A lafeo co-modified with au and cl 3 Ethanol gas sensor and preparation method thereof

Abstract

The invention belongs to the technical field of gas sensor production, and provides an Au and Cl co-modified LaFeO3-based ethanol gas sensor and a production method thereof. The method comprises the following steps: adding an aqueous HAuCl4 solution with the mass fraction being 1% into a LaFeO3 solution according to a mass ratio of the aqueous HAuCl4 solution to the LaFeO3 solution of 1:100, preparing Au and Cl co-modified LaFeO3 nano-powder through a sol-gel technology, and producing an indirectly-heated ceramic tube structure gas sensor element. The best working temperature of the produced gas sensor element to ethanol is 128 DEG C; the gas response to 100 ppm of ethanol at the best working temperature is 47.7, and has no much change 96 h later, so the gas sensor element has a good stability; the response to 100 ppm of DMF, dichloromethane, n-hexane, carbon dioxide, and hydrogen gases is 23.3 or less, and has a good selectivity; the gas response to 20 ppm of ethanol is 19.5, and thegas sensor element has a very high gas response to a low-concentration ethanol gas.

Description

technical field [0001] The invention belongs to the technical field of gas sensor preparation, in particular to a LaFeO co-modified with Au and Cl 3 Ethanol-based gas sensor and its preparation method, LaFeO co-modified with Au and Cl 3 Nano-powder is the working substance, which can significantly improve the LaFeO 3 The gas response of the ethanol-based gas sensor element, where the gas response is defined as the ratio of the resistance of the sensor element in the gas environment to be measured to the resistance in dry air. Background technique [0002] With the development of modern society, people pay more and more attention to health and safety issues. Ethanol is the main component of all kinds of alcohol, and it is also a flammable gas. Excessive drinking, drunk driving and leakage of ethanol have great health and safety Therefore, a highly sensitive, highly selective, stable and reliable ethanol gas sensor is of great significance to human health and life safety. C...

AI Technical Summary

Problems solved by technology

However, based on the previous research work of scientific researchers, we found that: LaFeO 3 The resistance itself is very large, which is not conducive to practical applications, and LaFeO 3 The optimal operating temperature of ethanol-based gas sensor components is still high, usually above 200 ° C, which is not conducive to the research of low-power devices; the gas response to ethanol gas is not high enough at the optimal operating temperature, especially for low concentrations The ethanol gas response needs to be improved

The current method is mainly to replace the position of trivalent La by doping divalent elements such as Ca, Sr, Ba, Pb, or replace the position of trivalent Fe by doping with elements such as Co, Mg, Ni, etc., to provide more holes. Carriers, thereby reducing the resistance of the material and improving its gas-sensing performance, but currently LaFeO 3 Gas response and selectivity of ethanol-based gas sensor elements still need to be improved

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