Tungsten oxide is a very classic low-dimensional transition metal oxide material, which is attracted by its special physical and chemical properties (such as electrochromism, photochromism, catalytic activity, superconductivity and large load capacity, etc.) A large number of materials, semiconductor devices, and physics and chemistry researchers are paying attention. However, there is no report on white tungsten oxide and its preparation method.
The chemical formula of white tungsten oxide is the same as that of purple tungsten oxide, which is W18O49. It can be excited to become blue under the irradiation of ultraviolet light, and it can be restored to white after removing the ultraviolet light. It is widely used in construction, automobiles and other fields.
A method of producing white W18O49, there are the following steps:
Disperse the tungsten hexachloride ultrasonically in anhydrous n-butanol, of which 150ml anhydrous n-butanol is used per gram of tungsten hexachloride. When the system turns from yellow to blue during the ultrasonic process, stop the ultrasound, and then add it to the system Sodium nitrate, the amount of sodium nitrate is 1.5-3 times the mass of tungsten hexachloride, put the mixed system into the reaction kettle, control the reaction temperature at 180-220°C, and control the reaction time at 6-12 hours; wait for the end of the reaction After cooling to room temperature, the obtained product was washed with water and ethanol, centrifuged, and dried to obtain powdery white W18O49.
This method uses tungsten hexachloride and n-butanol as reactants. The color of the reaction product W18O49 can be adjusted by controlling the amount of sodium nitrate added. When the mass ratio of sodium nitrate and tungsten hexachloride is more than 3:2, white 118049 can be obtained. . The advantage is that by adding sodium nitrate to the system to modify the surface of the tungsten oxide, white tungsten oxide is obtained, which is obviously different from the W18O49 obtained by the general solvothermal method in appearance and color; and the production is simple and easy.