Tungsten Oxide

Tungsten oxide is a kind of tungstic anhydride, which is a tungstate product. Tungsten oxide type includes tungsten trioxide and tungsten dioxide. In actual industrial production, it is rare to have tungsten dioxide. Tungsten dioxide is also known as brown tungsten oxide. The formula WO 2  tungsten dioxide is an intermediate transition state of ammonium paratungstate into tungsten trioxide. Its appearance is tan monoclinic powder crystal, and tungsten dioxide is the most commonly known, the role is to manufacture tungsten powder and tungsten trioxide. Tungsten trioxide, also known as yellow tungsten oxide, chemical formula WO 3 , is the main tungsten oxide product of our country before the eighties. Yellow powder is insoluble in water, soluble in alkali and slightly soluble in acid. Its density is 7.16 g / cm 3 ; The melting point is 1473 ° C; the boiling point is about 1700 ° C. Mainly used in the system of high melting point alloys and cemented carbide, tungsten wire and fire gas se

Ball mill is a fine equipment used in industry and can also be used for mixing. The ball mill is composed of a cylinder and sphere, its working principle is when the cylinder rotates, installed in the cylinder body and the grinding body in grinding by centrifugal force and friction force with the cylinder to rotate to a height, and then automatically fall, the material in the cylinder impact and the grinding and grinding material. The main factors affecting the efficiency of the ball mill are the speed of the ball mill, the quantity of the ball, the amount of water and electrolyte, the time and the loading. The normal milling time is about 24-72 hours, and the length of the ball milling time directly affects the quality of the ball milling product. Generally speaking, coarse grained material is easier to grind to coffee, and the time is shorter. However, the milling time of gal material to cut below is usually prolonged by several times or longer. However, with the prolongation of ball

Tungsten trioxide (WO 3 ) is a kind of transition metal oxides, it is not only a kind of N type semiconductor material, is also a kind of "d0" oxide, this dual identity so it has many characteristics. The research shows that there is rod, plate and rod plate three kinds of nano tungsten oxide crystal, gas sensing properties of tungsten oxide with different crystal morphology is slightly different, some scholars use tungsten trioxide for four kinds of common harmful gases were tested and concluded. (1) The best working temperature of WO 3  sensor in ethanol, acetone, ammonia and formaldehyde is 350 ℃, 300 ℃, 325 ℃ and 250 ℃, respectively, and the sensitivity reaches the maximum at gas concentration of 1000 ppm. 21.29, 10.82, 24.32 and 9.68 respectively, and the lowest detection concentration of gas sensors for four gases are 100ppm, 50ppm, 25ppm and 100ppm, respectively. (2) The best working temperature of nano-plate WO 3  gas sensor is 350 ℃, 300 ℃, 325 ℃ and 250 ℃, respecti

Nano tungsten trioxide is a typical N-type semiconductor gas sensing material, which has a large specific surface area, stable chemical properties, a variety of toxic gases have good sensitivity, can effectively improve sensitivity and responsiveness of gas sensors effectively reduce the harmful effects of harmful gases on human health. The preparation of nano tungsten trioxide by hydrothermal method can overcome the problems that the nano rods prepared in the prior art have larger diameters, uneven distribution of rods and other forms of particles.  Using ammonium metatungstate as tungsten source, citric acid as the profile control agent, according to a certain proportion in the mixed solution, adding concentrated hydrochloric acid solution was adjusted by drops in pH magnetic stirring at room temperature is equal to 1.5, half an hour so that the magnetic stirring solution mixing, the mixed solution was transferred to a hydrothermal reaction kettle PTFE capacity of 100 mL in seal, pl