Tungsten disulfide is a fine gray crystalline or powder with metallic luster. It belongs to hexagonal crystal system. It has semiconductor and diamagnetic properties, layered structure, easy dissociation, and lubricating properties similar to graphite. It is mainly used as lubricant. Its performance is better than molybdenum disulfide. Its friction coefficient is lower and its compressive strength is higher.

Transition metal oxides can be used in various fields. Molybdenum oxide and tungsten oxide, as two important transition metal oxides, have attracted the attention of scholars and experts in the fields of photocatalysis and gas sensors for a long time. In the past few years, it has been found that the properties of binary molybdenum tungsten oxide (MoxW1-xO3) materials can be greatly improved due to the "synergistic effect" of the two elements. Therefore, by changing the composition and structure of materials, we can make this "synergistic effect" play a stronger role.

Tungsten carbide is the main raw material for the manufacture of cemented carbide products, and its particle size has a decisive influence on the properties of cemented carbide products. The preparation of nano tungsten carbide has become the main way to improve the strength and toughness of cemented carbide products. Cemented carbide is brittle material. There is a contradiction between its hardness and strength. High hardness leads to low strength, while high strength leads to low hardness.

Zirconium tungstate is a special kind of negative thermal expansion material with isotropic negative thermal expansion property. It reaches thermodynamic stability in the temperature range of 1378K-1530K, and exists in metastable state at room temperature. At present, three kinds of phases have been found: low temperature cubic phase a-ZrW₂O₈, high temperature phase beta-ZrW₂O₈ and high pressure phase gamma-ZrW₂O₈. Their thermal expansion coefficients are aalpha=-8.7x10^-6/K, abet=-4.9x10^-6/K and agamma=-1x10^-6/K.

At present, the commonly used preparation methods of tungsten trioxide thin films are atomic layer deposition, chemical vapor deposition and electrodeposition. However, the tungsten trioxide thin films based on the above methods require high equipment, complex preparation process, high cost, and can not prepare large-area films. Therefore, it is imperative to develop a tungsten oxide PEC semiconductor electrode material with simple production process, low cost, high purity and high photoelectric conversion efficiency.

PM2.5 is an important factor affecting air quality. Coal-fired power plants, oil-fired automobile ships, especially diesel engine automobile ships, are the sources of PM2.5. With the development of China's automobile industry and the increase of automobile ownership, the treatment technology of automobile exhaust has attracted more and more attention.

Because of its high chromogenic efficiency and low price, nano tungsten trioxide has always been the preferred electrochromic compound. In addition, as a photocatalytic hydrogen production electrode material, nano-tungsten trioxide has also been widely concerned.

Environmental protection and sustainable development have become important issues that human beings must consider. Photocatalytic technology, as a branch of green chemistry, is an important environmental protection treatment industry in the future.

Although tungsten carbide has platinum-like catalytic performance and strong anti-CO poisoning ability, its dispersibility is poor, its specific surface area is small, it is easy to agglomerate, and its conductivity is poor, and its catalytic activity is not ideal. Compared with platinum and other noble metal catalysts, there is still a big gap.

The results show that the one-dimensional tungsten oxide nanostructures have large specific surface area, surface activity and strong gas adsorption capacity, which can accelerate the reaction between gases, further improve the sensitivity and effectively lower the working temperature. In order to obtain such a high performance gas sensor, the first step is to prepare nanomaterials that can meet these requirements.