In 1972, Honda and Fujishima successfully used n-TiO₂ electrode to produce hydrogen from water by photolysis of solar energy, which made people realize the application prospect of Photoelectrochemical conversion of solar energy to electric energy and chemical energy. At the same time, this technology is applied to solve the problem of dye wastewater and other industrial wastewater.

Electrochromism refers to the phenomenon that the optical properties (transmissivity, reflectance or absorptivity) of materials in the ultraviolet, visible or (and) near infrared region produce stable and reversible changes under the action of external electric field, which shows reversible changes of color and transparency in appearance.

Bactericide wastewater is a typical kind of toxic and harmful industrial wastewater which is difficult to degrade, such as wastewater from pesticide industry and some chemical industry. Because of the high concentration of bactericide in wastewater, it can kill and inhibit the growth of microorganisms. On the other hand, most of the organic fungicides are polycyclic or heterocyclic organic compounds with poor biodegradability. Therefore, it is difficult to treat the bactericide wastewater directly by biotechnology.

Polluted wastewater and anti biotic wastewater are typical toxic and harmful industrial wastewater that are difficult to degrade, such as wastewater from pesticide industry and wastewater from some chemical industry. Because of the high concentration of fungicides in wastewater, which can kill and inhibit the growth of microorganisms, it is difficult to treat this kind of wastewater directly by biotechnology.

Tungsten is an irreplaceable key material in many fields due to its excellent high temperature resistance, high strength and hardness, especially in the fields of national defense industry and aerospace. Compared with the pure tungsten, the aluminum oxide coated tungsten and tungsten alloy can greatly increase the strength of tungsten, refine the grains, reduce the particle size, increase the toughness and tensile strength of the material.

Through a simple hydrothermal method, the researchers prepared a wide range of tungsten oxide nanowire gas sensing materials on a large scale, and then provided a tungsten oxide nanowire sensor with high sensitivity, good repeatability and high stability for H₂, CO and NH₃. The operation process is as follows:

Scheelite is a troublesome raw material in tungsten smelting. After the popularization of alkaline pressure leaching technology in the last century, the smelting capacity and scale of scheelite have been greatly improved, and the technology and process have been further mature. Due to the use of excessive alkali process, although a large part of alkali is consumed in the leaching process, the amount of residual alkali in the crude sodium tungstate solution is still very high after the reaction.

Tungsten oxide is a kind of transition metal oxide, which belongs to n-type semiconductor. At present, a large number of researches have found that w-based oxides not only act as catalytic, electrochromic, solar energy absorbing and invisible materials, but also have the characteristics of semiconductor functional materials such as heat sensitive, pressure-sensitive and gas sensitive.

In recent years, with the development of industrialization and the rapid improvement of people's living standards, environmental pollution has become the main problem facing human beings, especially water pollution, which has attracted more and more attention. Industrial waste water accounts for a large part of the water pollution sources. Because of its dark color and strong toxicity, it is difficult to treat.

To produce tungsten powder from ammonium paratungstate, it is usually necessary to first burn tungsten oxide in a weak reducing atmosphere, and then carry out hydrogen reduction to produce tungsten powder. Most of the tungsten powders prepared by this process are very regular polycrystalline, which are the main raw materials for the preparation of tungsten alloy and tungsten carbide.