Nano gas-sensitive film sensing element and preparation method thereof
By dripping nanomolybdenum sulfide or nanocerium oxide materials on the electrode substrate and adding ethyl cellulose, the problem of missing and poor reproducibility of catalytic luminescent gas sensitive components is solved, and efficient detection of CO, H2S and other gases is achieved, improving the improvement of Real-time warning capabilities on site.
Patent Information
- Application Number
- CN202411342733.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2024-12-31
AI Technical Summary
The sensors used in the prior art to detect gases such as CO, H2S in limited spaces have insufficient detection specificity, stability and detection accuracy, which cannot reflect the level of occupational hazards that workers come into contact in real time and lack the standardization of catalytic luminescent gas sensitive components. Production technology.
Using nanomolybdenum sulfide or nanocerium oxide as gas-sensitive material, the nano-film material solution is applied droplets on the electrode substrate and heated in a vacuum environment, combined with the use of ethyl cellulose to improve the uniformity and bonding of the material. , realize the production of catalytic luminescent gas sensitive components.
The production reproducibility and sensing response strength of catalytic luminescent gas sensitive components are improved, efficient detection of specific target gases is achieved, and real-time early warning and protection capabilities are enhanced.
Smart Images
Figure CN119224056A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of nano-catalytic luminescence, and in particular to a nano-gas-sensitive thin film sensor element and a preparation method thereof. Background Art
[0002] Power transmission and distribution projects involve confined spaces such as cable tunnels, power shafts, power supply trenches, and gas insulated transmission line (GIL) corridors. There may be gases such as CO, H2S, SF6, and CH4, or lack of oxygen, which may harm the health of workers in confined spaces. According to incomplete statistics, hundreds of people die from poisoning and suffocation in confined spaces every year across the country. With the construction of new power systems, more and more urban lines use cables, and there are more and more cable tunnels, power shafts, power supply trenches, and corridors. When power transmission and distribution workers enter confined spaces such as cable tunnels to work, suffocation and poisoning accidents may occur.
[0003] At present, the online or portable monitoring and alarm devices for confined spaces mainly use electrochemical, catalytic combustion, semiconductor, infrared, PID photoionization and other sensors. Among them, electrochemical sensors have poor selectivity and are temperature sensitive; catalytic combustion sensors have a short life, demanding process conditions, and the possibility of explosion; semiconductor sensors require high temperature conditions, poor selectivity and stability; infrared sensors are easily interfered by water vapor, temperature and humidity, and similar gases, such as water vapor and CO2 interference on CO; PID photoionization sensors obtain responses for all volatile organic compounds (VOCs) with ionization energy less than 11.7ev, and cannot detect specific VOCs. The above technologies have the limitations of insufficient detection specificity, stability and detection accuracy, and cannot quickly reflect the level of occupational hazards that workers in confined spaces are exposed to in real time, which is not conducive to real-time early warning and protection on site.
[0004] In recent years, gas sensing methods based on catalytic luminescence detection of CO, H2S and other gases have been reported one after another. Catalytic luminescence sensors have high specificity and low interference. However, catalytic luminescence needs to be measured at a higher temperature, and there is a lack of standardized production technology for catalytic luminescence gas sensors. Catalytic luminescence sensors often use metal oxides as gas-sensitive materials. The metal types are diversified and have multiple valence states, it is easy to achieve multi-element doping, the surface morphology and electronic structure are controllable and adjustable, and it has the advantages of thermal conductivity, wear resistance, small thermal expansion coefficient, low production cost, and easy batch preparation. It is an ideal gas-sensitive material. Catalytic luminescence gas-sensitive materials act as catalysts in the sensing process, and the measurement process is non-consumable, so they have a long service life and good stability. In addition, not all gas-solid interface effects can produce catalytic luminescence signals. Therefore, compared with other sensing technologies, the specificity and selectivity of catalytic luminescence sensing technology have been greatly improved, and specific target gases in complex environments can be detected. However, there is currently a lack of standardized production technology for catalytic luminescence gas sensors, and the reproducibility between batches of gas sensor production is poor. Summary of the invention
[0005] The embodiment of the present invention provides a nano gas-sensitive thin film sensor element and a preparation method thereof to solve the above technical problems in the prior art.
[0006] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.
[0007] According to a first aspect of an embodiment of the present invention, a nano gas-sensitive thin film sensor element is provided.
[0008] In one embodiment, the nano gas sensitive film sensor element is made by dripping a pre-configured nano film material solution onto an electrode substrate, wherein the raw materials for preparing the nano film material solution include anhydrous ethanol and nano film material; the nano film material includes nano molybdenum sulfide or nano cerium oxide.
[0009] In one embodiment, the electrode substrate includes interdigitated electrodes and a ceramic backing plate, wherein the interdigitated electrodes are disposed on the ceramic backing plate.
[0010] In one embodiment, the raw materials for preparing the nano film material solution further include: ethyl cellulose.
[0011] In one embodiment, the ratio of raw materials for preparing the nano film material solution includes:
[0012] 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-molybdenum sulfide.
[0013] In one embodiment, the ratio of raw materials for preparing the nano film material solution includes:
[0014] 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-cerium oxide.
[0015] In one embodiment, the ratio of raw materials for preparing the nano film material solution includes:
[0016] 0.395-0.789 parts of anhydrous ethanol, 0.05-1.5 parts of nano-molybdenum sulfide, and 0.02-0.05 parts of ethyl cellulose.
[0017] In one embodiment, the ratio of raw materials for preparing the nano film material solution includes:
[0018] 0.395-0.789 parts of anhydrous ethanol, 0.05-1.5 parts of nano-cerium oxide, and 0.02-0.05 parts of ethyl cellulose.
[0019] According to a second aspect of an embodiment of the present invention, a method for preparing a nano gas-sensitive thin film sensor element is provided.
[0020] In one embodiment, the method for preparing the nano gas sensitive film sensor element comprises:
[0021] Pre-configuring a nano-film material solution and an electrode substrate; wherein the raw materials of the nano-film material solution include nano-film material and anhydrous ethanol, and the nano-film material includes nano-molybdenum sulfide or nano-cerium oxide;
[0022] Absorbing the nano film material solution, drop-coating it on the electrode substrate, and leaving it to dry at room temperature;
[0023] The dried electrode substrate is placed in a vacuum environment for heat treatment, and after the heat treatment is completed, it is naturally cooled to room temperature and placed in a dry and cool place for a predetermined number of days for aging.
[0024] In one embodiment, the method for preparing the nano film material solution includes: mixing the nano film material and the anhydrous ethanol, and stirring the mixture by ultrasonic oscillation to obtain the nano film material solution.
[0025] In one embodiment, the raw material of the nano film material solution further includes ethyl cellulose; and the method for preparing the nano film material solution includes: mixing the ethyl cellulose with the nano film material and the anhydrous ethanol, and stirring by ultrasonic oscillation to obtain the nano film material solution.
[0026] In one embodiment, when the heat treatment is performed under a vacuum environment, the temperature is increased to 300-500° C. at a heating rate of 15-25° C. / min in a muffle furnace under a vacuum environment and maintained for 1-3 hours for annealing treatment, and the predetermined number of days is 1-2 days.
[0027] In one embodiment, the preparation method of the nano molybdenum sulfide comprises:
[0028] Pre-prepare ammonium molybdate, thioacetamide and deionized water;
[0029] The ammonium molybdate is mixed and dissolved with corresponding deionized water to obtain an ammonium molybdate solution; and thioacetamide is mixed and dissolved with corresponding deionized water to obtain a thioacetamide solution;
[0030] The thioacetamide solution is added to the ammonium molybdate solution and stirred evenly to obtain a mixed solution, and the mixed solution is transferred to an autoclave for high-temperature reaction to obtain a reaction product;
[0031] After the reaction product is cooled, the product is washed with deionized water and ethanol, and dried in a vacuum drying oven to obtain nano molybdenum sulfide powder.
[0032] In one embodiment, when performing high temperature reaction, the temperature is 180-210° C., and the reaction time is 12-24 hours; when drying in a vacuum drying oven, the temperature of the vacuum drying oven is 50-80° C.; and the drying time is 8-12 hours.
[0033] In one embodiment, the method for preparing nano cerium oxide comprises:
[0034] Pre-prepare cerium nitrate, deionized water and ammonia water;
[0035] The cerium nitrate and the corresponding deionized water are stirred and dissolved, and ammonia water is added dropwise under stirring until the pH value reaches a predetermined value to form a precipitate;
[0036] Filtering the stirred mixed solution to obtain a precipitate, and washing the precipitate with deionized water and ethanol;
[0037] After the precipitate is dried, the precipitate is calcined to obtain nano cerium oxide powder.
[0038] In one embodiment, the predetermined value is 8.0 to 8.5; during the calcination treatment, the calcination temperature is 300 to 500° C.; and the calcination time is 1 to 3 hours.
[0039] In one embodiment, when the nanometer thin film material solution is sucked and dripped onto the electrode substrate, the lowest point of the nanometer thin film material solution is tangent to the upper surface of the interdigital electrode on the electrode substrate.
[0040] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:
[0041] The present invention prepares nano film materials by using nano molybdenum sulfide or nano cerium oxide, and drips the nano film materials onto an electrode substrate, so that when the gas sensor is exposed to the air, the nano molybdenum sulfide or nano cerium oxide can absorb oxygen in the air to form adsorbed oxygen on the surface of the gas sensor; when hydrogen sulfide contacts the surface of the gas sensor, it is oxidized by the adsorbed oxygen to generate an excited intermediate; when the excited intermediate transitions back to the ground state, catalytic luminescence is generated, thereby realizing the manufacture of the catalytic luminescence gas sensor, and solving the problem of lack of a manufacturing process for the catalytic luminescence gas sensor in the traditional technology.
[0042] In addition, the present invention achieves further dispersion of powder materials by adding ethyl cellulose, increases uniformity, and can increase the adhesion between nanomaterials and substrates, making it easy to control the formation of a dense film, so that the film material is not easy to fall off, thereby improving the reproducibility of sensor element production, solving the technical problem of poor reproducibility between batches in the production of catalytic luminescence gas-sensitive elements, and realizing standardized production of gas-sensitive elements; at the same time, after adding ethyl cellulose, more powder materials can be fixed on a unit substrate area, thereby improving the sensor response intensity.
[0043] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0045] Figure 1 is a schematic flow chart of a method for preparing a nano gas-sensitive thin film sensor element according to an exemplary embodiment;
[0046] Figure 2 is a schematic diagram showing the response intensity of 20 ppm hydrogen sulfide measured by four sensor elements according to an exemplary embodiment;
[0047] Figure 3 It is a schematic diagram showing the response intensity of five batches of elements 2 measuring 20 ppm hydrogen sulfide according to an exemplary embodiment. DETAILED DESCRIPTION
[0048] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.
[0049] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0050] As used herein, the term "plurality" means two or more than two, unless otherwise specified.
[0051] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.
[0052] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.
[0053] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
[0054] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.
[0055] According to an embodiment of the present invention, a nano gas-sensitive thin film sensor element is provided, wherein the nano gas-sensitive thin film sensor element is made by drop-coating a pre-configured nano film material solution on an electrode substrate, wherein the raw materials for preparing the nano film material solution include anhydrous ethanol and nano film material; the nano film material includes nano molybdenum sulfide or nano cerium oxide; the electrode substrate includes interdigitated electrodes and a ceramic pad, and the interdigitated electrodes are arranged on the ceramic pad.
[0056] In this optional embodiment, the ratio of raw materials for preparing the nano-thin film material solution includes: 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-molybdenum sulfide; or 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-cerium oxide.
[0057] In addition, in this optional embodiment, in order to further disperse the powder material and increase the uniformity, ethyl cellulose may be added to the nano film material solution, that is, the raw materials for preparing the nano film material solution include anhydrous ethanol, nano film material and ethyl cellulose.
[0058] Specifically, the ratio of raw materials for preparing the nano film material solution includes: 0.05-1.5 parts of nano molybdenum sulfide, 0.395-0.789 parts of anhydrous ethanol, and 0.02-0.05 parts of ethyl cellulose; or 0.05-1.5 parts of nano cerium oxide, 0.395-0.789 parts of anhydrous ethanol, and 0.02-0.05 parts of ethyl cellulose.
[0059] According to an embodiment of the present invention, a method for preparing a nano gas sensitive thin film sensor element is also provided. Figure 1 The process of preparing the nano gas sensitive film sensor element of the present invention is shown.
[0060] In an alternative embodiment, if Figure 1As shown, the method for preparing the nano gas sensitive thin film sensor element comprises:
[0061] Step S101, pre-configuring a nano-thin film material solution and an electrode substrate; wherein the raw materials of the nano-thin film material solution include nano-thin film material and anhydrous ethanol, and the nano-thin film material includes nano-molybdenum sulfide or nano-cerium oxide;
[0062] Step S103, taking the nano film material solution, dripping it on the electrode substrate, and leaving it to dry at room temperature;
[0063] Step S105, placing the dried electrode substrate in a vacuum environment for heat treatment, cooling it naturally to room temperature after the heat treatment is completed, and placing it in a dry and cool place for a predetermined number of days to continue aging.
[0064] In this optional embodiment, the method for preparing the nano film material solution includes: mixing the nano film material and the anhydrous ethanol, and stirring the mixture by ultrasonic oscillation to obtain the nano film material solution.
[0065] Of course, in order to further disperse the powder material and increase the uniformity, ethyl cellulose can also be added to the nano film material solution, that is, the raw materials for preparing the nano film material solution include anhydrous ethanol, nano film material and ethyl cellulose; and then the method for configuring the nano film material solution includes: mixing the ethyl cellulose with the nano film material and the anhydrous ethanol, and performing ultrasonic oscillation stirring to obtain a nano film material solution.
[0066] In order to better understand the above technical solution of the present invention, the above technical solution of the present invention is described in detail from the perspective of practical application based on material preparation, substrate preparation, slurry preparation and drop coating film formation, as follows:
[0067] In practical application, the above-mentioned method for preparing the nano gas sensitive thin film sensor element can be implemented in four steps: material preparation, substrate preparation, slurry preparation and drop coating film formation, as follows:
[0068] 1) Material preparation: The material preparation is the preparation of nano film material, specifically including the preparation method of nano molybdenum sulfide and the preparation method of nano cerium oxide; wherein, the preparation method of nano molybdenum sulfide comprises: dissolving 0.25g of ammonium molybdate in 30mL of deionized water, dissolving 0.375g of thioacetamide (TAA) in 30mL of deionized water, then slowly adding the TAA solution to the ammonium molybdate solution and stirring evenly, transferring the mixed solution to an autoclave, reacting at 200°C for 24 hours, washing the product with deionized water and ethanol after cooling, and finally drying in a vacuum drying oven at 60°C for 12 hours to obtain nano molybdenum sulfide powder. The preparation method of nano cerium oxide comprises: dissolving 0.25g of cerium nitrate in 25mL of deionized water, adding ammonia water dropwise under stirring until the pH value reaches 8.0-8.5, forming a precipitate, washing the precipitate with deionized water and ethanol after filtering, and calcining at 500°C for 3 hours after drying to obtain nano cerium oxide powder.
[0069] 2) Substrate preparation: The interdigital electrode (substrate material is alumina, size is 8×4 mm, conductive layer is gold) is ultrasonically cleaned in anhydrous ethanol and deionized water for 5 minutes to remove surface oil and other impurities, then placed on non-woven fabric to absorb water and dry for standby use.
[0070] 3) Slurry preparation: According to the formula requirements, use an analytical balance to accurately weigh a certain amount of nano-molybdenum sulfide or nano-cerium oxide, transfer it to a clean beaker, add nothing, or add ethyl cellulose and anhydrous ethanol, and stir it in ultrasound for 2 minutes for use. Prepare different sensor elements according to the slurry shown in Table 1.
[0071] Table 1 shows the slurry ratios of different nano gas sensitive film sensor elements
[0072]
[0073] 4) Drop coating: Place the interdigital electrode on a ceramic pad, use a pipette to absorb 5 μL of slurry, and release the droplet about 5 mm above the electrode sheet (the distance should be such that the lowest point of the droplet is just tangent to the electrode sheet). The material will be coated on the electrode sheet through the diffusion of the liquid on the solid surface, and then stand and dry at room temperature. Finally, heat to 300-500°C at a heating rate of 15-25°C / min in a muffle furnace under a vacuum environment, keep annealing for 1-2 hours, cool naturally to room temperature, and place in a dry and cool place for aging for 1-2 days to complete the preparation.
[0074] In addition, in order to verify the characteristics of the nano gas-sensitive thin film sensor element prepared by the above-mentioned nano gas-sensitive thin film sensor element preparation method of the present invention, 20 ppm hydrogen sulfide measurement can be performed on the prepared four sensor elements. Figure 2A schematic diagram showing the response intensity of 4 sensing elements for measuring 20 ppm hydrogen sulfide is shown in FIG. Figure 2 It can be seen that element 1 has a stronger response than element 2. In addition, the addition of ethyl cellulose can improve the sensor response strength, because ethyl cellulose can further disperse the powder material, increase the uniformity, and increase the adhesion between the nanomaterial and the substrate to form a dense film, and the film material is not easy to fall off.
[0075] In order to further verify the characteristics of the nano gas-sensitive thin film sensor element prepared by the above-mentioned nano gas-sensitive thin film sensor element preparation method of the present invention, the prepared 5 batches of sensor elements 2 can be subjected to 20ppm hydrogen sulfide measurement. Figure 3 The response intensity of 20 ppm hydrogen sulfide measured by 5 batches of element 2 is shown; see Figure 3 It can be seen that the response intensity reproducibility among the five batches of sensor elements is good, and the relative standard deviation is 2.6%.
[0076] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.
Claims
1. A nano gas sensitive film sensor element, characterized in that: The nano gas sensitive film sensor element is made by dripping a pre-configured nano film material solution onto an electrode substrate, wherein the raw materials for preparing the nano film material solution include anhydrous ethanol and nano film material; the nano film material includes nano molybdenum sulfide or nano cerium oxide.
2. The nano gas sensitive film sensor element according to claim 1, characterized in that: The electrode substrate comprises interdigital electrodes and a ceramic backing plate, wherein the interdigital electrodes are arranged on the ceramic backing plate.
3. The nano gas sensitive film sensor element according to claim 1, characterized in that: The raw materials for preparing the nano film material solution also include: ethyl cellulose.
4. The nano gas sensitive film sensor element according to claim 1, characterized in that: The ratio of raw materials for preparing the nano film material solution includes: 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-molybdenum sulfide.
5. The nano gas sensitive film sensor element according to claim 1, characterized in that: The ratio of raw materials for preparing the nano film material solution includes: 0.395-0.789 parts of anhydrous ethanol and 0.05-1.5 parts of nano-cerium oxide.
6. The nano gas sensitive film sensor element according to claim 3, characterized in that: The ratio of raw materials for preparing the nano film material solution includes: 0.05-1.5 parts of nano-molybdenum sulfide, 0.395-0.789 parts of anhydrous ethanol, and 0.02-0.05 parts of ethyl cellulose.
7. The nano gas sensitive film sensor element according to claim 3, characterized in that: The ratio of raw materials for preparing the nano film material solution includes: 0.05-1.5 parts of nano-cerium oxide, 0.395-0.789 parts of anhydrous ethanol, and 0.02-0.05 parts of ethyl cellulose.
8. A method for preparing a nano gas sensitive thin film sensor element, characterized in that: include: Pre-configuring a nano-film material solution and an electrode substrate; wherein the raw materials of the nano-film material solution include nano-film material and anhydrous ethanol, and the nano-film material includes nano-molybdenum sulfide or nano-cerium oxide; Absorbing the nano film material solution, drop-coating it on the electrode substrate, and leaving it to dry at room temperature; The dried electrode substrate is placed in a vacuum environment for heat treatment, and after the heat treatment is completed, it is naturally cooled to room temperature and placed in a dry and cool place for a predetermined number of days for aging.
9. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: The method for preparing the nano film material solution comprises: The nano film material and the anhydrous ethanol are mixed and subjected to ultrasonic oscillation stirring to obtain a nano film material solution.
10. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: The raw material of the nano film material solution also includes ethyl cellulose; and the preparation method of the nano film material solution includes: The ethyl cellulose is mixed with the nano film material and the anhydrous ethanol, and ultrasonically stirred to obtain a nano film material solution.
11. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: When the heat treatment is performed under a vacuum environment, the temperature is heated to 300-500° C. at a heating rate of 15-25° C. / min in a muffle furnace under a vacuum environment and maintained for 1-3 hours for annealing treatment. The predetermined number of days is 1-2 days.
12. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: The preparation method of the nano molybdenum sulfide comprises: Pre-prepare ammonium molybdate, thioacetamide and deionized water; The ammonium molybdate is mixed and dissolved with corresponding deionized water to obtain an ammonium molybdate solution; and thioacetamide is mixed and dissolved with corresponding deionized water to obtain a thioacetamide solution; The thioacetamide solution is added to the ammonium molybdate solution and stirred evenly to obtain a mixed solution, and the mixed solution is transferred to an autoclave for high-temperature reaction to obtain a reaction product; After the reaction product is cooled, the product is washed with deionized water and ethanol, and dried in a vacuum drying oven to obtain nano molybdenum sulfide powder.
13. The method for preparing a nano gas sensitive thin film sensor element according to claim 12, characterized in that: When the high temperature reaction is carried out, the temperature is 180-210° C. and the reaction time is 12-24 hours; when the drying is carried out in a vacuum drying oven, the temperature of the vacuum drying oven is 50-80° C. and the drying time is 8-12 hours.
14. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: The preparation method of the nano cerium oxide comprises: Pre-prepare cerium nitrate, deionized water and ammonia water; The cerium nitrate and the corresponding deionized water are stirred and dissolved, and ammonia water is added dropwise under stirring until the pH value reaches a predetermined value to form a precipitate; Filtering the stirred mixed solution to obtain a precipitate, and washing the precipitate with deionized water and ethanol; After the precipitate is dried, the precipitate is calcined to obtain nano cerium oxide powder.
15. The method for preparing a nano gas sensitive thin film sensor element according to claim 14, characterized in that: The predetermined value is 8.0 to 8.5; during the calcination treatment, the calcination temperature is 300 to 500° C.; and the calcination time is 1 to 3 hours.
16. The method for preparing a nano gas sensitive thin film sensor element according to claim 8, characterized in that: When the nanometer film material solution is sucked and dripped onto the electrode substrate, the lowest point of the nanometer film material solution is tangent to the upper surface of the interdigital electrode on the electrode substrate.