WO3 (VK-W50) xanthelatine has a large specific surface area and significant surface effect. It is a good catalyst, which can be used as both the main catalyst and the cocatalyst, and has high selectivity for the reaction. WO3 has a strong ability to absorb electromagnetic wave, and can be used as an excellent solar energy absorbing material and recessive material. WO3 is an N-type semiconductor material with excellent gas sensitivity and is sensitive to H2S, NH3, H2, O3 and other gases, so it can be used to make gas sensitive sensors.
In recent years, through the joint efforts of many researchers at home and abroad, progress has been made in improving the gas sensitivity, selectivity, reducing the working temperature, different doping and improving the process of WO3 (VK-W50) based gas sensitive materials. In addition, with a band gap of about 2.5eV, tungsten trioxide has potential photocatalytic ability in visible light with a wavelength <500nm. Therefore, WO3 (VK-W50) has a potential application prospect in the treatment of water contaminated by organic dyes. The properties of nano – tungsten trioxide (VK-W50) are greatly affected by its morphology, microstructure and composition. Therefore, it is necessary to study the preparation of nano-tungsten trioxide (VK-W50) with different morphology and structure, and to discuss the effects of nano-size effect and special morphology effect on the gas sensitivity and photocatalytic properties of nano-tungsten trioxide.
Nano-tungsten trioxide has the following applications in gas sensing:
1, used for flammable gas leakage alarm and humidity sensor, the gas is mainly CO, CH4, H2, NH3, NO2, SO2, etc., which is mainly in the application of environmental monitoring.
2. In the civil area, it can detect the leakage of natural gas, liquefied petroleum gas and city gas and other civil gas and the gas produced when cooking food in the microwave oven to automatically control the cooking of food in the microwave oven. It can also detect some unpleasant gases in housing, buildings and other public places.
3, in the industry, for the detection of carbon dioxide, nitrogen oxides, sulfur oxides and other highly toxic gases in the petrochemical industry; Detecting hydrogen produced in the process of power transformer oil deterioration; Testing the freshness of perishable foods such as meat; It can also detect the concentration of ethanol gas in the breath of drivers in highway traffic to prevent drunk driving and reduce traffic accidents.
Nano-tungsten trioxide has the following applications in photocatalysis:
1. Application in the field of air purification. Photocatalytic technology in the field of air purification refers to the photocatalytic can directly use the oxygen in the air as an oxidizing agent, effectively decompose indoor and outdoor organic pollutants, oxidation to remove nitrogen oxides, sulfides and all kinds of odor in the atmosphere, and the reaction conditions are mild, is a very convenient air purification technology.
2, in the application of pharmaceutical wastewater. With the rapid development of the pharmaceutical industry, it has brought great economic benefits at the same time, its discharge of waste water to the environment pollution is also increasingly aggravated. Pharmaceutical wastewater has high concentration of organic matter, poor biodegradability, deep color, complex composition, containing oil, amine, acid, demulsifier and other pollutants, which is difficult to degrade organic wastewater, bringing unpredictable impact and harm to the ecosystem. Therefore, in recent years, more and more researches have been made on the degradation of organic pollutants by photocatalytic oxidation.
3. Application in wastewater treatment. In 1985, Wenshu et al. first reported the experiment of treating printing and dyeing wastewater with WO3 (VK-W50) as photocatalyst. The results showed that when visible light irradiates the semiconductor powder suspended in aqueous solution, the dyes are decomposed into CO2, H2O, N2, etc., thus reducing COD and chroma.