Tungsten Oxide

In the past few years, an increasing interest has been put on the tungsten oxide films due to their potential applications in smart windows, gas sensors, photocatalytic reactions, and optoelectronic devices etc. The unique properties of the tungsten oxide films were usually determined by the oxygen defects and the valence states of tungsten ions. Besides, it is very important to improve the properties of tungsten oxide films and other oxide films by controlling their morphologies and crystalline phases,which mainly depend on the preparation technologies and thermal treating temperatures and atmospheres. When the temperature of the source and substrate changes, the growth of the tungsten oxide nanowires changes with regularity. i.e., as the temperature of the source of evaporation and substrate increases, the diameter of tungsten oxide nanowires increases gradually and its diameter increases faster than its height; as the temperature of the substrate increase, the height of t...

Nano-sized materials and products have been used widely in many applications because of their outstanding properties, different from those of the bulk materials. In early investigations into nanotechnology, the arc discharge technique was the first well-developed method used to manufacture nanoproducts. However, owing to difficulties involved in controlling the manufacturing parameters, the purity and quality of nanoproducts synthesized by arc discharge called for improvement. The inert gas condensation (IGC) system was thus established by Gleiter. Because there are no catalysts or containments, it is considered the cleanest method of producing high quality products. In this system, metals are first placed in a tungsten or graphite boat and evaporated. The metal vapor is then cooled under an inert gas atmosphere (e.g. helium or argon) to condense into clusters or nanoparticles. Although the arc method has a higher production rate than IGC system, the latter produces larger ...

Composites calcined in the silica pores of silica acid is converted to form the influential tungsten oxide , tungsten oxide calcination temperature of crystallization and its mesoporous structure. This paper explores at 550-950 ℃ between different calcination temperature impact of mesoporous tungsten oxide structure. Ethanol as a dispersant, and silicotungstic acid silica mesoporous material than m (WO3) / m (SiO2) 3/1, after calcination at different temperatures HF treated tungsten oxide. When the calcination temperature at 550 ℃, almost no diffraction peaks in the small, indicating the degree of structural ordering poor, while N2 adsorption - desorption characterization of the specific surface area of ​​42.7m2 • g-1, and after more than 600 ℃ calcined surface area of ​​68.0m2 • g-1 there were significant decreases when the calcination temperature is 600-750 ℃ ​​when, in the vicinity of 2θ = 1 ° there is a clear diffraction peaks, indicating that the tungsten oxide upon calcination ...

Electrochromic film materials include various organic and inorganic compounds, of which the most studied is tungsten oxide , the main methods of preparation include vacuum thermal evaporation, electron beam evaporation, sputtering, vapor deposition, electrodeposition and sol - gel method. Electrochromic film a certain temperature heat treatment can improve their adhesion and cycle life, but the high temperature heat treatment tends to affect the magnitude of the response time and color film. General physical preparation methods require high temperature heat treatment, such as electron beam evaporation method needs a heat treatment 500e, 350e thermal evaporation requiredRF sputtering need 200 ~ 300e. These methods are often due to expensive equipment, technical complexity and demanding process conditions and subject to certain restrictions; the chemical preparation of the sol - gel method is a simple equipment, low temperature deposition uniformity and easy preparation method for pre...