A lafeo with high gas sensitivity 3 Ethanol gas sensor and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of gas sensors, and provides a LaFeO3-based ethanol gas sensor with high gas-sensitive property and a preparation method thereof. La2 / 3Ba1 / 3Fe2 / 3Ti1 / 3O3 nano-powder prepared with a sol-gel method is taken as a working mediumsubstance for preparing a nindirectly-heated heater-type ceramic tube constructed gas sensor element. In a LaFeO3 lattice, an equivalent quantity of Ba elements and Ti elements with an equivalent quantity are introduced at a La bit and an Fe bit, so that the surface oxygen adsorption performance of the nano-powderis improved, the ethanol gas sensor element is lower in working temperature under the condition of not adding heavy metals or rare earth precious metals, and is higher in gas response and selectivity.The high gas-sensitive property LaFeO3-based ethanol gas sensor with high gas-sensitive property is 128 DEG C in best working temperature specific to the ethanol, is 48.1 in gas response specific to100ppm ethanol at the best working temperature, is below 22.4 and below in gas response specific to 100ppm acetone, DMF (Dimethyl Fformamide), dichloromethane, n-hexane, carbon dioxide and hydrogen gas response, and is up to 15.1 in gas response specific to 20ppm ethanol.

Description

technical field [0001] The invention belongs to the technical field of preparation of gas sensors, in particular to a LaFeO with high gas-sensing performance 3 Ethanol-based gas sensor and its preparation method, using LaFeO 3 The nanoparticle is the sensor element of the basic working substance, and its ethanol gas sensing performance is improved. 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. Currently, doped semiconductor oxides SnO 2 , ZnO, TiO 2 , Fe 2 o 3 , V 2 o 5 etc. are widely used in the detection of ethanol gas. The principle is to use the oxygen adsorbed o...

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 the current LaFeO with higher gas response 3 Ethanol-based gas sensor element, whose optimum working temperature is LaFeO below 200°C 3 The ethanol-based gas sensor element either contains heavy metal elements such as Pb, which is not conducive to environmental protection, or contains rare earth precious metals such as Sm, and the cost is relatively high

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