Preface
Trioxide (Nano-WO₃ ) , as a transition metal oxide with excellent physical and chemical properties, occupies an important position in the fields of materials science, chemical engineering and nanotechnology. Its unique semiconductor properties, optical properties and high specific surface area make it show a wide range of application potential in many fields such as photocatalysis, electrochromism, gas sensors and energy storage. The purpose of this book is to systematically sort out the scientific basis, preparation process, characterization method and application scenarios of nano tungsten trioxide, and at the same time combine patented technology, international standards and safety assessment to provide a comprehensive and practical reference guide for academic researchers, engineers and industry practitioners. By integrating the latest research progress and industrial practice, we hope to reveal the complete path of nano tungsten trioxide from laboratory exploration to industrial application, and promote its technological innovation in the fields of new energy, environmental protection and intelligent manufacturing.
Research significance and development history of nano-tungsten oxide
The research significance of nano tungsten oxide first comes from its excellent performance as an n-type semiconductor material. Its band gap energy range (2.4-2.8 eV) gives it strong visible light absorption ability, which gives it significant advantages in the field of photocatalysis, such as water splitting to produce hydrogen and degradation of organic pollutants. Compared with traditional photocatalysts (such as TiO₂ ) , nano-WO₃ is more responsive in the visible light region and can effectively utilize solar energy, which makes it a key material for solving energy crises and environmental pollution problems. In addition, WO₃ ’s electrochromic properties—the ability to control color and transmittance through electric fields—make it a core component for smart windows, displays, and dynamic thermal management devices. Nanoscale WO₃ also performs well in gas sensors (such as detecting NO₂ and H₂) and energy storage materials (such as lithium-ion battery anodes and supercapacitor electrodes) due to its high specific surface area (20-50 m² / g , compared to 5-10 m²/ g of micron – scale WO₃) and abundant surface active sites. Nanoscale quantum effects and surface effects further enhance their catalytic activity, ion diffusion rate, and photoelectric conversion efficiency, making them irreplaceable in interdisciplinary applications.
The unique properties of nano-tungsten oxide have not only promoted basic scientific research, but also opened up broad prospects for industrial applications. For example, its application in photocatalytic air purification and self-cleaning coatings has entered the commercialization stage, while its exploration in the fields of flexible electronics and biomedicine indicates the future development direction. However, the widespread application of nano-WO₃ is also accompanied by challenges, including how to achieve low-cost large-scale production, improve performance stability in complex environments, and evaluate its biological and environmental safety at the nanoscale. These issues are not only the focus of academic research, but also the focus of industry and policymakers.
The research and development of nano tungsten oxide can be traced back to the initial exploration of tungsten compounds in the late 19th century. As a rare metal, tungsten oxides first attracted attention due to the needs of the metallurgical industry. Yellow tungsten oxide (WO₃ ), as the main oxidation state of tungsten , has been widely studied due to its chemical stability, high temperature resistance (melting point of about 1473°C) and bright yellow appearance. At the end of the 19th century, chemists prepared WO₃ through the acidification reaction of tungstates (such as sodium tungstate Na ₂ WO ₄ ) , and initially revealed its amphoteric oxide properties – it can react with acids to form tungstates, and react with alkalis to form tungstates. The research at this stage mainly focused on the chemical properties and industrial preparation of WO₃ , laying the foundation for subsequent applications.
In the mid-20th century, with the rise of semiconductor physics, the study of WO₃ entered a new stage. In the 1960s, researchers first discovered that WO₃ could change color after applying an electric field. This electrochromic property was driven by the formation of tungsten bronze structures (such as H ₓ WO₃ ). This discovery quickly triggered research on its optical applications, such as anti-glare glasses and early display devices. Subsequently, the proposal of the Honda-Fujishima effect ( TiO ₂ photocatalytic decomposition of water) in the 1970s set off a wave of photocatalytic research. WO₃ was regarded as a strong competitor to TiO ₂ due to its lower band gap and better photochemical stability . For example, a study in 1976 showed that WO₃ could decompose water to produce oxygen under ultraviolet light, and this achievement promoted its in-depth exploration in the field of photocatalysis.
The rise of nanotechnology marks another leap forward in WO₃ research . Entering the 21st century, especially after 2000, with the breakthrough of nano-preparation technology (such as hydrothermal method and vapor deposition method), the synthesis of nano-scale WO₃ has become a reality. In 2004, researchers used a hydrothermal method to prepare WO₃ nanoparticles with a diameter of about 20 nm for the first time . Their photocatalytic activity was nearly three times higher than that of micron -sized materials . Subsequently, the development of morphologies such as nanowires, nanosheets, and porous structures further optimized their performance. For example, a 2010 study showed that WO₃ The nanowires have a high surface area of 40 m² / g, which increases their sensitivity in NO₂ detection by 5 times . At the same time, doping modification (such as N and S doping) and composite material design (such as WO₃ /gC ₃ N ₄ , WO₃ / TiO ₂ ) significantly improved its photocatalytic efficiency and electrical properties. In recent years, the application of nano-WO₃ in the field of energy storage has expanded rapidly. For example, a study in 2018 demonstrated the high capacity (>600 mAh /g) and cycle stability of WO₃ /graphene composites in lithium-ion batteries . In addition, its potential in emerging fields such as antibacterial coatings (using photocatalysis to produce active oxygen), thermochromic materials (doping V to adjust the color change temperature) and bioimaging (quantum dots WO₃ ) is gradually emerging.
Although the research on nano-WO₃ has made remarkable progress, its development still faces many challenges. The complexity of the preparation process limits large-scale production, the agglomeration effect of nanoparticles may reduce performance, and their long-term safety in the body still needs in-depth evaluation. These issues have driven technological innovations around the world, such as China’s breakthrough in high-purity WO₃ production (YS/T 572-2007 standard) and Europe and the United States’ efforts on nanomaterial safety specifications (ASTM B922-20). This book was written in this context. It aims to build a bridge from basic research to industrial application by systematically analyzing the structure, preparation, application and safety of nano-WO₃ , and to provide scientific support for solving major challenges in the fields of energy, environment and intelligent technology.
This book is divided into nine chapters, starting with the structure and properties of nano-tungsten oxide, and gradually exploring its preparation process, characterization technology, application fields, patents and standards, safety assessment and future prospects. The appendix provides data sheets, experimental guides, patent lists, standard comparisons and multilingual glossaries, striving to create a comprehensive and practical knowledge platform for readers around the world. We hope that this book will not only inspire new ideas for academic research, but also inject momentum into the industrialization process of nano-WO₃ .
Table of Contents
Preface
Research Significance and Development History of Nano-Tungsten Oxide
Chapter 1: Introduction to Nano-Tungsten Oxide
1.1 Basic Concepts of Tungsten Oxide
1.1.1 Definition and Chemical Formula (WO₃)
1.1.2 Color Variations of Tungsten Oxide (Yellow, Blue, Black)
1.1.3 Unique Properties at the Nanoscale
1.2 History and Development of Nano-Tungsten Oxide
1.2.1 Early Research and Discoveries
1.2.2 Progress Driven by Nanotechnology
1.3 The Status of Nano-Tungsten Oxide in Materials Science
1.3.1 Comparison with Other Nanomaterials
1.3.2 Industry and Academic Research Hotspots
Chapter 2: Structure and Properties of Nano-Tungsten Oxide
2.1 Chemical Structure
2.1.1 Crystal Structure of WO₃ (Monoclinic, Orthorhombic, Tetragonal Phase)
2.1.2 Impact of Nanostructures on Structure
2.1.3 Surface Chemistry and Bond State Analysis
2.2 Physical Properties
2.2.1 Particle Size and Morphology (Nanoparticles, Nanowires, Nanosheets)
2.2.2 Density, Hardness, and Thermodynamic Properties
2.2.3 Specific Surface Area and Pore Structure
2.3 Optical Properties
2.3.1 Bandgap Energy (2.4–2.8 eV)
2.3.2 Absorption Edge and Color Mechanism
2.3.3 Photochromic and Electrochromic Properties
2.4 Electrical Properties
2.4.1 Characteristics of N-Type Semiconductors
2.4.2 Conductivity and Carrier Concentration
2.4.3 Dielectric Constant and Electrochemical Properties
2.5 Chemical Properties
2.5.1 Redox Behavior
2.5.2 Stability and Volatility
2.5.3 Reactivity with Acids, Bases, and Reducing Agents
Chapter 3: Preparation Methods of Nano-Tungsten Oxide
3.1 Wet Chemical Methods
3.1.1 Hydrothermal Method
3.1.2 Solvothermal Method
3.1.3 Acid Precipitation
3.2 Thermochemical Methods
3.2.1 Thermal Decomposition
3.2.2 Calcination
3.2.3 Microwave-Assisted Synthesis
3.3 Gas Phase Methods
3.3.1 Chemical Vapor Deposition (CVD)
3.3.2 Physical Vapor Deposition (PVD)
3.3.3 Vapor Phase Oxidation
3.4 Other Methods
3.4.1 Mechanical Alloying
3.4.2 Electrochemical Synthesis
3.4.3 Biosynthesis
3.5 Process Parameter Optimization
3.5.1 Temperature, Pressure, and Time Control
3.5.2 Precursor Selection and Reaction Conditions
3.5.3 Morphology and Particle Size Control Technology
Chapter 4: Characterization Techniques for Nano-Tungsten Oxide
4.1 Structural Characterization
4.1.1 X-Ray Diffraction (XRD)
4.1.2 Transmission Electron Microscopy (TEM)
4.1.3 Scanning Electron Microscopy (SEM)
4.2 Chemical Characterization
4.2.1 Fourier Transform Infrared Spectroscopy (FTIR)
4.2.2 X-Ray Photoelectron Spectroscopy (XPS)
4.2.3 Energy Dispersive X-Ray Spectroscopy (EDS)
4.3 Physical Characterization
4.3.1 BET Surface Area Analysis
4.3.2 Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC)
4.3.3 Particle Size Analysis
4.4 Optical and Electrical Characterization
4.4.1 Ultraviolet-Visible Spectroscopy (UV-Vis)
4.4.2 Four-Point Probe Method
4.4.3 Cyclic Voltammetry
4.5 Characterization Data Analysis and Interpretation
4.5.1 Crystal Form and Phase Purity
4.5.2 Surface Chemistry and Defects
4.5.3 Quantification of Performance Parameters
Chapter 5: Applications of Nano-Tungsten Oxide
5.1 Photocatalysis
5.1.1 Water Splitting and Hydrogen Production
5.1.1.1 Photocatalytic Water Splitting Mechanism of Nano-WO₃
5.1.1.2 Doping Modification (Such as N, S) to Improve Hydrogen Production Efficiency
5.1.1.3 Heterojunction Design with Other Semiconductors (Such as TiO₂)
5.1.1.4 Experimental Case: Solar-Driven Hydrogen Production Performance
5.1.2 Degradation of Organic Pollutants
5.1.2.1 Degradation of Dyes (Such as Methylene Blue) by Nano-WO₃
5.1.2.2 Visible Light Responsiveness and Oxidative Free Radical Generation
5.1.2.3 Application Examples in Industrial Wastewater Treatment
5.1.2.4 Cyclic Stability and Photcorrosion Issues
5.1.3 Design of Composite Photocatalysts
5.1.3.1 Preparation and Properties of WO₃/g-C₃N₄ Composites
5.1.3.2 Synergistic Effect of WO₃/TiO₂ Core-Shell Structure
5.1.3.3 Precious Metal (Such as Pt, Au) Loading to Enhance Photocatalysis
5.1.3.4 Emerging Composite Systems (Such as WO₃/BiVO₄)
5.1.4 Photocatalytic Films and Devices
5.1.4.1 Design and Preparation of Self-Cleaning Glass Coating
5.1.4.2 Application in Air Purification Devices
5.1.4.3 Industrialization Attempt of Photocatalytic Reactor
5.2 Electrochromic Devices
5.2.1 Smart Windows and Displays
5.2.1.1 Color-Changing Mechanism of Nano-WO₃ in Smart Windows
5.2.1.2 Optimization of Optical Modulation Range and Response Time
5.2.1.3 Application Cases in Building Energy Conservation
5.2.1.4 High-Resolution Applications in Displays
5.2.2 Preparation and Properties of WO₃ Films
5.2.2.1 Sputtering Deposition and Sol-Gel Method for Thin Film Preparation
5.2.2.2 Effect of Nanostructure (e.g., Porous Membrane) on Performance
5.2.2.3 Cyclic Stability and Durability Test
5.2.2.4 Doping (Such as Ni, Mo) to Improve Color Change Efficiency
5.2.3 All-Solid-State Electrochromic System
5.2.3.1 Matching of WO₃ and Counter Electrode (e.g., NiO)
5.2.3.2 Selection and Optimization of Solid Electrolytes
5.2.3.3 Device Packaging and Mass Production Technology
5.2.3.4 Development of Flexible Electrochromic Devices
5.2.4 Emerging Applications
5.2.4.1 Electrochromic Mirror and Anti-Glare Application
5.2.4.2 Infrared Control in Dynamic Thermal Management
5.2.4.3 Integrated Sensors and Multifunctional Devices
5.3 Gas Sensors
5.3.1 Detection of Gases Such as NO₂, H₂, CO, etc.
5.3.1.1 Mechanism of High Sensitivity of Nano-WO₃ to NO₂
5.3.1.2 Selectivity and Responsiveness in H₂ Detection
5.3.1.3 CO and Other Volatile Organic Compounds (VOC) Detection
5.3.1.4 Effect of Different Morphologies (e.g., Nanowires)
5.3.2 Doping and Sensitivity Improvement
5.3.2.1 Enhancement by Doping with Noble Metals (Such as Pt and Pd)
5.3.2.2 Transition Metal (Such as Fe, Cu) Modification
5.3.2.3 Heterojunction (e.g., WO₃/SnO₂) Synergistic Effect
5.3.2.4 Doping Process and Performance Optimization
5.3.3 Microsensor Development
5.3.3.1 MEMS Technology Integrated Nano-WO₃
5.3.3.2 Flexible and Wearable Sensor Design
5.3.3.3 Low-Temperature Operation and Energy Consumption Reduction
5.3.3.4 Industrial and Environmental Monitoring Cases
5.3.4 Challenges and Future Directions
5.3.4.1 Humidity Interference and Anti-Interference Technology
5.3.4.2 Long-Term Stability and Aging Issues
5.3.4.3 Array Sensors for Multi-Gas Detection
5.4 Energy Storage Materials
5.4.1 Lithium-Ion Battery Negative Electrode
5.4.1.1 Embedding/De-Embedding Mechanism of Nano-WO₃
5.4.1.2 High Capacity and Cycle Performance Optimization
5.4.1.3 Composite with Carbon Materials (Such as WO₃/Graphene)
5.4.1.4 Rapid Charge and Discharge Performance Test
5.4.2 Supercapacitor Electrodes
5.4.2.1 Pseudocapacitance Characteristics of Nano-WO₃
5.4.2.2 Specific Capacitance and Power Density Improvement
5.4.2.3 Nanostructure Design (e.g., Nanosheet Arrays)
5.4.2.4 Symmetrical and Asymmetric Supercapacitors
5.4.3 Application in Sodium-Ion Batteries
5.4.3.1 Potential of Nano-WO₃ in Sodium-Ion Batteries
5.4.3.2 Volume Expansion and Stability Improvement
5.4.3.3 Electrolyte Matching and Performance Optimization
5.4.3.4 Comparison with Other Transition Metal Oxides
5.4.4 New Energy Storage Devices
5.4.4.1 Flexible and Wearable Energy Storage Devices
5.4.4.2 Zinc-Ion Batteries and Hybrid Capacitors
5.4.4.3 Exploration of Nano-WO₃ in Solid-State Batteries
5.5 Other Applications
5.5.1 Thermochromic Materials
5.5.1.1 Thermochromic Mechanism of Nano-WO₃
5.5.1.2 Doping (Such as V, Mo) to Adjust Color Change Temperature
5.5.1.3 Building and Automotive Temperature Control Coatings
5.5.1.4 Infrared Reflection Performance in Thermal Management
5.5.2 Antimicrobial Coatings
5.5.2.1 Antibacterial Mechanism of Photocatalytic Generation of Reactive Oxygen Species
5.5.2.2 Application of Nano-WO₃ in Medical Devices
5.5.2.3 Antimicrobial Efficacy and Safety Assessment
5.5.2.4 Development of Composite Coatings (Such as WO₃/Ag)
5.5.3 Pigments and Ceramic Additives
5.5.3.1 Yellow Pigment Properties of Nano-WO₃
5.5.3.2 Weather Resistance and Color Stability
5.5.3.3 Reinforcement and Modification in Ceramics
5.5.3.4 Application in Industrial Coatings and Plastics
5.5.4 Emerging and Cross-Domain Applications
5.5.4.1 Potential of Nano-WO₃ in Bioimaging
5.5.4.2 Photoelectric Applications of Quantum Dot WO₃
5.5.4.3 Catalyst Carrier and Chemical Applications
5.5.4.4 High-Temperature Resistance in Aerospace Materials
5.6 Challenges and Solutions in Applications
5.6.1 Improvement of Photocatalytic Efficiency and Visible Light Utilization
5.6.2 Lifespan and Cost Control of Electrochromic Devices
5.6.3 Selectivity and Environmental Adaptability of Gas Sensors
5.6.4 Volume Expansion and Cyclic Attenuation in Energy Storage Materials
5.6.5 Multifunctional Integration and Industrialization Bottlenecks
Chapter 6: Patent Overview of Nano-Tungsten Oxide
6.1 Preparation Method Patents
6.1.1 US7591984B2: “Impact Precipitation” Method for Nano-WO₃
6.1.2 CN103803644A: Preparation of Nano-WO₃ by Hydrothermal Method
6.1.3 JP2006169092A: Production of WO₃ Fine Particles
6.2 Application-Related Patents
6.2.1 US20110111209A: Highly Durable Electrochromic WO₃ Film
6.2.2 US10266947B2: Nano-WO₃ Gas Sensor
6.2.3 EP2380687A1: WO₃ Photocatalytic Coating
6.3 Patent Analysis
6.3.1 Global Patent Distribution and Trends
6.3.2 Technological Innovation and Competitive Landscape
6.3.3 Patent Protection and Industrialization Prospects
Chapter 7: Relevant Standards for Nano-Tungsten Oxide
7.1 Chinese Standards
7.1.1 YS/T 572-2007: Tungsten Oxide
7.1.2 YS/T 535-2006: Ammonium Metatungstate
7.2 Japanese Standards
7.2.1 JIS K 1462:2015: Analysis Methods for Tungsten Compounds
7.3 German Standards
7.3.1 DIN 51078:2002: Testing of Oxide Ceramic Materials
7.4 Russian Standards
7.4.1 GOST 25702-83: Chemical Analysis of Tungstates
7.5 Korean Standards
7.5.1 KS D 9502:2018: Analysis of Tungsten and Tungsten Alloys
7.6 International Standards
7.6.1 ASTM B922-20: Metal Powder Specific Surface Area Test
7.6.2 ISO 16962:2017: Surface Chemical Analysis
7.7 Standard Comparison and Application
7.7.1 Differences and Applicability of National Standards
7.7.2 Impact on Quality Control of Nano-WO₃
Chapter 8: Safety and Environmental Impact of Nano-Tungsten Oxide
8.1 Toxicity Assessment
8.1.1 Acute and Chronic Toxicity
8.1.2 Biosafety of Nanoscale WO₃
8.2 Occupational Health and Safety
8.2.1 Exposure Limits and Protective Measures
8.2.2 Dust and Waste Gas Treatment
8.3 Environmental Impact
8.3.1 Ecotoxicity and Water Pollution
8.3.2 Environmental Footprint of the Production Process
8.4 Green Manufacturing Technology
8.4.1 Low-Energy-Consumption Preparation Process
8.4.2 Waste Recovery and Recycling
8.5 Material Safety Data Sheet (MSDS) of Nano-Tungsten Oxide by CTIA GROUP LTD
8.5.1 Product Labeling and Ingredient Information
8.5.2 Hazard Identification (Physical, Chemical, and Health Risks)
8.5.3 Handling and Storage Recommendations
8.5.4 Emergency Measures (Leakage, Fire, First Aid)
8.5.5 Shipping and Regulatory Information
References
Appendix
Appendix A: Physical and Chemical Data Sheet of Nano-Tungsten Oxide
Including Detailed Parameters Such as Density, Melting Point, Band Gap, etc.
Appendix B: Experimental Procedures for Commonly Used Analytical Methods
XRD, FTIR, SEM, TEM, UV-Vis, BET, etc. Operation Guide
Appendix C: List of Patents Related to Nano-Tungsten Oxide
Detailed Listing of Patent Number, Title, and Abstract
Appendix D: List of Nano-Tungsten Oxide Standards
Comparison with Chinese, Japanese, German, Russian, Korean, and International Standards
Appendix E: Nano-Tungsten Oxide Multi-Language Terminology Table
Chinese, English, Japanese, and Korean Terminology Comparison Table
READ MORE:Nano Tungsten Oxide -Physical & Chemical Properties, Production Process, & Applications
Customized R&D and Production of Tungsten, Molybdenum Products
Chinatungsten Online and CTIA GROUP LTD have been working in the tungsten industry for nearly 30 years, specializing in flexible customization of tungsten and molybdenum products worldwide, which are tungsten and molybdenum design, R&D, production, and overall solution integrators with high visibility and credibility worldwide.
Chinatungsten Online and CTIA GROUP LTD provide products mainly including: tungsten oxide products, such as tungstates such as APT/WO3; tungsten powder and tungsten carbide powder; tungsten metal products such as tungsten wire, tungsten ball, tungsten bar, tungsten electrode, etc.; high-density alloy products, such as dart rods, fishing sinkers, automotive tungsten crankshaft counterweights, mobile phones, clocks and watches, tungsten alloy shielding materials for radioactive medical equipment, etc.; tungsten silver and tungsten copper products for electronic appliances. Cemented carbide products include cutting tools such as cutting, grinding, milling, drilling, planing, wear-resistant parts, nozzles, spheres, anti-skid spikes, molds, structural parts, seals, bearings, high-pressure and high-temperature resistant cavities, top hammers, and other standard and customized high-hardness, high-strength, strong acid and alkali resistant high-performance products. Molybdenum products include molybdenum oxide, molybdenum powder, molybdenum and alloy sintering materials, molybdenum crucibles, molybdenum boats, TZM, TZC, molybdenum wires, molybdenum heating belts, molybdenum spouts, molybdenum copper, molybdenum tungsten alloys, molybdenum sputtering targets, sapphire single crystal furnace components, etc.
For more information about tungsten chemical products please visit the website: tungsten-powder.com
If you are interested in related products, please contact us:
Email: sales@chinatungsten.com
Tel: +86 592 5129696 / 86 592 5129595
