecular Recognition Between Discrete Molecules 26.2.2 Soft Matter/Gels 26.2.3 Mechanochromism and Aggregation-Induced Emission 26.3 Intercomponent Electronic Energy and Electron Transfer Processes 26.3.1 Electronic Energy Transfer in Supramolecular Systems 26.3.2 Reversible Electronic Energy Transfer 26.3.3 Photoinduced Electron Transfer 26.4 Other Photoactive Multicomponent Systems and Approaches 26.5 Conclusion References Part VI: Heterogeneous Systems 27 Fundamental Principles of Semiconductor/Electrolyte Junctions 27.1 Introduction 27.2 Operation of a Semiconductor Electrode 27.2.1 Description of the Equilibrium State of a Semiconductor Immersed in Liquid Solution 27.2.2 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by an Applied Pot... Energy Band Diagrams Governing Equations 27.2.3 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by Suprabandgap I... 27.2.4 Steady-State Condition of a Semiconductor Immersed in Liquid Solution Perturbed Away from Equilibrium by an Applied Pot... 27.2.5 Effect of Surface States on the Operation of a Semiconductor Electrode 27.3 Rate Constants for Heterogeneous Charge Transfer at Semiconductor/Solution Interfaces 27.3.1 Historical Context 27.3.2 Reorganization Energy 27.3.3 Fluctuating Energies of Redox Molecules in Solution and Models for Heterogeneous Charge Transfer at Semiconductor/Solut... 27.3.4 Explicit Expressions for Electron and Hole Transfer at Semiconductor/Solution Interfaces 27.3.5 Franck-Condon Factor and the Inverted Region 27.3.6 Upper Bounds on Rate Constant Values 27.4 Summary References 28 Discovery and Development of Semiconductors and Structures for Photoelectrochemical Energy Conversion 28.1 Background 28.1.1 Introduction 28.1.2 Physical Foundations: Semiconductor Physics and Photoelectrochemistry Early Discoveries and Fundamental Mechanisms The Semiconductor-Liquid Junction Charge Transport and Transfer to the Electrolyte Multijunction Photoelectrochemical Cells Performance Metrics of Semiconductor Photoelectrodes 28.1.3 Structural Principles: Roles of Electronic and Crystalline Structures Structural Origins of Bands in Solids: Relationships to Bandgaps, Band Energies, and Band Dispersion Crystal Structure to Electronic Structure Relationships of Semiconductors Interactions of Charge Carriers with the Crystal Lattice 28.2 State of the Field: Current Semiconductors and Their Properties 28.2.1 Metal Oxides Photoanodes Photocathodes 28.2.2 Metal Chalcogenides Photocathodes 28.2.3 Metal Nitrides and Oxynitrides 28.2.4 Main Group Compounds: Silicon and III-V Compounds 28.3 Concluding Thoughts: Current Challenges and Promising Pathways References 29 Advanced Understanding of Kinetics and Reaction Mechanisms on Semiconductor Surfaces 29.1 Introduction 29.2 Reaction Pathways Photogenerated Charge Carrier on Semiconductor Surface 29.2.1 Direct Charge Transfer Versus Surface Charge Trapping 29.2.2 Surface Electron-Hole Recombination 29.2.3 Surface State Charge Transfer 29.3 Some Chemically Valuable Reactions 29.3.1 Oxygen Evolution Reaction 29.3.2 Hydrogen Evolution Reactions 29.3.3 Carbon Dioxide Reduction Reaction 29.4 Key Factors Controlling the Dynamics of Charge Carriers on Semiconductor Surface 29.4.1 Surface States 29.4.2 Crystal Orientation at the Surface 29.5 Modification of Semiconductor Surfaces for Enhanced PEC Performance 29.5.1 Noncatalytic Modification 29.5.2 Catalyst Modification 29.6 Operando Characterization of Kinetics and Mechanism of Reactions on Semiconductor Surface 29.6.1 Photoelectrochemical Characterization Cyclic Voltammetry Photoelectrochemical Impedance Spectroscopy (EIS) Intensity Modulated Photocurrent Spectroscopy Dual Working Electrode Photoelectrochemistry 29.6.2 Spectroelectrochemistry UV-Vis Spectroelectrochemistry Attenuated Total Reflection Infrared Spectroscopy Ambient Pressure X-Ray Photoelectron Spectroscopy In-Situ X-Ray Absorption Spectroscopy 29.7 Summary References 30 Solid-Solid Interfaces in Photoelectrochemistry: Co-catalysts, Surface Passivation, and Corrosion Protection 30.1 Introduction 30.2 Semiconductor Corrosion and Photo-Corrosion 30.2.1 Thermodynamics of Dark Corrosion for Photoelectrochemical Materials 30.2.2 Pourbaix Diagrams, Cathodic, and Anodic Corrosion Potentials 30.2.3 Energetics of Photocorrosion 30.2.4 Surface Pourbaix Diagram and Local Corrosion 30.2.5 Kinetics for Photocorrosion 30.2.6 Effect of Defects on Local Photocorrosion 30.2.7 Passivation and Stabilization: Strategies Moving Forward 30.3 Solid-Solid Interfaces of Photocathodes 30.3.1 Co-catalysts for Photocathodes: Improving Kinetics, Charge Separation, and Surface Passivation 30.3.2 Co-catalysts as Coatings: Multifunctional Protective Coatings 30.3.3 Multifunctional Passivation Layer and Coatings 30.3.4 Protective Coatings for Materials TiO2/Catalyst Coating CdS/Catalyst Coating Solid-Solid Interface with 2D Layered Materials TiO2 and Co-catalysts with Organic Photoabsorbers 30.3.5 Co-optimization of Interfacial Layers and Co-catalysts for Photocathodes 30.4 Methods to Characterize Charge Separation, Surface-State Passivation, and Charge-Transfer Kinetics 30.4.1 Quantification of Photocurrent Carrier-Separation Efficiency (Fig. 30.4) 30.4.2 Quantification of Charge-Injection Efficiency 30.4.3 Effect of Co-catalyst Surface Layers 30.4.4 Quantifying Electron-Hole Recombination 30.4.5 Modification of Band Edge Alignment by Surface Layers 30.4.6 Photocathode/Co-catalyst Interfaces: Adaptive Junctions and Pinch-off Effect 30.5 Solid-Solid Interfaces for Photoanodes 30.5.1 Challenges of Photoanodic Corrosion Mitigation 30.5.2 Hybrid Semiconductor/Liquid Junctions: 2D Materials as Interfacial Layers 30.5.3 Metal-Coating-Semiconductor Photoanodes Oxide Coatings Tunnel Interfacial Layer as Coatings 30.5.4 Protective Coatings for Buried Heterojunction Interfaces Heterojunctions of Absorbers and Intermediate-Band Transport Coatings Catalyst on Photoanodes Without Explicit Coating 30.5.5 Photoanode/Back Contact Interfaces and Graded Compositional Doping 30.5.6 Wide Bandgap Photoanode/Co-catalyst Solid-Solid Interfaces Methods of Co-catalyst Deposition Contacts of Porous Co-catalysts and Liquids with Oxides Oxide/Coating or Oxide/Oxide Heterojunctions for Photoanodes Heterojunction or Homojunction of n-Type Photoanode Absorber and p-Type Overlayer Type II Heterojunction with n-Type Photoanode Band Edge Position Manipulation by Overlayers Heterojunction of Nitrides and Ternary Oxynitride Photoanodes 30.6 Other Cases of Solid-Solid Interfaces on Photoanodes 30.6.1 Co-optimization of Multiple Element Alloy Co-catalysts on Absorbers 30.6.2 Hybrid Composite Absorber/Coating Interface 30.7 Summary References 31 Molecular Functionalization of Semiconductor Surfaces 31.1 Introduction 31.2 Surface-Bound Molecules and the Contacting Phase 31.2.1 Surfaces Under Vacuum 31.2.2 Metallic Contacts/Schottky Junctions 31.2.3 Interfaces with Solution 31.3 Metal Chalcogenides 31.3.1 Dipole Modulation of Metal Chalcogenides 31.4 Metal Oxide Semiconductors 31.4.1 Molecular Control of Band Edge Positions on Oxide Semiconductors 31.4.2 Photoelectrosynthesis Cells 31.5 Silicon 31.5.1 Synthetic Surface Chemistry on Silicon Surfaces Silicon-Carbon Bond Formation Noncarbon Linkages 31.5.2 Dipole Tuning on Silicon 31.5.3 Catalyst Attachment on Silicon 31.6 III-V Semiconductors (GaP, GaAs, and GaInP2) 31.6.1 Dipole Manipulation on III-V Semiconductors 31.6.2 Molecular Catalyst Incorporation on III-V Semiconductors 31.7 Conclusions and Future Outlook References 32 Solar Fuels Devices: Multi-Scale Modeling and Device Design Guidelines 32.1 Introduction 32.2 Modeling on Multiple Scales 32.2.1 Macroscale Device Modeling Device Description Methodology and Governing Equations Application to H2O Splitting via Practical Photoelectrochemical Devices Component Choice Results Application to Concurrent CO2 and H2O Splitting via Practical Photoelectrochemical Devices Component Choice Results 32.2.2 Mesoscale Digitalization of the Exact Morphology Methodology and Governing Equations Application to an Anode in a Water Splitting Device Application to a Cathode in CO2 Reduction Device 32.3 Non Continuum-Scale and Coupling of Multiple Scales 32.4 Conclusions References 33 Exciton Transport and Interfacial Charge Transfer in Semiconductor Nanocrystals and Heterostructures 33.1 Introduction 33.2 Electronic Structures of NCs and Band Alignment of NC Heterostructures 33.2.1 Electronic Structures of 0D, 1D, and 2D NCs 33.2.2 Band Alignments and Examples of NC Heterostructures 33.3 Exciton Transport in 1D NRs and 2D NPLs 33.4 Single-Electron Transfer from NCs 33.4.1 Dependence on Electronic Coupling 33.4.2 Dependence on Driving Force 33.4.3 Dependence on NC Lateral Dimension 33.4.4 Hot Electron Transfer 33.5 Multi-electron Transfer from NCs 33.5.1 Lifetime of Multi-excit