Lecture Notes in Chemistry

Volume 100

Series editors

Barry Carpenter, Cardiff, UKPaola Ceroni, Bologna, ItalyBarbara Kirchner, Bonn, GermanyKatharina Landfester, Mainz, GermanyJerzy Leszczynski, Jackson, USATien-Yau Luh, Taipei, TaiwanEva Perlt, Bonn, GermanyNicolas C. Polfer, Gainesville, USAReiner Salzer, Dresden, Germany

The Lecture Notes in Chemistry

The series Lecture Notes in Chemistry (LNC) reports new developments inchemistry and molecular science-quickly and informally, but with a high qualityand the explicit aim to summarize and communicate current knowledge for teachingand training purposes. Books published in this series are conceived as bridgingmaterial between advanced graduate textbooks and the forefront of research. Theywill serve the following purposes:

• provide an accessible introduction to the field to postgraduate students andnonspecialist researchers from related areas,

• provide a source of advanced teaching material for specialized seminars, coursesand schools, and

• be readily accessible in print and online.

The series covers all established fields of chemistry such as analytical chemistry,organic chemistry, inorganic chemistry, physical chemistry including electrochem-istry, theoretical and computational chemistry, industrial chemistry, and catalysis. Itis also a particularly suitable forum for volumes addressing the interfaces ofchemistry with other disciplines, such as biology, medicine, physics, engineering,materials science including polymer and nanoscience, or earth and environmentalscience.

Both authored and edited volumes will be considered for publication. Editedvolumes should however consist of a very limited number of contributions only.Proceedings will not be considered for LNC.

The year 2010 marks the relaunch of LNC.

More information about this series at http://www.springer.com/series/632

Jinlong Zhang • Baozhu Tian • Lingzhi WangMingyang Xing • Juying Lei

PhotocatalysisFundamentals, Materials and Applications

Jinlong ZhangKey Laboratory for AdvancedMaterials & Institute of Fine ChemicalsEast China University of Science &TechnologyShanghai, China

Baozhu TianKey Laboratory for AdvancedMaterials & Institute of Fine ChemicalsEast China University of Science &TechnologyShanghai, China

Lingzhi WangKey Laboratory for AdvancedMaterials & Institute of Fine ChemicalsEast China University of Science &TechnologyShanghai, China

Mingyang XingKey Laboratory for AdvancedMaterials & Institute of Fine ChemicalsEast China University of Science &TechnologyShanghai, China

Juying LeiKey Laboratory for AdvancedMaterials & Institute of Fine ChemicalsEast China University of Science &TechnologyShanghai, China

ISSN 0342-4901 ISSN 2192-6603 (electronic)Lecture Notes in ChemistryISBN 978-981-13-2112-2 ISBN 978-981-13-2113-9 (eBook)https://doi.org/10.1007/978-981-13-2113-9

Library of Congress Control Number: 2018954494

© Springer Nature Singapore Pte Ltd. 2018This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or partof the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission orinformation storage and retrieval, electronic adaptation, computer software, or by similar or dissimilarmethodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specific statement, that such names are exemptfrom the relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in this bookare believed to be true and accurate at the date of publication. Neither the publisher nor the authors or theeditors give a warranty, express or implied, with respect to the material contained herein or for any errorsor omissions that may have been made. The publisher remains neutral with regard to jurisdictional claimsin published maps and institutional affiliations.

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Foreword

In the twenty-first century, humanity is facing serious and urgent issues of energydepletion and environmental degradation. Due to rapid economic growth, we areexperiencing the most extensive energy shortages and environmental pollution inhistory, also resulting in globally destructive climate change. While our industriesare constantly providing a variety of innovative new products and materials, it isbecoming imperative to focus on the recycling and treatment of waste materials aswell. Moreover, we need to reduce the consumption of natural resources and raiseawareness of the great impact of our consumerism so that the technologies, products,and materials we develop are environmentally harmonious and sustainable.

Many of the recent Nobel prizes in physics and chemistry are related to photo-chemistry and catalytic chemistry as well as materials or systems related to theseareas. Photocatalysis which induces efficient and effective reactions at room tem-perature under sunlight irradiation has been the focus of much attention for itspotential to establish ideal technologies which can convert clean, safe, and abundantsolar energy into electrical and/or chemical energy.

In fact, in the last 45 years since the discovery of the sensitizing effect of a TiO2

electrode for the electrolysis of water by Honda and Fujishima, much research hasbeen carried out on the development of semiconductor photocatalysis using variousmetal oxide catalysts. New breakthrough technologies such as the separate produc-tion of H2 and O2 from water, CO2 reduction with H2O, the transformation orcomplete mineralization of organic molecules, reduction of heavy metal ions aswell as nontoxic deodorization, antisepsis, decontamination, and sterilization pro-cesses will be essential in the reduction or elimination of harmful compounds frompolluted air, water, and soil. This book brings to light much of the recent research inthe development of such semiconductor photocatalytic systems.

In order to prepare highly efficient and functional photocatalysts, their meticulousdesign and construction are vital, and this book delves into molecular level inves-tigations of their nanoscale structures as well as the mechanisms behind theirreactivity. Modification methods to improve their performance includingion-doping, heterojunction structural development, noble metal deposition, and

v

morphological control are also covered. In addition, dye sensitization processes toextend their light absorption ranges from UV to visible regions as well as to reduceelectron-hole recombination are also explored. This book will thus be of interest toresearchers in materials sciences, environmental science and technologies, energystorage and conversion, photocatalytic processes, and industrial applications.

The lead author, Prof. Jinlong Zhang, has studied fine chemical synthesis at theEast China University of Science and Technology (Shanghai, China) where hereceived a PhD from the Department of Applied Chemistry in 1993. In 1996, hereceived the Japan Society for the Promotion of Science (JSPS) Award for innova-tive research. He then carried out research at the Department of Applied Chemistryof Osaka Prefecture University (Sakai City, Osaka, Japan) as a postdoctoralresearcher for 4 years. After Dr. Zhang’s return to Shanghai, he was promoted tofull professor of East China University of Science and Technology in 2000. He haspublished over 380 original papers which have been cited more than 14,000 times.He serves as editor of the international journal, Research on Chemical Intermediates(Springer), and is also on the editorial boards of several international journals such asScientific Reports, Applied Catalysis B: Environmental Science and Technology,Dyes and Pigments, and Photographic Science and Photochemistry.

We hope this book will contribute to the advancement of photocatalytic researchfor environmental purification and renewable energy technologies in order thatfuture societies may thrive and prosper.

Prof. Masakazu AnpoEmeritus Professor of Osaka PrefectureUniversity (Japan)International Advisor and Special Honorary ProfessorState Key Laboratory of Photocatalysis on Energyand EnvironmentFuzhou University (China)

Editor-in-Chief, Res. Chem. Intermed. (Springer)Member, Academia EuropaeMember, Science Council of Japan

vi Foreword

Contents

1 Mechanism of Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 TiO2 Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Mechanism of Photocatalytic Oxidation Reactions . . . . . . . . . . . 21.4 Influence of Different Parameters on the Degradation

of Pollutants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4.1 Catalyst Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.4.2 pH Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.4.3 Surface Area and Morphology . . . . . . . . . . . . . . . . . . . 71.4.4 Effect of Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 91.4.5 Effect of Contaminant Concentration . . . . . . . . . . . . . . . 91.4.6 Influence of Calcination Temperature . . . . . . . . . . . . . . 10

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2 In Situ Characterization of Photocatalytic Activity . . . . . . . . . . . . . 172.1 Fluorescence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.1.1 Types of Probing Agents for ROS . . . . . . . . . . . . . . . . . 182.1.2 Single-Molecule Spectroscopy . . . . . . . . . . . . . . . . . . . 19

2.2 Infrared Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262.2.1 Gas-Phase Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . 272.2.2 Aqueous-Phase Photocatalysis . . . . . . . . . . . . . . . . . . . 27

2.3 Raman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332.4 In Situ Atomic Force Microscopy and Fluorescence . . . . . . . . . . 382.5 In Situ NMR and ESR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3 Titanium-Based Mesoporous Materials for Photocatalysis . . . . . . . 473.1 The History of Mesoporous Materials . . . . . . . . . . . . . . . . . . . . . 47

vii

3.2 The Development of Mesoporous TiO2 in Photocatalysis . . . . . . . 483.2.1 The Preparation of Mesoporous TiO2 . . . . . . . . . . . . . . 483.2.2 Doping Modification on Mesoporous TiO2 . . . . . . . . . . 493.2.3 Mesoporous TiO2–Graphene Materials . . . . . . . . . . . . . 51

3.3 The Development of TiO2–SiO2 Mesoporous Materials . . . . . . . . 523.3.1 The Preparation of TiO2–SiO2 Mesoporous Materials . . . 533.3.2 The Application of TiO2–SiO2 Mesoporous Materials

in Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543.4 Visible Light Response Metal–Organic Frameworks (MOFs) . . . . 593.5 The Development of Mesoporous Ti–SiO2 Materials in

Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 633.5.1 The Preparation of Ti–SiO2 Mesoporous Materials . . . . . 643.5.2 The Application of Ti–SiO2 Mesoporous Materials

in Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

4 Preparation of Reduced TiO2–x for Photocatalysis . . . . . . . . . . . . . . 754.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754.2 Synthesis of TiO2–x Photocatalysts . . . . . . . . . . . . . . . . . . . . . . . 76

4.2.1 Reduction Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764.2.2 Oxidation Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

4.3 Properties of TiO2–x Photocatalysts . . . . . . . . . . . . . . . . . . . . . . 844.4 Applications of TiO2–x Photocatalysts . . . . . . . . . . . . . . . . . . . . 874.5 Modification on TiO2–x Photocatalysts . . . . . . . . . . . . . . . . . . . . 88

4.5.1 TiO2–x Doped with Nonmetal Elements . . . . . . . . . . . . . 894.5.2 TiO2–x Grafted with Metals . . . . . . . . . . . . . . . . . . . . . . 904.5.3 TiO2–x Composited with Carbon . . . . . . . . . . . . . . . . . . 924.5.4 TiO2–x Composited with Other Compounds . . . . . . . . . . 934.5.5 TiO2–x with Ordered Morphology . . . . . . . . . . . . . . . . . 944.5.6 TiO2–x with Special Facets Exposed . . . . . . . . . . . . . . . 95

4.6 Summary and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

5 Graphene-Modified TiO2 with Enhanced Visible LightPhotocatalytic Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1075.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1075.2 TiO2/Graphene Composite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

5.2.1 Two-Dimensional TiO2/Graphene Composites . . . . . . . . 1085.2.2 Three-Dimensional TiO2/Graphene Composite . . . . . . . . 118

5.3 Applications in Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . 1235.3.1 Photodegradation of Organic Pollutants . . . . . . . . . . . . . 1235.3.2 Water Splitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1245.3.3 CO2 Photoreduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5.4 Conclusions and Prospective . . . . . . . . . . . . . . . . . . . . . . . . . . . 127References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

viii Contents

6 Phase Control of TiO2 Photocatalyst . . . . . . . . . . . . . . . . . . . . . . . . 1336.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1336.2 Phases of TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

6.2.1 Structure Properties of Rutile, Anatase, and Brookite . . . 1356.2.2 Stability and Phase Transformation . . . . . . . . . . . . . . . . 1366.2.3 Photocatalytic Activity of Rutile, Anatase,

and Brookite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1376.3 Synthesis of Mixed-Phase TiO2 Photocatalysts . . . . . . . . . . . . . . 138

6.3.1 Hydrothermal Method and Solvothermal Method . . . . . . 1396.3.2 Microemulsion-Mediated Solvothermal Method . . . . . . . 1436.3.3 Sol–Gel Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1456.3.4 Solvent Mixing and Calcination Method . . . . . . . . . . . . 1476.3.5 High-Temperature Calcination Method . . . . . . . . . . . . . 148

6.4 Applications of Mixed-Phase TiO2 in Photocatalysis . . . . . . . . . . 1506.4.1 Photocatalytic Hydrogen Production . . . . . . . . . . . . . . . 1506.4.2 Photocatalytic Reduction of CO2 with Water on

Mixed-Phase TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1546.4.3 Photocatalytic Degradation of Organic Pollutants on

Mixed-Phase TiO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1566.5 Mechanism of the Enhanced Photocatalytic Activities by the

Mixed-Phase TiO2 Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . 1616.6 Conclusion and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

7 The Preparation and Applications of g-C3N4/TiO2 HeterojunctionCatalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1737.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1737.2 The Preparation Methods of g-C3N4/TiO2 Heterojunction

Catalyst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1747.2.1 Physically Mixing g-C3N4 and TiO2 . . . . . . . . . . . . . . . 1757.2.2 Growing TiO2 on g-C3N4 . . . . . . . . . . . . . . . . . . . . . . . 1767.2.3 Loading g-C3N4 on TiO2 . . . . . . . . . . . . . . . . . . . . . . . 180

7.3 The Applications of g-C3N4/TiO2 Heterojunction Catalyst . . . . . . 1827.3.1 Degradation of Organic Pollutants . . . . . . . . . . . . . . . . . 1827.3.2 Hydrogen Generation from Water . . . . . . . . . . . . . . . . . 1877.3.3 Other Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

7.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

8 Modifications of Photocatalysts by Doping Methods . . . . . . . . . . . . 1978.1 Preparation of Visible Light-Responsive TiO2 Photocatalysts

by Chemical Doping Modification Methods . . . . . . . . . . . . . . . . 1978.1.1 Metal Doping Modification . . . . . . . . . . . . . . . . . . . . . . 2028.1.2 Nonmetal Doping Modification . . . . . . . . . . . . . . . . . . . 2058.1.3 Co-doping Modification . . . . . . . . . . . . . . . . . . . . . . . . 208

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Contents ix

9 Hollow or Yolk–Shell-Type Photocatalyst . . . . . . . . . . . . . . . . . . . . 2239.1 Synthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

9.1.1 Non-template Route . . . . . . . . . . . . . . . . . . . . . . . . . . . 2239.1.2 Hard-Template Route . . . . . . . . . . . . . . . . . . . . . . . . . . 226

9.2 Spatial Arrangement of Different Functions . . . . . . . . . . . . . . . . 2289.3 Acceleration of Photo-Carrier Separation . . . . . . . . . . . . . . . . . . 2319.4 Multiple Light Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

10 Heterogeneous Photo-Fenton Technology . . . . . . . . . . . . . . . . . . . . 24110.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24110.2 Graphene/Iron (Hydr)oxide Composites Applied in Fenton

Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24310.2.1 Graphene/Fe2O3 Composite as Photocatalyst in Fenton

Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24310.2.2 Graphene/Fe3O4 Composite as Photocatalyst in Fenton

Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24810.2.3 Graphene/Other Iron (Hydr)oxide Composite as

Photocatalyst in Fenton Reaction . . . . . . . . . . . . . . . . . 25210.3 Conclusions and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

11 Photo-Fenton Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25911.1 Homogeneous Photo-Fenton Reaction . . . . . . . . . . . . . . . . . . . 26011.2 Heterogeneous Photo-Fenton Reaction . . . . . . . . . . . . . . . . . . . 261

11.2.1 Membrane and Fabrics . . . . . . . . . . . . . . . . . . . . . . . . 26111.2.2 Resin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26211.2.3 Clay Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26211.2.4 Porous Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26311.2.5 Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26511.2.6 Iron Oxide–Semiconductor . . . . . . . . . . . . . . . . . . . . . 26711.2.7 Zerovalent Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26911.2.8 Noble Metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270

11.3 Thermal-Assisted Photo-Fenton Reaction . . . . . . . . . . . . . . . . . 27111.4 The Detrimental Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273

12 Roles and Properties of Cocatalysts in Semiconductor-BasedMaterials for Efficient CO2 Photoreduction . . . . . . . . . . . . . . . . . . . 27512.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27512.2 Basic Principles of CO2 Photoreduction . . . . . . . . . . . . . . . . . . 27612.3 Cocatalysts in Semiconductor-Based CO2 Photoreduction . . . . . 285

12.3.1 Preparations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28512.4 Roles and Properties of Different Cocatalysts . . . . . . . . . . . . . . 290

12.4.1 Promote the Charge Separation and Transfer . . . . . . . . 29012.4.2 Improve CO2 Adsorption and Activation . . . . . . . . . . . 29712.4.3 Surface Active Sites in CO2 Photoreduction . . . . . . . . . 298

x Contents

12.5 Summary and Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

13 Syntheses and Applications of Silver Halide-BasedPhotocatalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30713.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30713.2 Properties of AgX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30813.3 Synthesis Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

13.3.1 Liquid–Solid Precipitation . . . . . . . . . . . . . . . . . . . . . 30913.3.2 In Situ Oxidation Transformation . . . . . . . . . . . . . . . . 31013.3.3 Ion Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

13.4 Synthesis and Application of AgX with DifferentMorphologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31113.4.1 1D Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31113.4.2 3D Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31513.4.3 Facet Exposed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318

13.5 Synthesis and Application of AgX-Based HeterojunctionStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32213.5.1 AgX–Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32213.5.2 Ag–AgX–Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

13.6 Z-Scheme Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32813.7 Recoverable AgX Photocatalytic Materials . . . . . . . . . . . . . . . . 333

13.7.1 Loaded on the Substrates . . . . . . . . . . . . . . . . . . . . . . 33313.7.2 Combined with Magnetic Components . . . . . . . . . . . . 334

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

14 Synthesis and Modifications of Mesoporous g-C3N4

Photocatalyst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34514.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34514.2 The Preparation of MCN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

14.2.1 Soft-Template Method . . . . . . . . . . . . . . . . . . . . . . . . 34814.2.2 Hard-Template Method . . . . . . . . . . . . . . . . . . . . . . . . 34914.2.3 Template-Free Methods . . . . . . . . . . . . . . . . . . . . . . . 35214.2.4 Sol–Gel Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353

14.3 The Modifications of MCN . . . . . . . . . . . . . . . . . . . . . . . . . . . 35514.3.1 Noble Metal Deposition . . . . . . . . . . . . . . . . . . . . . . . 35614.3.2 Metallic Oxide Loading . . . . . . . . . . . . . . . . . . . . . . . 35814.3.3 Nonmetal Doping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35914.3.4 Dye Photosensitization . . . . . . . . . . . . . . . . . . . . . . . . 36014.3.5 Polyoxometalate Immobilization . . . . . . . . . . . . . . . . . 362

14.4 Summery and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

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15 MoS2 Applications in Photo-Fenton Technology . . . . . . . . . . . . . . . 36715.1 The Brief Introduction of Fenton Technology . . . . . . . . . . . . . . 36715.2 Photo-Fenton Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368

15.2.1 UV Light-Assisted Fenton Process . . . . . . . . . . . . . . . 36815.2.2 Visible Light-Assisted Fenton Process . . . . . . . . . . . . . 36915.2.3 Fenton-Like Process . . . . . . . . . . . . . . . . . . . . . . . . . . 369

15.3 Transition Metal Catalysts as Fenton Reagents . . . . . . . . . . . . . 37015.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

16 Transition Metal Phosphide As Cocatalysts for Semiconductor-Based Photocatalytic Hydrogen Evolution Reaction . . . . . . . . . . . . 37516.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37516.2 Preparation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377

16.2.1 Organophosphorus Sources . . . . . . . . . . . . . . . . . . . . . 37716.2.2 Inorganic Phosphorus Sources . . . . . . . . . . . . . . . . . . . 380

16.3 Effect of P on Photocatalytic Hydrogen Evolution Reactions . . . 38416.3.1 The Role of P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38416.3.2 The Effect of P Content . . . . . . . . . . . . . . . . . . . . . . . 38616.3.3 Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387

16.4 Applications of TMPs in Photocatalytic Hydrogen EvolutionReactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38716.4.1 The Origin of TMPs Acted As Cocatalysts in

Photocatalytic Hydrogen Evolution Reactions . . . . . . . 38716.4.2 Explanation of TMPs As Cocatalysts . . . . . . . . . . . . . . 38816.4.3 Semiconductors Motivated by TMPs for

Photocatalytic Hydrogen Evolution . . . . . . . . . . . . . . . 38916.5 Conclusion and Prospects . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397

17 Novel Porous Metal–Organic Frameworks (MOFs) for WaterSplitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40317.1 Metal–Organic Frameworks (MOFs) . . . . . . . . . . . . . . . . . . . . 40317.2 Hydrogen Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40317.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409

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