Nano WO₃ has a strong absorption capacity for electromagnetic wave. It can be used as an excellent absorption material in the utilization of solar energy and an important invisible material in the military. It also has a huge specific surface area and remarkable surface effect. It has been widely used in fuel cells, chemical sensors, optoelectronic devices and other fields.

Tungsten oxide is a typical transition metal oxide with a band gap of 2.4-2.8ev, which belongs to a typical n-type semiconductor. In addition to catalysis, electrochromism, battery electrode, solar energy absorbing material and invisible material, tungsten oxide also has the properties of semiconductor functional materials such as pressure sensitive, thermal sensitive and gas sensitive.

Metal oxides play a key role in the development of many advanced functional materials and smart devices. Among many metal oxides, tungsten trioxide (WO₃) is a kind of unique material, which has attracted much attention due to its versatility. For example, WO₃ is an n-type semiconductor with various crystal forms, band gap width of 2.5-2.8ev, and visible light response characteristics. Therefore, WO₃ can be used as light sensing device, photochromic device, transparent electrode, visible light catalyst, etc.

The preparation of core-shell nanocomposites is mainly divided into several methods, such as interface polymerization, condensed phase separation, drying bath and sol-gel method.