VTO is the short for violet tungsten oxide, also known as γ-tungsten oxide. It is a kind of violet or blue-violet crushed crystalline powder that is soluble in ammonia water and alkali solution. And it is insoluble in alcohol, water and most of acid. Its chemical formula is WO2.72 or W18O49 with the molecular weight of 227.36.
Producing Method
Violet tungsten oxide is manufactured under a certain reduction condition from the raw materials of ammonium paratungstate (APT), tungstic acid or tungsten trioxide (WO3). 
The producing methods of violet tungsten oxide are mainly APT wet hydrogen direct reduction, tungstic acid hydrogen reduction and APT mild reduction method, ect.
Applications
1. Prepare tungsten powder, especially the production of nano, submicron or super-fine tungsten powder.
2. To prepare tungsten carbide, super-fine WC-Co powder.
3. Apply in the gas sensor, showing a good gas sensitive to nitrogen dioxide (NO2) under room temperature.
More details, please visit:
http://www.tungsten-powder.com/violet-tungsten-oxide.html
