Yellow tungsten oxide applied for photocatalytic degradation is known as tungsten trioxide or WO3, which has the characteristics of a small forbidden band width. And the absorption edge of WO3 extends into the visible light region. So, tungsten trioxide exhibits good photocatalytic degradation effect under visible light irradiation.

WO3 hollow sphere is a non-toxic semiconductor material with narrow band gap (2.4-2.8eV), which can be used as a catalyst for the catalytic degradation of organic matter in sewage in visible light catalytic reaction. It has been reported that the photocatalytic performance of WO3 hollow spheres can be characterized by the degradation of Rhodamine B.

Nano yellow tungsten oxide, or nano tungsten trioxide or nano WO3, is a new type of nano material that can be applied for pollutant adsorption. The particle size of tungsten trioxide is very small, so it has a large specific surface area, which makes it have good physical adsorption and chemical adsorption properties. In addition, WO3 is an acidic oxide, and its surface has acidic properties, thereby it can effectively adsorb basic dyes and heavy metal ions.

Yellow tungsten oxide hollow sphere is also called tungsten trioxide hollow sphere or WO3 hollow sphere, which has two surfaces - internal surface and external surface. And it is the two surfaces that allow WO3 to use light reflected into the interior multiple times through reflection, and therefore WO3 has unique applications, such as photocatalytic degradation of Rhodamine B solution.