In-situ synthesis of cadmium oxide nanometer gas-sensitive element with secondary pore structure

Abstract

The invention discloses a cadmium oxide nanometer gas-sensitive element with a secondary pore structure. The cadmium oxide nanometer gas sensitive element is synthesized through the following steps: with ethylene glycol monomethyl ether as a solvent, preparing a mixed solution of 0.1 M of zinc acetate and 0.2 M of ethanolamine, soaking a glass slide into the mixed solution, and carrying out annealing treatment; preparing a mixed solution of 0.025 M of zinc nitrate and 0.025 M of hexamethylene tetramine, soaking the above-mentioned glass slide into the mixed solution, and carrying out heat-preserving so as to obtain a nanorod array of zinc oxide, wherein the nanorod array is used as a seed layer for growing cadmium oxide; placing cadmium sulfide (CdS) powder into an evacuated tubular furnace, placing an above-mentioned zinc oxide-grown substrate at a position 30 cm below the cadmium sulfide (CdS) powder, then introducing nitrogen and air, carrying out heating to 650 DEG C so as to obtain a nanosheet array of cadmium (Cd), and carrying out heat-preserving at 360 to 440 DEG C for 30 min so as to obtain a nanometer structure of cadmium oxide; and cutting the glass slide into a rectangular shape with a size of 0.5 cm * 1.0 cm, and carrying out coating with electrodes so as to prepare the gas-sensitive element. The gas-sensitive element provided by the invention has the following advantages: at a temperature of 215 DEG C, sensitivity to diethyl ether with a concentration 100 ppm is 138%, and response time and recovery time are 15 seconds and 27 seconds, respectively; meanwhile, the synthetic process is simple, safe and controllable, has low cost and is applicable to large-scale production.

Description

technical field [0001] The invention relates to a gas sensor, in particular to a cadmium oxide nanometer gas sensor with a secondary hole structure synthesized in situ by a chemical vapor deposition method. Background technique [0002] Diethyl ether is a colorless, flammable liquid with a special smell and is widely used in industrial production and scientific research. Molecular formula of diethyl ether C 2 h 5 OC 2 h 5 , is a colorless, flammable, highly volatile liquid with a pungent smell, used as an inhalational anesthetic, and is also a common drug. Ether vapor can form an explosive mixture with air. When it encounters sparks, high temperature, oxidants, perchloric acid, chlorine, oxygen, ozone, etc., there is a danger of combustion and explosion, and sometimes it is also ignited by static electricity (explosion limit 1.9%~ 36%, V / V). Because it is extremely volatile, it inevitably penetrates into people's lives and endangers people's health. Long-term low-conce...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problems that the existing two-dimensional materials are easy to agglomerate when used as gas-sensing materials, and there are few studies on in-situ synthesis of gas-sensing devices, especially the complex preparation process of ether detection devices and poor selectivity to ether. Zinc oxide nanorod arrays are used as the seed layer, and cadmium nanosheet arrays are grown on the zinc oxide nanorod seed layer by chemical vapor deposition, and cadmium oxide nanosheet arrays with secondary hole structure are oxidized in air, and then synthesized in situ Gas sensor, realizing a gas sensor with high selectivity to ether and short response time

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