Jianmin Ma is the professor in the University of Electronic Science and Technology of China. He received his B.S. degree in Chemistry from the Shanxi Normal University in 2003 and Ph.D. degree in Materials Physics and Chemistry from Nankai University in 2011. During 2011-2015, he also conducted the research in several overseas universities as a postdoctoral research associate. He serves as the Academic Editor for Rare Metals, the Associate Editor for Chinese Chemical Letters, Chair and editorial board member for Journal of Energy Chemistry, Nano-Micro Letters, Journal of Physics: Condensed Matter, JPhys Energy, and others. His research interest focuses on energy storage devices and components including metal anodes and electrolytes, and theoretical calculations from Density Functional Theory and Molecular Dynamics to Finite Element Analysis.

Preface xiii 1 Oxygen Reduction Reaction Electrocatalysts 1Xinwen Peng and Lei Zhang 1.1 Introduction 1 1.2 Pt-Based ORR Electrocatalysts 2 1.2.1 Facet-Controlled Catalysts 2 1.2.2 Multimetallic Nanocrystals 3 1.2.2.1 Pt Alloys 3 1.2.2.2 Supported-Enhanced Catalysts 6 1.3 Transition-Metal-Based Materials 10 1.3.1 Metals and Alloys 10 1.3.2 Transition Metal Oxides/Sulfides 12 1.4 Atomically Dispersed Metal in Carbon Materials 19 1.5 Metal-Free ORR Electrocatalysts 23 1.6 Conclusion 25 References 26 2 Electrocatalytic Oxygen Evolution Reaction 35Guanyu Liu and Joel W. Ager 2.1 Introduction 35 2.2 Bioinspiration: OER in Photosystem II 36 2.3 Fundamentals of Electrocatalytic OER 36 2.3.1 Electrode Substrate 37 2.3.2 Electrolyte 38 2.3.3 Onset Potential and Overpotential 38 2.3.4 Tafel Analysis of the Rate-Determining Step 38 2.3.5 pH Dependence: The Nernst Equation 39 2.3.6 Long-Term Stability 41 2.3.7 Other Parameters 41 2.4 Reaction Mechanisms 41 2.4.1 WNA Mechanism 42 2.4.2 I2M Mechanism 44 2.5 OER Catalysts 44 2.5.1 Molecular OER Catalysts 44 2.5.1.1 Ru- and Ir-Based Molecular Catalysts 45 2.5.1.2 Earth-Abundant Transition Metal-Based Molecular Catalysts 46 2.5.1.3 Stabilization Strategies for Molecular Catalysts 47 2.5.1.4 All-Inorganic Polyoxometalates 48 2.5.2 Heterogeneous OER Catalysts 48 2.5.2.1 Metal Oxides 48 2.5.2.2 (Oxy)Hydroxides and Double Hydroxides 54 2.5.2.3 Metal Chalcogenides 55 2.5.2.4 Metal Pnictides 57 2.5.2.5 Carbon-Based Materials 58 2.5.2.6 Crystalline Frameworks and Their Derivatives 59 2.6 Challenges for Practical Catalytic Electrodes for OER 62 2.6.1 Industrially Viable Fabrication Techniques 62 2.6.2 Gas Bubble Formation on the Surface of Electrodes 62 2.6.3 Novel Approaches Toward Catalyst Discovery 65 2.7 Conclusions 67 References 68 3 Electrochemical Hydrogen Evolution Reaction 87Guoqiang Zhao and Wenping Sun 3.1 Introduction 87 3.2 HER Mechanism 89 3.2.1 HER Mechanism in Acid Media 89 3.2.2 HER Mechanism in Alkaline Media 93 3.3 Key Parameters for Evaluating Catalytic Activity 96 3.3.1 Overpotential 96 3.3.2 Turnover Frequency 97 3.4 PGMs-Based Electrocatalysts 98 3.4.1 PGM Alloys 99 3.4.2 PGM Heterostructured Electrocatalysts 101 3.4.3 PGM Single-Atom Electrocatalysts 106 3.5 PGM-Free Materials 108 3.5.1 2D Transition Metal Dichalcogenides 108 3.5.2 Transition Metal Phosphorus/Nitrides/Carbides 111 3.5.3 PGM-Free Heterostructured Electrocatalysts 112 3.6 Summary 117 References 118 4 Electrocatalytic Water Splitting 123Suraj Gupta 4.1 Introduction 123 4.2 Fundamental Concepts 124 4.2.1 Electric Double Layer 124 4.2.2 Standard Electrode Potential 125 4.2.3 Overpotential 129 4.2.4 Electrode Kinetics 129 4.3 Industrial Systems for Electrocatalytic Water Splitting 133 4.3.1 Alkaline Water Electrolyzers 133 4.3.2 Proton Exchange Membrane Water Electrolyzers 135 4.3.2.1 Membrane Electrode Assembly 136 4.3.2.2 Current Collectors 137 4.3.2.3 Bipolar/Separator Plates 138 4.3.3 Zero-Gap AWE 138 4.3.4 Comparing PEMWE and AWE 139 4.3.5 Other Types of Water Electrolyzers 141 4.3.5.1 Solid Oxide Electrolyzers 141 4.3.5.2 Microbial Electrolyzers (MEs) 144 4.4 Electrocatalysts for HER and OER 145 4.5 Electrocatalytic Seawater Splitting 147 4.5.1 Demographic Analysis 147 4.5.2 Challenges in Electrocatalytic Seawater Splitting 147 4.5.3 State-of-the-Art 151 4.5.4 Prospects for Electrocatalytic Splitting of Seawater 153 4.6 Conclusions 154 References 154 5 Electrochemical Carbon Dioxide Reduction Reaction 159Yating Zhu, Congyong Wang, Zengqiang Gao, Junjun Li, and Zhicheng Zhang 5.1 Introduction 159 5.2 Principles 160 5.2.1 The Conversion of CO2 to C1 Products 160 5.2.2 The Conversion of CO2 to Multi-Carbon Products 161 5.3 Materials for Electrochemical CO2RR 163 5.3.1 Metallic Materials 163 5.3.1.1 Transition Metallic Materials 163 5.3.1.2 Other Metallic Materials 165 5.3.2 Carbon Materials 165 5.3.2.1 Carbon Nanofibers 167 5.3.2.2 Carbon Nanotubes 167 5.3.2.3 Mesoporous Carbon 168 5.3.2.4 Graphene (Graphene Quantum Dots) 168 5.3.2.5 Diamond 170 5.3.3 Organic Framework Materials 171 5.3.3.1 Metal-Organic Frameworks 172 5.3.3.2 Covalent Organic Frameworks 176 5.4 Conclusion 178 References 180 6 Electrochemical N2 Reduction 183Yulu Yang, Jiandong Liu, Huapin Wang, and Jianmin Ma 6.1 Introduction 183 6.2 Fundamentals of Electrocatalytic Nitrogen Reduction 184 6.3 Product Detection and Efficiency Evaluation 186 6.4 NRR Catalysts 188 6.4.1 Noble Metal Catalysts 188 6.4.1.1 Au Base Catalyst 188 6.4.1.2 Ru Base Catalyst 190 6.4.1.3 Pd Base Catalyst 191 6.4.1.4 Pt Base Catalyst 191 6.4.2 Non-noble Metal Catalyst 191 6.4.2.1 Mo Base Catalyst 194 6.4.2.2 Ni, Co and Fe Base Catalyst 197 6.4.2.3 Metal-Free Catalysts 197 6.4.3 Monatomic Catalysts 197 6.5 Conclusion and Prospects 202 References 202 7 Photoelectrochemical Water Splitting 205Yangqin Gao, Ge Lei, Zhijie Tian, Hongying Zhu, and Lianzheng Ma 7.1 Introduction 205 7.2 Photoelectrochemical Cells 208 7.2.1 Water Splitting 209 7.2.2 Types of Photoelectrochemical Devices 209 7.2.2.1 Photoelectrolysis Cell 210 7.2.2.2 Photo-Assisted Electrolysis Cell 210 7.2.2.3 Photovoltaic Electrolysis Cell 210 7.3 Basic Concepts in Semiconductors 211 7.3.1 Electronic Properties of Semiconductors 211 7.3.2 Optical Properties of Semiconductors 218 7.3.3 Quasi Thermal Equilibrium and Quasi Fermi Level Splitting 222 7.4 General Properties of a Semiconductor/Liquid Junction 224 7.4.1 Equilibrium State at a Semiconductor/Liquid Junction 224 7.4.2 Charge Transfer at a Semiconductor/Liquid Junction 229 7.5 The Current-Voltage Behaviours of a Semiconductor/Liquid Junction 231 7.5.1 The Current-Voltage Characteristics of a Semiconductor/Liquid Junction in Dark 231 7.5.2 The Current-Voltage Characteristics of a Semiconductor/Liquid Junction under Illumination 233 7.6 Energy Conversion Efficiency 234 7.7 Summary 235 References 236 8 Photoelectrocatalytic Solar Water Splitting 241Deyu Liu and Yongbo Kuang 8.1 Introduction 241 8.2 Basic Concepts of Nonbiased PEC System 242 8.2.1 Thermodynamics of PEC System 242 8.2.2 Photoelectrodes and Photoelectrochemical Cells 244 8.2.3 Unbiased PEC Solar Water Splitting Cells 245 8.2.4 Selection of Semiconducting Materials 246 8.3 Design of Photoelectrodes from System-Wide View 250 8.3.1 From Semiconductor Materials to Photoelectrodes 250 8.3.2 Parameters of the Photoelectrodes 252 8.3.3 Functionalization Layers and Cocatalysts 255 8.3.4 Testing and Operation Conditions 258 8.4 Design of Integrated PEC Systems 261 8.5 Techno-Economic Assessment 264 8.6 Summary and Overlook 268 References 271 9 Photoelectrochemical Reduction of CO2 275Yuchen Qin and Haoyi Wu 9.1 Introduction 275 9.2 Fundamental Principles of PEC CO2 Reduction 276 9.2.1 Mechanism 276 9.2.2 Reaction Conditions 277 9.2.2.1 pH Value 277 9.2.2.2 Electrolyte Type 277 9.2.2.3 Reaction Temperature and Pressure 278 9.2.3 Evaluation Parameters for PEC CO2 Reduction 278 9.2.3.1 Product Evolution Rate and Catalytic Current Density 278 9.2.3.2 Faradaic Efficiency 278 9.2.3.3 Turnover Number and Turnover Frequency 278 9.2.3.4 Quantum Yield 279 9.3 Strengthen Strategies for PEC CO2 Reduction 279 9.3.1 Advanced Design for Photoelectrode 279 9.3.1.1 Photocathodes and Dark Anodes 279 9.3.1.2 Photoanodes and Dark Cathodes 285 9.3.1.3 Photoanodes and Photocathodes 286 9.3.1.4 PEC-Photovoltaic Cell Tandem and Wireless Monolithic Devices 286 9.3.2 PEC Reactor Configuration 287 9.3.2.1 Light Source 288 9.3.2.2 Heat Transfer 289 9.3.2.3 Utilization of CO2 289 9.3.2.4 Classification of Reactors 289 9.4 Summary and Perspectives 289 References 292 10 Photoelectrochemical Oxygen Evolution 301Hoi Ying Chung, Hao Wu, Xuelian Wu, Chenliang Su, and Yun Hau Ng 10.1 Introduction of Photoelectrochemical Oxygen Evolution 301 10.2 Working Principles of Photoelectrochemical Oxygen Evolution 302 10.3 Promising Visible Light Active Photoanode for PEC Oxygen Evolution 305 10.3.1 Tungsten Oxide (WO3) Photoanode 305 10.3.2 Hematite (¿-Fe2O3) Photoanode 308 10.3.3 Bismuth-Based Ternary Oxide Photoanode 311 10.3.3.1 Bismuth vanadate (BiVO4) 312 10.3.3.2 Bismuth Tungstate (Bi2WO6) 319 10.3.3.3 Bismuth Molybdate (Bi2MoO6) 322 10.3.4 Tantalum Oxynitride (TaON) and Tantalum Nitride (Ta3N5) 324 10.4 Summary and Outlook 328 References 329 11 Photoelectrochemical Nitrogen Reduction Reaction 339Gnanaprakasam Janani, Subramani Surendran, Hyeonuk Choi, and Uk Sim 11.1 Introduction 339 11.2 Nitrogen Reduction Reaction 341 11.3 Photoelectrochemistry for Provision of Sustainable Energy Sources 342 11.4 Fundamentals of Photoelectrochemical Nitrogen Reduction Reaction (PEC NRR) 344 11.5 Hitches in NRR 347 11.5.1 Semiconductor Considerations 347 11.5.2 H2 Evolution Reaction and Selectivity 348 11.6 Mechanisms 350 11.7 Contribution of Catalysts in PEC NRR 352 11.7.1 Semiconductors 352 11.7.2 Plasmon-Induced Ammonia Synthesis 360 11.7.3 Black Phosphorus-based Catalysts 366 11.7.4 Role of Diamond 367 11.8 Beyond Conventional Catalysts 369 11.8.1 Electrolytes 370 11.8.2 Diffusion of N2 Gas 370 11.8.3 Prototypes 370 11.8.4 N2 Adsorption and Activation on the Catalyst Surface 371 11.9 Methods to Measure Ammonia 373 11.9.1 Colorimetric Method 373 11.9.2 Ion Chromatography Method 374 11.9.3 Ion-Selective Electrode Method 374 11.9.4 Fluorometric Method 375 11.9.5 Conductivity Method 375 11.9.6 Titrimetric Method 376 11.9.7 In situ Fourier Transform Infrared spectroscopy 376 11.9.8 Nuclear Magnetic Resonance 376 11.10 Formulas 377 11.11 From the Holy Grail to Practical Systems 377 11.12 Conclusion 378 References 378 12 Photocatalytic Oxygen Reduction 389Hai-Ying Jiang and Xianguang Meng 12.1 Formation of ROS 389 12.2 Detection of ROS 393 12.2.1 Detection of 1O2 393 12.2.2 Detection of O¿¿2 394 12.3 Detection of H2O2 397 12.3.1 DPD-POD Method 397 12.3.2 DMP Method 398 12.4 Detection of ¿OH 398 12.5 Applications of Photocatalytic Oxygen Reduction 402 12.5.1 Synthetic Applications 403 12.5.2 Environmental Applications 404 12.5.3 Photocatalytic H2O2...