Industrial harmful gas sensor and preparation method thereof

Abstract

The invention belongs to the technical field of industrial harmful gas sensing, and particularly relates to an industrial harmful gas sensor and a preparation method thereof. According to the invention, the structural color change of the photonic crystal gas-sensitive chip is utilized to realize high-sensitivity detection of harmful gas, can accurately identify low-concentration harmful gas, can capture the color change of the photonic crystal in real time, provides instant gas concentration information, avoids direct contact between the sensor and the harmful gas, prolongs the service life of equipment, and improves the detection efficiency. According to the method, complex RGB data can be processed, the reliability of a detection result is improved, a worker can rapidly take measures, accidents are prevented, and the safety of personnel and properties is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial harmful gas sensors, and in particular relates to an industrial harmful gas sensor and a preparation method thereof. Background Art

[0002] Harmful gases such as ammonia, benzene and aldehydes emitted during industrial production are generally highly toxic and flammable. They not only cause central nervous system depression, respiratory damage, cardiovascular system effects, liver and kidney damage, and skin and mucous membrane burns to the human body. Moreover, such harmful gases usually cause serious pollution to the ecological environment. Therefore, it is very necessary to improve the harm of industrial harmful gases to human health and the environment and develop intelligent gas sensors with excellent sensitivity and selectivity to industrial harmful gases.

[0003] At present, industrial harmful gases have the characteristics of scattered points, wide distribution, and large emissions, which makes them difficult to detect, monitor, and judge. At present, the qualitative detection and identification of volatile organic compound gases from industrial sources are mostly carried out by gas chromatography-mass spectrometry, ion mobility spectrometry and other gas phase chemical reagent detection technologies at home and abroad. However, the analytical instruments are usually large, cannot be moved, are expensive, require professional operators, and usually cannot respond quickly. Summary of the invention

[0004] The purpose of the present invention is to provide an industrial harmful gas sensor that can improve the response speed of harmful gas detection, accurately identify mixed gases, and reduce interference.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An industrial harmful gas sensor includes a power supply module, a sensor module, a video monitoring module, a sensor control and processing module and an alarm module;

[0007] The power supply module is used to provide power to the sensor module, the video monitoring module, the sensor control and processing module and the alarm module;

[0008] The sensing module includes a photonic crystal gas-sensing chip, which is used to detect the gas in the environment and generate an optical response to change the structural color of the photonic crystal gas-sensing chip;

[0009] The video monitoring module is used to extract the structural color change picture of the photonic crystal in the sensor module, convert it into RGB value, and output it to the sensor control and processing module;

[0010] The sensor control and processing module is used to identify harmful gases in the environment according to RGB values;

[0011] The alarm module is used to send out an alarm message when harmful gases in the environment are identified;

[0012] The power supply module, sensor module, video monitoring module and alarm module are respectively connected to the sensor control and processing module.

[0013] In a preferred embodiment, the operating state of the sensing control and processing module is as follows:

[0014] Obtaining image information of structural color changes of the sensor module in response to gas;

[0015] Extract RGB values ​​based on structural color change image information;

[0016] Preprocess the RGB values ​​to obtain feature data sets;

[0017] Use the support vector machine classification algorithm to analyze the feature data set to determine whether there are industrial harmful gases in the environment;

[0018] If there is industrial hazardous gas, the alarm module will be controlled to operate.

[0019] The present invention also provides a method for preparing an industrial harmful gas sensor, which is used for the above industrial harmful gas sensor, comprising:

[0020] Prepare a photonic crystal structure based on MOFs material on the surface of single crystal silicon to obtain a photonic crystal gas-sensitive chip that is specific to industrial harmful gases;

[0021] Integrate the power supply module, sensor module, video monitoring module, sensor control and processing module and alarm module into an intelligent photoelectric industrial harmful gas sensor;

[0022] The sensor module is fixed in the air chamber, and the video detection module is installed above it.

[0023] In a preferred embodiment, the step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes:

[0024] Mixing the metal ion source compound and the organic ligand to obtain a mixed solution 1;

[0025] An acid modulator is added to the mixed solution 1 to react and obtain monodispersed MOFs nanoparticles;

[0026] Mix 8 ml of tetrabutyl titanate with 4 ml of isopropanol to obtain a mixed solution 2;

[0027] 0.42 ml of deionized water and 34 μL of concentrated hydrochloric acid were respectively added dropwise into 8 ml of isopropanol to obtain mixed dropwise solution 1 and mixed dropwise solution 2, respectively;

[0028] Stir the mixed drop solution 1 and the mixed drop solution 2 at room temperature for at least 10 minutes;

[0029] The stirred mixed drop solution 1 and the mixed drop solution 2 were added to the mixed solution 2, and then 13 ml of isopropanol was added, and stirred at room temperature for 12 hours to obtain a monodispersed TiO2 colloidal solution;

[0030] One-dimensional photonic crystals based on MOFs materials were prepared by spin coating.

[0031] In a preferred embodiment, the reaction temperature of the mixed solution 1 and the acid modulator is 120°C and the reaction time is 12-24h;

[0032] The metal ion source compound includes zirconium chloride;

[0033] The organic ligand comprises terephthalic acid;

[0034] The acid modulator includes acetic acid;

[0035] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0036] The amount of the acid modulator added is 0 mol / L-5 mol / L, preferably 1 mol / L-2 mol / L.

[0037] In a preferred embodiment, the step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes:

[0038] mixing the metal ion source compound and the organic ligand to obtain a mixed solution three;

[0039] An acid modulator is added to the mixed solution 3 to react and obtain monodispersed MOFs nanoparticles;

[0040] Surface functionalization of monodisperse MOFs nanoparticles using surfactants;

[0041] The surface functionalized monodispersed MOFs nanoparticles were dispersed in a mixture of ethanol and water, and 100 μl was dropped onto the surface of the mixture of ethanol and water to obtain a mixture 1;

[0042] Add 2-3 drops of sodium dodecyl sulfate aqueous solution to mixture 1 to obtain mixture 2;

[0043] The thin film of mixture 2 on the water surface is transferred to the surface of a silicon wafer to obtain a two-dimensional photonic crystal based on MOFs.

[0044] In a preferred embodiment, the reaction temperature of the mixed solution 3 and the acid modulator is 120°C, and the reaction time is 12-24h;

[0045] The metal ion source compound includes zirconium chloride;

[0046] The organic ligand comprises terephthalic acid;

[0047] The acid modulator includes acetic acid;

[0048] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0049] The amount of the acid modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L;

[0050] The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride;

[0051] The surfactant concentration is 1-4wt%, preferably 2wt%;

[0052] The ratio of ethanol to water in the mixture of ethanol and water is 1:1;

[0053] The concentration of the sodium dodecyl sulfate is 2 wt %.

[0054] In a preferred embodiment, the step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes:

[0055] Mixing the metal ion source compound and the organic ligand to obtain a mixed solution IV;

[0056] An acid modulator is added to the mixed solution 4 to react and obtain monodispersed MOFs nanoparticles;

[0057] Surface functionalization of monodisperse MOFs nanoparticles using surfactants;

[0058] The functionalized monodispersed MOFs nanoparticles were re-dispersed by ultrasonication in deionized water or ethanol solution to form a MOFs colloidal suspension;

[0059] 100 μl of MOFs colloidal suspension was spontaneously formed into a dense and porous MOFs three-dimensional photonic crystal structure on the surface of a silicon substrate through solvent evaporation self-assembly, spin coating, LB film technology or layer-by-layer self-assembly technology.

[0060] In a preferred embodiment, the reaction temperature of the mixed solution 4 and the acid modulator is 120° C., and the reaction time is 12-24;

[0061] The metal ion source compound includes any one of Zn(CH3COO)2·2H2O and zirconium chloride;

[0062] The organic ligand includes any one of 2-methylimidazole and terephthalic acid;

[0063] The acid modulator includes any one of acetic acid, hydrochloric acid and hydrofluoric acid;

[0064] The base modulator includes triethylamine.

[0065] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0066] The amount of the acid-base modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L;

[0067] The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride;

[0068] The surfactant concentration is 1-4wt%, preferably 2wt%;

[0069] The concentration of the MOFs colloidal suspension is about 2 wt %.

[0070] And, a terminal of an industrial harmful gas sensor, comprising:

[0071] one or more processors;

[0072] a storage device having one or more programs stored thereon;

[0073] When the one or more programs are executed by the one or more processors, the one or more processors implement the industrial hazardous gas sensor.

[0074] The technical effects achieved by the present invention are:

[0075] The present invention utilizes the structural color change of the photonic crystal gas-sensitive chip to achieve high-sensitivity detection of harmful gases, can accurately identify low-concentration harmful gases, can capture the color change of the photonic crystal in real time, and provide instant gas concentration information, thereby avoiding direct contact between the sensor and the harmful gas, extending the service life of the equipment, being able to process complex RGB data, and improving the reliability of the detection results, so that the staff can quickly take measures to prevent accidents and ensure the safety of personnel and property. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a system module diagram provided by the present invention;

[0077] Figure 2This is a schematic diagram of the MOFs-based photonic crystal array provided by the present invention. DETAILED DESCRIPTION

[0078] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0079] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0080] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0081] Secondly, the present invention is described in detail in conjunction with schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the schematic diagrams are only examples and should not limit the scope of protection of the present invention.

[0082] Please see attached Figure 1 and Figure 2 As shown, an industrial harmful gas sensor is provided, including a power supply module, a sensor module, a video monitoring module, a sensor control and processing module and an alarm module;

[0083] The power supply module is used to provide power to the sensor module, video monitoring module, sensor control and processing module and alarm module;

[0084] The sensing module includes a photonic crystal gas-sensing chip, which is used to detect the gas in the environment and generate an optical response to change the structural color of the photonic crystal gas-sensing chip;

[0085] The video monitoring module is used to extract the structural color change image of the photonic crystal in the sensor module, convert it into RGB value, and output it to the sensor control and processing module;

[0086] The sensor control and processing module is used to identify harmful gases in the environment based on RGB values;

[0087] The alarm module is used to send out alarm information when harmful gases in the environment are identified;

[0088] The power supply module, the sensor module, the video monitoring module and the alarm module are respectively connected to the sensor control and processing module.

[0089] The power supply module adopts a rechargeable lithium-ion battery with a capacity of 3000 mA h. The sensing module adopts a 2×2 sensor array, including MOFs photonic crystal gas-sensitive chips based on UIO-66, ZIF-8, ZIF-67 or MIL-101 (Cr). The alarm module adopts sound and light alarm.

[0090] As mentioned above, the power supply module provides stable power for the entire sensor system to ensure the normal operation of each module. The sensor module contains a photonic crystal gas-sensitive chip. When harmful gases exist in the environment, these gas molecules will interact with the photonic crystal, causing the structural color of the photonic crystal to change. This change is a physical phenomenon caused by the gas concentration and can reflect the presence and concentration of harmful gases in the environment. The video monitoring module uses high-precision camera equipment to capture the changes in the structural color of the photonic crystal in real time and generate corresponding image data. Then, these image data are converted into RGB values ​​to extract information about color changes. The sensor control and processing module receives the RGB values ​​from the video monitoring module and processes these data through a preset support vector machine (SVM) classification algorithm. According to the RGB The sensor control and processing module detects the presence of harmful gases and exceeds the safety threshold, and the alarm module will be triggered immediately to issue an audible and visual alarm or other forms of alarm to remind the staff to take necessary safety measures. The structural color change of the photonic crystal gas sensitive chip is used to achieve high-sensitivity detection of harmful gases, which can accurately identify low-concentration harmful gases, capture the color changes of photonic crystals in real time, provide instant gas concentration information, avoid direct contact between sensors and harmful gases, extend the service life of the equipment, and process complex RGB data, which improves the reliability of the detection results, allowing staff to take measures quickly to prevent accidents and ensure the safety of personnel and property.

[0091] In a specific implementation, the operating state of the sensor control and processing module is as follows:

[0092] Obtaining image information of structural color changes of the sensor module in response to gas;

[0093] Extract RGB values ​​based on structural color change image information;

[0094] Preprocess the RGB values ​​to obtain feature data sets;

[0095] Use the support vector machine classification algorithm to analyze the feature data set to determine whether there are industrial harmful gases in the environment;

[0096] If there is industrial hazardous gas, the alarm module will be controlled to operate.

[0097] As mentioned above, the sensor control and processing module first receives the signal from the sensor module. The photonic crystal gas-sensitive chip of the sensor module reacts to harmful gases in the environment, which causes changes in the structural color of the photonic crystal. These changes are captured as image information by the camera of the video monitoring module. The sensor control and processing module extracts the RGB value of the structural color change from the captured image information. The RGB value reflects the color change of the photonic crystal gas-sensitive chip after being affected by the gas, and is a characterization of the gas concentration and type. The extracted RGB value needs to be preprocessed, including noise removal, normalization processing and other operations to ensure the validity and consistency of the data. Through these preprocessing, a feature data set for subsequent analysis is obtained. The sensor control and processing module uses a support vector machine (SVM) classification algorithm to analyze the preprocessed feature data set. SVM is a common machine learning classification algorithm. It can judge whether there is industrial harmful gas in the current environment based on the RGB value feature data set by training the model. When the results of the SVM algorithm analysis indicate that there are harmful gases in the environment, the sensor control and processing module will immediately trigger the alarm module to sound an alarm. The alarm can be in the form of sound and light alarms or other information transmission methods to promptly remind relevant personnel to take necessary safety measures. Through the introduction of the SVM classification algorithm, the RGB value feature data set can be accurately analyzed, which greatly improves the accuracy and sensitivity of harmful gas detection. Compared with traditional methods, it can effectively reduce false alarms and missed alarms. It has strong data processing capabilities and can judge the gas state in real time and respond quickly. From obtaining image information to extracting RGB values ​​and analyzing them, the entire process is completed quickly, ensuring real-time monitoring of harmful gases. Once the presence of gas is detected, an alarm can be issued immediately to ensure safety and improve the speed of response. Non-contact video monitoring is used to obtain RGB values, which avoids direct contact between traditional sensors and gases, reduces the maintenance and replacement frequency of sensors, and extends the service life of the equipment.

[0098] Please see attached Figure 1 and Figure 2 As shown, the present invention also provides a method for preparing an industrial harmful gas sensor, which is used for the above industrial harmful gas sensor, comprising:

[0099] Prepare a photonic crystal structure based on MOFs material on the surface of single crystal silicon to obtain a photonic crystal gas-sensitive chip that is specific to industrial harmful gases;

[0100] Integrate the power supply module, sensor module, video monitoring module, sensor control and processing module and alarm module into an intelligent photoelectric industrial harmful gas sensor;

[0101] The sensor module is fixed in the air chamber, and the video detection module is installed above it.

[0102] It should be noted that the photonic crystal structure of the MOFs material includes any one of a one-dimensional photonic crystal structure of the MOFs material, a two-dimensional photonic crystal structure of the MOFs material, or a three-dimensional photonic crystal structure of the MOFs material.

[0103] As mentioned above, firstly, a photonic crystal structure based on metal organic framework materials (MOFs) is constructed on the surface of single crystal silicon. Due to its highly ordered pore structure and chemical selectivity, MOFs materials can trigger structural color changes of photonic crystals by interacting with specific harmful gases. The prepared photonic crystal structure has specificity, that is, it can produce different optical responses to different types of harmful gases. Since the adsorption of gas by this photonic crystal gas-sensitive chip is highly correlated with the change of photonic crystal structure, it can detect gas concentration and show structural color changes. After assembling the sensing module, power supply module, video monitoring module, sensing control and processing module and alarm module into an intelligent photoelectric industrial harmful gas sensor, it can automatically detect the gas in the environment. The sensing module includes a photonic crystal gas-sensitive chip, which is fixed in an air chamber. The air chamber is used to maintain the stability of the gas sample and control the gas flow, so as to ensure that the gas-sensitive chip can respond stably to the surrounding gas. The video detection module is installed above the sensing module, and the structural color changes of the photonic crystal are monitored in real time by a camera. When harmful gases enter the air chamber, they interact with the M on the photonic crystal gas-sensitive chip. The interaction between OFs materials causes the structure of the crystal to change, which in turn produces color changes. The video monitoring module captures this change in real time, converts it into an image signal, and extracts the RGB value. The sensor control and processing module analyzes the RGB value and determines whether there is harmful gas through classification algorithms, such as support vector machines, and triggers the alarm module to issue an early warning based on the detection results. The photonic crystal structure based on MOFs material has a high degree of chemical selectivity and gas adsorption capacity. By preparing it on the surface of single crystal silicon, it can accurately detect and identify specific industrial harmful gases to ensure the accuracy and reliability of the detection results. The pore structure of MOFs material is adjustable, so different sensors can be designed according to different gases, which enhances its application flexibility. The reaction of the photonic crystal structure to changes in gas concentration is manifested by color changes. The video monitoring module can immediately capture these tiny changes and realize real-time detection of gas concentration. In this way, it can quickly respond to harmful gases in the environment and ensure timely alarm when the concentration of dangerous gases rises. The various modules are integrated into an intelligent photoelectric sensor to achieve a high degree of integration of the equipment.

[0104] In the first embodiment, the steps of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon include:

[0105] Mixing the metal ion source compound and the organic ligand to obtain a mixed solution 1;

[0106] An acid modulator is added to the mixed solution 1 to react and obtain monodispersed MOFs nanoparticles;

[0107] Mix 8 ml of tetrabutyl titanate with 4 ml of isopropanol to obtain a mixed solution 2;

[0108] 0.42 ml of deionized water and 34 μL of concentrated hydrochloric acid were respectively added dropwise into 8 ml of isopropanol to obtain mixed dropwise solution 1 and mixed dropwise solution 2, respectively;

[0109] Stir the mixed drop solution 1 and the mixed drop solution 2 at room temperature for at least 10 minutes;

[0110] The stirred mixed drop solution 1 and the mixed drop solution 2 were added to the mixed solution 2, and then 13 ml of isopropanol was added, and stirred at room temperature for 12 hours to obtain a monodispersed TiO2 colloidal solution;

[0111] One-dimensional photonic crystals based on MOFs materials were prepared by spin coating.

[0112] Among them, when using the spin coating method to prepare one-dimensional photonic crystals based on MOFs materials, the optimal experimental parameters are determined by continuously adjusting the speed and working time of the spin coating machine motor, the concentration of the colloidal solution and the number of cycles (the TiO2 layer and the MOFs layer are one cycle), and a one-dimensional photonic crystal with the best reflection spectrum is prepared;

[0113] The rotation speed of the electrode is preferably 3000-4000r / min, and the working time is preferably 30s-1min;

[0114] The concentration of the MOFs solution is preferably 50-100 mg / ml, and the number of cycles is preferably 3-4 cycles.

[0115] It should be noted that the reaction temperature of the mixed solution 1 and the acid modulator is 120°C and the reaction time is 12-24h;

[0116] Metal ion source compounds include zirconium chloride;

[0117] Organic ligands include terephthalic acid;

[0118] Acid modulators include acetic acid;

[0119] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0120] The amount of the acid modulator added is 0 mol / L-5 mol / L, preferably 1 mol / L-2 mol / L.

[0121] As described above, first, a metal ion source compound (such as zirconium chloride) and an organic ligand (such as terephthalic acid) are mixed, and an acid modulator (such as acetic acid) is added to react at 120° C. for 12-24 hours to form monodisperse MOFs nanoparticles with a highly ordered pore structure. The preparation of the MOFs material controls the morphology and size of the nanoparticles by adjusting the molar ratio of the metal ion to the organic ligand and the concentration of the acid modulator, thereby obtaining a MOFs gas-sensitive material that is selective for specific harmful gases. Then, tetrabutyl titanate and isopropanol are mixed (mixed solution 2), and deionized water and concentrated hydrochloric acid are respectively dripped into the isopropanol (i.e., mixed drop solution 1 and mixed drop solution 2). ), stirring the mixed drop liquid 1 and the mixed drop liquid 2 separately and then mixing them with the mixed liquid 2, then adding isopropanol, stirring at room temperature to form a TiO2 colloidal solution, by controlling the mixed drop liquid 1 and the mixed drop liquid 2 and the stirring time, the generated TiO2 colloidal solution is made stable and uniform, ensuring that the TiO2 layer can form a stable one-dimensional photonic crystal structure with the MOFs material in the subsequent spin coating process, and the prepared TiO2 colloidal solution and MOFs nanoparticles are alternately deposited on the surface of the single crystal silicon to form a one-dimensional photonic crystal structure. The spin coating method controls the number of layers and thickness of the crystal by changing parameters such as the speed of the motor, the concentration of the colloidal solution and the number of cycles. Specifically, the TiO2 layer The alternating deposition of TiO2 and MOFs layers is one cycle, and 3-4 cycles are usually selected to ensure that the crystal has ideal optical properties. The speed of the spin coater motor (3000-4000r / min) and the spin coating time (30 seconds to 1 minute) are adjusted to control the uniform deposition of the material and the layer thickness of the crystal. By adjusting the concentrations of TiO2 colloid solution and MOFs solution (50-100mg / ml), the consistency of the optical properties of each layer of the crystal is ensured, and its gas sensing performance is improved. By controlling the number of cycles (3-4 cycles), the reflection spectrum of the photonic crystal is ensured to be in a specific wavelength range, thereby achieving high-sensitivity detection of harmful gases. The one-dimensional optical crystal prepared by the above process steps The reflection spectrum of the photonic crystal can be optimized by adjusting the thickness of the deposited layer, the number of periods and the refractive index of the material. The photonic crystal structure has selective reflection of light of different wavelengths. When harmful gases interact with MOFs materials, it will cause microscopic changes in the crystal structure, resulting in changes in the reflection spectrum of the photonic crystal, resulting in detectable color differences. The one-dimensional photonic crystal structure constructed by spin coating can achieve precise adjustment of the reflection spectrum by precisely controlling the number of periods, thickness and material concentration of the TiO2 layer and the MOFs layer. The interference effect of the photonic crystal on the incident light enables it to produce obvious color changes for harmful gases of different concentrations, which is convenient for detection by optical methods.

[0122] Embodiment 2 is the second embodiment of the present invention. This embodiment is further improved on the basis of Embodiment 1. The difference between this embodiment and Embodiment 1 is that the photonic crystal structure based on MOFs material is different. The steps of preparing the photonic crystal structure based on MOFs material on the surface of single crystal silicon include:

[0123] mixing the metal ion source compound and the organic ligand to obtain a mixed solution three;

[0124] An acid modulator is added to the mixed solution 3 to react and obtain monodispersed MOFs nanoparticles;

[0125] Surface functionalization of monodisperse MOFs nanoparticles using surfactants;

[0126] The surface functionalized monodispersed MOFs nanoparticles were dispersed in a mixture of ethanol and water, and 100 μl was dropped onto the surface of the mixture of ethanol and water to obtain a mixture 1;

[0127] Add 2-3 drops of sodium dodecyl sulfate aqueous solution to mixture 1 to obtain mixture 2;

[0128] The thin film of mixture 2 on the water surface is transferred to the surface of a silicon wafer to obtain a two-dimensional photonic crystal based on MOFs.

[0129] Among them, MOFs is 5mg-15mg, preferably 10mg.

[0130] It should be noted that the reaction temperature of the mixed solution 3 and the acid modulator is 120°C and the reaction time is 12-24h;

[0131] Metal ion source compounds include zirconium chloride;

[0132] Organic ligands include terephthalic acid;

[0133] Acid modulators include acetic acid;

[0134] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0135] The amount of the acid modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L;

[0136] The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride;

[0137] The surfactant concentration is 1-4wt%, preferably 2wt%;

[0138] The ratio of ethanol to water in a mixture of ethanol and water is 1:1;

[0139] The concentration of sodium lauryl sulfate was 2 wt%.

[0140] As described above, monodisperse MOFs nanoparticles are generated by reacting a metal ion source (such as zirconium chloride) with an organic ligand (such as terephthalic acid) under the action of an acid modulator (such as acetic acid). The reaction is usually carried out at 120° C. for 12-24 hours to ensure the stability and high porosity of the MOFs structure. The size and morphology of the MOFs particles are controlled by adjusting the molar ratio of the metal ions to the organic ligands and the concentration of the acid modulator, thereby optimizing its gas sensing performance. The surface of the prepared MOFs nanoparticles is surface functionalized by a surfactant (such as polyvinyl pyrrolidone or hexadecyltrimethylammonium chloride). The purpose of the surface functionalization is to enhance the dispersibility of the MOFs particles and the interaction with the environment, while preventing the nanoparticles from agglomerating and ensuring that they are evenly distributed in the subsequent two-dimensional photonic crystals. The concentration of the surfactant is precisely controlled (1-4wt%, preferably 2 wt%) can effectively improve the functionalization effect and ensure the optical performance of the photonic crystal structure. The functionalized MOFs nanoparticles are dispersed in a 1:1 mixture of ethanol and water, and a stable surface film is formed by dropping a sodium dodecyl sulfate solution. Sodium dodecyl sulfate, as a surfactant, can reduce surface tension and promote the self-assembly of MOFs particles on the water surface to form a uniform two-dimensional film. After the film is formed on the water surface, it is transferred to the surface of a single crystal silicon wafer, thereby constructing a MOFs-based two-dimensional photonic crystal structure. Through this step, the MOFs nanoparticles can be arranged in an orderly manner on the surface of the silicon wafer to form a photonic crystal with a periodic structure. The structure can produce an interference effect on light of a specific wavelength, and then respond to the presence of a gas, and can produce a specific optical response to different gases. The optical properties of the photonic crystal can be flexibly adjusted to achieve detection of different gases.

[0141] Embodiment 3 is the third embodiment of the present invention. This embodiment is further improved on the basis of Embodiment 1. The difference between this embodiment and Embodiment 1 is that the photonic crystal structure based on MOFs material is different. The steps of preparing the photonic crystal structure based on MOFs material on the surface of single crystal silicon include:

[0142] Mixing the metal ion source compound and the organic ligand to obtain a mixed solution IV;

[0143] An acid modulator is added to the mixed solution 4 to react and obtain monodispersed MOFs nanoparticles;

[0144] Surface functionalization of monodisperse MOFs nanoparticles using surfactants;

[0145] The functionalized monodispersed MOFs nanoparticles were re-dispersed by ultrasonication in deionized water or ethanol solution to form a MOFs colloidal suspension;

[0146] 100 μl of MOFs colloidal suspension was spontaneously formed into a dense and porous MOFs three-dimensional photonic crystal structure on the surface of a silicon substrate through solvent evaporation self-assembly, spin coating, LB film technology or layer-by-layer self-assembly technology.

[0147] It should be noted that the reaction temperature of the mixed solution 4 and the acid modulator is 120°C and the reaction time is 12-24;

[0148] The metal ion source compound includes any one of Zn(CH3COO)2·2H2O and zirconium chloride;

[0149] The organic ligand includes any one of 2-methylimidazole and terephthalic acid;

[0150] The acid modulator includes any one of acetic acid, hydrochloric acid and hydrofluoric acid;

[0151] Base modulators include triethylamine.

[0152] The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32;

[0153] The amount of the acid-base modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L;

[0154] The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride;

[0155] The surfactant concentration is 1-4wt%, preferably 2wt%;

[0156] The concentration of MOFs colloidal suspension is about 2 wt%.

[0157] As described above, after a metal ion source (such as Zn(CH3COO)2·2H2O or zirconium chloride) is mixed with an organic ligand (such as 2-methylimidazole or terephthalic acid), a reaction is carried out under the action of an acid modulator (such as acetic acid, hydrochloric acid or hydrofluoric acid) to generate monodisperse MOFs nanoparticles. The reaction temperature is 120°C and the time is 12-24 hours to ensure that the MOFs material has a highly ordered porous structure. The size, morphology and porosity of the MOFs particles are adjusted by controlling the molar ratio of metal ions and organic ligands (1:1-1:80) and the concentration of the acid-base modulator. After the MOFs nanoparticles are synthesized, a surfactant (such as polyvinyl pyrrolidone or hexadecyltrimethylammonium bromide, etc.) is used to functionalize the surface of the MOFs nanoparticles. The surfactant can enhance the dispersibility of the MOFs particles and improve the orderliness of the arrangement of the particles in the subsequent self-assembly process. The surfactant concentration is generally 1-4wt%, preferably 2wt%. The concentration of the surfactant is adjusted to ensure that the MOFs nanoparticles have a highly ordered porous structure. To ensure the stability of the particles in the solution, the surface functionalized MOFs nanoparticles are redispersed in deionized water or ethanol, and a stable MOFs colloidal suspension is formed by ultrasonic treatment. The concentration of the suspension is controlled at about 2wt% to ensure the formation of a uniform film when subsequently deposited on the substrate. The colloidal suspension can be deposited on the surface of the silicon substrate by a variety of methods in an appropriate dispersed state, and the MOFs colloidal suspension is evenly distributed on the surface of the single crystal silicon by solvent evaporation self-assembly, spin coating, Langmuir-Blodgett (LB) film technology or layer-by-layer self-assembly technology to form a dense porous MOFs three-dimensional photonic crystal structure. Spin coating and LB film technology can accurately control the thickness and arrangement of the film, thereby ensuring the periodic arrangement of the MOFs structure. The structure of the three-dimensional photonic crystal enables it to produce an interference effect with light waves, produce a specific reflection spectrum, and effectively detect external gases. The three-dimensional photonic crystal structure has high durability and is suitable for long-term use.

[0158] And, a terminal of an industrial harmful gas sensor, comprising:

[0159] one or more processors;

[0160] a storage device having one or more programs stored thereon;

[0161] When one or more programs are executed by one or more processors, the one or more processors implement an industrial hazardous gas sensor.

[0162] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. An industrial harmful gas sensor, characterized in that: It includes power supply module, sensor module, video monitoring module, sensor control and processing module and alarm module; The power supply module is used to provide power to the sensor module, the video monitoring module, the sensor control and processing module and the alarm module; The sensing module includes a photonic crystal gas-sensing chip, which is used to detect the gas in the environment and generate an optical response to change the structural color of the photonic crystal gas-sensing chip; The video monitoring module is used to extract the structural color change picture of the photonic crystal in the sensor module, convert it into RGB value, and output it to the sensor control and processing module; The sensor control and processing module is used to identify harmful gases in the environment according to RGB values; The alarm module is used to send out an alarm message when harmful gases in the environment are identified; The power supply module, sensor module, video monitoring module and alarm module are respectively connected to the sensor control and processing module.

2. The industrial harmful gas sensor according to claim 1, characterized in that: The operating status of the sensor control and processing module is as follows: Obtaining image information of structural color changes of the sensor module in response to gas; Extract RGB values ​​based on structural color change image information; Preprocess the RGB values ​​to obtain feature data sets; Use the support vector machine classification algorithm to analyze the feature data set to determine whether there are industrial harmful gases in the environment; If there is industrial hazardous gas, the alarm module will be controlled to operate.

3. A method for preparing an industrial harmful gas sensor, applied to the industrial harmful gas sensor according to any one of claims 1 to 2, characterized in that: include: Prepare a photonic crystal structure based on MOFs material on the surface of single crystal silicon to obtain a photonic crystal gas-sensitive chip that is specific to industrial harmful gases; Integrate the power supply module, sensor module, video monitoring module, sensor control and processing module and alarm module into an intelligent photoelectric industrial harmful gas sensor; The sensor module is fixed in the air chamber, and the video detection module is installed above it.

4. The method for preparing an industrial harmful gas sensor according to claim 3, characterized in that: The step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes: Mixing the metal ion source compound and the organic ligand to obtain a mixed solution 1; An acid modulator is added to the mixed solution 1 to react and obtain monodispersed MOFs nanoparticles; Mix 8 ml of tetrabutyl titanate with 4 ml of isopropanol to obtain a mixed solution 2; 0.42 ml of deionized water and 34 μL of concentrated hydrochloric acid were respectively added dropwise into 8 ml of isopropanol to obtain mixed dropwise solution 1 and mixed dropwise solution 2, respectively; Stir the mixed drop solution 1 and the mixed drop solution 2 at room temperature for at least 10 minutes; The stirred mixed drop solution 1 and the mixed drop solution 2 were added to the mixed solution 2, and then 13 ml of isopropanol was added, and stirred at room temperature for 12 hours to obtain a monodispersed TiO2 colloidal solution; One-dimensional photonic crystals based on MOFs materials were prepared by spin coating.

5. The industrial harmful gas sensor according to claim 4, characterized in that: The reaction temperature of the mixed solution 1 and the acid modulator is 120°C and the reaction time is 12-24h; The metal ion source compound includes zirconium chloride; The organic ligand comprises terephthalic acid; The acid modulator includes acetic acid; The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32; The amount of the acid modulator added is 0 mol / L-5 mol / L, preferably 1 mol / L-2 mol / L.

6. The industrial harmful gas sensor according to claim 3, characterized in that: The step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes: mixing the metal ion source compound and the organic ligand to obtain a mixed solution three; An acid modulator is added to the mixed solution 3 to react and obtain monodispersed MOFs nanoparticles; Surface functionalization of monodisperse MOFs nanoparticles using surfactants; The surface functionalized monodispersed MOFs nanoparticles were dispersed in a mixture of ethanol and water, and 100 μl was dropped onto the surface of the mixture of ethanol and water to obtain a mixture 1; Add 2-3 drops of sodium dodecyl sulfate aqueous solution to mixture 1 to obtain mixture 2; The thin film of mixture 2 on the water surface is transferred to the surface of a silicon wafer to obtain a two-dimensional photonic crystal based on MOFs.

7. The industrial harmful gas sensor according to claim 6, characterized in that: The reaction temperature of the mixed solution 3 and the acid modulator is 120°C, and the reaction time is 12-24h; The metal ion source compound includes zirconium chloride; The organic ligand comprises terephthalic acid; The acid modulator includes acetic acid; The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32; The amount of the acid modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L; The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride; The surfactant concentration is 1-4wt%, preferably 2wt%; The ratio of ethanol to water in the mixture of ethanol and water is 1:1; The concentration of the sodium dodecyl sulfate is 2 wt %.

8. The industrial harmful gas sensor according to claim 3, characterized in that: The step of preparing a photonic crystal structure based on MOFs material on the surface of single crystal silicon includes: Mixing the metal ion source compound and the organic ligand to obtain a mixed solution IV; An acid modulator is added to the mixed solution 4 to react and obtain monodispersed MOFs nanoparticles; Surface functionalization of monodisperse MOFs nanoparticles using surfactants; The functionalized monodispersed MOFs nanoparticles were re-dispersed by ultrasonication in deionized water or ethanol solution to form a MOFs colloidal suspension; 100 μl of MOFs colloidal suspension was spontaneously formed into a dense and porous MOFs three-dimensional photonic crystal structure on the surface of a silicon substrate through solvent evaporation self-assembly, spin coating, LB film technology or layer-by-layer self-assembly technology.

9. The industrial harmful gas sensor according to claim 8, characterized in that: The reaction temperature of the mixed solution 4 and the acid modulator is 120° C., and the reaction time is 12-24; The metal ion source compound includes any one of Zn(CH3COO)2·2H2O and zirconium chloride; The organic ligand includes any one of 2-methylimidazole and terephthalic acid; The acid modulator includes any one of acetic acid, hydrochloric acid and hydrofluoric acid; The base modulator includes triethylamine. The molar ratio of the metal ion to the organic ligand in the metal ion source compound is 1:1-1:80, preferably 1:1-1:32; The amount of the acid-base modulator added is 0mol / L-5mol / L, preferably 1mol / L-2mol / L; The surfactant includes any one of polyvinyl pyrrolidone, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride; The surfactant concentration is 1-4wt%, preferably 2wt%; The concentration of the MOFs colloidal suspension is about 2 wt %.

10. An industrial harmful gas sensor terminal, characterized in that: include: one or more processors; a storage device having one or more programs stored thereon; When the one or more programs are executed by the one or more processors, the one or more processors implement the industrial hazardous gas sensor according to any one of claims 1 to 2.

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