Ethanol-sensitive Co-doped graded porous structure ZnO microspheres, preparation and applications thereof

Abstract

The invention relates to a Co-doped ZnO microsphere with hierarchical porous structure sensitive to ethanol and its preparation and application. The method is to configure a certain concentration of urea and ascorbic acid solution, and then add a zinc source to the solution to dissolve to form a homogeneous solution . Then the above solution is subjected to hydrothermal treatment, and then washed, filtered, dried, and roasted to obtain Co-doped hierarchical structure ZnO microspheres sensitive to ethanol. Through the slow decomposition of urea in the hydrothermal process, the pH value of the reaction system is self-regulated to realize the microsphere structure; through the roasting treatment, the formation of mesopores is realized. The preparation method does not require a template, the process and process are simple, the parameters can be adjusted in a wide range, the repeatability is strong, and the cost is low. The various pore structures of the material can increase the proportion of the volume of the depletion layer in the material and improve the sensitivity to gases. , a Co-doped hierarchically porous ZnO microsphere sensing material with excellent sensitivity to ethanol was obtained.

Description

technical field [0001] The invention relates to a preparation method of a gas-sensitive sensing material sensitive to ethanol, and belongs to the technical field of preparation of inorganic nanometer materials. Background technique [0002] In the past few decades, with the development of industry and the great improvement of living standards, the demand for qualitative and quantitative detection of different analytes has increased. On-line analysis of gas mixtures is an essential method for quality control of industrial production, environmental protection and ensuring workplace safety. With the wide-scale use of biogas and the increase of nitrogen production, the detection of explosive gases is becoming more and more important. Automobile exhaust emits a large amount of CO, NOx. SO 2 , soot particles and hydrocarbons, forcing people to carry out mandatory monitoring of the city's air quality. Alcohol breath detection analyzers based on ethanol sensors have gradually rep...

AI Technical Summary

Problems solved by technology

[0005] (1) The sensitivity is too low or too high

If the sensitivity is too low, it will fail to meet the requirements for detecting trace gases, and if the sensitivity is too high, it may cause false alarms caused by the interference of ambient gases

[0006] (2) poor selectivity

Poor selectivity will cause the sensor to be interfered by interfering gases in the environment, resulting in false alarms

[0007] (3) Poor long-term stability

The sensitivity and baseline resistance of the gas sensor will change over time, reducing the life of the element and the reliability of the detection will also be affected

[0008] (4) High working temperature

[0009] (5) The resistance value of the component is highly dispersed

The resistance value of the element is affected by many factors such as the process, which makes the resistance of the element highly dispersed, which in turn leads to poor repeatability of the gas sensing performance of the element produced by the same preparation process

[0010] (6) Catalyst poisoning

The type and amount of additives can lead to significant differences in gas-sensing properties such as sensitivity, selectivity and operating temperature

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