ZnSe/ZnO based nitrogen dioxide gas sensor and preparation processthereof

Abstract

The invention discloses a ZnSe/ZnO based nitrogen dioxide gas sensor and a preparation process thereof. The sensor comprises a gas sensitive material and a heating electrode, wherein the gas sensitivematerial is coated on the surface of the heating electrode, the coating thickness is 50-80 microns, and the gas sensitive material is a heterojunction composite nano-material formed by zinc selenideand zinc oxide. The preparation process comprises the steps of first, placing zinc selenide powder in an ark, putting the ark in a tubular furnace, introducing a dry gas mixture of 20% of oxygen and 80% of nitrogen for heating at the same time, and reacting at a temperature of 400 DEG C-600 DEG C for 0.5h-4h, then naturally cooling to the room temperature to obtain a ZnSe/ZnO heterojunction; second, putting the ZnSe/ZnO heterojunction powder into a mortar, adding deionized water, and grinding until the solution is in uniform suspension; taking the suspension, coating the suspension on the surface of the heating electrode, placing the sensor in a drying oven to dry at a temperature of 80 DEG C so as to obtain a nitrogen dioxide gas sensor. The nitrogen dioxide gas sensor has the advantagesof simple processing steps, low cost and sensitive response to nitrogen dioxide.

Description

technical field [0001] The invention belongs to the technical field of nitrogen dioxide gas sensors, and in particular relates to a ZnSe / ZnO-based nitrogen dioxide gas sensor and a preparation process. Background technique [0002] Nitrogen dioxide is one of the most common toxic gases that cause air pollution. It mainly comes from high-temperature calcination of fossil fuels, industrial waste gas, and exhaust emissions from motor vehicles. In view of the toxicity of nitrogen dioxide, when the human body is in an environment of nitrogen dioxide with a concentration greater than 8ppm for more than 5 hours, the human body will cause irreversible and serious damage. In recent years, gas sensors for detecting nitrogen dioxide are mostly made of metal oxide semiconductor materials. This type of sensor generally requires a high temperature working environment above 300°C, and its response sensitivity and anti-interference performance are average. In terms of technology, ceramic ...

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Problems solved by technology

In terms of technology, the heating resistance wire embedded in the ceramic tube is mainly used, and the preparation process is relatively cumbersome.

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