Amorphous Nanomaterials
Preparation, Characterization and Applications

A valuable overview covering important fundamental and applicative aspects of amorphous nanomaterials!

Amorphous nanomaterials are very important in non-crystalline solids, which have emerged as a new category of advanced materials. Compared to the crystalline counterpart, amorphous nanomaterials with isotropic nature always exhibit fast ion diffusion, relieved strain, and higher reactivity, enabling such materials to exhibit high performance in mechanics and catalysis, as well as other interesting properties.

Amorphous Nanomaterials: Preparation, Characterization, and Applications covers the fundamental concept, synthesis, characterization, properties, and applications of nanoscaled amorphous materials. It starts with the introduction of amorphous materials, then gives a global view of the history, structure, and growth mechanism of amorphous nanomaterials. Subsequently, some powerful techniques to characterize amorphous materials, such as X-ray absorption fine structure spectroscopy, spherical aberration electron microscope, in-situ-Transmission Electron Microscope, Electron Energy Loss Spectroscopy, and some other defect characterization technologies are included. Furthermore, the emerging innovative methods to fabricate well-defined, regularshaped amorphous nanomaterials, including zero-, one-, two-, and three-dimensional amorphous nanomaterials are systematically introduced. The fascinating properties and applications related to amorphous nanomaterials including the applications in electrocatalysis, batteries, supercapacitors, photocatalysis, mechanics, etc., are presented. It will greatly help the researchers to find professional answers related to amorphous materials.

• Great topic: amorphous nanomaterials are a very large and important field in both academia and industry
• Comprehensive: in-depth discussion of various important aspects, from both a fundamental and an applied point of view, on the chemistry, physics and technological importance of the amorphous nanomaterials are presented
• Vitally needed: the understanding of the fundamentals of amorphous nanomaterials is a prerequisite for devising new applications of such materials
• Highly relevant: amorphous nanomaterials have found specific applications in chemistry, catalysis, physics, sensing, batteries, supercapacitors, and engineering

Amorphous Nanomaterials is a vital resource for materials scientists, inorganic and physical chemists, solid state chemists, physicists, catalytic and analytical chemists, as well as organic chemists.

Foreword xi

Preface xiii

1 Introduction 1

1.1 Introduction of Amorphous Materials 1

1.2 Structural Differences between Amorphous Materials and Crystals 3

1.2.1 Crystals and Quasicrystals 3

1.2.2 Amorphous Materials 5

1.3 History of Amorphous Materials 7

1.3.1 Establishment of Crystallography 8

1.3.2 Enlightenment of Amorphous Materials 9

1.3.3 Modern Amorphous Materials 1-Disordered Elementary Substance 10

1.3.4 Modern Amorphous Materials 2-Metallic Glass 11

1.3.5 Modern Amorphous Materials 3-Nontraditional Amorphous Nanomaterials 14

1.4 Growth Mechanisms of Amorphous Nanomaterials 15

1.4.1 Classical Nucleation Theory 15

1.4.2 Multistep Transformation Mechanism with Amorphous Participation 17

1.4.3 Complex Growth Process in Solution 19

1.5 Summary and Outlook 19

References 20

2 Local Structure and Electronic State of Amorphous Nanomaterials 23

2.1 Spherical Aberration-Corrected Transmission Electron Microscopy 23

2.1.1 Introduction 23

2.1.2 Spherical Aberration-Corrected Transmission Electron Microscopy 24

2.1.3 Electron Energy Loss Spectroscopy in TEM 28

2.1.4 Applications in Amorphous Nanomaterial Characterization 34

2.1.5 Summary and Outlook 41

2.2 X-ray Absorption Fine Structure Spectrum 41

2.2.1 Introduction 41

2.2.2 Extended X-ray Absorption Fine Structure 42

2.2.3 X-ray Absorption Near-Edge Structure 45

2.2.4 Application in Amorphous Nanomaterial Characterization 47

2.2.5 Summary and Outlook 51

References 52

3 Defect Characterization of Amorphous Nanomaterials 61

3.1 Introduction 61

3.2 Positron Annihilation Spectrum 64

3.3 Electron Paramagnetic Resonance 71

3.4 Photoluminescence Spectroscopy 79

3.5 Summary and Outlook 82

References 84

4 Synthesis of 0D Amorphous Nanomaterials 89

4.1 Introduction 89

4.2 Bottom-Up Method 90

4.2.1 Solution-Based Chemical Method 90

4.2.2 Thermal Treatment Method 98

4.2.3 Other Methods 101

4.3 Top-Down Method 104

4.4 Summary and Outlook 106

References 106

5 Synthesis of 1D Amorphous Nanomaterials 111

5.1 Introduction 111

5.2 Hydrothermal/Solvothermal Method 113

5.3 Chemical Precipitation Method 116

5.4 Electrochemical Deposition Method 120

5.5 Templating Method 122

5.6 Other Synthetic Methods 124

5.7 Summary and Outlook 131

References 132

6 Synthesis of 2D Amorphous Nanomaterials 137

6.1 Introduction 137

6.2 Thermal Decomposition Method 138

6.3 Exfoliation Method 139

6.4 Deposition Method 143

6.4.1 Physical Vapor Deposition Method 143

6.4.2 Electrodeposition Method 143

6.5 Chemical Precipitation Method 147

6.6 Templating Method 148

6.7 Phase Transformation Method 151

6.8 Sol–Gel Method 151

6.9 Element Doping Method 152

6.10 Summary and Outlook 155

References 155

7 Synthesis of 3D Amorphous Nanomaterials 163

7.1 Introduction 163

7.2 Template-Engaged Strategies 163

7.2.1 Coordinating Etching Method 164

7.2.2 Acid/Alkali Etching Method 166

7.2.3 Redox Etching Method 169

7.2.4 Self-Templated Method 171

7.3 Electrochemical Method 173

7.4 Hydrothermal/Solvothermal Method 174

7.5 Common Solution Method 176

7.6 Laser/Ultrasonic-Assisted Solution Method 177

7.7 Other Synthetic Methods 179

7.8 Summary and Outlook 182

References 183

8 Synthesis of Amorphous-Coated and Amorphous-Doped Nanomaterials 189

8.1 Introduction 189

8.2 Amorphous Coated Nanomaterials by ALD 190

8.2.1 Amorphous Metal Oxide Coating 190

8.2.2 Amorphous Metal Fluoride Coating 192

8.3 Amorphous-Coated Nanomaterials With Different Dimensions 193

8.3.1 1D Amorphous-Coated Nanomaterials 193

8.3.1.1 Homojunction Structure 193

8.3.1.2 Hetrojuction Structure 197

8.3.2 2D Amorphous-Coated Nanomaterials 198

8.3.2.1 Carbon-Based Nanomaterials 198

8.3.2.2 Ni-Based Nanomaterials 200

8.3.2.3 Other Metal-based Nanomaterials 201

8.3.3 3D Amorphous-Coated Nanomaterials 202

8.3.3.1 Silica Coating 202

8.3.3.2 Carbon Coating 204

8.3.3.3 Metal Oxide Coating 205

8.3.3.4 Metal Sulfide Coating 207

8.4 Amorphous-Doped or Hybrid Nanomaterials 208

8.4.1 2D Amorphous-Doped Nanomaterials 208

8.4.2 3D Amorphous-Doped Nanomaterial 211

8.5 Summary and Outlook 215

References 215

9 Applications of Amorphous Nanomaterials in Electrocatalysis 223

9.1 Introduction 223

9.2 Fundamentals of Electrocatalysis 225

9.3 Amorphous Nanomaterials as Electrocatalysts for Water Splitting 226

9.3.1 Amorphous Nanomaterials for HER 226

9.3.1.1 Amorphous Single Metallic Nanomaterials for HER 226

9.3.1.2 Amorphous Binary Metallic Nanomaterials for HER 232

9.3.1.3 Amorphous Composite Nanomaterials for HER 234

9.3.2 Amorphous Nanomaterials for OER 237

9.3.2.1 Amorphous Single Metallic Nanomaterials for OER 238

9.3.2.2 Amorphous Binary Metallic Nanomaterials for OER 241

9.3.2.3 Amorphous Polynary Metal Nanomaterials for OER 244

9.3.2.4 Amorphous Composites for OER 246

9.3.3 Amorphous Nanomaterials for ORR 248

9.3.3.1 Amorphous Noble Metal-based Nanomaterials for ORR 249

9.3.3.2 Amorphous 3d Metal-based Nanomaterials for ORR 249

9.3.4 Amorphous Nanomaterials for CRR 251

9.3.5 Amorphous Nanomaterials for NRR 252

9.3.6 Amorphous Nanomaterials as Bifunctional Electrocatalysts 253

9.3.6.1 Amorphous Nanomaterials as Bifunctional Electrocatalysts of HER and OER 254

9.3.6.2 Amorphous Nanomaterials as Bifunctional Electrocatalysts of ORR and OER 256

9.4 Summary and Outlook 256

References 258

10 Applications of Amorphous Nanomaterials in Batteries 269

10.1 Introduction 269

10.2 Negative Electrodes in Batteries 269

10.2.1 Amorphous Phosphorus Compounds 269

10.2.2 Amorphous Silicon Compounds 273

10.2.3 Amorphous Transition Metal Oxides 280

10.2.3.1 Amorphous Iron Oxides 280

10.2.3.2 Amorphous Titanium Oxides 281

10.2.3.3 Amorphous Vanadium-Based Oxides 282

10.2.3.4 Amorphous Tin-Based Oxides 288

10.2.4 Amorphous Carbon 289

10.3 Positive Electrodes in Batteries 295

10.3.1 Amorphous Ferric Phosphate 295

10.3.2 Amorphous Vanadium-Based Oxides 300

10.3.3 Amorphous Metal Polysulfides 302

10.4 Summary and Outlook 304

References 306

11 Applications of Amorphous Nanomaterials in Supercapacitors 317

11.1 Introduction 317

11.2 Applications in Electric Double-Layer Capacitors 318

11.3 Applications in Pseudocapacitors 324

11.3.1 Amorphous Metal Oxides 325

11.3.2 Amorphous Metal Sulfides 334

11.3.3 Other Amorphous Nanomaterials 337

11.4 Summary and Outlook 341

References 342

12 Applications of Amorphous Nanomaterials in Photocatalysis 347

12.1 Introduction 347

12.2 Photocatalytic Degradation 349

12.3 Photocatalytic Decomposition of Water 355

12.4 Photo-Electrocatalysis 359

12.5 Amorphous Nanomaterial as Cocatalyst in Photocatalysis 363

12.6 Other Applications in Photocatalysis 366

12.7 Summary and Outlook 370

References 370

13 Engineering Applications of Amorphous Nanomaterials 375

13.1 Introduction 375

13.2 Mechanical Properties of Amorphous Nanomaterials 376

13.2.1 Amorphous Alloys/Metals 376

13.2.2 Amorphous Nonmetallic Materials 382

13.3 Strategy for Enhancing the Mechanical Performance 386

13.3.1 Introduction of Micro/Nanosecond Phase 387

13.3.2 Introduction of Micro/Nano-Inhomogeneity 393

13.3.3 Surface Modification 395

13.3.4 Amorphous Based Composite Materials 396

13.4 Summary and Outlook 401

References 402

Index 407

Lin Guo, Professor, is the executive dean of School of Chemistry, Beihang University, China. He has received several scientific awards including the Humboldt Fellowship Award, Germany in 2001, the Outstanding Youth Fund from Nature Science Foundation of China in 2007, the Yangtze River Scholars Distinguished Professor in 2011, and Second Prize of National Natural Science of China in 2013. Also, he was awarded the Fellow of the Royal Society Chemistry in 2015. His research interests focus on synthesis, characterization, and applications of zero-, one-, two- and threedimensional nanomaterials.