A gas sensor surface anti-interference coating and a preparation method thereof

Abstract

The application provides a gas sensor surface anti-interference coating, which comprises the following materials in parts by mass: nanometer silicon dioxide 5.5-10.5 parts, nanometer titanium dioxide 3.5-5.6 parts, nanometer tin dioxide 10-15.5 parts, palladium chloride substrate 1-2 parts and distilled water. The application also provides a preparation method of the gas sensor surface anti-interference coating, which comprises the following steps: mixing nanometer tin dioxide, nanometer silicon dioxide and nanometer titanium dioxide, grinding, sintering treatment, mixing the sintered nanometer composite material with a water solution of the palladium chloride substrate and a polar protic solvent, grinding again, drying treatment, removing the solvent, and forming a final gas sensor nanometer composite anti-interference material coating. The nanometer composite anti-interference material coating prepared by the application has strong adsorption capacity for interference substances of the gas sensor, meanwhile, the permeability of detection gases such as methane is not affected, the response voltage of the gas sensor to the interference substances is significantly reduced, the anti-interference capacity is improved, and the surface coating does not have a failure phenomenon.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensor coatings, and particularly relates to an anti-interference coating for the surface of a gas sensor and a preparation method thereof. Background Art

[0002] The main function of a gas sensor for combustible gas is to monitor the concentration of combustible or toxic gases in the environment in real time. Through chemical or physical reactions, such as resistance change, current change, infrared absorption, etc., the gas concentration is converted into an electrical signal, and when the concentration exceeds the safety threshold, an alarm or linkage control is triggered to prevent safety accidents such as explosions and poisonings. Application in households: Detect gas leakage in the kitchen to prevent explosions or poisonings. Application in industry: Monitor gas leakage in gas pipelines, storage tanks, and production workshops.

[0003] Existing gas sensors for combustible gas have poor anti-interference performance. Gas sensors for combustible gas, such as those for detecting gases like methane and propane, are often used in gas alarm devices in actual applications and are often interfered by ethanol, smoke, lampblack, etc., resulting in false alarms or decreased sensitivity. In order to improve the anti-interference performance, existing gas sensors for combustible gas use materials such as activated carbon to wrap the gas sensor to adsorb small organic molecules in lampblack, such as aldehydes and olefins, to reduce chemical interference to the sensor. However, activated carbon is very easy to失效 when exposed to air for a long time. The adsorption of activated carbon is mainly based on physical adsorption: van der Waals force between molecules, and a small amount of chemical adsorption: such as forming chemical bonds with some polar molecules. Its adsorption capacity depends on the "storage space" provided by the pore structure. But this adsorption is reversible and limited: when the pores of activated carbon are filled with impurity molecules in the air, it can no longer adsorb new substances, that is, "adsorption saturation"; the binding force of physical adsorption is weak, and changes in environmental conditions, such as temperature increase and humidity change, will cause the adsorbed molecules to desorb, releasing the pore space, but at the same time, it will also accelerate the adsorption of new impurities, shortening the effective life and resulting in a rapid decline in the adsorption capacity for sensor interferents.

[0004] The most important thing during the use of a sensor is to ensure its sensitivity. Although those skilled in the art have tried to set a coating on the surface of the sensor, it is generally used for low-sensitivity materials, mainly for the following purposes: 1. Adsorb more gas molecules through the porous and high-surface-area structure of the coating itself to improve the sensitivity of the sensor, but this use is not applicable to nanoscale materials; 2. Reduce the influence of a specific environment on the gas-sensitive sensor, such as moisture-proof, but at the same time, it will greatly reduce the sensitivity of the sensor. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an anti-interference coating for the surface of a gas sensor and a preparation method thereof, which solve the problem that the anti-interference performance of the current gas sensor material is poor and cannot meet the phenomenon of false alarms caused by the influence of interfering gases on the product.

[0006] To achieve the above-mentioned technical objectives, the present invention provides the following technical solution:

[0007] An anti-interference coating for a gas sensor surface comprises the following materials in parts by weight: 5.5-10.5 parts of nano-silica, 3.5-5.6 parts of nano-titanium dioxide, 10-15.5 parts of nano-tin dioxide, 1-2 parts of palladium chloride substrate, and distilled water.

[0008] Preferably, the material comprises the following parts by weight: 8.3-9.7 parts of nano-silica, 4.2-5.2 parts of nano-titanium dioxide, 10.8-13.2 parts of nano-tin dioxide, 1-2 parts of 10% palladium chloride substrate, and distilled water.

[0009] The most preferred composition comprises the following materials in parts by weight: 9.1 parts nano-silica, 4.6 parts nano-titanium dioxide, 11.8 parts nano-tin dioxide, 1.5 parts palladium chloride substrate, and distilled water.

[0010] A method for preparing an anti-interference coating on the surface of a gas sensor includes the following steps:

[0011] S1: Thoroughly mix and grind nano-tin dioxide, nano-silicon dioxide, and nano-titanium dioxide.

[0012] S2: The material mixed with S1 is sintered at a temperature of 300℃-500℃ for 1-2 hours.

[0013] S3: The nanocomposite material sintered from S2 is mixed with a chemical aqueous solution of palladium chloride substrate and a polar protic solvent, and then ground again.

[0014] S4: The nanocomposite material after S3 mixing and grinding is dried to remove the solvent, forming the final gas sensor nanocomposite anti-interference material coating.

[0015] Preferably, the tin dioxide in step S1 is tin dioxide prepared by chemical oxidation or calcination of metallic tin with a purity of 99.999%.

[0016] Preferably, the sintering temperature in step S2 is 340℃-440℃ and the time is 2h, and the drying temperature in step S4 is 60℃-100℃.

[0017] Most preferably, the sintering temperature in step S2 is 380℃ and the time is 2h.

[0018] Most preferably, the drying temperature in step S4 is 80°C.

[0019] Preferably, the palladium chloride substrate chemical aqueous solution in step S3 is a palladium chloride substrate chemical aqueous solution with a mass fraction of 10%, and the polar protic solvent is water or ethanol.

[0020] The beneficial effects of this invention are as follows:

[0021] The nanocomposite anti-interference material coating prepared by this invention has a strong adsorption capacity for interfering substances in gas sensors, greatly reducing their penetration, while not affecting the transmittance of detection gases such as methane. The response voltage of the gas sensor to interfering substances is significantly reduced, improving the anti-interference capability. The surface coating does not fail, solving the problem of poor anti-interference performance of current gas sensor materials, which cannot meet the requirements of sensors that generate false alarms due to the influence of interfering gases. The nanocomposite anti-interference coating prepared by this invention adheres to the sensor surface without affecting the sensor's sensitivity, breaking the perception in the field that sensor surface coatings necessarily affect sensor sensitivity. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the anti-interference coating on the surface of the gas sensor prepared according to the present invention.

[0023] Figure 2 This is a diagram showing the adhesion state of the anti-interference coating on the gas sensor surface of the present invention on the gas sensor. Detailed Implementation

[0024] To make the technical objectives, solutions, and effects of this invention easier to understand, further explanation is provided below in conjunction with the accompanying drawings and specific embodiments.

[0025] Using a gas sensor without an anti-interference coating as a control, 3000 ppm methane was used as the target gas and 3000 ppm ethanol as the interfering gas. The gas sensor was placed in a sealed transparent box, and methane and ethanol gases were simultaneously injected into the transparent box. Timing started after the gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the uncoated gas sensor are shown in Table 1. The response voltage values ​​of the target gas methane and the interfering gas ethanol are relatively close, which easily leads to false alarms.

[0026] Table 1 Anti-interference performance of uncoated sensors

[0027] Example 1

[0028] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0029] 5.5g of nano-silica, 3.5g of nano-titanium dioxide, 10.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0030] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0031] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0032] (2) Mixing and grinding: Mix 5.5g of nano silicon dioxide, 3.5g of nano titanium dioxide and 10.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0033] (3) Sintering: The mixed materials are sintered at 300℃ for 1 hour to ensure the crystallinity and density of the materials.

[0034] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0035] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 60°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0036] 3. Anti-interference performance verification

[0037] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 2. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.31V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0038] Table 2. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 1.

[0039] Example 2

[0040] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0041] 6g of nano-silica, 3.5g of nano-titanium dioxide, 10.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0042] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0043] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0044] (2) Mixing and grinding: Mix 6g of nano silicon dioxide, 3.5g of nano titanium dioxide and 10.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0045] (3) Sintering: The mixed materials are sintered at a temperature of 320°C for 1.5 hours to ensure the crystallinity and density of the materials.

[0046] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0047] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0048] 3. Anti-interference performance verification

[0049] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 3: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.29V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0050] Table 3. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 2.

[0051] Example 3

[0052] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0053] 6.5g of nano-silica, 4.5g of nano-titanium dioxide, 10.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0054] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0055] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0056] (2) Mixing and grinding: Mix 5.5g of nano silicon dioxide, 3.5g of nano titanium dioxide and 10.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0057] (3) Sintering: The mixed materials are sintered at a temperature of 340℃ for 2 hours to ensure the crystallinity and density of the materials.

[0058] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0059] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0060] 3. Anti-interference performance verification

[0061] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 4: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.35V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0062] Table 4. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 3.

[0063] Example 4

[0064] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0065] 7g of nano-silica, 4.5g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0066] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0067] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0068] (2) Mixing and grinding: Mix 7g of nano silicon dioxide, 4.5g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0069] (3) Sintering: The mixed materials are sintered at a temperature of 360°C for 1 hour to ensure the crystallinity and density of the materials.

[0070] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0071] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0072] 3. Anti-interference performance verification

[0073] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 5: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.33V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0074] Table 5. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 4.

[0075] Example 5

[0076] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0077] 7.5g of nano-silica, 4.5g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0078] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0079] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0080] (2) Mixing and grinding: Mix 7.5g of nano silicon dioxide, 4.5g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0081] (3) Sintering: The mixed materials are sintered at a temperature of 380℃ for 2 hours to ensure the crystallinity and density of the materials.

[0082] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0083] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0084] 3. Anti-interference performance verification

[0085] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 6. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.40V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0086] Table 6. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 5.

[0087] Example 6

[0088] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0089] 8g of nano-silica, 5.2g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0090] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0091] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0092] (2) Mixing and grinding: Mix 8g of nano silicon dioxide, 5.2g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0093] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1 hour to ensure the crystallinity and density of the materials.

[0094] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0095] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0096] 3. Anti-interference performance verification

[0097] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 7. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.37V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0098] Table 7. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 5.

[0099] Example 7

[0100] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0101] 10g of nano-silica, 3.5g of nano-titanium dioxide, 13.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0102] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0103] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0104] (2) Mixing and grinding: 10g of nano silicon dioxide, 3.5g of nano titanium dioxide and 13.5g of nano tin dioxide are thoroughly mixed and ground with an automatic grinder to ensure that they are evenly distributed.

[0105] (3) Sintering: The mixed materials are sintered at a temperature of 480℃ for 1.5h to ensure the crystallinity and density of the materials.

[0106] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0107] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0108] 3. Anti-interference performance verification

[0109] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 8. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.44V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0110] Table 8. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 7.

[0111] Example 8

[0112] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0113] 10.5g of nano-silica, 5.6g of nano-titanium dioxide, 15.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0114] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0115] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0116] (2) Mixing and grinding: Mix 10.5g of nano silicon dioxide, 5.6g of nano titanium dioxide and 15.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0117] (3) Sintering: The mixed materials are sintered at a temperature of 500℃ for 2 hours to ensure the crystallinity and density of the materials.

[0118] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0119] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0120] 3. Anti-interference performance verification

[0121] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 9: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.42V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0122] Table 9. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 8.

[0123] Example 9

[0124] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0125] 8.5g of nano-silica, 5.2g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0126] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0127] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0128] (2) Mixing and grinding: Mix 8.5g of nano silicon dioxide, 5.2g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0129] (3) Sintering: The mixed materials are sintered at a temperature of 420°C for 1.5 hours to ensure the crystallinity and density of the materials.

[0130] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0131] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 70°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0132] 3. Anti-interference performance verification

[0133] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 10: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.49V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0134] Table 10. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 9.

[0135] Example 10

[0136] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0137] 9g of nano-silica, 5.5g of nano-titanium dioxide, 12.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0138] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0139] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0140] (2) Mixing and grinding: Mix 9g of nano silicon dioxide, 5.5g of nano titanium dioxide and 12.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0141] (3) Sintering: The mixed materials are sintered at a temperature of 440℃ for 2 hours to ensure the crystallinity and density of the materials.

[0142] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0143] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 60°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0144] 3. Anti-interference performance verification

[0145] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 11: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.46V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0146] Table 11. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 10.

[0147] Example 11

[0148] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0149] 9.5g of nano-silica, 5.5g of nano-titanium dioxide, 12.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0150] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0151] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0152] (2) Mixing and grinding: Mix 9.5g of nano silicon dioxide, 5.5g of nano titanium dioxide and 12.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0153] (3) Sintering: The mixed materials are sintered at a temperature of 460℃ for 1 hour to ensure the crystallinity and density of the materials.

[0154] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0155] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 70°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0156] 3. Anti-interference performance verification

[0157] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 12: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.54V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0158] Table 12. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 11.

[0159] Example 12

[0160] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0161] 8.6g of nano-silica, 4.1g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0162] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0163] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0164] (2) Mixing and grinding: Mix 8.6g of nano silicon dioxide, 4.1g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0165] (3) Sintering: The mixed materials are sintered at a temperature of 380℃ for 1.5h to ensure the crystallinity and density of the materials.

[0166] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0167] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0168] 3. Anti-interference performance verification

[0169] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 13: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.51V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0170] Table 13. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 12.

[0171] Example 13

[0172] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0173] 8.9g of nano-silica, 4.4g of nano-titanium dioxide, 12.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0174] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0175] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0176] (2) Mixing and grinding: Mix 8.9g of nano silicon dioxide, 4.4g of nano titanium dioxide and 12.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0177] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 2 hours to ensure the crystallinity and density of the materials.

[0178] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0179] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 70°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0180] 3. Anti-interference performance verification

[0181] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 14: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.59V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0182] Table 14. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 13.

[0183] Example 14

[0184] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0185] 8g of nano-silica, 3.5g of nano-titanium dioxide, 10.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0186] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0187] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0188] (2) Mixing and grinding: Mix 8g of nano silicon dioxide, 3.5g of nano titanium dioxide and 10.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0189] (3) Sintering: The mixed materials are sintered at a temperature of 340℃ for 1 hour to ensure the crystallinity and density of the materials.

[0190] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0191] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0192] 3. Anti-interference performance verification

[0193] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 2: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.28V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0194] Table 15 shows the anti-interference performance and adhesion molding capability of the coated sensor in Example 14.

[0195] Example 15

[0196] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0197] 8.3g of nano-silica, 3.8g of nano-titanium dioxide, 15.5g of nano-tin dioxide, 2g of palladium chloride substrate and 15mL of distilled water.

[0198] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0199] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0200] (2) Mixing and grinding: Mix 8.3g of nano silicon dioxide, 3.8g of nano titanium dioxide and 15.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0201] (3) Sintering: The mixed materials are sintered at a temperature of 360°C for 1 hour to ensure the crystallinity and density of the materials.

[0202] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0203] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 60°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0204] 3. Anti-interference performance verification

[0205] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 16: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.25V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0206] Table 16 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 15.

[0207] Example 16

[0208] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0209] 8g of nano-silica, 4.1g of nano-titanium dioxide, 11g of nano-tin dioxide, 1.5g of palladium chloride substrate and 10mL of distilled water.

[0210] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0211] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0212] (2) Mixing and grinding: Mix 8g of nano silicon dioxide, 4.1g of nano titanium dioxide and 11g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0213] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1.5h to ensure the crystallinity and density of the materials.

[0214] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0215] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0216] 3. Anti-interference performance verification

[0217] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 17: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.32V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0218] Table 17 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 16.

[0219] Example 17

[0220] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0221] 9.5g of nano-silica, 5g of nano-titanium dioxide, 14.5g of nano-tin dioxide, 2g of palladium chloride substrate and 15mL of distilled water.

[0222] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0223] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0224] (2) Mixing and grinding: Mix 9.5g of nano silicon dioxide, 5g of nano titanium dioxide and 14.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0225] (3) Sintering: The mixed materials are sintered at a temperature of 440℃ for 2 hours to ensure the crystallinity and density of the materials.

[0226] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0227] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0228] 3. Anti-interference performance verification

[0229] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 18: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.29V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0230] Table 18 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 17.

[0231] Example 18

[0232] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0233] 9.8g of nano-silica, 5.3g of nano-titanium dioxide, 15.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0234] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0235] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0236] (2) Mixing and grinding: Mix 9.8g of nano silicon dioxide, 5.3g of nano titanium dioxide and 15.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0237] (3) Sintering: The mixed materials are sintered at a temperature of 460℃ for 1 hour to ensure the crystallinity and density of the materials.

[0238] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0239] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 85°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0240] 3. Anti-interference performance verification

[0241] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 19: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.36V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0242] Table 19 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 18.

[0243] Example 19

[0244] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0245] 4.1g of nano-silica, 5.6g of nano-titanium dioxide, 15.5g of nano-tin dioxide, 1.5g of palladium chloride substrate and 15mL of distilled water.

[0246] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0247] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0248] (2) Mixing and grinding: Mix 4.1g of nano silicon dioxide, 5.6g of nano titanium dioxide and 15.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0249] (3) Sintering: The mixed materials are sintered at a temperature of 340℃ for 1.5h to ensure the crystallinity and density of the materials.

[0250] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0251] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 90°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0252] 3. Anti-interference performance verification

[0253] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 20: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.33V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0254] Table 20 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 19.

[0255] Example 20

[0256] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0257] 7.2g of nano-silica, 3.5g of nano-titanium dioxide, 10g of nano-tin dioxide, 2g of palladium chloride substrate and 10mL of distilled water.

[0258] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0259] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0260] (2) Mixing and grinding: Mix 7.2g of nano silicon dioxide, 3.5g of nano titanium dioxide and 10g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0261] (3) Sintering: The mixed materials are sintered at a temperature of 360°C for 2 hours to ensure the crystallinity and density of the materials.

[0262] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0263] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 95°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0264] 3. Anti-interference performance verification

[0265] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 21: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.40V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0266] Table 21. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 20.

[0267] Example 21

[0268] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0269] 7.6g of nano-silica, 3.8g of nano-titanium dioxide, 10.5g of nano-tin dioxide, 1g of palladium chloride substrate and 15mL of distilled water.

[0270] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0271] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0272] (2) Mixing and grinding: Mix 7.6g of nano-silica, 3.8g of nano-titanium dioxide and 10.5g of nano-tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0273] (3) Sintering: The mixed materials are sintered at a temperature of 380℃ for 1 hour to ensure the crystallinity and density of the materials.

[0274] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0275] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 100°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0276] 3. Anti-interference performance verification

[0277] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 22: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.38V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0278] Table 22 Anti-interference performance and adhesion / forming ability of the coating sensor in Example 21

[0279] Example 22

[0280] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0281] 9.2g of nano-silica, 4.7g of nano-titanium dioxide, 13.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0282] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0283] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0284] (2) Mixing and grinding: Mix 9.2g of nano silicon dioxide, 4.7g of nano titanium dioxide and 13.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0285] (3) Sintering: The mixed materials are sintered at a temperature of 420°C for 1 hour to ensure the crystallinity and density of the materials.

[0286] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0287] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0288] 3. Anti-interference performance verification

[0289] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 23: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.45V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0290] Table 23 Anti-interference performance and adhesion / forming ability of the coating sensor in Example 22

[0291] Example 23

[0292] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0293] 9.2g of nano-silica, 5g of nano-titanium dioxide, 12.5g of nano-tin dioxide, 1.5g of palladium chloride substrate and 15mL of distilled water.

[0294] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0295] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0296] (2) Mixing and grinding: Mix 9.2g of nano silicon dioxide, 5g of nano titanium dioxide and 12.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0297] (3) Sintering: The mixed materials are sintered at a temperature of 460℃ for 1.5h to ensure the crystallinity and density of the materials.

[0298] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0299] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0300] 3. Anti-interference performance verification

[0301] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 24: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.43V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0302] Table 24. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 23.

[0303] Example 24

[0304] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0305] 8.8g of nano-silica, 4.7g of nano-titanium dioxide, 12g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0306] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0307] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0308] (2) Mixing and grinding: Mix 8.8g of nano silicon dioxide, 4.7g of nano titanium dioxide and 12g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0309] (3) Sintering: The mixed materials are sintered at a temperature of 440℃ for 1 hour to ensure the crystallinity and density of the materials.

[0310] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0311] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0312] 3. Anti-interference performance verification

[0313] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 25: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.50V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0314] Table 25. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 24.

[0315] Example 25

[0316] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0317] 9.6g of nano-silica, 5.3g of nano-titanium dioxide, 13g of nano-tin dioxide, 2g of palladium chloride substrate and 10mL of distilled water.

[0318] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0319] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0320] (2) Mixing and grinding: Mix 9.6g of nano silicon dioxide, 5.3g of nano titanium dioxide and 13g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0321] (3) Sintering: The mixed materials are sintered at a temperature of 380℃ for 2 hours to ensure the crystallinity and density of the materials.

[0322] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0323] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 85°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0324] 3. Anti-interference performance verification

[0325] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box, and methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 26: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.47V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0326] Table 26 shows the anti-interference performance and adhesion molding capability of the coated sensor in Example 25.

[0327] Example 26

[0328] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0329] 8.4g of nano-silica, 4.4g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 2g of palladium chloride substrate and 15mL of distilled water.

[0330] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0331] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0332] (2) Mixing and grinding: Mix 8.4g of nano silicon dioxide, 4.4g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0333] (3) Sintering: The mixed materials are sintered at a temperature of 420°C for 2 hours to ensure the crystallinity and density of the materials.

[0334] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0335] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0336] 3. Anti-interference performance verification

[0337] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 27: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.55V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0338] Table 27 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 26.

[0339] Example 27

[0340] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0341] 10g of nano-silica, 5.6g of nano-titanium dioxide, 13.5g of nano-tin dioxide, 1g of palladium chloride substrate and 15mL of distilled water.

[0342] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0343] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0344] (2) Mixing and grinding: Mix 10g of nano silicon dioxide, 5.6g of nano titanium dioxide and 13.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0345] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1 hour to ensure the crystallinity and density of the materials.

[0346] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0347] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 90°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0348] 3. Anti-interference performance verification

[0349] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box, and methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 28: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.25V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0350] Table 28 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 27.

[0351] Example 28

[0352] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0353] 10.4g of nano-silica, 3.8g of nano-titanium dioxide, 14g of nano-tin dioxide, 1.5g of palladium chloride substrate and 10mL of distilled water.

[0354] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0355] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0356] (2) Mixing and grinding: Mix 10.4g of nano silicon dioxide, 3.8g of nano titanium dioxide and 14g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0357] (3) Sintering: The mixed materials are sintered at a temperature of 420°C for 1.5 hours to ensure the crystallinity and density of the materials.

[0358] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0359] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 65°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0360] 3. Anti-interference performance verification

[0361] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 29: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.22V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0362] Table 29 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 28.

[0363] Example 29

[0364] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0365] 10.5g of nano-silica, 3.5g of nano-titanium dioxide, 14.5g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0366] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0367] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0368] (2) Mixing and grinding: Mix 10.5g of nano silicon dioxide, 3.5g of nano titanium dioxide and 14.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0369] (3) Sintering: The mixed materials are sintered at a temperature of 440℃ for 2 hours to ensure the crystallinity and density of the materials.

[0370] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0371] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 70°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0372] 3. Anti-interference performance verification

[0373] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 30: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.41V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0374] Table 30 shows the anti-interference performance and adhesion molding capability of the coated sensor in Example 29.

[0375] Example 30

[0376] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0377] 10.5g of nano-silica, 4.5g of nano-titanium dioxide, 15g of nano-tin dioxide, 1g of palladium chloride substrate, and 15mL of distilled water.

[0378] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0379] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0380] (2) Mixing and grinding: Mix 10.5g of nano-silica, 4.5g of nano-titanium dioxide and 15g of nano-tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0381] (3) Sintering: The mixed materials are sintered at a temperature of 460℃ for 1 hour to ensure the crystallinity and density of the materials.

[0382] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0383] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 75°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0384] 3. Anti-interference performance verification

[0385] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 31: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.28V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0386] Table 31. Anti-interference performance and adhesion molding capability of the coated sensor in Example 30.

[0387] Example 31

[0388] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0389] 10.5g of nano-silica, 5.5g of nano-titanium dioxide, 15g of nano-tin dioxide, 1.5g of palladium chloride substrate and 15mL of distilled water.

[0390] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0391] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0392] (2) Mixing and grinding: 10.5g of nano silicon dioxide, 5.5g of nano titanium dioxide and 15g of nano tin dioxide (3) Sintering: Sinter the mixed materials at a temperature of 500℃ for 2 hours to ensure the crystallinity and density of the materials.

[0393] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0394] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0395] 3. Anti-interference performance verification

[0396] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 32: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.26V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without large cracks, and showed no peeling or cracking after being scratched by sharp objects or clamped.

[0397] Table 32 Anti-interference performance and adhesion / forming ability of the coating sensor in Example 31

[0398] Example 32

[0399] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0400] 8.3g of nano-silica, 4.2g of nano-titanium dioxide, 10.8g of nano-tin dioxide, 2g of palladium chloride substrate and 10mL of distilled water.

[0401] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0402] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0403] (2) Mixing and grinding: Mix 8.3g of nano silicon dioxide, 4.2g of nano titanium dioxide and 10.8g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0404] (3) Sintering: The mixed materials are sintered at a temperature of 340℃ for 1 hour to ensure the crystallinity and density of the materials.

[0405] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0406] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0407] 3. Anti-interference performance verification

[0408] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 33: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.67V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface with almost no cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0409] Table 33. Anti-interference performance and adhesion molding capability of the coated sensor in Example 32.

[0410] Example 33

[0411] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0412] 8.6g of nano-silica, 4.4g of nano-titanium dioxide, 11.3g of nano-tin dioxide, 1g of palladium chloride substrate and 15mL of distilled water.

[0413] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0414] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0415] (2) Mixing and grinding: Mix 8.6g of nano silicon dioxide, 4.4g of nano titanium dioxide and 11.3g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0416] (3) Sintering: The mixed materials are sintered at a temperature of 360°C for 1.5 hours to ensure the crystallinity and density of the materials.

[0417] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0418] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 90°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0419] 3. Anti-interference performance verification

[0420] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 34: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.64V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface with almost no cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0421] Table 34. Anti-interference performance and adhesion molding capability of the coating sensor in Example 33.

[0422] Example 34

[0423] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0424] 9.1g of nano-silica, 4.6g of nano-titanium dioxide, 11.8g of nano-tin dioxide, 1.5g of palladium chloride substrate and 10mL of distilled water.

[0425] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0426] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0427] (2) Mixing and grinding: Mix 9.1g of nano silicon dioxide, 4.6g of nano titanium dioxide and 11.8g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0428] (3) Sintering: The mixed materials are sintered at a temperature of 380℃ for 2 hours to ensure the crystallinity and density of the materials.

[0429] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0430] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0431] 3. Anti-interference performance verification

[0432] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 35: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.77V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface without cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0433] Table 35. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 34.

[0434] Example 35

[0435] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0436] 9.35g of nano-silica, 4.8g of nano-titanium dioxide, 12.3g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0437] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0438] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0439] (2) Mixing and grinding: Mix 9.35g of nano silicon dioxide, 4.8g of nano titanium dioxide and 12.3g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0440] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1 hour to ensure the crystallinity and density of the materials.

[0441] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0442] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 85°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0443] 3. Anti-interference performance verification

[0444] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 36: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.69V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface with almost no cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0445] Table 36. Anti-interference performance and adhesion / forming ability of the coating sensor in Example 35.

[0446] Example 36

[0447] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0448] 9.5g of nano-silica, 5g of nano-titanium dioxide, 12.8g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0449] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0450] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0451] (2) Mixing and grinding: Mix 9.5g of nano silicon dioxide, 5g of nano titanium dioxide and 12.8g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0452] (3) Sintering: The mixed materials are sintered at a temperature of 440℃ for 1.5h to ensure the crystallinity and density of the materials.

[0453] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0454] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 90°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0455] 3. Anti-interference performance verification

[0456] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 37: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.72V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating adhered to the sensor surface with almost no cracks, and showed no peeling or cracking after scratching with sharp objects or clamping.

[0457] Table 37. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 36.

[0458] Example 37

[0459] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0460] 9.7g of nano-silica, 5.2g of nano-titanium dioxide, 13.2g of nano-tin dioxide, 1.5g of palladium chloride substrate and 15mL of distilled water.

[0461] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0462] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0463] (2) Mixing and grinding: Mix 9.7g of nano silicon dioxide, 5.2g of nano titanium dioxide and 13.2g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0464] (3) Sintering: The mixed materials are sintered at a temperature of 460℃ for 2 hours to ensure the crystallinity and density of the materials.

[0465] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0466] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 100°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0467] 3. Anti-interference performance verification

[0468] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion formation ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box, and methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 38: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 1.74V at the maximum response voltage, indicating no false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating showed large cracks on the sensor surface, and peeling and cracking occurred when scratched by sharp objects or clamped, indicating insufficient adhesion formation ability.

[0469] Table 38 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 37.

[0470] Example 38

[0471] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0472] 5.2g of nano-silica, 3.3g of nano-titanium dioxide, 9.5g of nano-tin dioxide, 1g of palladium chloride substrate and 10mL of distilled water.

[0473] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0474] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0475] (2) Mixing and grinding: Mix 5.2g of nano silicon dioxide, 3.3g of nano titanium dioxide and 9.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0476] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1.5h to ensure the crystallinity and density of the materials.

[0477] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0478] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0479] 3. Anti-interference performance verification

[0480] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the box, and timing began after injection. The gas was then evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 39. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 0.70V at the maximum response voltage, which could lead to false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating showed large cracks on the sensor surface, and detachment and cracking occurred due to scratches from sharp objects and clamping.

[0481] Table 39 shows the anti-interference performance and adhesion molding capability of the coating sensor in Example 38.

[0482] Example 39

[0483] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0484] 10.8g of nano-silica, 5.9g of nano-titanium dioxide, 16g of nano-tin dioxide, 2g of palladium chloride substrate, and 15mL of distilled water.

[0485] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0486] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0487] (2) Mixing and grinding: Mix 10.8g of nano silicon dioxide, 5.9g of nano titanium dioxide and 16g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0488] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1.5h to ensure the crystallinity and density of the materials.

[0489] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 15 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0490] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0491] 3. Anti-interference performance verification

[0492] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box, and methane and ethanol gases were simultaneously injected into the box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 40: The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 0.68V at the maximum response voltage, which could lead to false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. The prepared coating showed large cracks on the sensor surface, and peeling and cracking occurred when scratched by sharp objects or clamped.

[0493] Table 40 shows the anti-interference performance and adhesion molding capability of the coated sensor in Example 39.

[0494] Example 40

[0495] 1. An anti-interference coating for the surface of a gas sensor, comprising the following materials in parts by weight:

[0496] 5.2g of nano-silica, 4.5g of nano-titanium dioxide, 11.5g of nano-tin dioxide, 1.5g of palladium chloride substrate and 10mL of distilled water.

[0497] 2. A method for preparing an anti-interference coating on the surface of a gas sensor, comprising the following steps:

[0498] (1) Preparation of nano tin dioxide: 99.999% pure metallic tin is oxidized into tin dioxide by chemical oxidation or calcination.

[0499] (2) Mixing and grinding: Mix 5.2g of nano silicon dioxide, 4.5g of nano titanium dioxide and 11.5g of nano tin dioxide thoroughly and grind them with an automatic grinder to ensure that they are evenly distributed.

[0500] (3) Sintering: The mixed materials are sintered at a temperature of 400℃ for 1.5h to ensure the crystallinity and density of the materials.

[0501] (4) Mix and grind with palladium chloride and trace chemical solvent: Mix the sintered nanocomposite material with 5 mL of 10% palladium chloride substrate chemical aqueous solution and 10 mL of distilled water, and grind again; palladium chloride may partially dissociate in the solvent to form palladium ion catalyst, which can interact with the tin dioxide surface to form doping or surface modification.

[0502] (5) Drying and forming materials: The mixed and ground nanocomposite material is dried at 80°C to remove the solvent and form the final gas sensor nanocomposite anti-interference material coating.

[0503] 3. Anti-interference performance verification

[0504] The nanocomposite anti-interference material coating prepared above was applied to a gas sensor, and its anti-interference performance, sensitivity, and adhesion and molding ability were then tested. Using 3000 ppm methane as the target gas and 3000 ppm ethanol as the interfering gas, the gas sensor was placed in a sealed transparent box. Methane and ethanol gases were simultaneously injected into the transparent box. Timing began after gas injection, and the gas was evacuated after 15 seconds. The anti-interference performance and sensitivity of the coated gas sensor are shown in Table 41. The response voltage values ​​of the target gas methane and the interfering gas ethanol differed significantly from the comparative example, with a difference of 0.71V at the maximum response voltage, which could lead to false alarms. Compared to the uncoated sensor, the sensor with the prepared coating also produced a larger response voltage at 9-12 seconds of detection time, indicating that the coating does not affect the sensor's gas detection sensitivity. Large cracks appeared on the surface of the prepared coating, and scratches from sharp objects and clamping caused detachment and cracking.

[0505] Table 41. Anti-interference performance and adhesion / forming ability of the coated sensor in Example 40.

[0506]

[0507] Table 42 shows the long-term stability test results of the gas sensor covered with the nanocomposite anti-interference material coating prepared in Examples 1-36. After 30 days of continuous testing, the average maximum response voltage of the gas methane and the interfering gas ethanol remained stable, indicating that the coating only plays a catalytic role against the interfering gas, can be reused, will not be consumed, and the surface coating will not fail.

[0508] Table 42 Long-term stability test of the coated sensor for detecting methane and ethanol.

[0509]

[0510] The comprehensive performance evaluation of the anti-interference ability and adhesion ability of the gas sensors with anti-interference coating prepared in Examples 1-40 of this invention is shown in Table 43, among which Example 34 is the example with the best material ratio and the best preparation method.

[0511] The relationship between the operating temperature and anti-interference performance of gas sensors with anti-interference coatings: Under normal circumstances, the stable operating temperature of a gas sensor is approximately 350℃. Without a coating, the sensor's operating temperature rises by less than 10℃ when exposed to methane or ethanol. However, a gas sensor with an anti-interference coating experiences a temperature rise of up to 40℃ when exposed to methane or ethanol. This significant difference is due to the crucial role of the anti-interference coating. On the surface of the gas sensor, the anti-interference coating possesses unique catalytic properties: when interfering gases such as ethanol come into contact with the coating, the coating catalyzes the reaction, causing a violent chemical combustion reaction. This reaction releases a large amount of heat, which is rapidly transferred to the sensor's interior, disrupting its original thermal equilibrium and resulting in a significant increase in the sensor's operating temperature.

[0512] In the series of embodiments involved in this invention, a clear pattern emerges: the sensors in all qualified and above embodiments exhibit a significantly greater increase in operating temperature compared to the sensors in unqualified embodiments and the uncoated sensors. This phenomenon fully demonstrates that the anti-interference coating plays a crucial role in improving the anti-interference performance of gas sensors. Sensors in qualified and above embodiments can more effectively catalyze the chemical reaction of interfering gases, resulting in a more significant change in operating temperature when facing interfering gases. This allows for more accurate differentiation between target and interfering gases, significantly improving the sensor's anti-interference capability and detection accuracy. Uncoated sensors, lacking this catalytic effect, are significantly inferior in anti-interference performance. Sensors in unqualified embodiments have defects in coating formulation and preparation processes, leading to poor catalytic effect, insignificant operating temperature changes, and unsatisfactory anti-interference performance.

[0513] Sensitivity analysis of gas sensors with anti-interference coating: Analysis of the changes in response voltage of the detected gas at different detection times reveals that the coated sensor not only has strong anti-interference and adhesion capabilities, but also has no impact on the sensor's sensitivity. The response voltage changes of gas sensors with and without coating are basically the same, indicating that the anti-interference coating does not affect the sensitivity of the gas sensor.

[0514] In summary, the gas sensor covered with the anti-interference coating has strong anti-interference and adhesion capabilities while maintaining its original sensitivity. This indicates that the coating only acts as a catalyst for interfering gases, can be reused, will not be consumed, and the surface coating will not fail.

[0515] Table 43 Comprehensive Evaluation of Interference Resistance and Adhesion of Overlay Coated Sensors

[0516]

Claims

1. An anti-interference coating for the surface of a gas sensor, characterized in that, The material is prepared by sintering from the following parts by weight: 5.5-10.5 parts of nano-silica, 3.5-5.6 parts of nano-titanium dioxide, 10-15.5 parts of nano-tin dioxide, 1-2 parts of palladium chloride substrate, and distilled water. The sintering process is as follows: first, nano-tin dioxide, nano-silica, and nano-titanium dioxide are mixed and ground, then sintered, and then mixed and ground with palladium chloride and dried to form an anti-interference material coating.

2. The anti-interference coating on the surface of a gas sensor according to claim 1, characterized in that, The material comprises the following parts by weight: 8.3-9.7 parts of nano-silica, 4.2-5.2 parts of nano-titanium dioxide, 10.8-13.2 parts of nano-tin dioxide, 1-2 parts of palladium chloride substrate, and distilled water.

3. The anti-interference coating on the surface of a gas sensor according to claim 2, characterized in that, The material comprises the following parts by weight: 9.1 parts nano-silica, 4.6 parts nano-titanium dioxide, 11.8 parts nano-tin dioxide, 1.5 parts palladium chloride substrate, and distilled water.

4. A method for preparing an anti-interference coating on the surface of a gas sensor as described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Thoroughly mix and grind nano-tin dioxide, nano-silicon dioxide, and nano-titanium dioxide; S2: The material mixed with S1 is sintered at a temperature of 300℃-500℃ for 1-2 hours. S3: The sintered nanocomposite material of S2 is mixed with a chemical aqueous solution of palladium chloride substrate and a polar protic solvent, and then ground again; S4: The nanocomposite material after S3 mixing and grinding is dried to remove the solvent, forming the final gas sensor nanocomposite anti-interference material coating.

5. The method for preparing an anti-interference coating on the surface of a gas sensor according to claim 4, characterized in that, The tin dioxide in step S1 is tin dioxide prepared by chemical oxidation or calcination of metallic tin with a purity of 99.999%.

6. The method for preparing an anti-interference coating on the surface of a gas sensor according to claim 4, characterized in that, In step S2, the sintering temperature is 340℃-440℃ and the time is 2 hours. In step S4, the drying temperature is 60℃-100℃.

7. The method for preparing an anti-interference coating on the surface of a gas sensor according to claim 6, characterized in that, In step S2, the sintering temperature is 380℃ and the time is 2 hours.

8. The method for preparing an anti-interference coating on the surface of a gas sensor according to claim 6, characterized in that, The drying temperature in step S4 is 80°C.

9. The method for preparing an anti-interference coating on the surface of a gas sensor according to claim 4, characterized in that, In step S3, the palladium chloride substrate chemical aqueous solution is a 10% palladium chloride substrate chemical aqueous solution, and the polar protic solvent is water or ethanol.

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