Application of crystal fiber red phosphorus in gas detection

Abstract

The present invention belongs to the field of sensor technology and discloses the application of crystal fiber red phosphorus in gas detection. The crystal fiber red phosphorus is used for gas detection by the following steps: step 1, uniformly dispersing the crystal fiber red phosphorus in a solvent medium and grinding it into a mixed slurry, then uniformly coating the mixed slurry on a ceramic tube, and drying the ceramic tube coated with the mixed slurry to solidify the mixed slurry to obtain a gas sensor; step 2, contacting the obtained gas sensor with a gas to be detected, and detecting the gas sensor after contact with the gas to be detected using a Raman / infrared method to detect the gas to be detected. The present invention uses crystal fiber red phosphorus for gas detection and can achieve a rapid response to ammonia at room temperature. The detection method is easy to operate, safe and efficient, paving the way for the detection of ammonia and the universal application of devices.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to an application of crystal fiber red phosphorus in gas detection. Background Art

[0002] Ammonia is a colorless, toxic gas with a strong, pungent odor. Direct contact or excessive inhalation can cause serious harm to human health. Therefore, detecting ammonia in the environment can be a preventive measure. There is an urgent need for a portable, repeatable, and highly sensitive ammonia sensor system to protect human health.

[0003] However, existing ammonia sensor materials suffer from poor material activity or poor gas adsorption, resulting in long sensor response times. Furthermore, existing ammonia sensor materials typically require high temperatures, which decompose ammonia into nitrogen and hydrogen. This high-temperature operating environment can affect accurate ammonia detection. Therefore, a material that is sensitive to ammonia at room temperature is needed to achieve precise and highly sensitive ammonia sensing.

[0004] To this end, the present invention provides an application of crystal fiber red phosphorus in gas detection, a detection method and a detection device. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention provides the use of crystal fiber red phosphorus in gas detection, a detection method, and a detection device. The ammonia sensor of the present invention can achieve a rapid response to ammonia gas at room temperature. The ammonia sensor of the present invention features a simple, safe, and efficient preparation process, paving the way for the widespread application of ammonia detection and devices.

[0006] The application of the crystal fiber red phosphorus in gas detection of the present invention is achieved through the following technical solutions:

[0007] The invention discloses an application of crystal fiber red phosphorus in gas detection.

[0008] Furthermore, the crystal fiber red phosphorus is used to detect reducing gases.

[0009] Furthermore, the reducing gas is ammonia.

[0010] Furthermore, the crystal fiber red phosphorus is made into a slurry and then coated on a carrier material. After the slurry is solidified, a gas sensor for detecting gas is obtained.

[0011] Furthermore, the crystal fiber red phosphorus detects gas through the following steps:

[0012] Step 1: uniformly dispersing crystalline fiber red phosphorus in a solvent medium and grinding it into a mixed slurry, then uniformly coating the mixed slurry on a carrier material, and solidifying the mixed slurry through drying to obtain a gas sensor;

[0013] Step 2: After the obtained gas sensor is brought into contact with the gas to be detected, the signal changes of the gas sensor after contact with the gas to be detected are captured using Raman / infrared method, and the detection and analysis of the gas to be detected are achieved by analyzing the captured signal changes.

[0014] Furthermore, the solvent medium is any one of water, ethanol and NMP.

[0015] Furthermore, the usage ratio of the crystal fiber red phosphorus to the solvent medium is 5-10 mg:1-10 mL.

[0016] Furthermore, the crystal fiber red phosphorus detects gas in a detection device, and the detection device includes:

[0017] The device body is hollow inside, and has an air inlet and an air outlet on two opposite sides.

[0018] Two light-transmitting sheets are detachably mounted on the upper and lower ends of the device body, respectively, and form a reaction chamber with the device body; and a sensing material made of crystal fiber red phosphorus is placed between the two light-transmitting sheets;

[0019] Two sealing rings are respectively arranged between the two light-transmitting sheets and the device body to achieve the reuse of the reaction device;

[0020] The clamp is arranged on the two light-transmitting sheets so that the two light-transmitting sheets are tightly connected to the device body to ensure the airtightness of the reaction chamber.

[0021] Furthermore, the material of the device body is hot melt adhesive.

[0022] Furthermore, the air inlet and the air outlet are respectively provided with a first conduit and a second conduit;

[0023] The first conduit is used to connect to a gas source of the gas to be detected;

[0024] The second conduit is used to discharge the detected gas out of the reaction chamber. In order to prevent the detected gas from being directly discharged into the atmosphere and causing pollution, the second conduit can be connected to a gas recovery device to prevent the detected gas from being directly discharged into the atmosphere.

[0025] Furthermore, the clamp is a rubber band.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] As a layered two-dimensional material, crystal fiber red phosphorus is bonded between layers by van der Waals forces. The crystal fiber red phosphorus along the 001 direction is arranged in parallel in a tubular shape, thereby exposing the most active sites. As a P-type semiconductor material exposed to an ammonia environment, the reduced ammonia loses electrons and the fiber red phosphorus gains electrons, thereby reducing its own conductivity and realizing the detection of ammonia gas. When the ammonia concentration in the environment in which the crystal fiber red phosphorus is located decreases, the ammonia molecules diffuse from high concentration (ammonia adsorbed on the surface of the material) to low concentration (the environment in which the crystal fiber red phosphorus is located), thereby allowing the ammonia molecules adsorbed on the surface of the material to escape and desorb, thereby enabling the crystal fiber red phosphorus to achieve rapid response and rapid detection of ammonia molecules.

[0028] The present invention realizes ammonia detection using crystalline red phosphorus fibers at room temperature. The device has a simple preparation process, fast response speed, high repeatability, and extremely broad market prospects.

[0029] The present invention adopts an in-situ Raman / infrared method, wherein the gas to be detected is introduced into the cavity, and then the light source of the Raman / infrared spectrometer is used to irradiate the gas sensor in the cavity. When the introduced gas contains the target detection object, the gas sensor can adsorb the gas to be detected and fix it on the gas sensor, which is then captured by the Raman / infrared spectrometer and the corresponding Raman / infrared spectrum of the target detection object is obtained, thereby realizing the detection of the target detection object in the gas to be detected, indicating that the response principle of the gas sensor prepared by the present invention is physical adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the detection device of the present invention;

[0031] Figure 2 Response test results of the gas sensor and ethanol in Example 1 under 100 ppm ammonia;

[0032] Figure 3 These are the response test results of the gas sensor of Example 1 under different ammonia concentrations. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that the present invention is not limited to the specific preparation method of crystalline fiber red phosphorus, and any preparation method disclosed in the prior art can be used, such as the typical CVT method, or the preparation method in the application number 202111289911.7 previously applied by the inventor.

[0034] Example 1

[0035] This embodiment provides an application of crystal fiber red phosphorus in gas detection. Taking ammonia as an example, this embodiment implements the detection of ammonia by crystal fiber red phosphorus through the following steps:

[0036] Step 1: uniformly dispersing crystalline fiber red phosphorus in a solvent medium and grinding it into a mixed slurry. The mixed slurry is then uniformly coated on a carrier material, dried, and the water in the mixed slurry is removed to solidify the slurry, thereby obtaining a gas sensor.

[0037] It should be noted that the specific composition and amount of the solvent medium are not limited in this embodiment, as long as they can evenly disperse the crystalline fiber red phosphorus. Solvents such as water, ethanol, and NMP that do not affect the material structure are sufficient. In this embodiment, deionized water can be optionally used as the solvent medium, and the ratio of crystalline fiber red phosphorus to deionized water is 5-10 mg:1-10 mL.

[0038] The specific grinding method in step 1 is not limited in this embodiment, as long as a uniform mixed slurry can be obtained so that it can be coated on the ceramic tube to form a uniform and dense sensing material. In this embodiment, a mortar can be optionally used for grinding, and the crystal fiber red phosphorus slurry is ground into a paste.

[0039] This embodiment does not limit the specific coating method of step 1, as long as it can be evenly coated on the carrier material. In this embodiment, a brushing method can be optionally used for coating.

[0040] This embodiment does not limit the specific type of carrier material, as long as it can serve as a carrier to evenly distribute the crystal fiber red phosphorus sensing material and does not affect the sensing function of the crystal fiber red phosphorus itself. In this embodiment, a traditional gas-sensitive ceramic tube can be optionally used as the carrier material, so that the prepared gas sensor can be used as a gas sensor.

[0041] The present embodiment does not limit the specific method of drying, as long as the solvent in the mixed slurry can be removed. In the present embodiment, the carrier material coated with the mixed slurry is optionally dried in an oven at 60° C. for 4 hours.

[0042] Step 2: contacting the obtained gas sensor with the gas to be detected, and detecting the gas to be detected using an in-situ Raman / infrared method;

[0043] It should be noted that the in-situ Raman / infrared method employed in this invention is primarily intended to illustrate the response principle of the gas sensor fabricated in this invention; other detection methods may also be employed. In this embodiment, the gas sensor is encapsulated in a cavity, into which the gas to be detected is introduced. The light source of a Raman / infrared spectrometer then illuminates the gas sensor within the cavity. When the introduced gas contains the target analyte, the gas sensor adsorbs the target analyte, thereby securing it to the gas sensor. This analyte is then captured by the Raman / infrared spectrometer, which generates a corresponding Raman / infrared spectrum, thereby enabling detection of the target analyte within the gas.

[0044] Example 2

[0045] In situ detection of Raman shifts, intensity changes, and changes in Raman peak shape caused by interactions between materials is intuitively visible for qualitative, structural, and quantitative analysis. However, the inventors have discovered that current gas Raman spectroscopy research primarily relies on ex-situ chemical adsorption between gases and solids, and no technological breakthroughs have been achieved in in-situ Raman research based on physical adsorption. Furthermore, existing in-situ Raman spectroscopy devices used to study material reaction processes are made of stainless steel, Teflon, or corundum, which significantly increases costs. Furthermore, their large size makes them difficult to load and unload, making them unsuitable for common Raman devices.

[0046] In order to facilitate the verification of the detection principle of crystal fiber red phosphorus for gas and to quickly realize the detection research of crystal fiber red phosphorus for gas, the present invention also provides a detection device based on crystal fiber red phosphorus. By placing crystal fiber red phosphorus in the detection device of this embodiment, gas detection is realized, such as Figure 1 As shown, the detection device based on crystal fiber red phosphorus in this embodiment includes a device body 1, two light-transmitting sheets 2, two sealing rings 3 and a clamp 4.

[0047] The device body 1 of this embodiment has an internally hollow annular structure, and an air inlet 11 and an air outlet 12 are respectively provided on its two opposite sides; a first conduit 13 and a second conduit 14 are respectively provided on the air inlet 11 and the air outlet 12; the first conduit 13 is used to connect to the gas source of the gas to be detected; the second conduit 14 is used to connect to a gas recovery device to prevent the detected gas from being discharged into the atmosphere.

[0048] In this embodiment, the specific types of the two light-transmitting sheets 2 are not limited, as long as the light source of the spectrometer can pass through the upper light-transmitting sheet to illuminate the gas sensor 5 on the lower light-transmitting sheet. In this embodiment, a glass slide is optionally used as the light-transmitting sheet.

[0049] In this embodiment, the arrangement of the two glass slides 2 on the device body 1 is not limited, as long as they can form a reaction chamber with the device body 1. In this embodiment, the glass slides 2 are optionally larger than the annular openings at the upper and lower ends of the device body 1, thereby forming a sealed reaction chamber. The gas sensor 5 described in Example 1 is placed between the two glass slides 2. In this embodiment, wires are extended from the gas sensor 5 and welded to a glass slide 2, and the wires on the gas sensor 5 are electrically connected to the detection instrument.

[0050] This embodiment does not limit the specific distance between the two glass slides 2 and can be set according to actual needs, as long as the position of the gas sensor 5 between the two glass slides 2 is ensured not to be offset.

[0051] In order to ensure the sealing between the glass slide 2 and the device body 1, in this embodiment, a sealing ring 3 is provided between the two glass slides 2 and the device body 1. The sealing ring 3 can play a sealing role, and the sealing ring 3 will not form a fixed bonding effect such as solidification on the contact surface and can be opened at any time, thereby realizing the reuse of the reaction device of the present invention.

[0052] The present embodiment does not limit the specific structure of the clamp 4, as long as it can make the two slides 2 tightly connected to the device body 1 to ensure the airtightness of the reaction chamber. In this embodiment, a rubber band can be optionally used as the clamp 4, which is set on the two slides 2.

[0053] In order to prevent the detected gas from being directly discharged into the atmosphere and causing pollution, the second conduit 14 may be connected to a gas recovery device to prevent the detected gas from being directly discharged into the atmosphere.

[0054] It should be noted that the detection principle of the gas sensor 5 in this embodiment is the same as that in Example 1 and will not be described in detail here. Furthermore, the detection device of this embodiment is capable of not only detecting gases but also collecting in-situ Raman (infrared) spectra of gas-solid, gas-liquid, liquid-liquid, liquid-solid, and solid-solid reaction processes.

[0055] Experimental part

[0056] In order to verify the detection effect of crystal fiber red phosphorus on ammonia and prove that the gas sensing principle of crystal fiber red phosphorus is physical adsorption, the present invention conducted the following experiments:

[0057] The present invention uses ammonia as the gas to be detected, the gas sensor prepared in Example 1 as the sensing material, and a gas-sensitive in-situ Raman spectroscopy as the detection instrument. The specific operation is as follows:

[0058] A glass slide was mounted on the lower end of the device body via a sealing ring. The gas sensor prepared in Example 1 was then secured to the glass slide using double-sided tape. Another glass slide was then mounted on the upper end of the device body via another sealing ring. A rubber band was then placed over both glass slides, ensuring that both glass slides were connected to the device body. This completed detection device was then placed at the focal point of a gas-sensitive in-situ Raman spectrometer, allowing the light source of the gas-sensitive in-situ Raman spectrometer to pass through the sensing material placed in the middle of the glass slide.

[0059] During the test, the gas-sensitive in-situ Raman is turned on, and 100 ppm of ammonia gas is introduced into the reaction chamber through the first conduit 13 and the air inlet 11. After the ammonia gas contacts the above-mentioned sensing material in the reaction chamber, the ammonia gas can be adsorbed and fixed on the sensing material, and then captured by the gas-sensitive in-situ Raman and the corresponding Raman spectrum of the ammonia gas is obtained. The test results are as follows: Figure 2 In addition, the present invention uses ethanol as a control example, and the experimental conditions are consistent with the experimental conditions of 100ppm ammonia. Its Raman spectrum is as follows Figure 2 shown.

[0060] Depend on Figure 2 As can be seen, the gas sensor's response to ammonia is much higher than that to ethanol, demonstrating excellent selectivity for ammonia. Furthermore, the gas sensor of the present invention exhibits a change in resistance when exposed to 100 ppm ammonia; this resistance recovers when air is introduced. The response time is approximately 35 seconds, and the recovery time is approximately 7 seconds. This demonstrates that the prepared crystal fiber red phosphorus sensing material exhibits high sensitivity, excellent response speed, and repeatability in response to 100 ppm ammonia, and that this rapid adsorption and desorption is attributed to the physical adsorption of ammonia by the material.

[0061] The present invention also uses the above test method to test the gas with different ammonia concentrations, and the test results are as follows: Figure 3 As shown in the figure, it can be seen that with the increase of ammonia concentration, the peak intensity gradually weakens and the peak position hardly changes, indicating that the adsorption between crystal fiber red phosphorus and ammonia is physical adsorption. This also provides a basis for understanding the rapid response of crystal fiber red phosphorus.

[0062] It should be noted that, in the above-mentioned in-situ test of the present invention, the experiment adopts nitrogen flushing device, and then introduces ammonia of different concentrations and obtains Raman signals in the ammonia atmosphere.

[0063] Obviously, the above embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. The application of crystal fiber red phosphorus in gas detection is characterized by: The crystal fiber red phosphorus is used to detect ammonia at room temperature; Crystal fiber red phosphorus detects gas through the following steps: Step 1: uniformly dispersing crystalline fiber red phosphorus in a solvent medium and grinding it into a mixed slurry, then uniformly coating the mixed slurry on a carrier material, and solidifying the mixed slurry through drying to obtain a gas sensor; Step 2: After the obtained gas sensor is brought into contact with the gas to be detected, a Raman / infrared method is used to capture the signal changes of the gas sensor after contact with the gas to be detected, and the detection and analysis of the gas to be detected is achieved by analyzing the captured signal changes; The solvent medium is any one of water, ethanol and NMP; The usage ratio of the crystal fiber red phosphorus to the solvent medium is 5-10 mg:1-10 mL; Crystal fiber red phosphorus detects gas in a detection device, the detection device comprising: The device body (1) is an annular structure with a hollow interior, and an air inlet (11) and an air outlet (12) are respectively provided on two opposite sides thereof; Two light-transmitting sheets (2) are detachably arranged at the upper end and the lower end of the device body (1), and form a reaction chamber with the device body (1); and a sensing material prepared using crystal fiber red phosphorus is placed between the two light-transmitting sheets (2); Two sealing rings (3) are respectively arranged between the two light-transmitting sheets (2) and the device body (1); The clamp (4) is arranged on the two light-transmitting sheets (2), so that the two light-transmitting sheets (2) are tightly connected to the device body (1).

2. The use of the crystal fiber red phosphorus in gas detection according to claim 1, characterized in that: The material of the device body (1) is hot melt adhesive.

3. The use of the crystal fiber red phosphorus in gas detection according to claim 1, characterized in that: The air inlet (11) and the air outlet (12) are respectively provided with a first conduit (13) and a second conduit (14); The first conduit (13) is used to connect to a gas source of the gas to be detected; The second conduit (14) is used to discharge the detected gas out of the reaction chamber.

4. The use of the crystal fiber red phosphorus in gas detection according to claim 1, characterized in that: The clamp (4) is a rubber band ring.

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