Tungsten Oxide

Tungsten trioxide is a unique n-type semiconductor material, that makes it one of the few oxide semiconductors which are easy-to-realize quantum size effect, and performances the excellent properties in photocatalysis, electrochromic, photochromic, gasochromic and other aspects, thus widely used in fields of chemical sensor, fuel cell, light catalyst and so on. Tungsten trioxide has orthogonal, monoclinic, cubic, hexagonal and other crystal structure. Among them, hexagonal tungsten oxide causes many concern because of its special hexagonal passage; many metal ions can be embedded in this hexagonal channel, thereby forming a hexagonal tungsten bronze which exhibits potential application in anode material and rechargeable lithium-ion battery. The crystal structure of the tungsten trioxide is ReO 3  type, the result of A-site cation Absence of ABO 3  perovskite structure, six oxygen atoms constituting the octahedron, W located therein and the neighbor WO6 octahedron l...

Hydrothermal process is carried in a special closed reaction vessel (reactor), the aqueous solution as medium, by heating the reaction vessel to create a high-temperature, high-pressure reaction environment to make the generally insoluble or poorly soluble material to dissolve and recrystallization, and then by filtering, washing, drying and other separation means to get the ultra-fine, high-purity particles. Hydrothermal method for preparing hexagonal tungsten trioxide, its crystalline form is affected by many factors, such as pH value, hydrothermal temperature and additives and others, the following will specifically analyze the impact of various factors. In the hydrothermal environment to prepare tungsten trioxide , the existence of hydrogen ions (H + ) is one of the important factors which affect crystal form of product, especially when the reaction condition is acidic environment. The influence mechanism of pH on tungsten trioxide crystal form is really complex, it is...