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.

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.

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.

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.