Photoelectrochemical Solar Cells

This book provides a broad overall view of the photoelectrochemical systems for solar hydrogen generation, and new and novel materials for photoelectrochemical solar cell applications.

Hydrogen has a huge potential as a safe and efficient energy carrier, which can be used directly in fuel cells to obtain electricity, or it can be used in the chemical industry, fossil fuel processing or ammonia production. However, hydrogen is not freely available in nature and it needs to be produced. Photoelectrochemical solar cells produce hydrogen from water using sunlight and specialized semiconductors, which use solar energy to directly dissociate water molecules into hydrogen and oxygen. Hence, these systems reduce fossil fuels dependency and curb carbon dioxide emissions.

Photoelectrochemical Solar Cells compiles the objectives related to the new semiconductor materials and manufacturing techniques for solar hydrogen generation. The chapters are written by distinguished authors who have extensive experience in their fields. Multidisciplinary contributors from physics, chemical engineering, materials science, and electrical and electronic information engineering, provide an in-depth coverage of the topic. Readers and users have the opportunity to learn not only about the fundamentals but also the various aspects of the materials science and manufacturing technologies for photoelectrochemical solar cells and the hydrogen generation systems via photoelectrochemical conversion.

This groundbreaking book features:

• Description of solar hydrogen generation via photoelectrochemical process

• Designs of photoelectrochemical systems

• Measurements and efficiency definition protocols for photoelectrochemical solar cells

• Metal oxides for solar water splitting

• Semiconductor photocatalysts

• Bismuth vanadate-based materials for solar water splitting

• Copper-based chalcopyrite and kesterite materials for solar water splitting

• Eutectic composites for solar water splitting

• Photocatalytic formation of composite electrodes

Autorentext

Nurdan Demirci Sankir is currently an Associate Professor in the Materials Science and Nanotechnology Engineering Department at the TOBB University of Economics and Technology (TOBB ETU), Ankara, Turkey. She received her M.Eng and PhD degrees in Materials Science and Engineering from the Virginia Polytechnic and State University, USA in 2005. Nurdan has actively carried out research and consulting activities in the areas of photovoltaic devices, solution based thin film manufacturing, solar driven water splitting, photocatalytic degradation and nanostructured semiconductors. Mehmet Sankir received his PhD in Macromolecular Science and Engineering from the Virginia Polytechnic and State University, USA in 2005. Dr. Sankir is currently an Associate Professor in the Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, Ankara, Turkey and group leader of Advanced Membrane Technologies Laboratory. Dr. Sankir has actively carried out research and consulting activities in the areas of membranes for fuel cells, flow batteries, hydrogen generation and desalination.

Inhalt
Preface xi

Part I: General Concepts and Photoelectrochemical Systems 1

1 Photoelectrochemical Reaction Engineering for Solar Fuels Production 3
Isaac Holmes-Gentle, Faye Alhersh, Franky Bedoya and Klaus Hellgardt

1.1 Introduction 3

1.1.1 Undeveloped Power of Renewables 4

1.1.2 Comparison Solar Hydrogen from Different Sources 5

1.1.3 Economic Targets for Hydrogen Production and PEC Systems 6

1.1.4 Goals of Using Hydrogen 8

1.2 Theory and Classification of PEC Systems 9

1.2.1 Classification Framework for PEC Cell Conceptual Design 10

1.2.2 Classification Framework for Design of PEC Devices 13

1.2.3 Integrated Device vs PV + Electrolysis 19

1.3 Scaling Up of PEC Reactors 19

1.4 Reactor Designs 20

1.5 Systems-Level Design 28

1.6 Outlook 30

1.6.1 Future Reactor Designs 30

1.6.1.1 Perforated Designs 30

1.6.1.2 Membrane-less and Microfluidic Designs 31

1.6.1.3 Redox-Mediated Systems 31

1.6.2 Avenues for Future Research 33

1.6.2.1 Intensification and Waste Heat Utilization 33

1.6.2.2 Usefulness of Oxidation and Coupled Process with Hydrogen Generation 33

1.7 Summary and Conclusions 34

References 35

2 The Measurements and Efficiency Definition Protocols in Photoelectrochemical Solar Hydrogen Generation 43
Jingwei Huang and Qizhao Wang

2.1 Introduction 43

2.2 PEC Measurement 44

2.2.1 Measurements of Optical Properties 44

2.2.2 Polarization Curve Measurements 45

2.2.3 Photocurrent Transients Measurements 46

2.2.4 IPCE and APCE Measurements 47

2.2.5 MottSchottky Measurements 48

2.2.6 Measurement (Calculation) of Charge Separation Efficiency 50

2.2.7 Measurements of Charge Injection Efficiency 51

2.8 Gas Evolution Measurements 52

2.3 The Efficiency Definition Protocols in PEC Water Splitting 53

2.3.1 Solar-to-Hydrogen Conversion Efficiency 53

2.3.2 Applied Bias Photon-to-Current Efficiency 54

2.3.3 IPCE and APCE 55

2.4 Summary 56

References 56

3 Photoelectrochemical Cell: A Versatile Device for Sustainable Hydrogen Production 59
Mohit Prasad, Vidhika Sharma, Avinash Rokade and Sandesh Jadkar

3.1 Introduction 60

3.2 Photoelctrochemical (PEC) Cells 61

3.2.1 Solar-to-Hydrogen (STH) Conversion Efficiency 65

3.2.2 Applied Bias Photon-to-Current Efficiency (ABPE) 65

3.2.3 External Quantum Efficiency (EQE) or Incident Photon-to-Current Efficiency (IPCE) 65

3.2.4 Internal Quantum Efficiency (IQE) or Absorbed Photon-to-Current Efficiency (APCE) 66

3.3 Monometal Oxide Systems for PEC H2 Generation 66

3.3.1 Titanium Dioxide (TiO2) 67

3.3.2 Zinc Oxide (ZnO) 68

3.3.3 Tungsten Oxide (WO3) 70

3.3.4 Iron Oxide (Fe2O3) 75

3.3.5 Bismuth Vandate (BiVO4) 76

3.4 Complex Nanostructures for PEC Splitting of Water 77

3.4.1 Plasmonic Metal Semiconductor Composite Photoelectrodes 77

3.4.2 Semiconductor Heterojunctions 80

3.4.3 Quantum Dots Sensitized Semiconductor Photoelectrodes 82

3.4.4 Synergistic Effect in Semiconductor Photoelectrodes 83

3.4.5 Biosensitized Semiconductor Photoelectrodes 85

3.4.6 Tandem Stand-alone PEC Water-Splitting Device 92

3.5 Conclusion and Outlook 98

Acknowledgments 101

References 101

4 Hydrogen Generation from Photoelectrochemical Water Splitting 121
Yanqi Xu, Qian Zhao, Cui Du, Chen Zhou, Huaiguo Xue and Shengyang Yang

4.1 Introduction 122

4.2 Principle of Photoelectrochemical (PEC) Hydrogen Generation 122

4.3 Photoeletrode Materials 125

4.3.1 Photoanode Materials 125

4.3.1.1 TiO2-Based Photoelectrode 125

4.3.1.2 BiVO4-Based Photoelectrode 126 4.3.1.3...