Micro-flower WO3 nano material as well as preparation method and application thereof

Abstract

The invention provides a micro-flower WO3 nano material and a preparation method and application thereof, and relates to the technical field of gas sensitive materials.The preparation method of the micro-flower WO3 nano material comprises the following steps that WCl6 is dissolved in absolute ethyl alcohol and stirred in a water bath; putting the washed and dried loofah sponge LO into the precursor solution, and standing at room temperature; the impregnated LO is taken out and put into a drying oven to be dried; and finally, calcining the dried LO in a muffle furnace to obtain the micro-flower WO3 nano material. The material can be used for gas detection, and due to the characteristic of the micro-flower structure, more detected gas is allowed to pass through, so that the gas contact surface is increased, the specific surface area is larger, the detection effect is better, and the detection efficiency is higher; meanwhile, the material can be used as a gas-sensitive semiconductor material; experiments prove that a triethylamine gas sensor prepared from the micro-flower WO3 nano material prepared by the method has a relatively high response value to triethylamine gas, and has relatively good selectivity and a relatively good detection effect.

Description

Technical Field

[0001] This invention relates to the field of gas-sensitive materials technology, and in particular to a micro-flower WO3 nanomaterial, its preparation method, and its application. Background Technology

[0002] Gas sensing is an indispensable core technology in many fields, playing a crucial role in environmental monitoring and industrial production process management.

[0003] Current gas-sensitive materials suffer from problems such as poor sensing quality, poor selectivity, and low response values ​​when used as gas sensors. Triethylamine, in particular, is a typical volatile organic compound with core physicochemical properties including flammability, high toxicity, and a pungent odor. Because triethylamine contains active amino functional groups, it can participate in a variety of chemical reactions. Based on this property, triethylamine is often used as a reaction intermediate or catalyst in organic synthesis, and it has shown an indispensable role in these fields. However, its flammability and high toxicity pose a significant threat to human health and production safety. Related studies have shown that long-term or short-term exposure to high concentrations of triethylamine may induce organic damage such as headaches, pulmonary edema, and gastroenteritis, and in severe cases, death. According to NIOSH standards, the concentration of triethylamine in the air must not exceed 10 ppm.

[0004] Currently, there are various methods for detecting triethylamine, such as chromatography and electrochemical analysis. However, these methods generally suffer from problems such as large equipment size and high instrument purchase cost, making it difficult to achieve widespread promotion and application in the market. Oxide semiconductor gas sensors have attracted widespread attention due to their ease of operation, high sensitivity, good stability, and fast response and recovery characteristics.

[0005] However, common semiconductor metal oxide gas-sensitive materials (such as SnO2 and ZnO) often suffer from poor selectivity and low response values ​​in the detection of triethylamine. Therefore, developing a novel sensitive material and a simple preparation method that combines high sensitivity, high selectivity, and excellent stability for triethylamine is of great significance for achieving efficient, accurate, and portable monitoring of triethylamine. Summary of the Invention

[0006] This invention proposes a micro-flower WO3 nanomaterial, its preparation method, and its application to solve the problems of poor selectivity and low response value in the detection of triethylamine.

[0007] In a first aspect, the present invention provides a method for preparing micro-flower WO3 nanomaterials, comprising the following steps: Step S1: Dissolve WCl6 in anhydrous ethanol and stir to form a precursor solution; Step S2: Immerse the washed and dried loofah sponge in the precursor solution and let it stand to allow the loofah sponge to fully absorb the precursor solution. Step S3: Remove the soaked loofah sponge and dry it; Step S4: Place the dried loofah sponge in a muffle furnace for calcination to obtain WO3 nanomaterials with microflower structure.

[0008] Further, in step S1, 1.2g of WCl6 is dissolved in 30ml of anhydrous ethanol, and the stirring is carried out in a water bath at a temperature of 50-60℃ for 30-60 minutes.

[0009] Furthermore, the amount of loofah sponge used in step S2 is 1g; the standing time is 12-24 hours at room temperature.

[0010] Furthermore, the drying described in step S3 is carried out in an oven at a temperature of 60°C for 12-24 hours.

[0011] Furthermore, the calcination temperature in step S4 is 600-1000℃, the time is 2 hours, and the heating rate is 5℃ / min.

[0012] Furthermore, the calcination temperature in step S4 is preferably 1000°C.

[0013] Secondly, the present invention provides a micro-flower WO3 nanomaterial, which is prepared by the above-described preparation method.

[0014] Secondly, the present invention also provides the application of the micro-flower WO3 nanomaterial as a gas-sensitive semiconductor material for the detection of triethylamine gas.

[0015] Furthermore, the specific application method is: The micro-flower WO3 nanomaterials were ground to obtain micro-flower WO3 nanomaterial powder; Microflower WO3 nanomaterial powder was mixed with deionized water and ethanol to form a viscous paste. The viscous paste is uniformly coated onto the surface of the metal electrode on the alumina ceramic tube; the viscous paste is also uniformly applied around the metal electrode. The coated alumina ceramic tube is fixed on the base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage for aging treatment to complete the preparation of the triethylamine gas sensor.

[0016] Furthermore, the specific application method is: Microflora WO3 nanomaterials with a mass percentage between 33% and 35% were ground in a mortar to obtain microflora WO3 nanomaterial powder. The micro-flower WO3 nanomaterial powder is mixed with 55%~58% deionized water and 9%~12% ethanol by mass to form a viscous paste. The viscous paste was uniformly coated onto the metal electrode surface of the alumina ceramic tube using screen printing technology, and the coating operation was repeated 5 to 7 times. Apply the viscous paste evenly around the metal electrode using a brushing method, applying 1 to 3 layers in total; The coated alumina ceramic tube is fixed on a six-legged base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage and aged at 100℃~200℃ for 24 hours to complete the preparation of the triethylamine gas sensor. The stable resistance value of the triethylamine gas sensor in a triethylamine atmosphere is Rg, and the stable resistance value in air is Ra. Its response performance is characterized by the ratio of Ra / Rg.

[0017] Compared with the prior art, the present invention has the following advantages: The micro-flower WO3 nanomaterials prepared by this invention can be used for gas detection. Due to their micro-flower structure, more gas can pass through, increasing the gas contact surface and resulting in a larger specific surface area, thus improving detection performance and efficiency. Furthermore, the micro-flower WO3 nanomaterials prepared by this invention can serve as gas-sensitive semiconductor materials. Experimental verification shows that the triethylamine gas sensor prepared using the micro-flower WO3 nanomaterials prepared by this invention exhibits a high response value to triethylamine gas, good selectivity, and excellent detection performance.

[0018] Based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods. Attached Figure Description

[0019] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 The XRD pattern of the micro-flower WO3 nanomaterial obtained in Example 1 of this invention; Figure 2This is a SEM image of the micro-flower WO3 nanomaterial obtained in Example 1 of the present invention; Figure 3 The response curves of the micro-flower WO3 nanomaterial obtained in Example 1 of this invention to 10 ppm triethylamine at different operating temperatures are shown. Figure 4 The image shows the dynamic response recovery curve of the micro-flower WO3 nanomaterial obtained in Example 1 of this invention to 10 ppm triethylamine. Figure 5 The response curves of the micro-flower WO3 nanomaterials obtained in Example 1 of this invention to different concentrations of triethylamine are shown. Figure 6 Figure (a) is a SEM image of the sheet-like WO3 material obtained in Example 2 of the present invention; Figure (b) is a SEM image of the particulate WO3 material obtained in Example 3 of the present invention. Detailed Implementation

[0020] The exemplary embodiments disclosed in this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0021] This invention provides a method for preparing micro-flower WO3 nanomaterials, comprising the following steps: Step S1: Dissolve WCl6 in anhydrous ethanol and stir to form a precursor solution; Step S2: Immerse the washed and dried loofah sponge (LO) into the precursor solution and let it stand to allow the loofah sponge to fully absorb the precursor solution; Step S3: Remove the soaked loofah sponge and dry it; Step S4: Place the dried loofah sponge in a muffle furnace for calcination to obtain WO3 nanomaterials with microflower structure.

[0022] Thus, microflora WO3 nanomaterials can be used for gas detection. Due to the characteristics of its microflora structure, more gas can pass through, increasing the gas contact surface, resulting in a larger specific surface area, better detection effect, and higher detection efficiency.

[0023] Optionally, in step S1, 1.2g of WCl6 is dissolved in 30ml of anhydrous ethanol, and the stirring is carried out in a water bath at a temperature of 50-60℃ for 30-60 minutes.

[0024] Thus, heating in a water bath can accelerate the dissolution rate of WCl6.

[0025] Optionally, the amount of loofah sponge used in step S2 is 1g, and loofah sponge is used as the template material for the first time; the standing is carried out at room temperature for 12-24 hours.

[0026] Optionally, the drying in step S3 is carried out in an oven at a temperature of 60°C for 12-24 hours.

[0027] In this way, allowing the solution to stand and dry allows the LO to absorb the solution better.

[0028] Optionally, the calcination temperature in step S4 is 600-1000℃, the time is 2 hours, and the heating rate is 5℃ / min.

[0029] Optionally, the calcination temperature in step S4 is preferably 1000°C.

[0030] Thus, it was found during the experiment that materials that could be calcined at a fixed temperature and formed into the desired morphology allowed more of the tested gas to pass through, increasing the gas contact surface and resulting in a larger specific surface area.

[0031] Secondly, the present invention provides a micro-flower WO3 nanomaterial, which is prepared by the above-described preparation method.

[0032] Thus, this material can be used for gas detection, and due to its spherical structure, it allows more gas to pass through, increasing the gas contact surface, resulting in a larger specific surface area, better detection effect, and higher detection efficiency.

[0033] Thirdly, the present invention also provides the application of the micro-flower WO3 nanomaterial as a gas-sensitive semiconductor material for the detection of triethylamine gas.

[0034] Alternatively, the specific application method is: The micro-flower WO3 nanomaterials were ground to obtain micro-flower WO3 nanomaterial powder; Microflower WO3 nanomaterial powder was mixed with deionized water and ethanol to form a viscous paste. The viscous paste is uniformly coated onto the surface of the metal electrode on the alumina ceramic tube; the viscous paste is also uniformly applied around the metal electrode. The coated alumina ceramic tube is fixed on the base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage for aging treatment to complete the preparation of the triethylamine gas sensor.

[0035] First, the micro-flower WO3 nanomaterial is ground to prevent material clumping and expose more fresh surface, which helps to improve the contact between conductive particles and thus improve the overall conductivity. Uniform coating is applied to achieve good coverage and ensure consistent performance in each part. The resistance wire is placed in the center to ensure uniform heating of the ceramic tube. Aging can improve the stability and reliability of the triethylamine gas sensor.

[0036] Alternatively, the specific application method is: Microflora WO3 nanomaterials with a mass percentage between 33% and 35% were ground in a mortar to obtain microflora WO3 nanomaterial powder. The micro-flower WO3 nanomaterial powder is mixed with 55%~58% deionized water and 9%~12% ethanol by mass to form a viscous paste. The viscous paste was uniformly coated onto the metal electrode surface of the alumina ceramic tube using screen printing technology, and the coating operation was repeated 5 to 7 times. Apply the viscous paste evenly around the metal electrode using a brushing method, applying 1 to 3 layers in total; The coated alumina ceramic tube is fixed on a six-legged base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage and aged at 100℃~200℃ for 24 hours to complete the preparation of the triethylamine gas sensor. The stable resistance value of the triethylamine gas sensor in a triethylamine atmosphere is Rg, and the stable resistance value in air is Ra. Its response performance is characterized by the ratio of Ra / Rg.

[0037] During the experiment, it was found that the triethylamine gas sensor exhibited the most stable performance, the highest response value to triethylamine, and the shortest response recovery time when treated according to the aforementioned temperature range and aging time. Experimental testing showed that the fabricated sensor achieved the highest response value to triethylamine, reaching 81.7.

[0038] Example 1: (1) Preparation of microflora WO3 precursor powder: Dissolve 1.2 g WCl6 in 30 ml anhydrous ethanol and stir for 30 min at 60 °C and 101.3 kPa to obtain a precursor solution. Add 1 g washed and dried LO to the precursor solution and let it stand at room temperature for 12 h. Take out the impregnated LO and dry it in an oven at 60 °C for 12 h.

[0039] (2) Preparation of micro-flower WO3 nano gas-sensitive material: The precursor powder obtained in step (1) was calcined in air at 1000℃ with a heating rate of 5℃ / min and held for 2h to obtain micro-flower WO3 nano gas-sensitive material. The XRD pattern and SEM image after calcination are shown below. Figure 1 , 2 As shown; from Figure 1 XRD analysis revealed the absence of other diffraction peaks, indicating a pure phase. According to... Figure 2 The SEM image shows that a microflower structure can be formed after calcination at 1000℃; the microflower structure allows more of the gas being tested to pass through, increasing the gas contact surface and resulting in a larger specific surface area.

[0040] Fabrication and performance testing of micro-flower WO3 nanomaterials in a triethylamine gas sensor: The micro-flower WO3 calcined at different temperatures with a mass ratio of 33%-35% in step (2) was placed in a mortar and mixed with 55%-58% deionized water and 9%-12% ethanol. The mixture was then ground into a paste. Next, using screen printing technology, this paste was evenly coated onto the metal electrode of the alumina ceramic tube, with a total of 6 coatings. Subsequently, the paste was evenly applied around the metal electrode using a brushing method, completing two layers of coating. A heating wire was inserted into the center of the ceramic tube and welded to the heating end of the six-legged base. The tube was then placed in an aging chamber and aged at 180°C for 24 hours. The generally accepted gas-sensitive mechanism is that when the micro-flower WO3 material is exposed to air, oxygen molecules in the air adsorb onto the surface of the micro-flower WO3, occupying vacancies on the material surface and forming surface-adsorbed oxygen (O2). - O - and O 2- During this process, an electron depletion layer gradually forms on the surface of the micro-flower WO3, leading to an increase in the sensor's resistance and a decrease in its conductivity. As a typical n-type semiconductor, when micro-flower WO3 is placed in a triethylamine atmosphere, the oxygen previously absorbed by the micro-flower WO3 and occupying holes reacts with these reducing gases, generating a large number of electrons. These electrons are released back into the conduction band of the micro-flower WO3, thinning the electron depletion layer on its surface, thereby reducing the sensor's resistance and increasing its conductivity.

[0041] Experimental verification showed that the micro-flower nanomaterials obtained in this embodiment exhibited the highest response value (81.7) to triethylamine gas at an operating temperature of 260℃. The welded triethylamine gas sensor was placed in a CGS-8 gas-sensitive analysis system, and the resistance of the sensor in triethylamine gas and air was recorded at different temperatures. The response value was calculated using the formula Ra / Rg, and a [further details needed for accurate translation] was produced. Figure 3 The line chart shown is based on Figure 3The optimal operating temperature for the microflower WO3 triethylamine gas sensor can be determined to be 260℃.

[0042] The welded triethylamine gas sensor is placed into the CGS-8 gas-sensitive analysis system. At an operating temperature of 260℃, the following formula is first applied: Where Q represents the liquid volume in mL, V is the chamber volume in mL, M is the relative molecular mass in g, d represents the liquid purity, C is the target gas concentration in ppm, ρ is the liquid density, and T... R and T B These represent the ambient temperature (°C) and the fixed chamber temperature (°C), respectively. The amount of triethylamine solution required to be injected at 10 ppm (according to NIOSH standards, the concentration of triethylamine in air must not exceed 10 ppm) was calculated. After evaporation, a gas was formed, and a concentration cycle was performed by switching between the triethylamine gas and air. The dynamic response recovery curve at 10 ppm was obtained, as shown below. Figure 4 As shown. According to Figure 4 It can be seen that the prepared micro-flower WO3 triethylamine gas sensor has a fast response recovery time.

[0043] The required amount of triethylamine solution at different concentrations was calculated. After evaporation, a gas was formed. A concentration cycle was then established, switching between triethylamine gas and air to obtain response recovery curves at different concentrations. Figure 5 As shown. According to Figure 5 It can be seen that the prepared micro-flower WO3 triethylamine gas sensor has a fast response and recovery time, the prepared micro-flower WO3 sensor has good response and recovery capabilities, and the detection limit is very low, at 1 ppm.

[0044] Example 2 The difference between this embodiment and Embodiment 1 is that the calcination temperature is 600℃, while all other parameters remain unchanged. The scheme of this comparative example will be described in detail below: 1.2 g of WCl6 was dissolved in 30 ml of anhydrous ethanol and stirred for 30 min at 60 °C and 101.3 kPa to obtain the mixed solution. 1 g of washed and dried LO was added to the precursor solution and allowed to stand at room temperature for 12 h. The impregnated LO was then removed and dried in an oven at 60 °C for 12 h. The resulting precursor powder was calcined in air at 600 °C at a heating rate of 5 °C / min for 2 h to obtain sheet-like WO3 nanomaterials such as... Figure 6 As shown in (a).

[0045] Experimental results show that the sheet material obtained in Example 2 has a gas response value of 17.6 at an operating temperature of 260°C.

[0046] Example 3 The difference between this embodiment and Embodiment 1 is that the calcination temperature is 800℃, while the other parameters remain unchanged. The following is a detailed description of the scheme of this embodiment: 1.2 g of WCl6 was dissolved in 30 ml of anhydrous ethanol and stirred for 30 min at 60 °C and 101.3 kPa to obtain the mixed solution. 1 g of washed and dried LO was added to the precursor solution and allowed to stand at room temperature for 12 h. The impregnated LO was then removed and dried in an oven at 60 °C for 12 h. The resulting precursor powder was calcined in air at 800 °C at a heating rate of 5 °C / min for 2 h to obtain particulate WO3 nanomaterials such as... Figure 6 As shown in (b).

[0047] Experimental verification showed that the particulate material obtained in Example 3 had a gas response value of 11 at an operating temperature of 260°C.

[0048] Based on the comparison results of Examples 2, 3 and 1 above, it can be seen that when the precursor powder is calcined in air at 600 / 800℃ with a heating rate of 5℃ / min and held for 2h, a micro-flower structure cannot be obtained, and the response value is lower than that at 1000℃.

[0049] To systematically evaluate the gas-sensing performance of the micro-flower WO3 nanomaterial, it was applied to the detection of various typical volatile organic compounds and harmful gases. Tests were conducted at the optimal operating temperature (260℃), and the sensor's response value was characterized by Ra / Rg (the ratio of the stable resistance value in air to the stable resistance value in the target gas). Specific performance data comparisons are shown in Table 1 below. Table 1: Comparison of gas-sensing response performance of micro-flower WO3 nanomaterials to various gases As can be seen from Table 1, the micro-flower WO3 nanomaterial provided in this application can be used as a gas-sensitive semiconductor material. When the gas-sensitive semiconductor material comes into contact with a specific gas, its resistance will change significantly. The performance can be determined by the relationship between the resistance in the air and the resistance in the specific gas.

[0050] As can be seen from the comparison in Table 1 above, the microflora WO3 nanomaterials provided in this application exhibit the best selectivity and effectiveness for triethylamine; therefore, the microflora WO3 nanomaterials provided in this application can be used in the preparation of triethylamine gas sensors. This triethylamine gas sensor can be used to detect the presence of triethylamine at low concentrations.

[0051] Experiments have verified that microflora WO3 cannot be generated without using LO as a template or without calcination at 1000℃ for 5℃ / min for 2 hours. To obtain the microflora WO3 nanomaterials claimed in this application, this invention utilizes the LO template method to prepare microflora WO3 nanomaterials and requests protection for their application in triethylamine detection. This invention uses WCl6, ethanol, and LO as raw materials, and for the first time synthesizes microflora WO3 nanomaterials at different calcination temperatures using a template method. This method for preparing microflora WO3 nanomaterials not only significantly improves sensing performance but also greatly expands its potential application areas. By controlling the calcination temperature, we successfully created more active sites to optimize the material's performance under various operating conditions, providing valuable theoretical basis and practical guidance for the development of high-performance gas sensors. Furthermore, microflora WO3, as a triethylamine gas-sensitive sensing material, has rapid reaction and recovery times, and its synthesis process is simple, environmentally friendly, and low-cost, making it suitable for large-scale production.

[0052] This invention utilizes a micro-flower-shaped WO3 nanomaterial, and for the first time, a micro-flower WO3 material was prepared using the LO template method, resulting in a high-performance gas sensor. Results show that the micro-flower WO3 sensor exhibits excellent response and selectivity to triethylamine, as well as strong long-term stability, excellent humidity resistance, and reproducibility during testing. These properties are attributed to the calcination temperature adjustment of the material; the flower-like structure derived from the LO template provides high-speed transport capabilities for electrons and gas molecules, greatly promoting gas adsorption and subsequent reactions. This unique interaction not only enhances sensing performance but also significantly broadens its potential application range. By precisely controlling the composition, more active sites can be created to optimize the material's performance in various operating environments. This work provides valuable insights for the development of high technology.

[0053] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing microflora WO3 nanomaterials, characterized in that, Includes the following steps: Step S1: Dissolve WCl6 in anhydrous ethanol and stir to form a precursor solution; Step S2: Immerse the washed and dried loofah sponge in the precursor solution and let it stand to allow the loofah sponge to fully absorb the precursor solution. Step S3: Remove the soaked loofah sponge and dry it; Step S4: Place the dried loofah sponge in a muffle furnace for calcination to obtain WO3 nanomaterials with microflower structure.

2. The method for preparing microflora WO3 nanomaterials according to claim 1, characterized in that, In step S1, 1.2g of WCl6 is dissolved in 30ml of anhydrous ethanol. The stirring is carried out in a water bath at a temperature of 50-60℃ for 30-60 minutes.

3. The method for preparing microflora WO3 nanomaterials according to claim 1, characterized in that, The amount of loofah sponge used in step S2 is 1g; the standing time is 12-24 hours at room temperature.

4. The method for preparing microflora WO3 nanomaterials according to claim 1, characterized in that, The drying process described in step S3 is carried out in an oven at a temperature of 60°C for 12-24 hours.

5. The method for preparing microflora WO3 nanomaterials according to claim 1, characterized in that, The calcination temperature in step S4 is 600-1000℃, the time is 2 hours, and the heating rate is 5℃ / min.

6. The method for preparing microflora WO3 nanomaterials according to claim 1, characterized in that, The preferred calcination temperature in step S4 is 1000℃.

7. A microflora WO3 nanomaterial, characterized in that, The material is prepared using the preparation method described in any one of claims 1-6.

8. An application of the micro-flower WO3 nanomaterial as described in claim 7 as a gas-sensitive semiconductor material.

9. The application of the microflora WO3 nanomaterial according to claim 8, characterized in that, This method is used for the detection of triethylamine gas. The specific application method is as follows: The micro-flower WO3 nanomaterials were ground to obtain micro-flower WO3 nanomaterial powder; Microflower WO3 nanomaterial powder was mixed with deionized water and ethanol to form a viscous paste. The viscous paste is uniformly coated onto the surface of the metal electrode on the alumina ceramic tube; the viscous paste is also uniformly applied around the metal electrode. The coated alumina ceramic tube is fixed on the base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage for aging treatment to complete the preparation of the triethylamine gas sensor.

10. The application of the microflora WO3 nanomaterial according to claim 9, characterized in that, The specific application method is as follows: Microflora WO3 nanomaterials with a mass percentage between 33% and 35% were ground in a mortar to obtain microflora WO3 nanomaterial powder. The micro-flower WO3 nanomaterial powder is mixed with 55%~58% deionized water and 9%~12% ethanol by mass to form a viscous paste. The viscous paste was uniformly coated onto the metal electrode surface of the alumina ceramic tube using screen printing technology, and the coating operation was repeated 5 to 7 times. Apply the viscous paste evenly around the metal electrode using a brushing method, applying 1 to 3 layers in total; The coated alumina ceramic tube is fixed on a six-legged base, and a heating resistance wire is installed in it to form a gas-sensitive element. The resistance wire is connected to the heating end in the center of the base to complete the assembly of the triethylamine gas sensor. The assembled triethylamine gas sensor was placed on an aging stage and aged at 100℃~200℃ for 24 hours to complete the preparation of the triethylamine gas sensor. The stable resistance value of the triethylamine gas sensor in a triethylamine atmosphere is Rg, and the stable resistance value in air is Ra. Its response performance is characterized by the ratio of Ra / Rg.

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