With the development of modern industry, the situation of air pollution, water pollution and soil pollution is getting worse and worse. People feel the harm of environmental pollution to themselves. Protecting the environment is to save themselves. People urgently need a low cost, high efficiency and energy for non-toxic degradation and purification.

Titanium dioxide is known as a photocatalyst material, but it has little function in the absence of ultraviolet radiation. Therefore, Scientists prefer to study visible-light tungsten trioxide photocatalysts.

Although sunlight is a clean energy source, many problems hinder its widespread use. The most important is its intermittence, which is not always sunny, and sunny periods are not always highly correlated with electricity demand. In addition, if the electricity generated by solar energy cannot be used or stored immediately, it will be wasted. Therefore, there is a need for a practical way to store solar energy, which can be used when needed. These means can make people use solar energy and hydrogen energy more efficiently and further reduce their dependence on oil.

Energy shortage and environmental deterioration have become the most important problems facing all countries in the world. The development of new functional materials will be an effective way to solve these problems. Because of its unique physical and chemical and electronic properties, tungsten oxide materials have good application prospects in the fields of color-changing window, photocatalysis, fuel cell, chemical sensor, environmental purification, solar energy conversion and other functions, and have become one of the hot topics in the current research of new materials.