阅读说明：本技术 用于检测三甲胺的气敏传感器 (Gas sensor for detecting trimethylamine ) 是由 吴洋 常训朋 李�杰 田照鹏 聂放 王昆 宋长燕 于 2019-09-05 设计创作，主要内容包括：本发明公开了一种用于检测三甲胺的气敏传感器,所述气敏传感器包括：氧化铝陶瓷管和所述氧化铝陶瓷管表面涂覆的气敏材料。根据本发明的气敏传感器对三甲胺具有高的选择性和灵敏度,同时响应时间短,检测限更低。同时工作温度相对于现有技术的其它氧化物气敏材料更低。(The invention discloses a gas sensor for detecting trimethylamine, which comprises: the gas-sensitive material is coated on the surfaces of the alumina ceramic tube and the alumina ceramic tube. The gas sensor has high selectivity and sensitivity to trimethylamine, short response time and lower detection limit. While operating at lower temperatures relative to other oxide gas sensitive materials of the prior art.)

1. A gas sensor for detecting trimethylamine, the gas sensor comprising: the gas-sensitive material is coated on the surfaces of the alumina ceramic tube and the alumina ceramic tube;

the preparation method of the gas sensor comprises the following steps:

1) cleaning an alumina ceramic tube with deionized water and acetone, and drying for later use;

2) uniformly coating a suspension of a gas-sensitive material with the weight percentage concentration of 1.5mg/ml on the alumina ceramic tube, and packaging the alumina ceramic tube;

3) aging at 150 to 350 ℃ for 4 to 6 days to prepare the gas sensor;

wherein, the gas sensitive material in the step 2) is prepared as follows:

21) mixing ammonium molybdate and SnCl₄Dissolving the mixture in deionized water according to the molar ratio of 1:0.8 to 1:1.2 to form a solution, dropwise adding ammonia water under the stirring condition to adjust the pH value of the solution to 9.7, continuously stirring for 3 hours, standing and settling, filtering, washing a filter cake for 3 times by using deionized water, placing the filter cake in a drying oven, heating to 350 ℃, preserving heat for 4 hours, cooling to room temperature, fully grinding to obtain MoO₃And SnO₂Composite nanoparticles;

22) adding CdCl₂Dissolving the mixture in deionized water to form a solution, and then adding the MoO obtained in the step 1)₃And SnO₂Composite nanoparticles incorporating the CdCl₂In solution, wherein, CdCl₂Molar amount of (2) and MoO₃And SnO₂The total molar weight ratio of the two is 1:6 to 1:10, and the mixed solution is mixed with CdCl under the condition of rapid stirring₂H is added dropwise under the condition that the molar ratio is 1:1₂Reacting the S solution for 2 hours, washing the filter cake for 3 times by deionized water after filtering, then placing the filter cake in an oven, heating to 250 ℃, preserving heat for 2 hours, cooling to room temperature, and then fully grinding to obtain the MoO₃、SnO₂And CdS.

2. Gas sensor for the detection of trimethylamine according to claim 1, wherein the preparation method of the gas sensitive material comprises ammonium molybdate and SnCl in step 21)₄The molar ratio is 1:1.

3. Gas sensor for the detection of trimethylamine according to claim 1, wherein the CdCl in step 22) of the process for the preparation of the gas sensitive material₂Molar amount of (2) and MoO₃And SnO₂Total molar amount of bothThe ratio of the ratio is 1: 8.

Technical Field

The invention belongs to the field of gas sensors, and particularly relates to a gas sensor for detecting trimethylamine, which has high sensitivity, quick response time and high stability.

Background

Gas sensors are sensors for detecting gas concentration and composition, and play an important role in environmental protection and safety supervision. Gas sensors are used by being exposed to gases of various components, and because the temperature and humidity change greatly on the detection site and a large amount of dust, oil mist and the like exist, the gas sensors have severe working conditions, and the gas generates chemical reactants for the material of a sensing element and adheres to the surface of the element, so that the performance of the gas sensors is often deteriorated. Therefore, the following requirements are imposed on the gas sensor: the gas concentration detector can detect the allowable concentration of alarm gas and the gas concentration of other standard values, can work stably for a long time, and has the advantages of good repeatability, high response speed, small influence caused by coexisting substances and the like.

Trimethylamine is one of the common main gas pollutants, is inflammable and explosive, and has stimulation effect on eyes, nose, throat and respiratory tract as main harm to human body. Concentrated aqueous trimethylamine solution can cause severe burning sensation and flushing of the skin, and spot bleeding can still remain on the skin after the solution is washed away. The eyes, the nose and the throat feel dry and uncomfortable after long-term contact. The fishy smell of the fish product mainly comes from trimethylamine, so that the gas sensor for detecting the freshness of the fish is realized by detecting the trimethylamine. Therefore, the method has important significance for accurately detecting the concentration of the trimethylamine.

At present, most of gas sensors for trimethylamine at home and abroad use metal oxide as gas sensitive material, such as SnO₂、TiO₂And ZnO, etc. However, the existing trimethylamine gas sensor has the defects of low sensitivity, long response time, high working temperature and the like. Chinese patent application No. 201810866248.4 discloses an organic-inorganic doped micron material and a gas sensor prepared from the same, wherein the material is prepared by doping N-N-hexyl-N' - (amino-1-ethanol) -1,6,7, 12-tetrahydro-3, 4:9, 10-perylene diimide and cadmium sulfide, although the material is claimed to work at room temperature, toxic reagents such as chloroform and the like are required in the preparation process due to the overlong response time, and the requirement of actual industrialization cannot be met. There is therefore a need to develop gas sensors that are more sensitive and simple to manufacture.

Disclosure of Invention

According to an aspect of the present invention, it is an object of the present invention to provide a gas sensor for detecting trimethylamine, the gas sensor comprising: the gas-sensitive material is coated on the surfaces of the alumina ceramic tube and the alumina ceramic tube.

According to another aspect of the present invention, it is an object of the present invention to provide a method for preparing the gas sensor, the method comprising the steps of:

1) cleaning an alumina ceramic tube with deionized water and acetone, and drying for later use;

2) uniformly coating a suspension of a gas-sensitive material with the weight percentage concentration of 1.5mg/ml on the alumina ceramic tube, and packaging the alumina ceramic tube;

3) aging at 150 to 350 ℃ for 4 to 6 days to prepare the gas sensor.

Wherein, the coating manner in step 2) is not particularly limited, and a conventional coating manner, such as spin coating or spray coating, may be adopted.

The gas-sensitive material in step 2) is prepared as follows:

21) mixing ammonium molybdate and SnCl₄Dissolving the mixture in deionized water according to the molar ratio of 1:0.8 to 1:1.2 to form a solution, dropwise adding ammonia water under the stirring condition to adjust the pH value of the solution to 9.7, continuously stirring for 3 hours, standing and settling, filtering, washing a filter cake for 3 times by using deionized water, placing the filter cake in a drying oven, heating to 350 ℃, preserving heat for 4 hours, cooling to room temperature, fully grinding to obtain MoO₃And SnO₂Composite nanoparticles;

22) adding CdCl₂Dissolving the mixture in deionized water to form a solution, and then adding the MoO obtained in the step 1)₃And SnO₂Composite nanoparticles incorporating the CdCl₂In solution, wherein, CdCl₂Molar amount of (2) and MoO₃And SnO₂The total molar weight ratio of the two is 1:6 to 1:10, and the mixed solution is mixed with CdCl under the condition of rapid stirring₂H is added dropwise under the condition that the molar ratio is 1:1₂Reacting the S solution for 2 hours, washing the filter cake for 3 times by deionized water after filtering, then placing the filter cake in an oven, heating to 250 ℃, preserving heat for 2 hours, cooling to room temperature, and then fully grinding to obtain the MoO₃、SnO₂And CdS.

Preferably, root ofAccording to step 21) of the above method for preparing a gas sensitive material, ammonium molybdate and SnCl₄The molar ratio is 1:1.

Preferably, CdCl is used in step 22) of the method for preparing the gas sensitive material₂Molar amount of (2) and MoO₃And SnO₂The ratio of the total molar weight of the two is 1: 8.

Advantageous effects

The gas sensor has high selectivity and sensitivity to trimethylamine, short response time and lower detection limit. While operating at lower temperatures relative to other oxide gas sensitive materials of the prior art.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Accordingly, the description herein is of preferred examples for the purpose of illustration only and is not intended to limit the scope of the present invention, so it will be understood that other equivalent implementations and modifications may be made without departing from the spirit and scope of the present invention.

The terms "first", "second", and the like, as used herein are used to explain various constituent elements, and they are used only for the purpose of distinguishing one constituent element from another constituent element.

Also, the terms used herein are used only for explaining exemplary embodiments, and are not intended to limit the present invention. Singular references also include plural references unless the context clearly dictates otherwise. Terms such as "comprising," "including," or "having," as used herein, are used to specify the presence of stated features, numbers, steps, components, or combinations thereof, and should be understood not to preclude the addition or presence of one or more other features, numbers, steps, components, or combinations thereof.

Also, if a layer or an element is referred to as being formed "on" or "over" a layer or an element, it means that each layer or element is directly formed on the layer or element, or other layers or elements may be formed between layers, bodies, or substrates.

The gas sensor is a sensitive device capable of sensing a certain gas and the concentration thereof in the environment, converts the information related to the type and the concentration of the gas into electric signals, and obtains the information related to the existence condition of the gas to be measured in the environment according to the strength of the electric signals. The working principle is that the principle that the semiconductor gas sensitive element is in contact with gas to cause the change of the properties of the semiconductor is utilized to detect the components or the concentration of specific gas.

The following examples are given by way of illustration of embodiments of the invention and are not to be construed as limiting the invention, and it will be understood by those skilled in the art that modifications may be made without departing from the spirit and scope of the invention. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products.