Nanomaterials have become one of the hotspots of current research due to their unique physical and chemical properties, such as high specific surface area, quantum size effect, small size effect and macroscopic quantum tunneling effect. In recent years, many Nano-Research centers have been established in China, and some remarkable achievements have been made in catalysis, gas sensing and other fields.

Tungsten oxide is a kind of tungstic anhydride and a kind of tungstate product. Tungsten oxide includes trioxide and tungsten dioxide. Tungsten oxide is partly used in the production of chemical products, such as paints and coatings, petroleum industrial catalysts, etc. But tungsten oxide is more an intermediate product and is widely used in the preparation of tungsten metal powder and tungsten carbide powder. It is used in the production of tungsten metal products and a large number of tungsten alloy products.

In the field of semiconductor photocatalysis, titanium dioxide has been widely studied, but its bandgap is wide (3.2ev). Only ultraviolet light can excite it to produce photogenerated carriers. In sunlight, the proportion of ultraviolet light is very small, so the utilization of sunlight in pure titanium dioxide photocatalysis process is very low.

When a semiconductor irradiates light with energy above bandgap, the electrons of valence band excite in the conduction band, generate holes in the valence band, and generate electrons in the conduction band. They have strong oxidation and reduction abilities respectively, and have redox effects on molecular species in contact with semiconductors. Such an action is called photocatalysis, and such semiconductors are called photocatalysts.