Yellow Tungsten Oxide Gas Sensing Property

In recent years, yellow tungsten oxide catches wide concentration in special application field, especially in gas sensing industry. Nano yellow tungsten oxide, can be used to synthesize exploring sensing system in national defense industry. It can inspect biology, atom nuclear weapons and chemical material, also provide nano virtual training system for computer system. Moreover, it provides many convenient condition for high property communicating system.

Yellow tungsten oxide is a transmission metal oxide, its color is yellow or light yellow in powder form. The melting point is 1473℃，boiling point is 1750℃, density is 7.16 g/cm3. Among inorganic acid, yellow tungsten oxide can only reacts with hydrofluoric acid. It can also react with ammonium and concentrated alkali solution.

Semiconductor gas sensing is semiconducting material has reduction reaction or oxide reaction under special gas atmosphere, results in electric resistance change of semiconducting material. It can transfer targeted gas and concentration into electric signal, then to certify if targeted gas has concentration problem. So as to inspect, monitor and alarm the targeted gas.

Nano yellow tungsten oxide is a typical N type semiconducting functional material, it has large surface area, stable chemical property, wide vacancy, low cost and good response to visible light, so it is welcomed in gas sensing material.

Nano yellow tungsten oxide has strong surface absorption ability, it has good sensing to most gas which is volatile, such as ethanol, methane, formaldehyde, acetone, carbides, hydrogen sulfide, ammonia and hydrogen. As we have seen in daily gas and gas detection alarms, ethanol gas detection, indoor gas CO detection and freon detection and other environmental monitoring equipment and instruments, nano-tungsten trioxide has inherent advantages over other materials.

The synthesis of nano yellow tungsten oxide usually uses gas phase method, solid phase method, liquid phase method, the wider the use of liquid phase method, hydrothermal method is the most common method of liquid phase. In fact, the manufacture of gas sensors with nano yellow tungsten oxide usually needs to be doped to improve their photoelectric gas-sensing properties. The tungsten-oxide-based gas sensors usually can only work out at operating temperatures above 150 ° C. Better gas sensitivity. Future tungsten oxide gas sensor research direction is to find new doping materials, the use of certain auxiliary reagents, accurately control the preparation conditions to optimize the gas-sensitive properties of yellow tungsten oxide.

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