3D quasi-vertical WO3 nanosheet film can be prepared by electrodeposition method. First, some experts used a simple solution method to prepare a WO3∙2H2O nanosheet sol with positive charges on the surface.

Amorphous tungsten trioxide is a type of tungsten trioxide, namely ɑ-WO3, which is an electrochromic material that can be used to prepare electrochromic film.

Tungsten trioxide can be applied for the preparation of smart window as WO3 has the advantages of high electrochromic color contrast, good cycle stability and good thermal stability. And therefore tungsten trioxide nano particles have become the most researched and commercialized inorganic electrochromic material in recent years.

Tungsten oxide smart window has excellent energy saving effect. According to statistics, if such new type of smart glass is used in glass curtain wall, it can reduce the operating cost of the building by 20%, including reducing its peak demand for electricity by 24%, reducing the load on the HVAC system by 25%, and reducing the lighting cost by 60%.