Noble metal doped particles and metallic oxide film integrated gas sensor and preparation method thereof

Abstract

The invention relates to a noble metal doped particles and metallic oxide film integrated gas sensor and a preparation method thereof. The integrated gas sensor comprises a substrate, a heating electrode, a heat-conductive insulating layer, a detecting electrode and a metallic oxide film, wherein the heating electrode is prepared on the substrate, the heat-conductive insulating layer is arranged between the heating electrode and the detecting electrode, and the metallic oxide film is covered on the detecting electrode; the integrated gas sensor is characterized in that noble metal particles are deposited on the metallic oxide film, and the noble metal particles are monatomically covered on the metallic oxide film, the coverage degree of the noble metal particles is 0.05-10% of the surface area of the metallic oxide film and the particle size is 0.2-0.4nm. The integrated gas sensor can effectively improve the gas sensitivity and the gas stability of the metallic oxide film; the metallic oxide film doped with noble metal particles can achieve the sensitivity improved to 9.46 of the noble metal and metallic oxide film from 1.51 of the pure metallic oxide film when used for testing 200ppm ethyl alcohol gas; furthermorethe gas sensitivity reaction temperature of the metallic oxide film is only 150 DEG C.

Description

technical field [0001] The invention belongs to the field of gas detection sensors, and in particular relates to an integrated gas sensor mixed with noble metal doped particles and metal oxide films and a preparation method thereof. Background technique [0002] With the development and improvement of the national economy, in industrial production and daily life, human activities emit a large amount of toxic and harmful gases, which makes the environment worse and seriously affects human health. At the same time, people's awareness of prevention of toxic and harmful gases in the environment has also been paid more and more attention. For example, the formaldehyde content in the home environment can cause chronic respiratory diseases; the leakage of flammable gases may cause explosions and fires; the emission of vehicle exhaust and the combustion of organic matter cause severe smog, and the toxic gases emitted by industries, especially chemical industries, are all harmful. I...

AI Technical Summary

Problems solved by technology

Although the magnetron sputtering method can obtain dense oxide films, the target utilization rate is not high, generally lower than 40%, and the plasma is unstable; the sol-gel method uses metal organic or inorganic compound solutions as raw materials. A method in which the submicron-sized ultrafine particle sol that shows dispersed fluidity in the solution generated by hydrolysis and condensation reaction is combined with the ultrafine particle to form a solidified gel on the outer layer, and then heat-treated to make it oxidized

Although the sol-gel method is suitable for large-scale industrial production, it has the following disadvantages: (1) most of the raw materials used are organic compounds, the cost is high, and the processing time is long, often up to 1-2 months; (2) ) The product is easy to crack, which is caused by the large amount of liquid in the gel and shrinkage during drying; (3) If the firing is not perfect, pores and OH radicals or C will remain in the product, and the latter will make the product black

However, the obtained noble metal particles are not easy to transfer and assemble, and are easy to contain impurities and aggregate

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