Nanostructured tungsten trioxide can be prepared by a sputtering method, a hydrothermal method, a sol-gel method, a thermal evaporation method, a chemical vapor deposition method, an anodization method, or a template method.

Tungsten trioxide is an important inorganic photochromic material that has a good application prospect in smart windows. In addition, WO3 has a good application prospect in the fields of photocatalysis, large-screen display, and high-density information storage. And thus WO3 nano powder has attracted widespread attention of scientists.

Some experts have proposed a method for preparing a high photoelectric WO3 film, which is composed of monoclinic tungsten trioxide nanosheets. The specific steps are as follows:

Tungsten oxide film with high photoelectric property can be prepared by hydrothermal method. Among them, experts use hydrochloric acid and heteropoly acid to co-acidify. They found that the incorporation of a small amount of heteropolyacid during the acidification process can greatly improve the photoelectric properties of the prepared WO3 film. The specific steps of this method to prepare high photoelectric WO3 film are shown as below: