Nanostructured Photocatalyst via Defect Engineering: Basic Knowledge and Recent Advances

Description

This book helps readers comprehend the principles and fundamentals of defect engineering toward realization of an efficient photocatalyst. The volume consists of two parts, each of which addresses a particulate type of defects. The first, larger section provides a comprehensive and rigorous treatment of the behaviour and nature of intrinsic defects. The author describes how their controlled introduction and consequent manipulation over concentration, distribution, nature and diffusion is one of the most effective and practical methodologies to modify the properties and characteristics of target photocatalytic materials. The second part of the book explains the formation of extrinsic defects in the form of metallic and non-metallic dopants and gives a detailed description of their characteristics as this approach is also often used to fabricate an efficient photocatalyst. Filling the gap in knowledge on the correlation between introduction of defects in various semiconducting materials and their photocatalytic performance, the book is ideal for graduate students, academics and researchers interested in photocatalysts, defect engineering, clean energy, hydrogen production, nanoscale advanced functional materials, CO2 deactivation, and semiconductor engineering. Preface Acknowledgments About the Book Contents About the Author Chapter 1: Photocatalysis: Fundamentals 1.1 Introduction 1.2 Case Example I: Photocatalytic Degradation of Pollutants in Water 1.3 Case Example II: Photocatalytic and Photoelectrochemical Water Splitting 1.4 Case Example III: Photoconversion of CO2 1.5 Case Example IV: Photocatalytic Nitrogen Fixation 1.6 Other Photocatalytic Reactions 1.6.1 Photocatalytic Reduction of Cr (VI) 1.6.2 Photocatalytic Reduction of Other Toxic and Nontoxic Metals 1.6.3 Photocatalytic Hydrogen Peroxide Production 1.6.4 Biomass Treatment: Photocatalytic Oxidation of Glucose 1.6.5 Several More Examples of Photocatalytic Reactions 1.7 Final Remarks on Photocatalysis References Chapter 2: General Principles of Defect Engineering 2.1 Introduction 2.2 Defect Engineering: Fundamentals 2.3 Point Defects 2.3.1 Brief Overview 2.3.2 Intrinsic and Extrinsic Defects: Difference and Particularities 2.3.3 Intrinsic Defects 2.3.3.1 Anion Vacancies 2.3.3.2 Cation Vacancies 2.3.4 Extrinsic Defects 2.3.4.1 Metal Doping 2.3.4.2 Non-metal Doping 2.4 Line Defects 2.5 Planar Defects 2.6 Volume Defects 2.7 Defects in Semiconductor Nanomaterials: Current Progress 2.7.1 General Methods to Produce Defects 2.7.2 Manipulation and Control of Defects 2.7.3 Materials Properties vs Defect Presence: Positive and Negative Sides 2.7.3.1 Positive Contribution of Defect Engineering 2.7.3.2 Negative Contribution of Defect Engineering 2.7.4 Current Challenges and Future Perspectives 2.8 Final Remarks on Defect Engineering References Chapter 3: Bulk vs Surface Defects 3.1 Introduction 3.2 Bulk Defects 3.3 Surface Defects 3.4 Distribution, Concentration, and Diffusion of Defects: Why Is It Important 3.4.1 Distribution of Defects 3.4.2 Concentration of Defects 3.4.3 Diffusion of Defects 3.5 Defect Engineering of 0-D, 1-D, 2-D, and 3-D Materials 3.5.1 Brief Overview 3.5.2 Defects in 0-D Materials 3.5.3 Defects in 1-D Materials 3.5.4 Defects in 2-D Materials 3.5.5 Defects in 3-D Materials 3.6 Final Remarks on Defect Localization References Chapter 4: Analysis of Defects 4.1 Introduction 4.2 Electron Microscopy, Surface Scan, and Visualization Techniques 4.2.1 Transmission Electron Microscopy 4.2.2 Scanning Probe Microscopy (SPM) 4.2.2.1 Brief Overview of SPM Techniques 4.2.2.2 Scanning Tunneling Microscopy (STM) 4.2.2.3 Atomic Force Microscopy (AFM) 4.2.2.4 Kelvin Probe Force Microscopy (KPFM) 4.2.2.5 Conductive Force Microscopy (C-AFM) 4.2.3 Another Microscopy Analysis 4.3 Spectroscopy Techniques 4.3.1 Electron Paramagnetic Resonance (EPR) 4.3.2 Positron Annihilation Spectroscopy (PAS) 4.3.3 X-ray Photoelectron Spectroscopy (XPS) 4.3.4 Valence Band X-ray photoelectron spectroscopy (VBXPS) 4.3.5 Fourier Transform Infrared Spectroscopy (FTIR) 4.3.6 Raman Spectroscopy 4.3.6.1 Brief Overview 4.3.6.2 Non-resonance Raman Spectroscopy 4.3.6.3 Resonance Raman Spectroscopy 4.3.7 Photoluminescence (PL) and Cathodoluminescence (CL) Spectroscopies 4.3.8 Transient Absorption Spectroscopy (TAS) 4.3.9 X-ray Absorption Spectroscopy (XAS) 4.4 X-ray Diffraction Analysis (XRD) 4.5 Other Analyzing Techniques 4.6 Final Remarks on Various Analysis Tools and Methods References Chapter 5: Case Study I Defect Engineering of TiO2 5.1 TiO2: Fundamentals 5.2 Intrinsic Defects in TiO2 5.2.1 Introduction 5.2.2 Defect Chemistry of TiO2 5.2.2.1 Brief Overview 5.2.2.2 Oxygen Vacancies 5.2.2.3 Titanium Vacancies 5.2.2.4 Titanium Interstitials 5.2.2.5 Oxygen Interstitials 5.2.3 How to Create Defects? 5.2.3.1 Hydrogenation 5.2.3.2 High-Energy Particles Bombardment 5.2.3.3 Thermal Treatment in Reducing Atmosphere 5.2.3.4 Vapor-Phase Synthesis 5.2.3.5 Chemical-Based Approaches 5.2.3.6 Electrochemical Methods 5.2.3.7 Mechanical Methods 5.2.3.8 Alternative Methods 5.2.3.9 Influence of TiO2 Crystallinity and Phase on the Formation of Defects 5.2.4 Properties of Defective TiO2 5.2.4.1 Structural Properties 5.2.4.2 Optical Properties 5.2.4.3 Chemical Modifications 5.2.4.4 Electronic Properties 5.2.4.5 Electrical Properties 5.2.4.6 Other Properties 5.2.5 Defective TiO2 via Theoretical Simulations 5.2.5.1 Various Simulation Models and Their Outcome 5.2.5.2 Comparison with Real Experimental Studies 5.2.5.3 Current Challenges 5.2.6 Application of Defective TiO2 as Photocatalyst 5.2.6.1 Brief Overview 5.2.6.2 Photocatalytic and Photoelectrochemical Water Splitting 5.2.6.3 Light-Induced Water Purification 5.2.6.4 Photoconversion of CO2 5.2.6.5 Other Applications 5.2.6.6 Current Challenges and Future Perspectives 5.2.7 Amorphous TiO2: Alternative to Defective TiO2 5.2.7.1 Introduction: Amorphous TiO2 vs Crystalline TiO2 5.2.7.2 How to Fabricate Amorphous TiO2: Morphology-Controlled Synthesis 5.2.7.3 Properties of Amorphous TiO2 5.2.7.4 Application of Amorphous TiO2 as Photocatalyst 5.3 Final Remarks About Defective TiO2 References Chapter 6: Case Study II: Defect Engineering of ZnO 6.1 ZnO: Fundamentals 6.2 Intrinsic Defects in ZnO 6.2.1 Introduction 6.2.2 Defect Chemistry of ZnO 6.2.2.1 Brief Overview 6.2.2.2 Oxygen vs Zinc Vacancies: Particularities in Electronic and Geometrical Configurations 6.2.3 How to Create Defects 6.2.3.1 Hydrogenation 6.2.3.2 High-Energy Particles Bombardment 6.2.3.3 Treatment in Reduced Atmosphere 6.2.3.4 Vapor Phase Synthesis 6.2.3.5 Chemical-Based Approaches 6.2.3.6 Electrochemical Methods 6.2.3.7 Mechanical Methods 6.2.3.8 Crystallinity, Size, and Dimension of ZnO vs Formation of Defects 6.2.4 Properties of Defective ZnO 6.2.4.1 Structural Properties 6.2.4.2 Optical Properties 6.2.4.3 Electronic Properties 6.2.4.4 Electrical Properties 6.2.4.5 Other Properties 6.2.5 Application of Defective ZnO as Photocatalyst 6.2.5.1 Brief Overview 6.2.5.2 Photocatalytic and Photoelectrochemical Water Splitting 6.2.5.3 Light-Induced Water Purification 6.2.5.4 Photoconversion of CO2 6.2.5.5 Antibacterial and Antimicrobial Applications 6.2.5.6 Other Applications 6.2.5.7 Current Challenges and Future Perspectives 6.3 Final Remarks About Defective ZnO References Chapter 7: Case Study III: Defect Engineering of Ta2O5, Ta3N5, and TaON 7.1 Ta2O5, Ta3N5, and TaON: Fundamentals 7.2 Intrinsic Defects in Ta2O5, Ta3N5, and TaON 7.2.1 Introduction 7.2.2 Defects in Oxide, Nitrides, and Oxynitrides: What Is Difference 7.2.2.1 Brief Overview 7.2.2.2 Defects in Ta2O5 7.2.2.3 Defects in Ta3N5 7.2.2.4 Defects in TaON 7.2.3 How to Create Defects 7.2.3.1 Ta2O5 7.2.3.2 TaN5 7.2.3.3 TaON 7.2.4 Properties of Defective Ta2O5, Ta3N5, and TaON 7.2.4.1 Structural Properties 7.2.4.2 Optical Properties 7.2.4.3 Electronic Properties 7.2.4.4 Electrical Properties 7.2.5 Application of Defective Ta2O5, Ta3N5, and TaON as Photocatalyst 7.2.5.1 Brief Overview 7.2.5.2 Photocatalytic and Photoelectrochemical Water Splitting 7.2.5.3 Light-Induced Water Purification 7.2.5.4 Photoconversion of CO2 7.2.5.5 Current Challenges and Future Perspectives 7.3 Final Remarks About Defective Ta2O5, Ta3N5, and TaON References Chapter 8: Case Study IV: Defect Engineering of MoS2 and WS2 8.1 MoS2 and WS2: Fundamentals 8.2 Intrinsic Defects in MoS2 and WS2 8.2.1 Introduction 8.2.2 Defects in MoS2 8.2.3 Defects in WS2 8.2.4 How to Create Defects 8.2.4.1 Exfoliation 8.2.4.2 Vapor Phase Synthesis 8.2.4.3 Hydrothermal Method 8.2.4.4 Other Methods 8.2.5 Properties of Defective MoS2 and WS2 8.2.5.1 Structural Properties 8.2.5.2 Optical Properties 8.2.5.3 Electronic Properties 8.2.5.4 Electrical Properties 8.2.6 Application of Defective MoS2 and WS2 as Photocatalyst 8.2.6.1 Brief Overview 8.2.6.2 Photocatalytic and Photoelectrochemical Water Splitting 8.2.6.3 Light-Induce Water Purification 8.2.6.4 Photoconversion of CO2 8.2.6.5 Other Applications 8.2.6.6 Current Challenges and Future Perspectives 8.3 Final Remarks About Defective MoS2 and WS2 References Chapter 9: Defect Engineering of Other Nanostructured Semiconductors 9.1 Introduction 9.2 Methods to Introduce Intrinsic Defects: Recent Trends and Future Perspectives 9.3 Defect-Controlled Properties: Tuning and Adjustment 9.4 Defective Nanostructures: Examples 9.4.1 Brief Overview 9.4.2 Case Example I: g-C3N4 9.4.2.1 g-C3N4: Fundamentals 9.4.2.2 How to Create Defects 9.4.2.3 Properties of Defective g-C3N4 9.4.2.4 Photocatalytic Application of Defective g-C3N4 9.4.3 Case Example II: WO3 9.4.3.1 WO3: Fundamentals 9.4.3.2 How to Create Defects 9.4.3.3 Properties of Defective WO3 9.4.3.4 Photocatalytic Application of Defective WO3 9.4.4 Case Example III: CuO and Cu2O 9.4.4.1 CuO and Cu2O: Fundamentals 9.4.4.2 How to Create Defects 9.4.4.3 Properties of Defective CuO and Cu2O 9.4.4.4 Photocatalytic Application of Defective CuO and Cu2O 9.4.5 Case Example IV: α-Fe2O3 9.4.5.1 α-Fe2O3: Fundamentals 9.4.5.2 How to Create Defects 9.4.5.3 Properties of Defective α-Fe2O3 9.4.5.4 Photocatalytic Application of Defective α-Fe2O3 9.4.6 Case Example V: Nb2O5 9.4.6.1 Nb2O5: Fundamentals 9.4.6.2 How to Create Defects 9.4.6.3 Properties of Defective Nb2O5 9.4.6.4 Photocatalytic Application of Defective Nb2O5 9.5 Final Remarks on Defective Nanostructured Semiconductors References Chapter 10: Extrinsic Defects in Nanostructured Semiconductors 10.1 Introduction 10.2 Advantages and Disadvantages of Using Extrinsic Deficiency 10.3 Case Study I: TiO2 10.3.1 Brief Overview 10.3.2 Metal Doping 10.3.3 Non-metal Doping 10.3.4 Photocatalytic Application of Doped TiO2 10.4 Case Study II: ZnO 10.4.1 Brief Overview 10.4.2 Metal Doping 10.4.3 Non-metal Doping 10.4.4 Photocatalytic Application of Doped ZnO 10.5 Case Study III: Ta2O5 10.5.1 Brief Overview 10.5.2 Metal Doping 10.5.3 Non-metal Doping 10.5.4 Photocatalytic Application of Doped Ta2O5 10.6 Case Study IV: Ta3N5 10.6.1 Brief Overview 10.6.2 Metal Doping 10.6.3 Non-metal Doping 10.6.4 Photocatalytic Application of Doped Ta3N5 10.7 Case Study V: Fe2O3 10.7.1 Brief Overview 10.7.2 Metal Doping 10.7.3 Non-metal Doping 10.7.4 Photocatalytic Application of Doped α-Fe2O3 10.8 Case Study VI: MoS2 and WS2 10.8.1 Brief Overview 10.8.2 Metal Doping 10.8.3 Non-metal Doping 10.8.4 Photocatalytic Application of Doped MoS2 and WS2 10.9 Final Remarks on Extrinsic Deficiency References Chapter 11: Comparison of Intrinsic and Extrinsic Deficiencies 11.1 Introduction 11.2 Comparison in Terms of Synthesis Approaches and Post-synthesis Treatment 11.2.1 Synthesis Approaches 11.2.2 Post-synthesis Treatment 11.3 Comparison in Terms of Effect and Influence on Materials Properties 11.3.1 Structural Properties 11.3.2 Optical Properties 11.3.3 Electronic Properties 11.3.4 Electrical Properties 11.4 Comparison in Terms of Photocatalytic Efficiency 11.4.1 Photocatalytic and Photoelectrochemical Water Splitting 11.4.2 Light-Induced Water Purification 11.4.3 Photoconversion of CO2 References Index