A graphene-based gas detection method, device and medium

Abstract

The application discloses a kind of based on graphene gas detection method, equipment and medium, it is related to gas detection field, including, on the surface of substrate construction has stable interface electric field sensing structure;In situ deposition nanoscale catalytic cluster on the surface of graphene, form the sensing structure with selective adsorption layer to target gas;In zero gas environment, apply low-frequency step wave bias, collect resistance time series, construct the frequency spectrum reference feature corresponding to target gas concentration;Under the environment to be measured, bias is repeatedly applied and resistance response is collected, and the main peak frequency and amplitude of the frequency spectrum feature are corrected by the temperature and humidity data obtained synchronously;Based on the corrected frequency spectrum feature, the target gas concentration is calculated using the inversion algorithm.The stable interface electric field and selective adsorption layer are constructed, the response sensitivity and selectivity of graphene to target gas are enhanced, and the temperature and humidity correction mechanism is introduced, which effectively improves the detection stability and accuracy in complex environmental conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas detection, and in particular to a graphene-based gas detection method, device and medium. BACKGROUND

[0002] Graphene is widely used in the research and development of new gas sensors due to its excellent specific surface area, electrical conductivity and surface sensitivity. Traditional graphene-based gas detection methods usually involve exposing graphene materials directly to target gases and monitoring changes in their resistance or conductance to detect gas concentrations. To improve detection selectivity and sensitivity, researchers have attempted to introduce metal nanoparticles or functional molecular modification layers on the surface of graphene to enhance the adsorption affinity for specific gases. In addition, constant voltage or alternating current excitation methods are often used in sensor driving and signal analysis to estimate gas concentrations through steady-state response values or transient curve analysis. These methods have the advantages of fast response and good repeatability and have been preliminarily applied in environmental monitoring, safety warning and medical detection.

[0003] However, the above conventional methods still have certain limitations in high-precision quantitative analysis of gas detection, mainly in two aspects: first, the signal response is easily affected by environmental temperature and humidity disturbances, leading to inconsistent sensing characteristics under different conditions and affecting the accuracy of concentration calculation; second, sensing signals are mostly based on changes in single resistance or conductance values, making it difficult to fully extract dynamic characteristic parameters during the complex gas interaction process, thereby limiting the recognition and discrimination ability in the presence of multiple gases. SUMMARY

[0004] In view of the above existing problems, the present application is proposed.

[0005] Therefore, the present application provides a graphene-based gas detection method to solve the problem of the influence of environmental disturbances on detection accuracy in the prior art.

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] In a first aspect, the present application provides a graphene-based gas detection method, which includes constructing an oriented dipole molecular monolayer as a polarization interface on the surface of a substrate and transferring a monolayer of graphene on the polarization interface to generate a sensing structure with a stable interface electric field.

[0008] The oriented dipole molecular monolayer is a monolayer of undecyl phosphoric acid molecules.

[0009] A nanoscale catalytic cluster is deposited in situ on the surface of the monolayer of graphene to generate a sensing structure with a selective adsorption layer.

[0010] The low-frequency stepped wave bias is applied to the sensing structure in a zero-gas environment, the resistance time sequence of the graphene is collected, and the frequency spectrum reference characteristic corresponding to the target gas concentration is established;

[0011] The low-frequency stepped wave bias is applied to the sensing structure in the to-be-measured environment, the frequency spectrum characteristic of the target gas response is acquired, and the main peak frequency and amplitude of the frequency spectrum characteristic are corrected according to the synchronously measured temperature and humidity data;

[0012] Based on the corrected frequency spectrum characteristic, the target gas is inversely calculated according to the frequency spectrum reference characteristic corresponding to the target gas concentration, and the target gas concentration is acquired.

[0013] As a preferred scheme of the graphene-based gas detection method, the oriented dipole molecule monolayer on the substrate surface is constructed as a polarization interface, and the specific steps are as follows,

[0014] The substrate surface is cleaned and dried, and the cleaned and dried substrate surface is placed in a self-assembly reaction solution;

[0015] The oriented dipole molecules in the self-assembly reaction solution are self-assembled on the substrate surface to obtain a uniform arrangement of the oriented dipole molecule monolayer on the substrate surface;

[0016] The formed oriented dipole molecule monolayer and the substrate are integrally heat-treated, and the heat-treated oriented dipole molecule monolayer is used as a polarization interface;

[0017] The self-assembly reaction solution refers to a undecyl phosphoric acid molecule solution with anhydrous ethanol as a solvent;

[0018] The heat treatment refers to heating the oriented dipole molecule monolayer and the substrate to a target temperature and keeping the temperature.

[0019] As a preferred scheme of the graphene-based gas detection method, the oriented dipole molecule monolayer on the substrate surface is constructed as a polarization interface, and the specific steps are as follows,

[0020] The oriented dipole molecule monolayer on the substrate surface is placed in a single-layer graphene transfer station as a polarization interface;

[0021] In the single-layer graphene transfer station, the single-layer graphene is carried by a polymethyl methacrylate film support layer;

[0022] The single-layer graphene with the polymethyl methacrylate film support layer is covered on the substrate surface of the polarization interface, so that the single-layer graphene directly contacts the oriented dipole molecule monolayer;

[0023] The polarized interface substrate surface covered with single-layer graphene is subjected to solvent immersion treatment to remove the polymethyl methacrylate film support layer carried by the single-layer graphene, and the polarized interface substrate surface covered with single-layer graphene is subjected to heat treatment to generate a sensing structure with a stable interface electric field.

[0024] The solvent used in the solvent immersion treatment is an acetone solution.

[0025] As a preferred scheme of the graphene-based gas detection method, the steps of in-situ depositing a nanoscale catalytic cluster on the surface of the single-layer graphene to generate a sensing structure with a selective adsorption layer are as follows:

[0026] The sensing structure with a stable interface electric field is fixed on a sample table of an in-situ deposition station.

[0027] A precursor gas is introduced into the in-situ deposition station, and the surface of the single-layer graphene of the sensing structure is fully contacted with the precursor gas.

[0028] The surface of the single-layer graphene is subjected to plasma to in-situ decompose the precursor gas on the surface of the single-layer graphene to generate a nanoscale catalytic cluster.

[0029] The average particle size of the nanoscale catalytic cluster generated in the in-situ deposition process is controlled to obtain a sensing structure with a stable interface electric field and a nanoscale catalytic cluster.

[0030] The sensing structure with a stable interface electric field and a nanoscale catalytic cluster is subjected to heat treatment to generate a selective adsorption layer with a specific adsorption potential well depth for the target gas.

[0031] The precursor gas is platinum tetrachloride vapor.

[0032] The control of the nanoscale catalytic cluster is achieved by adjusting the plasma treatment time, adjusting the partial pressure of the precursor gas, and using short-time plasma pulse intermittence to control the nucleation and growth process of the nanoscale catalytic cluster, so that the average particle size is stable at the nanoscale.

[0033] As a preferred scheme of the graphene-based gas detection method, the steps of applying a low-frequency stepped wave bias to the sensing structure in a zero-gas environment are as follows:

[0034] The sensing structure with a selective adsorption layer is placed in a zero-gas environment, and a target gas is introduced.

[0035] The sensing structure electrode in the zero-gas environment is connected to a low-frequency stepped wave bias generator.

[0036] The parameters of the low-frequency stepped wave bias generator are set to apply a low-frequency stepped wave bias to the sensing structure electrode.

[0037] As a preferred scheme of the graphene-based gas detection method, the resistance time sequence of the graphene is collected, and a frequency spectrum reference feature corresponding to the target gas concentration is established, and the specific steps are as follows,

[0038] When the low-frequency step wave bias is applied, the electrodes of the sensing structure are connected with the high-precision resistance measuring instrument;

[0039] In the zero gas environment, the sensing structure is continuously collected, and the resistance time sequence of the target gas in the zero gas environment is obtained;

[0040] The resistance time sequence is subjected to short-time Fourier transform, and the frequency spectrum data of the target gas concentration in the zero gas environment is obtained;

[0041] The frequency spectrum feature peak frequency and the frequency spectrum feature peak amplitude corresponding to the target gas concentration are extracted from the frequency spectrum data, and the frequency spectrum feature parameters corresponding to the target gas concentration are obtained;

[0042] The frequency spectrum feature parameters corresponding to the target gas concentration are taken as the frequency spectrum reference feature, and the frequency spectrum reference feature corresponding to the target gas concentration is established.

[0043] As a preferred scheme of the graphene-based gas detection method, the low-frequency step wave bias is applied to the sensing structure in the to-be-detected environment, the frequency spectrum feature of the target gas response is obtained, and the main peak frequency and the amplitude of the frequency spectrum feature are corrected according to the simultaneously measured temperature and humidity data, and the specific steps are as follows,

[0044] The sensing structure is placed in the to-be-detected environment, the low-frequency step wave bias is applied to the sensing structure in the same setting as in the zero gas environment, the resistance of the sensing structure is collected, and the resistance time sequence of the target gas response is obtained;

[0045] When the resistance of the sensing structure is collected, the temperature and humidity data are simultaneously collected;

[0046] The resistance time sequence of the target gas response is subjected to short-time Fourier transform, and the frequency spectrum feature of the target gas response is obtained;

[0047] The main peak frequency of the frequency spectrum feature of the target gas response and the main peak amplitude of the frequency spectrum feature are corrected by using the collected temperature and humidity data.

[0048] As a preferred scheme of the graphene-based gas detection method, the target gas concentration is obtained by inversely calculating the corrected frequency spectrum feature main peak position and the frequency spectrum feature main peak amplitude according to the stored frequency spectrum reference feature through multivariate nonlinear empirical inversion.

[0049] In a second aspect, the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and wherein the computer program, when executed by the processor, implements any step of the graphene-based gas detection method according to the first aspect of the present application.

[0050] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any step of the graphene-based gas detection method according to the first aspect of the present application.

[0051] The present application has the following advantages: by depositing nanoscale catalytic clusters in situ on the surface of graphene, a sensing structure with a selective adsorption layer having a specific adsorption potential well depth is constructed, thereby effectively enhancing the adsorption capacity of target gas molecules; by constructing an oriented dipole molecular monolayer on the surface of the substrate and transferring the monolayer graphene, a sensing structure with a stable interfacial electric field is generated, thereby improving the working stability of the sensor and enhancing the repeatability and reliability of long-term operation; by synchronously collecting temperature and humidity data and introducing temperature and humidity disturbance correction, the adaptability to complex environments is improved. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0053] Fig. 1 The flowchart of the graphene-based gas detection method.

[0054] Fig. 2 The flowchart of generating a sensing structure with a stable interfacial electric field.

[0055] Fig. 3 The flowchart of generating a selective adsorption layer with a specific adsorption potential well depth for target gas.

[0056] Fig. 4 The flowchart of inversion calculation. DETAILED DESCRIPTION

[0057] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0058] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description. In other instances, well-known methods have not been described in detail in order not to unnecessarily obscure aspects of the present application.

[0059] Second, the "one embodiment" or "an embodiment" as used herein means a specific implementation that can include features, structures or characteristics that are not included in other implementations. The various embodiments described throughout this specification are not necessarily mutually exclusive, and the specific features, structures, or characteristics of one embodiment can be combined with or substituted for those of another without deviating from the scope of the application.

[0060] Reference Figs. 1-4 For one embodiment of the present application, the embodiment provides a graphene-based gas detection method, comprising the following steps:

[0061] S1: Constructing an oriented dipole monolayer on the surface of the substrate as a polarization interface, and transferring a single-layer graphene on the polarization interface to generate a sensing structure with a stable interface electric field.

[0062] The surface of the substrate is cleaned and dried, and the cleaned and dried substrate surface is placed in a self-assembly reaction solution.

[0063] Further, the silicon or silicon dioxide substrate to be treated is sequentially immersed in deionized water, ethanol and isopropanol for ultrasonic cleaning to remove surface impurities and organic contaminants.

[0064] The cleaned substrate is blown dry with an inert gas, such as high-purity nitrogen, and dried in an oven to ensure that there is no water residue on the surface of the substrate.

[0065] In a clean reaction container, a solution of undecylphosphonic acid molecules with oriented dipole characteristics is prepared, the solvent is anhydrous ethanol, and the solution is stirred thoroughly, filtered to remove impurities, and a self-assembly reaction solution is obtained.

[0066] The oriented dipole molecules in the self-assembly reaction solution undergo self-assembly reaction on the surface of the substrate to obtain a uniform arrangement of oriented dipole monolayer on the surface of the substrate.

[0067] Further, the cleaned and dried substrate surface is vertically immersed in the self-assembly reaction solution, the reaction temperature is controlled at room temperature, and the oriented dipole molecules are allowed to fully self-assemble on the surface of the substrate to form a monolayer.

[0068] The formed oriented dipole monolayer is heat treated together with the substrate, and the heat-treated oriented dipole monolayer is used as a polarization interface.

[0069] Further, the substrate after soaking is rinsed with anhydrous ethanol to remove unbound molecules, and the substrate is placed in an inert gas and continuously replaced three times. After completion, the oriented dipole molecular monolayer and the substrate as a whole are heated to the target temperature and kept until the heat treatment is completed. The oriented dipole molecular monolayer after heat treatment is obtained, and the oriented dipole molecular monolayer after heat treatment is used as a polarization interface.

[0070] The substrate surface with the oriented dipole molecular monolayer as the polarization interface is placed in a single-layer graphene transfer station.

[0071] Further, the single-layer graphene transfer station refers to a vacuum adsorption platform of the single-layer graphene transfer station.

[0072] Further, after placing the substrate surface with the polarization interface on the vacuum adsorption platform of the single-layer graphene transfer station, the position is adjusted so that the substrate surface is in a horizontal state.

[0073] In the single-layer graphene transfer station, a single-layer graphene is carried by a polymethyl methacrylate film support layer.

[0074] Further, in the single-layer graphene transfer station, a single-layer graphene grown on a copper foil is spin-coated with a polymethyl methacrylate solution on the surface of the single-layer graphene, and is dried to form a polymethyl methacrylate support layer.

[0075] The single-layer graphene with the polymethyl methacrylate film support layer is covered on the substrate surface with the polarization interface, so that the single-layer graphene is in direct contact with the oriented dipole molecular monolayer.

[0076] Further, the single-layer graphene with the polymethyl methacrylate support layer is peeled off from the copper foil by a humidity transfer method, and is slowly covered on the substrate surface with the polarization interface, so that the active surface of the single-layer graphene is in direct contact and adhesion with the oriented dipole molecular monolayer.

[0077] The polarization interface substrate surface covered with the single-layer graphene is subjected to solvent soaking treatment to remove the polymethyl methacrylate film support layer carried by the single-layer graphene, and the polarization interface substrate surface covered with the single-layer graphene is subjected to heat treatment to generate a sensing structure with a stable interface electric field.

[0078] Further, the polarization interface substrate surface covered with the single-layer graphene is immersed in acetone solution for sufficient solvent soaking treatment to sufficiently dissolve and remove the polymethyl methacrylate film support layer, and is rinsed with anhydrous ethanol to remove residual solvents, and is blown dry with an inert gas.

[0079] Further, the polarization interface substrate surface after removing the polymethyl methacrylate support layer is placed in an inert environment for heat treatment to obtain a sensing structure with a stable interface electric field.

[0080] S2: In-situ deposition of nanoscale catalytic clusters on the single-layer graphene surface to generate a sensing structure with a selective adsorption layer.

[0081] Further, the sensing structure with a stable interfacial electric field is fixed on the sample stage of the in-situ deposition station, and an electrode insulation shielding treatment is performed.

[0082] Further, the sensing structure with a stable interfacial electric field is fixed on the sample stage of the in-situ deposition station, and an electrode insulation shielding treatment is performed.

[0083] Further, the electrode insulation shielding treatment is specifically as follows: the sensing structure with a stable interfacial electric field is positioned and determined on the clean sample stage using an optical microscope, and a peelable insulation protective glue, such as a polyimide tape, a polytetrafluoroethylene film, or a high-temperature silicon glue protective layer, is coated on the electrode surface to ensure that the covered area covers the electrode lead-out end and the pad area and does not shield the effective sensing area of the single-layer graphene.

[0084] The precursor gas is introduced into the in-situ deposition station, and the single-layer graphene surface of the sensing structure is fully contacted with the precursor gas.

[0085] Further, the precursor gas is introduced into the in-situ deposition station, and the single-layer graphene surface of the sensing structure with a stable interfacial electric field is fully contacted with the precursor gas, wherein the precursor gas is platinum tetrachloride vapor.

[0086] The single-layer graphene surface is subjected to plasma to in-situ decompose the precursor gas to generate nanoscale catalytic clusters.

[0087] Further, the plasma is applied, specifically as follows: an argon plasma or an argon-hydrogen mixed plasma is used.

[0088] The average particle size of the nanoscale catalytic clusters generated during the in-situ deposition process is controlled to obtain the sensing structure with a stable interfacial electric field and nanoscale catalytic clusters.

[0089] Further, the nucleation and growth process of the nanoscale catalytic clusters is regulated by shortening or lengthening the plasma treatment time, reducing or increasing the partial pressure of the precursor gas, and setting multiple short-time plasma pulse intervals to stabilize the average particle size at the nanoscale. The particle size is rechecked by in-situ reflection high-energy electron diffraction to obtain the sensing structure with a stable interfacial electric field and nanoscale catalytic clusters.

[0090] The sensing structure with a stable interfacial electric field and nanoscale catalytic clusters is subjected to heat treatment to generate a sensing structure with a selective adsorption layer.

[0091] S3: Apply low-frequency stepped wave bias to the sensing structure in a zero-gas environment, collect the resistance time series of graphene, and establish the frequency spectrum reference characteristics corresponding to the target gas concentration.

[0092] Put the sensing structure with a selective adsorption layer into a zero-gas environment and introduce the target gas.

[0093] Further, the zero-gas environment refers to a reference atmosphere that does not contain the target gas component to be measured and has extremely low impurity content, wherein the main component is high-purity carrier gas, such as high-purity nitrogen, high-purity argon, or purified air.

[0094] It should be noted that the impurity content is extremely low, and the purity is generally ≥99.999%.

[0095] Further, in the zero-gas environment, the target gas with a concentration of is introduced.

[0096] Connect the sensing structure electrode in the zero-gas environment with the target gas introduced to the low-frequency stepped wave bias generator.

[0097] Set the low-frequency stepped wave bias generator parameters to apply low-frequency stepped wave bias to the sensing structure electrode.

[0098] Further, the set low-frequency stepped wave bias generator parameters include DC bias, stepped amplitude, stepped update frequency, and duration of each stepped.

[0099] When applying low-frequency stepped wave bias, connect the electrode of the sensing structure to a high-precision resistance measuring instrument.

[0100] Further, four-terminal measurement method is used to eliminate the influence of lead resistance.

[0101] In the zero-gas environment with the target gas introduced, collect the resistance of the sensing structure continuously to obtain the resistance time series of the target gas in the zero-gas environment.

[0102] Perform short-time Fourier transform on the resistance time series to obtain the frequency spectrum data of the target gas concentration in the zero-gas environment.

[0103] Further, normalize the resistance time series to obtain the normalized resistance time series.

[0104] Perform short-time Fourier transform on the normalized resistance time series, represented as:

[0105] ;

[0106] wherein, represents the time-frequency spectrum complex value at the analysis frequency and time , denotes the analysis frequency of the short-time Fourier transform, denotes time, denotes the normalized resistance time series, is the imaginary unit, is the constant of the circle, denotes the window function.

[0107] Extracting the spectral feature peak frequency and the spectral feature peak amplitude corresponding to the target gas concentration in the spectral data, obtaining the spectral feature parameters corresponding to the target gas concentration.

[0108] Further, the search frequency band is , at the center of the steady-state time window, extracting the spectral feature peak frequency and the spectral feature peak amplitude .

[0109] The spectral feature peak frequency is expressed as:

[0110] ;

[0111] The spectral feature peak amplitude is expressed as:

[0112] ;

[0113] Taking the spectral feature parameters corresponding to the target gas concentration as the spectral reference features, the spectral reference features corresponding to the target gas concentration are established.

[0114] Further, the spectral feature parameters include the spectral feature peak frequency and the spectral feature peak amplitude.

[0115] Resistive time series detection is performed on a plurality of different concentrations of target gas, and the spectral feature parameters corresponding to the target gas under different concentrations are obtained.

[0116] The obtained spectral feature parameters are fitted by a linear regression equation, a quantitative relationship between the gas concentration and the spectral feature parameters is established, and a relationship data set between the spectral feature parameters and the gas concentration is formed.

[0117] The spectral feature parameters under the target gas concentration are stored as spectral reference features, serving as standard reference data for the target gas concentration.

[0118] S4: applying a low-frequency step wave bias to the sensing structure in the environment to be measured, obtaining the spectral features of the target gas response, and correcting the main peak frequency and amplitude of the spectral features according to the simultaneously measured temperature and humidity data.

[0119] Put the sensing structure into the environment to be measured, apply the same low-frequency stepped wave bias as in the zero-gas environment to the sensing structure, collect the resistance of the sensing structure, and obtain the resistance time sequence of the target gas response.

[0120] Further, put the sensing structure into the closed environment of the environment to be measured, connect the sensing structure in the environment to be measured with the low-frequency stepped wave bias generator, set the same low-frequency stepped wave bias parameters in the zero-gas environment in the low-frequency stepped wave bias generator, start the low-frequency stepped wave bias generator, and apply the low-frequency stepped wave bias signal to the sensing structure in the environment to be measured; at the same time of applying the low-frequency stepped wave bias signal, connect the electrodes of the sensing structure with the high-precision resistance measuring instrument, and collect the resistance time sequence of the sensing structure.

[0121] Collect the temperature and humidity data synchronously when collecting the resistance of the sensing structure.

[0122] Further, fix the temperature sensor and the humidity sensor in the environment to be measured, and place the sensing structure at a normal distance, for example, 1 cm, from the sensors and at the same height plane, and synchronously collect the temperature and humidity data in real time.

[0123] Perform short-time Fourier transform on the resistance time sequence of the target gas response, and obtain the frequency spectrum characteristics of the target gas response.

[0124] Further, perform frequency spectrum analysis on the resistance time sequence of the target gas response by short-time Fourier transform, and obtain the frequency spectrum characteristics of the target gas response.

[0125] The frequency spectrum characteristics of the target gas response include the main peak frequency of the target gas response and the main peak amplitude of the target gas response.

[0126] Correct the frequency spectrum characteristics of the target gas response by using the collected temperature and humidity data.

[0127] Further, use the synchronously collected temperature and humidity data as the frequency spectrum correction parameters, assume that the temperature and humidity have a certain influence on the frequency spectrum characteristics of the target gas response, and then the temperature and humidity correction calculation formula of the time-frequency spectrum complex value is represented as:

[0128] ;

[0129] wherein, represents the corrected time-frequency spectrum complex value at the analysis frequency and the time , , respectively represent the frequency spectrum correction coefficients of the temperature and the humidity, represents the temperature value at the time , representing time representing the humidity value at the time, representing a reference temperature, representing a reference humidity.

[0130] It should be noted that the relative change ratio of the spectral characteristic peak frequency and the peak amplitude is measured under the typical working conditions of low temperature, normal temperature and high temperature, for example, 0℃, 25℃ and 50℃, and linear regression is used for fitting to obtain the upper and lower bounds [0.85, 1.15] of the spectral correction coefficient of temperature.

[0131] Under the conditions of constant gas concentration and constant temperature, the relative humidity is controlled under the typical working conditions of low humidity, medium humidity and high humidity, for example, 25%RH, 50%RH and 80%RH, and the change ratio of the spectral characteristic peak amplitude is measured, and the effective interval [0.90, 1.20] of the spectral correction coefficient of humidity is determined by exponential function fitting.

[0132] The spectral characteristic peak frequency and the spectral characteristic peak amplitude responding to the target gas are extracted from the corrected spectral characteristic to obtain the spectral characteristic parameters responding to the target gas.

[0133] S5: Based on the corrected spectral characteristic, the target gas is inversely calculated according to the spectral reference characteristic corresponding to the target gas concentration to obtain the target gas concentration.

[0134] According to the stored spectral reference characteristic, the corrected spectral characteristic main peak position and the spectral characteristic main peak amplitude are inversely calculated by a multivariate nonlinear empirical inversion formula to obtain the target gas concentration.

[0135] Further, the multivariate nonlinear empirical inversion formula is represented as:

[0136] ;

[0137] wherein, represents the target gas concentration obtained by inversion, represents the main peak amplitude corrected by temperature and humidity, represents the main peak frequency corrected by temperature and humidity, , respectively represent the proportional coefficients of the main peak amplitude and the main peak frequency corrected by temperature and humidity.

[0138] It should be noted that, , The value of is obtained by fitting the data set between the spectral characteristic parameters and the gas concentration, wherein, , The value range of the target gas concentration is determined by performing multi-point sampling on the corrected response amplitude and the main peak frequency in a standard environment with a known gas concentration gradient, and performing parameter regression through a multivariate nonlinear empirical inversion formula.

[0139] The corrected inversion result of the target gas concentration is subjected to numerical reservation processing, and the target gas concentration is output.

[0140] The embodiment also provides a computer device suitable for the case of the graphene-based gas detection method, including a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to realize the graphene-based gas detection method proposed in the above embodiment.

[0141] The computer device can be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to perform wired or wireless communication with an external terminal. The wireless communication can be achieved through WIFI, an operator network, NFC (Near Field Communication) or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse, etc.

[0142] The embodiment also provides a storage medium having a computer program stored thereon, the program being executed by a processor to realize the graphene-based gas detection method proposed in the above embodiment. The storage medium can be realized by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk or an optical disk.

[0143] To sum up, the application effectively enhances the adsorption capacity of target gas molecules by in-situ depositing nanoscale catalytic clusters on the surface of graphene to construct a selective adsorption layer with a specific adsorption potential well depth; improves the working stability of the sensor, and enhances the repeatability and reliability of long-term operation by constructing an oriented dipole molecular monolayer on the surface of the substrate and transferring a monolayer of graphene to generate a sensing structure with a stable interface electric field; and improves the adaptability to complex environments by synchronously collecting temperature and humidity data and introducing temperature and humidity disturbance correction.

[0144] It should be noted that the above examples are only used to illustrate the technical solutions of the application and are not limiting. Although the application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the application, and they should be covered in the scope of the claims of the application.

Claims

1. A graphene-based method of gas detection, characterized by: Comprising, a sensing structure with stable interface electric field is generated by transferring single-layer graphene on the polarized interface; wherein the oriented dipole molecule monolayer is a undecyl phosphoric acid molecule monolayer; a sensing structure with selective adsorption layer is generated by depositing nanoscale catalytic clusters on the surface of single-layer graphene in situ; a low-frequency step wave bias is applied to the sensing structure in a zero-gas environment, and the resistance time series of graphene is collected, and a frequency spectrum reference feature corresponding to the target gas concentration is established; a low-frequency step wave bias is applied to the sensing structure in the environment to be measured, the frequency spectrum feature of the target gas response is obtained, and the main peak frequency and amplitude of the frequency spectrum feature are corrected according to the simultaneously measured temperature and humidity data; based on the corrected frequency spectrum feature, the target gas concentration is obtained by inverse calculation according to the frequency spectrum reference feature corresponding to the target gas concentration; the specific steps of transferring single-layer graphene on the polarized interface to generate a sensing structure with stable interface electric field are as follows, the substrate surface of the oriented dipole molecule monolayer as the polarized interface is placed in a single-layer graphene transfer station; in the single-layer graphene transfer station, the single-layer graphene is supported by a polymethyl methacrylate film support layer; the single-layer graphene with the polymethyl methacrylate film support layer is covered on the substrate surface of the polarized interface, so that the single-layer graphene is in direct contact with the oriented dipole molecule monolayer; the polarized interface substrate surface covered with single-layer graphene is subjected to solvent immersion treatment to remove the polymethyl methacrylate film support layer carried by the single-layer graphene, and the polarized interface substrate surface covered with single-layer graphene is subjected to heat treatment to generate a sensing structure with stable interface electric field; wherein the solvent used in the solvent immersion treatment is acetone solution; the specific steps of depositing nanoscale catalytic clusters on the surface of single-layer graphene in situ to generate a sensing structure with selective adsorption layer are as follows, the sensing structure with stable interface electric field is fixed on a sample table of an in-situ deposition station; a precursor gas is introduced into the in-situ deposition station, and the surface of the single-layer graphene of the sensing structure is in full contact with the precursor gas; a plasma is applied to the surface of the single-layer graphene to decompose the precursor gas in situ on the surface of the single-layer graphene, thereby generating nanoscale catalytic clusters; the average particle size of the nanoscale catalytic clusters generated during the in-situ deposition process is controlled to obtain a sensing structure with stable interface electric field and nanoscale catalytic clusters; the sensing structure with stable interface electric field and nanoscale catalytic clusters is subjected to heat treatment to generate a selective adsorption layer with a specific adsorption potential well depth for the target gas; wherein the precursor gas is platinum tetrachloride vapor; the average particle size of the nanoscale catalytic clusters is controlled by adjusting the plasma treatment time, adjusting the partial pressure of the precursor gas, and using short plasma pulse intermittence to control the nucleation and growth process of the nanoscale catalytic clusters, so that the average particle size is stable at the nanoscale; the target gas concentration is obtained by inverse calculation of the main peak position and amplitude of the corrected frequency spectrum feature based on the stored frequency spectrum reference feature through multivariate nonlinear empirical inverse formula.

2. The graphene-based gas detection method of claim 1, wherein: The step of constructing the oriented dipole molecule monolayer as the polarization interface on the surface of the substrate is specifically as follows, The surface of the substrate is cleaned and dried, and the cleaned and dried surface of the substrate is placed in a self-assembly reaction solution; The oriented dipole molecules in the self-assembly reaction solution are self-assembled on the surface of the substrate to obtain the oriented dipole molecule monolayer uniformly arranged on the surface of the substrate; The formed oriented dipole molecule monolayer and the substrate are integrally heat-treated, and the heat-treated oriented dipole molecule monolayer is used as the polarization interface; The self-assembly reaction solution refers to a solution of undecyl phosphonic acid molecules in anhydrous ethanol; The heat treatment refers to heating the oriented dipole molecule monolayer and the substrate integrally to a target temperature and keeping the temperature.

3. The graphene-based gas detection method of claim 2, wherein: The step of applying the low-frequency stepped wave bias to the sensing structure in the zero-gas environment is specifically as follows, The sensing structure with the selective adsorption layer is placed in the zero-gas environment, and the target gas is introduced; The electrode of the sensing structure in the zero-gas environment is connected to the low-frequency stepped wave bias generator; The parameters of the low-frequency stepped wave bias generator are set to apply the low-frequency stepped wave bias to the electrode of the sensing structure.

4. The graphene-based gas detection method of claim 3, wherein: The step of collecting the resistance time sequence of the graphene and establishing the frequency spectrum reference feature corresponding to the target gas concentration is specifically as follows, When the low-frequency stepped wave bias is applied, the electrode of the sensing structure is connected to the high-precision resistance measuring instrument; In the zero-gas environment, the resistance of the sensing structure is continuously collected to obtain the resistance time sequence of the target gas in the zero-gas environment; The resistance time sequence is subjected to short-time Fourier transform to obtain the frequency spectrum data of the target gas concentration in the zero-gas environment; The peak frequency and the peak amplitude of the frequency spectrum feature corresponding to the target gas concentration are extracted from the frequency spectrum data to obtain the frequency spectrum feature parameters corresponding to the target gas concentration; The frequency spectrum feature parameters corresponding to the target gas concentration are used as the frequency spectrum reference feature to establish the frequency spectrum reference feature corresponding to the target gas concentration.

5. The graphene-based gas detection method of claim 4, wherein: The step of applying the low-frequency stepped wave bias to the sensing structure in the to-be-measured environment, obtaining the frequency spectrum feature of the target gas response, and correcting the main peak frequency and the amplitude of the frequency spectrum feature according to the synchronously measured temperature and humidity data is specifically as follows, The sensing structure is placed in the to-be-measured environment, and the low-frequency stepped wave bias applied to the sensing structure in the zero-gas environment is applied to the sensing structure in the to-be-measured environment. The resistance of the sensing structure is collected to obtain the resistance time sequence of the target gas response; When the resistance of the sensing structure is collected, the temperature and humidity data are synchronously collected; The resistance time sequence of the target gas response is subjected to short-time Fourier transform to obtain the frequency spectrum feature of the target gas response; The main peak frequency of the frequency spectrum feature and the main peak amplitude of the frequency spectrum feature of the target gas response are corrected using the collected temperature and humidity data. 6.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is characterized in that: The processor executes the computer program to implement the steps of the graphene-based gas detection method according to any one of claims 1-5.

7. A computer readable storage medium having stored thereon a computer program, characterized in that: The computer program is executed by the processor to implement the steps of the graphene-based gas detection method according to any one of claims 1-5.

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