Nano-structural ordered porous thin-film type gas sensor and method for preparing same

Abstract

The invention discloses a nano-structure orderly porous thin film gas-sensing element and preparation method. The element includes the substrate, the electrode and the thin file on it, especially the substrate being curved surface, and the thin film formed by spherical hole-shaped metal oxide, its aperture size 200~1000nm, thin film thickness 100~5000nm. The method includes the single layer colloidal crystal template, with steps (1) putting the single layer colloidal crystal template into the metal oxide precursor solution or sol of concentration 0.1~0.5M, and waiting for it detached from the substrate and floating on the surface of the precursor solution or sol, with the required shape electrode substrate to salvage the single layer colloidal crystals and covering it on the substrate surface; (2) first putting it under the temperature 80~120DEG C for heating 1~2 hours, then raising under the temperature 200~500DEG C for sintering 2~3 hours; (3) repeat the above (1) and (2) steps for more than 0 times, to make the nano-structure orderly porous thin film gas-sensing element. It can be widely used for environmental monitoring, chemical industry and many other fields.

Description

technical field [0001] The invention relates to a gas sensor and its preparation method, in particular to a gas sensor with nanostructure ordered porous film type and its preparation method. Background technique [0002] At present, gas sensors are widely used in many fields such as environmental monitoring and chemical industry. As one of them, thin-film gas sensors are favored because of their sensitive response, small size and stable and reliable operation. For example, various commercially available of. It consists of a substrate, electrodes, and a thin film covering it. In order to obtain it, physical methods such as vacuum evaporation, sputtering, plasma enhanced chemical vapor deposition and chemical methods such as sol-gel method are often used. But this film-type gas sensor and its manufacture method all have weak point, at first, the specific surface area of ​​element is little, makes its sensitivity low, and is difficult to improve, can not be used for some high...

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Problems solved by technology

But this film-type gas sensor and its manufacture method all have weak point, at first, the specific surface area of ​​element is little, makes its sensitivity low, and is difficult to improve, can not be used for some higher occasions; secondly, physical The equipment of the method is expensive, the operation is complicated, and it is mainly used for making on a flat substrate; again, when the sol-gel method is used as a commonly used chemical method to make components, the sol is preformed by manual coating. It is coated on the substrate and then heat-treated. Although this method can be produced on the substrate-ceramic tube with a curved surface, due to human factors, the thickness of the film on the surface of the element is not uniform, and the gas-sensitive material is easy to fall off. The stability and repeatability of the gas sensor are seriously affected

In order to overcome the above difficulties, people have made some attempts and efforts to increase the specific surface area of ​​the film by changing the size of the particles in the film. The measures adopted include photolithography, electron beam etching, micro-contact imprinting technology, etc.; however, There are also the defects of expensive equipment, complicated operation, and difficulty in direct synthesis on non-flat surfaces, especially the failure to synthesize nano-scale porous film-type gas sensors on curved substrates.

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