Contents

Cover

Title page

Copyright page

Preface

Part I: General Concepts and Photoelectrochemical Systems

Chapter 1: Photoelectrochemical Reaction Engineering for Solar Fuels Production
1. 1.1 Introduction
2. 1.2 Theory and Classification of PEC Systems
3. 1.3 Scaling Up of PEC Reactors
4. 1.4 Reactor Designs
5. 1.5 System-Level Design
6. 1.6 Outlook
7. 1.7 Summary and Conclusions
8. References
Chapter 2: The Measurements and Efficiency Definition Protocols in Photoelectrochemical Solar Hydrogen Generation
1. 2.1 Introduction
2. 2.2 PEC Measurement
3. 2.3 The Efficiency Definition Protocols in PEC Water Splitting
4. 2.4 Summary
5. References
Chapter 3: Photoelectrochemical Cell: A Versatile Device for Sustainable Hydrogen Production
1. 3.1 Introduction
2. 3.2 Photoelectrochemical (PEC) Cells
3. 3.3 Monometal Oxide Systems for PEC H₂ Generation
4. 3.4 Complex Nanostructures for PEC Splitting of Water
5. 3.5 Conclusion and Outlook
6. Acknowledgments
7. References
Chapter 4: Hydrogen Generation from Photoelectrochemical Water Splitting
1. 4.1 Introduction
2. 4.2 Principle of Photoelectrochemical (PEC) Hydrogen Generation
3. 4.3 Photoeletrode Materials
4. 4.4 Advances in Photoelectrochemical (PEC) Hydrogen Generation
5. 4.5 Pros and Cons of Photoelectrodes and Photocatalysts
6. 4.6 Conclusion and Outlook
7. Acknowledgments
8. References

Part II: Photoactive Materials for Solar Hydrogen Generation

Chapter 5: Hematite Materials for Solar-Driven Photoelectrochemical Cells
1. 5.1 Introduction
2. 5.2 Physical Properties of Hematite
3. 5.3 Experimental Strategies to Enhance the Photoactivity of Hematite
4. 5.4 Fundamental Characteristics of the PEC Behaviors of Hematite
5. 5.5 Summary
6. References
Chapter 6: Design of Bismuth Vanadate-Based Materials: New Advanced Photoanodes for Solar Hydrogen Generation
1. 6.1 Introduction
2. 6.2 Photoanodes in Photoelectrochemical Processes
3. 6.3 Bismuth Vanadate (BiVO₄)
4. 6.4 BiVO₄ as Photoanode for Solar Hydrogen Generation
5. 6.5 Modified BiVO₄ Photoanodes
6. 6.6 Conclusion
7. 6.7 Acknowledgments
8. References
Chapter 7: Copper-Based Chalcopyrite and Kesterite Materials for Solar Hydrogen Generation
1. 7.1 Introduction
2. 7.2 Chalcopyrite I-III-VI₂ Semiconductors
3. 7.3 Cu-Based Kesterite (I₂-II-IV-VI₄) Semiconductors
4. 7.4 Concluding Remarks
5. References
Chapter 8: Eutectic Composites for Photoelectrochemical Solar Cells (PSCs)
1. 8.1 Introduction
2. 8.2 The Photoelectrolysis of Water as a Source of Hydrogen
3. 8.3 Experimental Methods for Studying Photoactive Materials Such as Electrochemical (Mott–Schottky Plots) and Photoelectrochemical Determination of the Flat-Band Potential, Impedance Spectroscopy, and Bandgap by Optical Spectroscopy
4. 8.4 Eutectic Composites
5. 8.5 Methods of Obtaining Eutectic Composites
6. 8.6 Eutectic Composites used for Photoelectrochemical Water Splitting
7. 8.7 Other Potential Eutectic Composites
8. 8.8 Modification of the Properties of Eutectic Composites
9. 8.9 Conclusions
10. References

Part III: Photoelectrochemical Related Systems

Chapter 9: Implementation of Multijunction Solar Cells in Integrated Devices for the Generation of Solar Fuels
1. 9.1 Introduction
2. 9.2 Multijunction Solar Cells as Photoelectrodes
3. 9.3 PV-EC Devices Based on Multijunction Solar Cells
4. 9.4 Promising Device Designs, Future Prospects
5. 9.5 Summary and Conclusions
6. References
Chapter 10: Photoelectrochemical Cells: Dye-Sensitized Solar Cells
1. 10.1 Introduction
2. 10.2 Brief History of Solar Cells to DSSCs
3. 10.3 Structure, Components, and Working Principle of the DSSC
4. 10.4 Characterization Techniques for DSSCs
5. 10.5 Plasmonic DSSCs
6. 10.6 Dye-Sensitized Solar Hydrogen Production
7. 10.7 Applications and Future Outlook of DSSC
8. 10.8 Academic
9. References
Chapter 11: Photocatalytic Formation of Composite Electrodes for Semiconductor-Sensitized Solar Cells
1. 11.1 Introduction
2. 11.2 Photocatalytic Deposition of Metal Sulfide Nanoparticles on the Surface of Wide-Bandgap Semiconductors
3. 11.3 Photocatalytic Deposition of Metal Selenides
4. 11.4 Conclusion and Outlook
5. References
Index
End User License Agreement

List of Illustrations

Chapter 2

Figure 1.1 Extractable and technical potentials for several renewable sources...
Figure 1.2 Timeline of solar to hydrogen (STH) conversion efficiencies for different...
Figure 1.3 Electrical symbols where the polarity of the electrodes is in reference...
Figure 1.4 Generic schematic of layout of photoelectrochemical cell...
Figure 1.5 Optical configurations for 1, 2 and 3 photoabsorbers...
Figure 1.7 Example optical designs demonstrating reactors designs with one (a, b, d)...
Figure 1.8 Demonstrating the transition between integrated PEC and PV + electrolysis...
Figure 1.9 Learning curve for selected PEC reactor design from literature. Net number...
Figure 1.10 Flow diagram of solar hydrogen production process...

Chapter 2

Figure 2.1 (a) UV–vis absorption spectrum of pristine Fe₂O₃...
Figure 2.2 Typical polarization curves of photoanode in PEC water splitting. The solid...
Figure 2.3 Transient photoresponse of Fe₂O₃ photoanodes using...
Figure 2.4 Representative Mott–Schottky plots of pristine...
Figure 2.5 Charge separation efficiency versus potential curves...
Figure 2.6 Charge injection efficiency versus potential curves...

Chapter 3

Figure 3.1 Schematic diagram of a basic photoelectrochemical cell...
Figure 3.2 Different morphologies for enhanced PEC response...
Figure 3.3 Schematic showing the effect of (a) plasmons and (b) quantum dots functionalized...

Chapter 4

Figure 4.1 The composition of a semiconductor–electrolyte junction. The depletion...
Figure 4.2 (a) O₂ production of different samples in five cycles and the dash...
Figure 4.3 (a) Solid line represents photocurrent density potential curves and dashed line...
Figure 4.4 Band alignment of (a) CGSe and (b) CGSe/CdS electrodes by calculating...
Figure 4.5 (a) Energy band positions of the semiconductors utilized in the multilayered...
Figure 4.6 Yellow solid line represents current-potential curves and blue squares represent...
Figure 4.7 Z-scheme photocatalytic water-splitting system. Reprinted from [152]...

Chapter 5

Figure 5.1 A schematic illustration of the working mechanism of a PEC cell. Upon...
Figure 5.2 Physical properties of hematite. (a) Crystal structure; (b) light absorption...
Figure 5.3 (a) A schematic illustration showing a typical linear scan voltammogram (LSV)...
Figure 5.4 Schematic illustration showing the hydrothermal growth process of the hematite...
Figure 5.5 (a) SEM images of unmodified hematite nanowires (top) and hematite nanocorals...
Figure 5.6 (a) Schematic illustration of the in situ transformation of hematite...
Figure 5.7 Morphology evolution and preservation at 800 °C. (a) A top-view SEM...
Figure 5.8 (a) Linear sweep voltammograms collected for pristine...
Figure 5.9 (a) Secondary ion mass spectrometry depth profile of the bidirectionally...
Figure 5.10 (a) The band structure of the p-CaFe₂O₄/n...
Figure 5.11 (a) The TA signal collected at different applied biases. The arrow indicates...
Figure 5.12 Schematic illustration of the different diffusion patterns of photoinduced...
Figure 5.13 A schematic illustration depicting the charge carrier dynamics of (a) pristine...
Figure 5.14 Two heterojunction configurations that facilitate charge separation. (a) A...

Chapter 6

Figure 6.1 PEC cells in (a) one-compartment and (b) two-compartment configuration. Donor...
Figure 6.2 Scheme of water splitting for H₂ and O₂ production...
Figure 6.3 SEM of surface of films deposited on Si/SiO₂ using BiVO₄...
Figure 6.4 Temperature-dependent XRD of pure BiVO₄ film deposited on...
Figure 6.5 Chronoamperographs of BiVO₄ photoanode and Pt-foil cathode under...
Figure 6.6 Hydrogen production rate (a) and cumulative H₂ production (b) using...
Figure 6.7 I-V curves measured using pure BiVO₄ photoanode and Pt-foil cathode...
Figure 6.8 I-V curves measured in NaHCO₃ electrolyte by LSV using Pt-foil...
Figure 6.9 I-V curves (red) measured by LSV using pristine (dashed line) and Nb-modified...
Figure 6.10 Electronic band structure at pH = 0 of BiVO₄...
Figure 6.11 Electronic band structure at pH = 0 of (a)...

Chapter 7

Figure 7.1 Crystal structure of the chalcopyrite CuInS/Se₂ unit cell...
Figure 7.2 TEM images of trigonal CuInSe₂ nanocrystals synthesized at different...
Figure 7.3 SEM images of CuInSe₂ particles synthesized by microwave-assisted...
Figure 7.4 SEM images (a–c) of the CuInS₂ nanorods prepared by microwave...
Figure 7.5 SEM images of the CuInS₂ nanowire arrrays obtained with different...
Figure 7.6 PEC properties of CuInS₂ nanosheet and nanoworm electrodes: (a)...
Figure 7.7 Short-circuit current (I_sc) and open-circuit voltage (V_oc)...
Figure 7.8 Schematic representation of kesterite crystal structure where blue-colored balls...
Figure 7.9 (a) TEM and (b) HRTEM image of solvothermally grown CZTS nanoparticles [136]...
Figure 7.10 (a) SEM and (b) TEM images of the synthesized CZTS powder by microwave...
Figure 7.11 (a) 3D scheme of VGF furnace for crystal growth, (b) image of CZTSSe ingot...
Figure 7.12 Effect of annealing temperature on surface morphology of CZTS thin films...
Figure 7.13 SEM images of CZTSe thin films grown by thermal coevaporation technique; (a)...
Figure 7.14 (a,b) Top and cross-sectional SEM images of Cu₂ZnSnS₄...
Figure 7.15 Photocurrent CZTS electrodes vs. RHE under 300 W Xe lamp. The Zn precursors...

Chapter 8

Figure 8.1 Different configurations of photoelectrochemical solar cells (PSCs); (a)...
Figure 8.2 Experimental methods for flat-band potential V_Fb determination; (a)...
Figure 8.3 Experimental methods for energy bandgap E_g determination; (a)...
Figure 8.4 Experimental methods for transient time constants determination; (a) different...
Figure 8.5 Spectral irradiance for AM1.5G air mass spectrum; λ is the wavelength...
Figure 8.6 Diagram showing particularly interesting properties of eutectic composites for...
Figure 8.7 The micro-pulling-down method: (a) scheme of the chamber inside used...
Figure 8.8 TiO₂-WO₃ (a, c, e) and TiO₂-SrTiO₃...
Figure 8.9 Double optical bandgaps in eutectic composites enabling broader absorption range...
Figure 8.10 Band positioning in n-TiO₂ and SrTiO₃ at pH = 0 with...

Chapter 9

Figure 9.1 Band diagram illustration of a multijunction photovoltaic cells made from thin...
Figure 9.2 (a): Open-circuit voltage U_ph^oc of...
Figure 9.3 Open-circuit voltages U_ph^OC as a...
Figure 9.4 Quantum efficiency curves of the a-Si:H/a-Si:H/µc-Si:H/µc-Si:H...
Figure 9.5 Illustration of the achievable solar-to-hydrogen efficiency...
Figure 9.6 Linear sweep voltammetry measurements of the PV-EC devices based on thin-film...
Figure 9.7 Band alignment of the interface between an a-Si:H/a-Si:H solar cell...
Figure 9.8 Calculated voltammograms of a-Si:H/a-Si:H (a)...
Figure 9.9 Chronoamperometric data evaluating the long-term stability of the triple- and...
Figure 9.10 (a) EQE of the aSi:H/a-Si:H/µc-Si:H solar cell, together with...
Figure 9.11 Normalized solar-to-hydrogen efficiency plotted versus the average photon...
Figure 9.12 Overall polarization characteristics for CO₂RR reaction and OER using...

Chapter 10

Figure 10.1 Schematic of the structure and working principle of the n-type DSSC...
Figure 10.2 FE-SEM images of various ETM structures for DSSC photoanodes: (a) Top: surface...
Figure 10.3 Schematic of the LSPR phenomenon and various energy transfer mechanisms...
Figure 10.4 (Source: Licheng Sun, 1^st) Dyenamo conference training and coaching...

Chapter 11

Figure 11.1 A schematic of the photocatalytic deposition of metal sulfide (MS) NPs via...
Figure 11.2 TEM/HRTEM images of photocatalytically deposited MoS₂ NPs (a), PbS...
Figure 11.3 Atomic force microscopic images of TiO₂/CdS composites produced...
Figure 11.4 (a, b) ZnO/CdS composites formed from ZnO NPs (a) and ZnO nanorods (b). Scale...
Figure 11.5 Temporal changes of voltage (a) and current (b,c) induced by the illumination...
Figure 11.6 Current–voltage dependences registered for FTO/ZnO/CdS-S (curve 1)...
Figure 11.7 (a) Absorption spectra of the nanocrystalline TiO₂ film (curve 1)...
Figure 11.8 (a) Transient differential absorption spectra of TiO₂/CdS...
Figure 11.9 SEM images of starting nanocrystalline TiO₂ film (a)...
Figure 11.10 SEM images of the photodeposited FTO/ZnO/Cu films (a, b)...
Figure 11.11 (a) Energy diagram of TiO₂/Se composite showing the position...
Figure 11.12 Size distributions of CdSe NPs photodeposited on the titania surface without...
Figure 11.13 Resonance Raman spectra of (a) CdSe NPs (curve 1) and core-shell CdSe/ZnS NPs...

List of Tables

Chapter 1

Table 1.1 Projected costs (long term) of hydrogen production...
Table 1.2 Targets set by US Department of Energy (DoE) [16]...
Table 1.3 Example conceptual designs...
Table 1.4 Engineering considerations when scaling up PEC reactors...
Table 1.5 Schematics for the design of various PEC devices found in literature...
Table 1.6 Comparison of selected reactor designs in literature where (t) indicates...

Chapter 2

Table 2.1 Semiconductor properties of pristine Fe₂O₃...

Chapter 3

Table 3.1 Summary of various semiconductor monometal oxide nanostructures used...
Table 3.2 Summary of various semiconductor complex metal oxide nanostructures used...
Table 3.3 Summary of various biomolecules embedded complex metal oxides nanostructures...
Table 3.4 A comparative table of various tandem systems reported for PEC water splitting...

Chapter 4

Table 4.1 Recent progress on PEC performance of α-Fe₂O₃-based...
Table 4.2 Z-scheme Photocatalytic Water Decomposition Systems under Visible Light...
Table 5.1 The photocatalytic performance of selected hematite photoanodes for PEC water...

Chapter 6

Table 6.1 Characteristics measured under solar radiation of BiVQ₄ photoanode...

Chapter 7

Table 7.1 Classification of binary, ternary, and quaternary sulfide semiconductors...
Table 7.2 Bandgaps, crystal structures, and lattice parameters of the selected bulk ternary...
Table 7.3 Overview of chalcopyrite ternary semiconductors applied on photoelectrochemical...
Table 7.4 Summary of different CZTS nanoparticles synthesized by hot-injection method...
Table 7.5 PEC performance summary of different CZTS nanoparticles synthesized by hot...

Chapter 8

Table 8.1 Various energy conversion efficiencies and their definitions...
Table 8.2 Examples of dopants used for improving PSC properties of SrTiO₃...

Chapter 10

Table 10.1 A summary of key events in the history of the DSSC...
Table 10.2 Comparison of the three high-performance HTMs in DSSCs...
Table 10.3 A summary of selected plasmonic DSSC publications over the years...

Chapter 11

Table 11.1 Some examples of SSSCs produced by the photodeposition of sensitizer NPs...
Table 11.2 Photoelectrochemical characteristics of the SSSCs based...

Scrivener Publishing
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Advances in Solar Cell Materials and Storage

Series Editors: Nurdan Demirci Sankir and Mehmet Sankir

Scope: Because the use of solar energy as a primary source of energy will exponentially increase for the foreseeable future, this new series on Advances in Solar Cell Materials and Storage will focus on new and novel solar cell materials and their application for storage. The scope of this series deals with the solution-based manufacturing methods, nanomaterials, organic solar cells, flexible solar cells, batteries and supercapacitors for solar energy storage, and solar cells for space.

Submission to the series: Please submit book proposals to Nurdan Sankir at dnurdan@yahoo.com

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This edition first published 2019 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA and Scrivener Publishing LLC, 100 Cummings Center, Suite 541J, Beverly, MA 01915, USA © 2019 Scrivener Publishing LLC
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Library of Congress Cataloging-in-Publication Data

Names: Demirci Sankir, Nurdan, author. | Sankir, Mehmet, author.

Title: Photoelectrochemical solar cells / Nurdan Demirci Sankir and Mehmet Sankir.
Description: Hoboken, New Jersey : John Wiley & Sons, Inc.; Salem, Massachusetts : Scrivener Publishing LLC, [2018] | Includes bibliographical references and index. |
Identifiers: LCCN 2018044559 (print) | LCCN 2018045026 (ebook) | ISBN 9781119459965 (Adobe PDF) | ISBN 9781119459972 (ePub) | ISBN 9781119459934 (hardcover)
Subjects: LCSH: Photoelectric cells. | Photoelectrochemistry. | Photovoltaic cells. | Solar cells. Classification: LCC QC715.4 (ebook) | LCC QC715.4 .D46 2018 (print) | DDC 621.31/244–dc23
LC record available at https://lccn.loc.gov/2018044559

Preface

Hydrogen has a huge potential as a safe and efficient energy carrier which can be used directly in the fuel cells to obtain electricity, or be used in the chemical industry, fossil fuel processing, or ammonia production. However, hydrogen is not freely available in nature and needs to be produced. Photoelectrochemical (PEC) 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, it is possible to store solar energy via photoelectrochemical conversion. Besides, PEC systems reduce fossil fuels dependency and curb the exhaust of carbon dioxide. “Advances in Solar Cell Materials and Storage” series aims to provide information on new and cutting-edge materials, advanced solar cell designs and architecture, and new concepts in photovoltaic conversion and storage. Photoelectrochemical Solar Cells, which is the second volume of this series, compiles the objectives related to the new semiconductor materials and manufacturing techniques for solar hydrogen generation.

Discussing the underlying basics as well as the advanced details in PEC solar cell designs is highly beneficial for science and engineering students as well as experienced engineers. Additionally, the book has been written to provide a comprehensive approach in the area of the photoactive materials for solar hydrogen generation for the readers with a wide variety of backgrounds. Therefore, the book has been written by distinguished authors with knowledge and expertise about solar hydrogen generation whose contributions can benefit readers from universities and industries. The editors wish to thank the authors for their efforts in writing their chapters.

This book is organized in three parts. Part I (Chapters 1–4) covers the general concepts such as economic targets for hydrogen generation, theory and classification of PEC systems, reactor designs, and the measurements and efficiency protocols in PEC solar cells. Part I also addresses the novel hybrid structures containing inorganic/organic composites, biosensitized semiconductors, and tandem configurations. Part II (Chapters 5–8) is devoted to photoactive materials used in PEC conversion of solar energy into chemical energy. Hematite materials, design of bismuth vanadate-based materials, copper-based chalcopyrite, and kesterite materials and eutectic composites for solar hydrogen generation are described in this part. Materials selection and photoactive electrode design are very crucial for the production of hydrogen in an efficient and economical route via PEC reaction. Therefore, the main focus of this part is to introduce the diverse range of photoactive materials especially the nanostructured semiconductors for PEC solar cells.

The book concludes with Part III (Chapters 9–11) covering photoelectrochemical-related systems. Implementation of multijunction solar cells in integrated devices for solar hydrogen generation, as well as the promising device design and the future prospects, are extensively summarized in this part. Photoelectrochemical energy and hydrogen production via dye-sensitized systems is also covered in Part III. Finally, photocatalytic formation of composite electrodes for solar cells is given in this book. Fundamentals of the photocatalytic deposition of metal sulfides on the nanostructured metal oxides, which are very promising materials for PEC systems, are summarized in the last section.

To conclude, we would like to emphasize that the second volume of the “Advances in Solar Cell Materials and Storage” series provides an overall view of the new and highly promising photoactive materials and system designs for solar hydrogen generation via photoelectrochemical conversion. Therefore, readers from diverse fields such as chemistry, physics, materials science, and engineering, mechanical and chemical engineering will definitely take advantage of this book to comprehend the impacts of the PEC solar cells.

Series Editors
Nurdan Demirci Sankır, PhD., and Nurdan Mehmet Sankır, PhD.
Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology August 2018