Electrode slurry for electrochemical hydrogen fluoride sensor as well as preparation method and application of electrode slurry

Abstract

The invention relates to electrode slurry for an electrochemical hydrogen fluoride sensor as well as a preparation method and application of the electrode slurry. The electrode slurry is composed of the following components in percentage by mass: 50-70% of inorganic oxide powder, 15-25% of conductive graphite powder, 5-8% of organic additive and the balance of terpilenol solvent, wherein the inorganic oxide is prepared by burning a mixture of zinc acetate, ferrous acetate, tartaric acid and absolute ethyl alcohol. The preparation method comprises the following steps: mixing the components, and grinding for 2-3 hours by using a ball mill at the rotating speed of 200-300rpm by using terpilenol as a solvent, thereby obtaining the product. The prepared electrode slurry can be coated on a sensor electrode of a hydrogen fluoride gas sensor; stable preparation of the hydrogen fluoride gas sensor is realized through regulation and control of the inorganic oxide nano powder and the electrolyte, the hydrogen fluoride gas sensor shows extremely high sensitivity and extremely high response speed to hydrogen fluoride gas, and the hydrogen fluoride gas sensor has the advantages of being high in sensitivity, quick in response, low in cost, convenient to produce in batches and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensor electrode materials, in particular to an electrode paste for an electrochemical hydrogen fluoride sensor, a preparation method and application thereof. BACKGROUND

[0002] Hydrogen fluoride is a gas with a pungent odor, colorless, toxic, and corrosive. When the human body comes into contact with hydrogen fluoride gas, the fluoride ions in hydrogen fluoride can penetrate into human tissues and combine with calcium ions and magnesium ions in the human body, disrupting the body's balance, leading to a decrease in blood calcium and magnesium, and further causing hypocalcemia, hypomagnesemia, arrhythmia, convulsions, and severe necrosis and metabolic disorder of human tissues. When the content of hydrogen fluoride gas in the atmosphere reaches 50 ppm, exposure for a few minutes can cause death.

[0003] Hydrogen fluoride is an important basic chemical raw material in the chemical industry, and its main application is as a raw material for the synthesis of fluorine-containing chemicals, such as fluorine-containing polymer production, refrigerant production, and special chemicals. The use of hydrogen fluoride in the electronics industry includes etching agents in semiconductor manufacturing, cleaning and etching silicon materials in solar cell production, etc. In the field of high-voltage insulation, sulfur hexafluoride (SF6) gas is commonly used as an arc-extinguishing medium and insulating medium for circuit breakers. In the fault diagnosis of electrical equipment, gas chromatography is often used for detection, but there are problems such as complicated sampling and inability to detect in real time and quickly. In the field of new energy power batteries, lithium hexafluorophosphate is often used as a battery electrolyte, and the leakage of the battery can be monitored by detecting hydrogen fluoride. Therefore, real-time, efficient, and rapid detection of the concentration of hydrogen fluoride gas is of great significance to human health, environmental protection, and industrial production.

[0004] Electrochemical gas sensors are one of the most commonly used methods for detecting gas concentration, and have the advantages of convenience, low cost, and the ability to detect gas concentration in real time and quickly. The invention disclosed in the application announcement No. CN118914319A discloses a method for preparing the working electrode of a hydrogen fluoride gas sensor, which reduces the disturbance of the sensor to the airflow by adding a buffer layer, but greatly increases the response time of the sensor to hydrogen fluoride gas, making it difficult to quickly detect gas leaks. Moreover, the use of rare and precious metals such as iridium greatly increases the production cost. The invention disclosed in the application announcement No. CN109180951A discloses a method for preparing a hydrogen fluoride gas sensor using a polyamine-based organic-inorganic hybrid compound as an electrode, but the preparation process is complex and difficult to mass-produce stably, and the prepared electrode requires a specific sensor module to cooperate, which is difficult to adapt to the commonly used pin-plug type module and instruments on the market, bringing many inconveniences to practical application. SUMMARY

[0005] To solve the above problems, the present application provides an electrode paste for an electrochemical hydrogen fluoride sensor, a preparation method and application thereof.

[0006] In a first aspect, the electrode paste for an electrochemical hydrogen fluoride sensor provided by the present application adopts the following technical solution: An electrode paste for an electrochemical hydrogen fluoride sensor, consisting of the following components in terms of weight percentage: 60-78% inorganic oxide powder, 15-22% conductive graphite powder, 5-8% organic additive, terpineol; terpineol is calculated separately as a solvent; The inorganic oxide powder is obtained by burning a mixture of zinc acetate, ferrous acetate, tartaric acid and anhydrous ethanol.

[0007] In some embodiments, the conductive graphite powder is spherical in shape, with a particle size range of 0.5-5 μm, and more preferably, a particle size range of 0.5-2 μm.

[0008] Further, the inorganic oxide powder is prepared by the following method: S1, mixing and stirring tartaric acid and anhydrous ethanol to obtain solution I; S2, mixing and stirring zinc acetate, ferrous acetate and anhydrous ethanol to obtain solution II; S3, pouring solution II into solution I and ultrasonic dispersion to obtain solution III; S4, transferring the uniformly mixed solution III to an evaporation dish, heating it to 300°C on a heating jacket, and evaporating the liquid in the evaporation dish completely, then obtaining a fluffy solid precursor after burning; S5, calcining the fluffy solid precursor powder at 350-400°C for 1-3 hours under a nitrogen atmosphere to obtain the inorganic oxide powder.

[0009] By adopting the above technical solution, the inorganic oxide powder prepared thereby has high catalytic properties, i.e., the catalytic activity of the nano-zinc oxide is further improved after being doped with iron elements, and the addition of an organic additive to form a paste with a certain viscosity facilitates batch and stable preparation of the electrode; after being assembled into a gas sensor, the gas sensor has high sensitivity to hydrogen fluoride gas, extremely fast response and recovery rates, and excellent linearity within the measurement range.

[0010] Further, the mixing mass ratio of zinc acetate, ferrous acetate, tartaric acid and anhydrous ethanol is 1:(0.01-0.05):(0.3-0.6):(6-8).

[0011] Further, the organic additive includes a binder, a plasticizer and a leveling agent; The binder is selected from at least one of thermoplastic acrylic resin, polyvinyl butyral, sodium carboxymethyl cellulose and polyalkyl carbonate; The plasticizer is selected from at least one of di(2-ethylhexyl) phthalate, diethyl phthalate and butyl benzyl phthalate; The leveling agent is selected from at least one of butyl cellulose, isophorone, modified acrylate leveling agent; And the mass ratio of the binder, the plasticizer and the leveling agent is 1:(0.05-0.2):(0.02-0.07).

[0012] In a second aspect, the application provides a preparation method of an electrode paste for an electrochemical hydrogen fluoride sensor, which adopts the following technical scheme: A preparation method of an electrode paste for an electrochemical hydrogen fluoride sensor, which comprises the following steps: The inorganic oxide powder, the conductive graphite powder, the organic additive and the remaining amount of terpineol are mixed, and then are ground by a ball mill at a rotating speed of 200-300 rpm for 2-3 h to obtain the electrode paste.

[0013] In a third aspect, the application provides an application of an electrode paste for an electrochemical hydrogen fluoride sensor, which adopts the following technical scheme: The electrode paste for an electrochemical hydrogen fluoride sensor and / or the electrode paste prepared by the preparation method of the electrode paste for an electrochemical hydrogen fluoride sensor are applied to the preparation of an electrochemical hydrogen fluoride sensor.

[0014] Further, the electrochemical hydrogen fluoride sensor comprises an electrochemical hydrogen fluoride sensor electrode and a neutral electrolyte.

[0015] Further, the neutral electrolyte is selected from at least one of lithium sulfate, lithium chloride, sodium chloride, sodium sulfate, sodium nitrate and calcium chloride. More preferably, it is one or more of lithium chloride, sodium chloride and sodium nitrate.

[0016] In some embodiments, the molar concentration of lithium sulfate is 0.04-0.08 mol / L, the molar concentration of lithium chloride is 6-9 mol / L, the molar concentration of sodium chloride is 2.0-2.5 mol / L, the molar concentration of sodium sulfate is 1.1-1.4 mol / L, the molar concentration of sodium nitrate is 3.8-6 mol / L, and the molar concentration of calcium chloride is 2-4 mol / L.

[0017] By adopting the above technical scheme, the flow and transmission of electric charges in the electrochemical hydrogen fluoride sensor are regulated by using the neutral electrolyte, thereby further reducing the response time of the sensor, improving the selectivity, greatly reducing the influence of environmental interference gases on the hydrogen fluoride sensor, and improving the detection accuracy. In particular, the sodium chloride or lithium chloride is selected as the electrode solution, which does not affect the response sensitivity of the hydrogen fluoride gas entering the sensor, and at the same time, the cross interference problem of the conventional acid or alkaline electrolyte to the signal is overcome, thereby improving the selectivity of the sensor.

[0018] Furthermore, the electrochemical hydrogen fluoride sensor electrode is prepared by coating an electrode slurry onto a polytetrafluoroethylene film and drying it at 70-80°C for 1-2 hours.

[0019] Furthermore, the electrode paste can be coated by one of the following methods: rolling, spraying, screen printing, and molding.

[0020] In summary, this application has the following beneficial effects: 1. This application employs a self-propagating combustion method to prepare nano-zinc oxide. The resulting nano-zinc oxide is spherical or near-spherical with a large specific surface area. After heat treatment in a nitrogen atmosphere, a loose porous structure is formed between the powder particles, effectively solving the problem of easy agglomeration of nano-powders. Nano-zinc oxide is a typical n-type semiconductor, which can provide free electrons as a carrier fluid. The inorganic oxide powder formed after introducing iron doping further increases the number and rate of free electrons generated when the catalyst reacts with the test gas, significantly enhancing the catalytic activity of the electrode and shortening the response recovery time. The electrochemical hydrogen fluoride gas sensor electrode assembled based on this electrode has high sensitivity to hydrogen fluoride, fast response recovery, and excellent linearity within the measurement range. 2. The electrochemical hydrogen fluoride sensor in this application uses a neutral electrolyte, which effectively shortens the sensor's response time, enhances selectivity, significantly reduces the impact of environmental interference gases on the sensor, and improves the accuracy of detection. 3. The electrochemical hydrogen fluoride sensor of this application has a simple preparation process, the raw materials are easy to obtain, and it is convenient for large-scale mass production. Attached Figure Description

[0021] Figure 1 This is a scanning electron microscope image of the inorganic oxide powder iron-doped nano zinc oxide powder prepared in the example of this application; Figure 2 The response recovery curves of Examples 1-5 of this application in 0-5 ppm hydrogen fluoride gas are shown. Figure 3 This is the step ventilation curve of Example 5 of this application in 0-10ppm hydrogen fluoride gas; Figure 4 The cyclic adsorption-desorption curves of Example 5 of this application in 0-10ppm hydrogen fluoride gas are shown. Detailed Implementation

[0022] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] The purpose of the present invention will be illustrated by the following examples. The components of the composition are described in parts by weight as a general standard. Unless otherwise specified, for the sake of brevity, "parts" and parts by weight are the same in the embodiments of the present invention.

[0024] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. All reagents and instruments used, unless otherwise specified below, are commercially available products. In this application, the conventional chemical reagents used were purchased from Sinopharm Chemical Reagent Co., Ltd., and were of AR analytical grade. The adhesive is selected from the high acetal degree B05, B06 and B08 series of Changchun Group, with a molecular weight of 40,000~80,000; or, QPAC40 and QPAC60 series, with a molecular weight of 100,000~250,000. The leveling agent is selected from the BYK345 and DC-51 series, with a solid content of 60~80wt%; The conductive graphite is selected from one or more of Cabot VXC72, Cabot 330R, and Yirui SFG6.

[0025] Performance testing Using the electrochemical hydrogen fluoride sensor prepared in the application examples and comparative examples as test samples, gas flow tests were conducted in 5 ppm hydrogen fluoride gas, and cross-response tests were conducted in gases of different concentrations. The test steps are as follows: (1) Gas flow test in 5ppm hydrogen fluoride gas: At room temperature, after the aged electrochemical hydrogen fluoride sensor was fitted with a special test gas cap, the concentration of hydrogen fluoride gas was controlled at 5ppm by a corrosion-resistant mass flow meter. The test circuit board and the host computer software were connected via a USB to RS485 window communication cable to read the data and graphs before and after gas flow, and the difference in the output current signal of the test circuit board before and after gas flow was recorded, thereby obtaining the ratio of the sensor's output current to the gas concentration, i.e., the sensitivity. This value reflects the sensor's response to changes in gas. The time required for the sensor's output change to reach 90% of the stable value when the gas concentration undergoes a step change was calculated, i.e., T90. This value reflects the sensor's rapid response to gas. (2) Cross-response test in different gases: At room temperature, after the electrochemical hydrogen fluoride sensor that has completed aging is installed with a special test gas cap, the concentration of the gas is controlled by a corrosion-resistant mass flow meter. The test circuit board and the host computer software are connected through a USB to RS485 window communication cable to read the data and graphs before and after the gas is vented, and the difference in the output current signal of the test circuit board before and after the gas is vented is recorded, so as to obtain the sensitivity performance of the sensor in different cross gases; The cross gases tested by the hydrogen fluoride sensor in this application are: 500 ppm ethanol, 500 ppm carbon monoxide, 500 ppm hydrogen, 100 ppm acetic acid, 20 ppm sulfur dioxide, 10 ppm hydrogen chloride, and 5 ppm chlorine.

[0026] Preparation Example 1 An inorganic oxide powder, specifically iron-doped nano-zinc oxide, is prepared using the following steps: S1. Mix 4.4g of tartaric acid with 14.0g of anhydrous ethanol to obtain solution I; S2. Mix 9.6g zinc acetate, 0.3g ferric acetate and 44.0g anhydrous ethanol to obtain solution II; S3. Add solution II to solution I and disperse by ultrasonication to obtain solution III; S4. Transfer the well-mixed solution III to an evaporating dish, place it on a heating mantle and heat it to 300°C. After the liquid in the evaporating dish has completely evaporated, a fluffy solid precursor is obtained after combustion. S5. The solid powder of the precursor is calcined at 380°C for 1.5 hours under a nitrogen atmosphere to obtain iron-doped nano zinc oxide powder.

[0027] from Figure 1 The scanning electron microscope (SEM) images show that the iron-doped zinc oxide nanoparticles prepared in Preparation Example 1 exhibit a spherical or near-spherical morphology with a particle size distribution of 50-100 nm. They have a large specific surface area, which is conducive to the accumulation and transport of charges on the surface of the spherical powder. At the same time, it can be seen that iron is uniformly doped on the surface of the zinc oxide nanoparticles in small particles, which further improves the particle aggregation. In addition, the loose and porous structure provides channels for gas transport, promotes gas diffusion and charge transfer rate, and thus greatly reduces the response time.

[0028] Example 1 An electrode paste for an electrochemical hydrogen fluoride sensor is prepared by means of the following components and by the following preparation method: 7.00g of iron-doped nano zinc oxide powder prepared in Preparation Example 1, 1.76g of conductive graphite, 0.78g of organic additives and 5.60g of terpineol were mixed and ball-milled at 280rpm for 2h to obtain a uniform slurry. The organic additives include binder (sodium carboxymethyl cellulose), plasticizer (butyl benzyl phthalate), and leveling agent (modified acrylate) with masses of 0.60g, 0.10g, and 0.08g, respectively.

[0029] Comparative Example 1 An electrode paste for an electrochemical hydrogen fluoride sensor is prepared in a manner similar to that of Example 1, except that the electrode paste for the electrochemical hydrogen fluoride sensor is composed of 2.80g of iron-doped nano zinc oxide, 1.96g of conductive graphite, 0.82g of organic additives, and 5.80g of terpineol.

[0030] Comparative Example 2 An electrode paste for an electrochemical hydrogen fluoride sensor is prepared in a manner similar to that of Example 1, except that the electrode paste for the electrochemical hydrogen fluoride sensor is composed of 3.80g of iron-doped nano zinc oxide, 1.85g of conductive graphite, 0.84g of organic additives, and 5.60g of terpineol.

[0031] Comparative Example 3 An electrode paste for an electrochemical hydrogen fluoride sensor is prepared in a manner similar to that in Example 1, except that the electrode paste for the electrochemical hydrogen fluoride sensor consists of 6.20 g of conductive graphite, 0.78 g of organic additives, and 5.60 g of terpineol.

[0032] Comparative Example 4 An electrode slurry for an electrochemical hydrogen fluoride sensor is prepared in a manner similar to that in Example 1, except that the nanopowder in the electrode slurry for the electrochemical hydrogen fluoride sensor is 3.50g of commercially available nano zinc oxide with a particle size distribution of 40-80nm.

[0033] Application Example 1 An electrochemical hydrogen fluoride sensor includes a plastic housing, within which a working electrode, a reference electrode, and a counter electrode are assembled. The spaces between the electrodes are filled with absorbent cotton and filled with electrolyte as a medium for charge transfer. The working electrode, reference electrode, and counter electrode are connected to a test circuit board via platinum wires and pins to achieve signal output. The plastic housing is equipped with an air inlet cover. After installing the working electrode, reference electrode and counter electrode inside the housing, add 350 μL of 5 mol / L sulfuric acid electrolyte. After assembling the air inlet cover, seal the housing. Finally, short-circuit the working electrode and counter electrode for 3 days to age the electrochemical hydrogen fluoride sensor. In this embodiment, the working electrode, reference electrode, and counter electrode are all made of electrochemical hydrogen fluoride sensor electrodes, wherein the working electrode and reference electrode are both φ14mm circular plates, and the counter electrode is a φ14*4mm circular ring. The above-mentioned electrochemical hydrogen fluoride sensor electrode was prepared by screen printing the electrode paste obtained in Example 1 onto a polytetrafluoroethylene film and drying it at 80°C for 1 hour.

[0034] Application Example 2 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrolyte in the electrode of the electrochemical hydrogen fluoride sensor is composed of a mixture of 150 μL of 5 mol / L sulfuric acid and 200 μL of 0.06 mol / L lithium sulfate.

[0035] Application Example 3 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrolyte in the electrode of the electrochemical hydrogen fluoride sensor consists of 350 μL of 0.06 mol / L lithium sulfate.

[0036] Application Example 4 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrolyte in the electrode of the electrochemical hydrogen fluoride sensor consists of 350 μL of 7.0 mol / L lithium chloride.

[0037] Application Example 5 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrolyte in the electrode of the electrochemical hydrogen fluoride sensor consists of 350 μL of 2.2 mol / L sodium chloride.

[0038] Application Comparative Example 1 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrode of the electrochemical hydrogen fluoride sensor is prepared by screen printing the electrode paste obtained in Comparative Example 1 onto a polytetrafluoroethylene film and drying it at 80°C for 1 hour.

[0039] Application Comparative Example 2 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrode of the electrochemical hydrogen fluoride sensor is prepared by screen printing the electrode paste obtained in Comparative Example 2 onto a polytetrafluoroethylene film and drying it at 80°C for 1 hour.

[0040] Application Comparative Example 3 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrode of the electrochemical hydrogen fluoride sensor is prepared by screen printing the electrode paste obtained in Comparative Example 3 onto a polytetrafluoroethylene film and drying it at 80°C for 1 hour.

[0041] Application Comparative Example 4 An electrochemical hydrogen fluoride sensor differs from Application Example 1 in that the electrode of the electrochemical hydrogen fluoride sensor is prepared by screen printing the electrode paste obtained in Comparative Example 4 onto a polytetrafluoroethylene film and drying it at 80°C for 1 hour.

[0042] For the electrochemical hydrogen fluoride sensors prepared in Application Example 1 and Comparative Examples 1-4, a gas flow test was conducted in 5 ppm hydrogen fluoride gas. The test results are shown in Table 1 below.

[0043] Table 1: Comparison of the response sensitivity of the electrochemical hydrogen fluoride sensor to 5 ppm hydrogen fluoride gas in Application Example 1 and Comparative Examples 1-4 Test item group Output signal (nA / ppm) T 90 (s) Application Example 1 248 28 Application Comparative Example 1 194 46 Application Comparative Example 2 226 40 Application Comparative Example 3 35 89 Application Comparative Example 4 133 41 As shown in Table 1, the sensor in Application Example 1 has a response sensitivity of 248 nA / ppm to hydrogen fluoride, while the sensor in Comparative Example 1, which uses less nano-zinc oxide in its electrode slurry, has a sensitivity to hydrogen fluoride reduced to 194 nA / ppm. Furthermore, increasing the amount of nano-zinc oxide in the electrode slurry did not improve the response sensitivity of the sensor in Comparative Example 2 to hydrogen fluoride; in fact, it slightly decreased. The main reason for this is likely that nano-zinc oxide, as the main component of the electrode's catalytic activity, cannot provide sufficient catalytic activity at low concentrations. Excessive introduction of nano-zinc oxide, on the other hand, causes the collapse and compression of the microscopic three-dimensional structure, inhibiting gas transport channels and diffusion rates, leading to a decrease in response sensitivity.

[0044] Furthermore, in Comparative Example 3, the sensor electrode slurry did not incorporate nano-zinc oxide as a catalytically active component, resulting in extremely low sensitivity to hydrogen fluoride and an inability to acquire a stable signal. In contrast, Comparative Example 4, which incorporated commercially available nano-zinc oxide into its sensor electrode slurry, showed a significant improvement in sensitivity to hydrogen fluoride. However, its sensitivity to hydrogen fluoride was not as high as in Application Example 1. This is mainly because the nano-zinc oxide prepared by the self-propagating combustion method has a loose structure and a large specific surface area. Furthermore, the number of active sites in the nanoparticles was increased a second time after iron doping, thereby achieving high catalytic activity.

[0045] Therefore, in the electrochemical hydrogen fluoride sensor of this application, when the slurry coated on the electrode surface of the electrochemical hydrogen fluoride sensor is composed of 60-78% iron-doped nano zinc oxide powder, 15-22% conductive graphite, 5-8% organic additives and the balance terpineol, the response sensitivity of the electrochemical hydrogen fluoride sensor can be improved. However, the above application example 1 still has the problem of a slightly long response time, which needs to be further optimized.

[0046] The electrochemical hydrogen fluoride sensors prepared in the above application examples 1-5 were subjected to cross-response tests in different gases. The test results are shown in Table 2 below.

[0047] Table 2: Cross-response test comparison table of electrochemical hydrogen fluoride sensors in Application Examples 1-5

[0048] As can be seen from the table above, the sensors in Application Examples 1-2 exhibit excessive cross-interference signals from acidic gases and oxidizing chlorine gases, making them unsuitable for practical applications. The sensor in Application Example 3, using lithium sulfate as the electrolyte, can shorten the sensor's response time, but the cross-interference signal from acidic gases remains high, posing a significant risk of false alarms. In contrast, the sensors in Application Examples 4-5, using lithium chloride or sodium chloride as the electrolyte, can significantly reduce the cross-interference signal from acidic gases while maintaining a lower response time.

[0049] The reason for this is likely that the acidity or alkalinity of the electrolyte significantly affects the transport rates of hydrogen and fluoride ions during the reaction process within the sensor. When the electrolyte is acidic, it inhibits the ionization of hydrogen ions from the dissolved hydrogen fluoride. However, in a neutral electrolyte environment, hydrogen ions in the hydrogen fluoride ionize rapidly and react with the catalyst electrode, allowing for smoother charge flow and thus improving the response rate. Therefore, using neutral lithium chloride or sodium chloride as the electrolyte enhances both the sensitivity and reaction rate after hydrogen fluoride gas enters the sensor, while simultaneously suppressing the influence of cross-interference gases, thereby improving the sensor's selectivity.

[0050] Depend on Figure 3 It can be seen that the hydrogen fluoride sensors in Application Examples 4 and 5 maintain a short response and recovery time for hydrogen fluoride gas within the concentration range of 0-10 ppm as the concentration of hydrogen fluoride gas increases, demonstrating excellent response and recovery characteristics. Simultaneously, the hydrogen fluoride gas concentration value maintains a good linear relationship with the output sensitivity value, indicating that the hydrogen fluoride sensor possesses an extremely low detection limit and excellent linearity within the measurement range.

[0051] Figure 4 The figures show the cyclic adsorption-desorption curves of the hydrogen fluoride sensors prepared in Application Examples 4 and 5 in 5 ppm hydrogen fluoride gas. As can be seen from the figures, the sensors exhibit good response sensitivity to hydrogen fluoride gas in each cycle of the test, and the response and desorption performance remain stable with excellent consistency.

[0052] The above are all modifications that can be made to this embodiment without contributing any inventive step, or solutions that clearly constitute technical teaching, after reading this specification. However, as long as they are within the scope of the claims of this application, they should be protected by patent law.

Claims

1. An electrode paste for an electrochemical hydrogen fluoride sensor, characterized in that, It consists of the following components by weight percentage: 60-78% inorganic oxide powder, 15-22% conductive graphite powder, 5-8% organic additives, and solvent terpineol. The inorganic oxide powder is prepared by burning a mixture of zinc acetate, ferrous acetate, tartaric acid, and anhydrous ethanol.

2. The electrode paste for an electrochemical hydrogen fluoride sensor according to claim 1, characterized in that, The inorganic oxide powder is prepared by the following method: S1. Tartaric acid and anhydrous ethanol are mixed and stirred to obtain solution I; S2. Mix zinc acetate, ferrous acetate and anhydrous ethanol and stir to obtain solution II; S3. Pour solution II into solution I and disperse by ultrasonication to obtain solution III; S4. Transfer the well-mixed solution III to an evaporating dish, place it on a heating mantle and heat it to 300°C. After the liquid in the evaporating dish has completely evaporated, a fluffy solid precursor is obtained after combustion. S5. Calcining the fluffy solid precursor powder at 350-400℃ for 1-3 hours under a nitrogen atmosphere yields the inorganic oxide powder.

3. The electrode paste for an electrochemical hydrogen fluoride sensor according to claim 1, characterized in that, The mass ratio of zinc acetate, ferrous acetate, tartaric acid and anhydrous ethanol is 1:(0.01-0.05):(0.3-0.6):(6-8).

4. The electrode paste for an electrochemical hydrogen fluoride sensor according to claim 1, characterized in that, The organic additives include binders, plasticizers, and leveling agents; The binder is selected from at least one of thermoplastic acrylic resin, polyvinyl butyral, sodium carboxymethyl cellulose, and polyalkyl polycarbonate; The plasticizer is selected from at least one of di(2-ethylhexyl) phthalate, diethyl phthalate, and butyl benzyl phthalate; The leveling agent is selected from at least one of butyl cellulose, isophorone, and modified acrylate leveling agents; Furthermore, the mass ratio of adhesive, plasticizer, and leveling agent is 1:(0.05-0.2):(0.02-0.07).

5. The method for preparing the electrode paste for an electrochemical hydrogen fluoride sensor according to any one of claims 1-4, characterized in that, Includes the following steps: The inorganic oxide powder, conductive graphite powder, organic additives and the balance terpineol are mixed and ground in a ball mill at 200-300 rpm for 2-3 hours to obtain the final product.

6. The use of the electrode slurry for electrochemical hydrogen fluoride sensors according to any one of claims 1-4 and / or the electrode slurry prepared by the method for preparing the electrode slurry for electrochemical hydrogen fluoride sensors according to claim 5 in the preparation of electrochemical hydrogen fluoride sensors.

7. The application according to claim 6, characterized in that, The electrochemical hydrogen fluoride sensor includes an electrochemical hydrogen fluoride sensor electrode and a neutral electrolyte.

8. The application according to claim 7, characterized in that, The neutral electrolyte is selected from at least one of lithium sulfate, lithium chloride, sodium chloride, sodium sulfate, sodium nitrate, and calcium chloride.

9. The application according to claim 7, characterized in that, The electrochemical hydrogen fluoride sensor electrode is prepared by coating an electrode slurry onto a polytetrafluoroethylene film and drying it at 70-80°C for 1-2 hours.

10. The application according to claim 9, characterized in that, The electrode paste can be coated by one of the following methods: rolling, spraying, screen printing, and molding.

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