Graphene-based gas detection method, equipment and medium

Abstract

The invention discloses a graphene-based gas detection method, graphene-based gas detection equipment and a graphene-based medium, and relates to the field of gas detection.The graphene-based gas detection method comprises the steps that a sensing structure with a stable interface electric field is constructed on the surface of a substrate; a nano-scale catalytic cluster is deposited on the surface of graphene in situ, and a sensing structure with a selective adsorption layer for target gas is formed; applying low-frequency step wave bias in a zero gas environment, collecting a resistance time sequence, and constructing a frequency spectrum reference feature corresponding to the target gas concentration; bias is repeatedly applied in a to-be-measured environment, resistance response is collected, and the main peak frequency and amplitude of the frequency spectrum characteristics are corrected through synchronously obtained temperature and humidity data; and calculating the concentration of the target gas by adopting an inversion algorithm based on the corrected spectrum characteristics. By constructing a stable interface electric field and a selective adsorption layer, the response sensitivity and selectivity of graphene to target gas are enhanced, and meanwhile, a temperature and humidity correction mechanism is introduced, so that the detection stability and accuracy under complex environmental conditions are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas detection, and particularly 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, and steady-state response values or transient curve analysis are used to estimate gas concentrations. 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, the sensing signal is mainly 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: 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. The oriented dipole molecular monolayer is a monolayer of undecyl phosphoric acid molecules. 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. A low-frequency step wave bias is applied to the sensing structure in a zero-gas environment, and the resistance time series of the graphene is collected to establish a frequency spectrum reference feature corresponding to the target gas concentration. A low-frequency stepped wave bias is applied to the sensing structure in the environment to be measured, the frequency spectrum characteristics of the target gas response are obtained, and the main peak frequency and amplitude of the frequency spectrum characteristics are corrected according to the temperature and humidity data measured synchronously; Based on the corrected frequency spectrum characteristics, the target gas is inversely calculated according to the frequency spectrum reference characteristics corresponding to the target gas concentration, and the target gas concentration is obtained.

[0007] As a preferred scheme of the graphene-based gas detection method, the steps of constructing an oriented dipole molecule monolayer as a polarization interface on the surface of the substrate are 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 molecule monolayer is obtained by self-assembly reaction of the oriented dipole molecules in the self-assembly reaction solution on the surface of the substrate; The formed oriented dipole molecule monolayer and the substrate are heat treated as a whole, and the heat treated oriented dipole molecule monolayer is used as a polarization interface; The self-assembly reaction solution refers to a solution of undecyl phosphoric acid molecules in anhydrous ethanol; The heat treatment refers to heating the oriented dipole molecule monolayer and the substrate as a whole to a target temperature and holding the temperature.

[0008] As a preferred scheme of the graphene-based gas detection method, the steps of transferring a single-layer graphene on the polarization interface to generate a sensing structure with a stable interface electric field are as follows, The surface of the substrate with the oriented dipole molecule monolayer as a polarization 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 surface of the substrate with the polarization interface, so that the single-layer graphene directly contacts the oriented dipole molecule monolayer; The polarization 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 polarization interface substrate surface covered with single-layer graphene is subjected to heat treatment to generate a sensing structure with a stable interface electric field; The solvent used in the solvent immersion treatment is acetone solution.

[0009] As a preferred scheme of the graphene-based gas detection method, the steps of depositing a nanoscale catalytic cluster in situ on the surface of the single-layer graphene to generate a sensing structure with a selective adsorption layer are as follows, Fixing the sensing structure with stable interface electric field on the sample table of the in-situ deposition station; Introducing the precursor gas into the in-situ deposition station, and fully contacting the single-layer graphene surface of the sensing structure with the precursor gas; Applying plasma to the single-layer graphene surface to decompose the precursor gas in-situ on the single-layer graphene surface to generate nanoscale catalytic clusters; Controlling the average particle size of the nanoscale catalytic clusters generated in the in-situ deposition process to obtain the sensing structure with stable interface electric field and nanoscale catalytic clusters; Performing heat treatment on the sensing structure with stable interface electric field and nanoscale catalytic clusters to generate a selective adsorption layer with a specific adsorption potential well depth for the target gas; The precursor gas is platinum tetrachloride vapor. The control method of the nanoscale catalytic clusters is to adjust the plasma treatment time, adjust the partial pressure of the precursor gas, and adjust the nucleation and growth process of the nanoscale catalytic clusters by using short plasma pulse intermittently, so that the average particle size is stable in the nanoscale.

[0010] As a preferred scheme of the graphene-based gas detection method, the low-frequency stepped wave bias is applied to the sensing structure in a zero-gas environment, and the specific steps are as follows: The sensing structure with the selective adsorption layer is placed in a zero-gas environment, and the target gas is introduced; The sensing structure electrode in the zero-gas environment is connected with the low-frequency stepped wave bias generator; The low-frequency stepped wave bias generator parameters are set to apply a low-frequency stepped wave bias to the sensing structure electrode.

[0011] As a preferred scheme of the graphene-based gas detection method, the resistance time sequence of the graphene is collected, and the frequency spectrum reference feature corresponding to the target gas concentration is established, and the specific steps are as follows: When the low-frequency stepped wave bias is applied, the electrode of the sensing structure is connected with a high-precision resistance measuring instrument; In the zero-gas environment, 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 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 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 taken as the frequency spectrum reference feature, and the frequency spectrum reference feature corresponding to the target gas concentration is established.

[0012] 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 environment to be detected, the frequency spectrum characteristics of the target gas response are obtained, and the main peak frequency and amplitude of the frequency spectrum characteristics are corrected according to the temperature and humidity data measured synchronously. The sensing structure is placed in the environment to be detected, the low-frequency step wave bias is applied to the sensing structure, and the resistance of the sensing structure is collected to obtain the resistance time sequence of the target gas response. The temperature and humidity data are collected synchronously when the resistance of the sensing structure is collected. The resistance time sequence of the target gas response is subjected to short-time Fourier transform to obtain the frequency spectrum characteristics of the target gas response. The main peak frequency of the frequency spectrum characteristics and the main peak amplitude of the frequency spectrum characteristics are corrected by using the collected temperature and humidity data.

[0013] 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 environment to be detected, the frequency spectrum characteristics of the target gas response are obtained, and the main peak frequency and amplitude of the frequency spectrum characteristics are corrected according to the temperature and humidity data measured synchronously.

[0014] 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 is executed by the processor to implement any step of the graphene-based gas detection method according to the first aspect of the present application.

[0015] In a third aspect, the present application provides a computer readable storage medium storing a computer program, wherein the computer program is executed by a processor to implement any step of the graphene-based gas detection method according to the first aspect of the present application.

[0016] The present application has the following advantages: by depositing nanoscale catalytic clusters on the surface of graphene in situ, a sensing structure with a selective adsorption layer having a specific adsorption potential well depth is constructed, the adsorption capacity of target gas molecules is effectively enhanced; by constructing an oriented dipole molecular monolayer on the surface of the substrate and transferring the monolayer graphene, a sensing structure with a stable interface electric field is generated, the working stability of the sensor is improved, and the repeatability and reliability of long-term operation are improved; 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

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Fig. 1 Flow chart for a graphene-based gas detection method.

[0019] Fig. 2 Flow chart for generating a sensing structure with a stable interfacial electric field.

[0020] Fig. 3 Flow chart for generating a selective adsorption layer with a specific adsorption potential well depth for a target gas.

[0021] Fig. 4 Flow chart for an inversion calculation. DETAILED DESCRIPTION

[0022] In order to make the above objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0023] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0024] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0025] REFERENCE Figs. 1-4 For one embodiment of the present application, the embodiment provides a graphene-based gas detection method, comprising the following steps: S1: constructing an oriented dipole monolayer as a polarization interface on a substrate surface, and transferring a monolayer graphene on the polarization interface to generate a sensing structure with a stable interfacial electric field.

[0026] The substrate surface is subjected to cleaning and drying treatment, and the cleaned and dried substrate surface is placed in a self-assembly reaction solution.

[0027] Further, the silicon or silicon dioxide substrate to be processed is sequentially immersed in deionized water, ethanol and isopropanol for ultrasonic cleaning to remove surface impurities and organic contaminants.

[0028] The cleaned substrate is dried with an inert gas, such as high-purity nitrogen, and is subjected to drying treatment in an oven to ensure that no moisture remains on the surface of the substrate.

[0029] In a clean reaction vessel, a solution of undecylphosphonic acid molecules with oriented dipole characteristics is prepared using anhydrous ethanol as the solvent, and is stirred thoroughly and filtered to remove impurities to obtain a self-assembly reaction solution.

[0030] The oriented dipole molecules in the self-assembly reaction solution undergo self-assembly reaction on the surface of the substrate to obtain a monolayer of oriented dipole molecules uniformly arranged on the surface of the substrate.

[0031] Further, the substrate after cleaning and drying treatment is vertically immersed in the self-assembly reaction solution, and the reaction temperature is controlled at room temperature to allow the oriented dipole molecules to undergo sufficient self-assembly reaction on the surface of the substrate to form a monolayer.

[0032] The formed monolayer of oriented dipole molecules is subjected to heat treatment together with the substrate, and the heat-treated monolayer of oriented dipole molecules is used as a polarization interface.

[0033] Further, the immersed substrate is rinsed with anhydrous ethanol to remove unbound molecules, and is placed in an inert gas and is subjected to continuous replacement for three times. After completion, the monolayer of oriented dipole molecules together with the substrate is heated to a target temperature and is kept at the temperature until heat treatment is completed to obtain a heat-treated monolayer of oriented dipole molecules, which is used as a polarization interface.

[0034] The substrate with the monolayer of oriented dipole molecules as the polarization interface is placed in a single-layer graphene transfer station.

[0035] Further, the single-layer graphene transfer station refers to a vacuum adsorption platform of the single-layer graphene transfer station.

[0036] Further, after the substrate with the polarization interface is placed on the vacuum adsorption platform of the single-layer graphene transfer station, the position is adjusted so that the surface of the substrate is in a horizontal state.

[0037] In the single-layer graphene transfer station, the single-layer graphene is carried by a polymethyl methacrylate film support layer.

[0038] Further, in the single-layer graphene transfer station, a polymethyl methacrylate solution is spin-coated on the surface of the single-layer graphene grown on a copper foil, and is subjected to drying to form a polymethyl methacrylate support layer.

[0039] The single-layer graphene with a polymethyl methacrylate supporting layer is covered on the substrate surface of the polar interface to make the single-layer graphene directly contact with the oriented dipole molecule monolayer.

[0040] Further, the single-layer graphene with a polymethyl methacrylate supporting layer is peeled off from the copper foil by a humidity transfer method and slowly covered on the substrate surface of the polar interface to make the active surface of the single-layer graphene directly contact and adhere to the oriented dipole molecule monolayer.

[0041] The substrate surface of the polar interface covered with the single-layer graphene is subjected to solvent immersion treatment to remove the polymethyl methacrylate film supporting layer of the single-layer graphene, and the substrate surface of the polar interface covered with the single-layer graphene is subjected to heat treatment to generate a sensing structure with a stable interface electric field.

[0042] Further, the substrate surface of the polar interface covered with the single-layer graphene is immersed in a acetone solution for sufficient solvent immersion treatment to sufficiently dissolve and remove the polymethyl methacrylate film supporting layer, and is rinsed with anhydrous ethanol to remove residual solvents and is blown dry with an inert gas.

[0043] Further, the substrate surface of the polar interface after removal of the polymethyl methacrylate supporting layer is placed in an inert environment for heat treatment to obtain a sensing structure with a stable interface electric field.

[0044] S2: In situ deposition of nanoscale catalytic clusters on the surface of the single-layer graphene to generate a sensing structure with a selective adsorption layer.

[0045] The sensing structure with a stable interface electric field is fixed on the sample stage of the in situ deposition station.

[0046] Further, the sensing structure with a stable interface electric field is fixed on the sample stage of the in situ deposition station and subjected to electrode insulation shielding treatment, and after the treatment, the in situ deposition station is subjected to gas evacuation and replacement with high-purity argon.

[0047] Further, the electrode insulation shielding treatment is as follows: the sensing structure with a stable interface electric field is positioned on a clean sample stage using an optical microscope to determine the electrode position, and a peelable insulation protective adhesive, such as a polyimide adhesive tape, a polytetrafluoroethylene film or a high-temperature silicone protective layer, is coated on the surface of the electrode to ensure that the covered area covers the electrode lead-out end and the pad area without shielding the effective sensing area of the single-layer graphene.

[0048] The precursor gas is introduced into the in situ deposition station, and the surface of the single-layer graphene of the sensing structure is in sufficient contact with the precursor gas.

[0049] Further, the precursor gas is introduced into the in-situ deposition station, and the single-layer graphene surface of the sensing structure with stable interface electric field is fully contacted with the precursor gas, wherein the precursor gas is platinum tetrachloride vapor.

[0050] The single-layer graphene surface is subjected to plasma, and the precursor gas is decomposed in-situ on the single-layer graphene surface to generate nanoscale catalytic clusters.

[0051] Further, the plasma is applied, specifically, argon plasma or argon-hydrogen mixed plasma is used.

[0052] The average particle size of the nanoscale catalytic clusters generated in the in-situ deposition process is controlled, and the sensing structure with stable interface electric field and nanoscale catalytic clusters is obtained.

[0053] Further, the nucleation and growth process of the nanoscale catalytic clusters is controlled 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, so that the average particle size is stabilized at the nanoscale. The particle size is rechecked by in-situ reflection high-energy electron diffraction, and the sensing structure with stable interface electric field and nanoscale catalytic clusters is obtained.

[0054] The sensing structure with stable interface electric field and nanoscale catalytic clusters is subjected to heat treatment to generate a sensing structure with a selective adsorption layer.

[0055] S3: A low-frequency stepped wave bias is applied to the sensing structure in a zero-gas environment, the resistance time series of the graphene is collected, and a frequency spectrum reference feature corresponding to the target gas concentration is established.

[0056] The sensing structure with a selective adsorption layer is placed in a zero-gas environment and the target gas is introduced.

[0057] Further, the zero-gas environment refers to a reference atmosphere that does not contain the measured target gas component and has extremely low impurity content, wherein the main component is high-purity carrier gas, for example, high-purity nitrogen, high-purity argon, or purified air.

[0058] It should be noted that the impurity content is extremely low, and the purity is generally ≥99.999%.

[0059] Further, in the zero-gas environment, the target gas with a concentration of is introduced.

[0060] The sensing structure electrode in the zero-gas environment with the target gas introduced is connected to the low-frequency stepped wave bias generator.

[0061] The low-frequency stepped wave bias generator parameters are set, and a low-frequency stepped wave bias is applied to the sensing structure electrode.

[0062] Further, the set low-frequency stepped wave bias generator parameters include DC bias, stepped amplitude, stepped update frequency and each stepped duration.

[0063] When the low-frequency stepped wave bias is applied, the electrodes of the sensing structure are connected with a high-precision resistance measuring instrument.

[0064] Further, four-terminal measurement method is used to eliminate the influence of lead resistance.

[0065] In a zero gas environment into which the target gas is introduced, the sensing structure is continuously collected for resistance, and a resistance time sequence of the target gas in the zero gas environment is obtained.

[0066] The resistance time sequence is subjected to short-time Fourier transform, and frequency spectrum data of the target gas concentration in the zero gas environment is obtained.

[0067] Further, the resistance time sequence is normalized, and a normalized resistance time sequence is obtained.

[0068] The normalized resistance time sequence is subjected to short-time Fourier transform, and is expressed as: ; Wherein, represents a time-frequency spectrum complex value at an analysis frequency and a time , represents an analysis frequency of the short-time Fourier transform, represents a time, represents the normalized resistance time sequence, is an imaginary unit, is a constant of pi, represents a window function.

[0069] In the frequency spectrum data, a frequency spectrum characteristic peak frequency and a frequency spectrum characteristic peak amplitude corresponding to the target gas concentration are extracted, and a frequency spectrum characteristic parameter corresponding to the target gas concentration is obtained.

[0070] Further, the search frequency band is set as , and at the center of the steady-state time window, a frequency spectrum characteristic peak frequency and a frequency spectrum characteristic peak amplitude are extracted.

[0071] Wherein, the frequency spectrum characteristic peak frequency is expressed as: ; The frequency spectrum characteristic peak amplitude is expressed as: ; The spectral feature parameter corresponding to the target gas concentration is taken as a spectral reference feature, and a spectral reference feature corresponding to the target gas concentration is established.

[0072] Further, the spectral feature parameter includes a spectral feature peak frequency and a spectral feature peak amplitude.

[0073] The resistance time sequence detection is performed on the target gas with multiple different concentrations, and the spectral feature parameters corresponding to the target gas with different concentrations are obtained.

[0074] 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.

[0075] The spectral feature parameters under the target gas concentration are stored as spectral reference features, serving as standard reference data of the target gas concentration.

[0076] S4: The sensing structure is subjected to a low-frequency stepped wave bias in the to-be-measured environment, the spectral feature of the target gas response is obtained, and the main peak frequency and amplitude of the spectral feature are corrected according to the synchronously measured temperature and humidity data.

[0077] The sensing structure is placed in the to-be-measured environment, the sensing structure is subjected to the same low-frequency stepped wave bias 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.

[0078] Further, the sensing structure is placed in the closed environment of the to-be-measured environment, the sensing structure in the to-be-measured environment is connected to the low-frequency stepped wave bias generator, the same low-frequency stepped wave bias parameters as in the zero-gas environment are set in the low-frequency stepped wave bias generator, the low-frequency stepped wave bias generator is started, and the sensing structure in the to-be-measured environment is subjected to a low-frequency stepped wave bias signal; while the low-frequency stepped wave bias signal is applied, the electrodes of the sensing structure are connected to the high-precision resistance measuring instrument, and the resistance time sequence of the sensing structure is collected.

[0079] When the resistance of the sensing structure is collected, the temperature and humidity data are synchronously collected.

[0080] Further, the temperature sensor and the humidity sensor are fixed in the to-be-measured environment, the sensing structure is at a normal distance, for example, 1 cm, from the sensor and is at the same height plane as the sensor, and the temperature data and the humidity data are synchronously and real-timely collected.

[0081] The resistance time sequence of the target gas response is subjected to short-time Fourier transform, and the spectral feature of the target gas response is obtained.

[0082] Furthermore, the spectral characteristics of the target gas response are obtained by performing spectral analysis on the resistance time series of the target gas response using short-time Fourier transform.

[0083] The spectral characteristics of the target gas response include the main peak frequency and the main peak amplitude of the target gas response.

[0084] The spectral characteristics of the target gas response are corrected using the collected temperature and humidity data.

[0085] Furthermore, using the synchronously acquired temperature and humidity data as spectral correction parameters, and assuming that temperature and humidity have a certain influence on the spectral characteristics of the target gas response, the formula for calculating the temperature and humidity correction of the time-frequency complex value is expressed as: ; in, Indicates the frequency of analysis and time The lower-corrected time-spectrum complex value. , These represent the spectral correction factors for temperature and humidity, respectively. Indicates time Temperature value at time, Indicates time Humidity value at any given time Indicates reference temperature. Indicates reference humidity.

[0086] It should be noted that the relative changes in the peak frequency and peak amplitude of the spectral characteristics were measured under typical operating conditions of low temperature, normal temperature and high temperature, such as 0℃, 25℃ and 50℃, and linear regression was used to fit the data to obtain the upper and lower bounds of the temperature spectral correction coefficient [0.85, 1.15].

[0087] Under constant gas concentration and temperature conditions, the relative humidity was controlled under typical operating conditions of low humidity, medium humidity and high humidity, such as 25%RH, 50%RH and 80%RH. The change ratio of the peak amplitude of the spectral characteristics was measured, and the effective range of the spectral correction coefficient of humidity [0.90, 1.20] was determined by fitting an exponential function.

[0088] Extract the peak frequency and peak amplitude of the spectral characteristics corresponding to the target gas response from the corrected spectral characteristics to obtain the spectral characteristic parameters corresponding to the target gas response.

[0089] S5: Based on the corrected spectral characteristics, the target gas concentration is obtained by inverting the calculation according to the spectral reference characteristics corresponding to the target gas concentration.

[0090] According to the stored spectral reference characteristics, the main peak position and the main peak amplitude of the corrected spectral characteristics are calculated by a multivariate nonlinear empirical inversion formula, and the target gas concentration is obtained.

[0091] Further, the multivariate nonlinear empirical inversion formula is represented as: ; Wherein, represents the target gas concentration obtained by inversion, represents the main peak amplitude after temperature and humidity correction, represents the main peak frequency after temperature and humidity correction, , respectively represent the proportional coefficient of the main peak amplitude and the main peak frequency after temperature and humidity correction.

[0092] 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 is determined by parameter regression through multivariate nonlinear empirical inversion formula by multi-point sampling of the corrected response amplitude and the main peak frequency in the standard environment with known gas concentration gradient.

[0093] After numerical retention processing of the correction and inversion result of the target gas concentration, the target gas concentration is output.

[0094] The embodiment also provides a computer device suitable for the case of the graphene-based gas detection method, comprising 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.

[0095] 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 by a system bus. The processor of the computer device is configured 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 running the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is configured to perform wired or wireless communication with an external terminal. The wireless communication can be achieved by 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.

[0096] The embodiment also provides a storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement the method for detecting a gas based on graphene as described in the above embodiment. The storage medium can be implemented 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 storage, a flash memory, a magnetic disk or an optical disk.

[0097] To sum up, the present application has the following advantages: by depositing nanoscale catalytic clusters on the surface of graphene in situ, a selective adsorption layer with a specific adsorption potential well depth is constructed, and the adsorption capacity of target gas molecules is effectively enhanced; by constructing an oriented dipole molecular monolayer on the surface of the substrate and transferring the monolayer graphene, a sensing structure with a stable interface electric field is generated, the working stability of the sensor is improved, and the repeatability and reliability of long-term operation are improved; by synchronously collecting temperature and humidity data, introducing temperature and humidity disturbance correction, the adaptability to complex environments is improved.

[0098] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A graphene-based gas detection method, characterized in that: include, An oriented dipole molecular monolayer was constructed on the substrate surface as a polarization interface, and a monolayer of graphene was transferred on the polarization interface to generate a sensing structure with a stable interfacial electric field. Among them, the oriented dipole molecular monolayer is an undecyl phosphate molecular monolayer; Nanoscale catalytic clusters are deposited in situ on the surface of monolayer graphene to generate a sensing structure with a selective adsorption layer. A low-frequency stepped wave bias was applied to the sensing structure in a zero-gas environment, the resistance time series of graphene was collected, and a spectral reference feature corresponding to the target gas concentration was established. A low-frequency stepped wave bias is applied to the sensing structure under the test environment to obtain the spectral characteristics of the target gas response, and the main peak frequency and amplitude of the spectral characteristics are corrected according to the synchronously measured temperature and humidity data. Based on the corrected spectral characteristics, the target gas concentration is obtained by inversion calculation according to the spectral reference characteristics corresponding to the target gas concentration.

2. The graphene-based gas detection method as described in claim 1, characterized in that: The specific steps for constructing an oriented dipole molecular monolayer as a polarization interface on the substrate surface are as follows: The substrate surface was cleaned and dried, and then placed in the self-assembly reaction solution. A monolayer of oriented dipole molecules with uniform arrangement on the substrate surface is obtained by self-assembling oriented dipole molecules in a self-assembly reaction solution on the substrate surface. The oriented dipole molecular monolayer and the substrate are heat-treated together, and the heat-treated oriented dipole molecular monolayer is used as the polarization interface. Among them, the self-assembly reaction solution refers to a solution of undecyl phosphate molecules using anhydrous ethanol as a solvent; Heat treatment refers to heating the oriented dipole molecular monolayer and the substrate to a target temperature and holding it at that temperature.

3. The graphene-based gas detection method as described in claim 2, characterized in that: The specific steps for transferring monolayer graphene on the polarization interface to generate a sensing structure with a stable interfacial electric field are as follows: The substrate surface, which serves as the polarization interface of the oriented dipole molecular monolayer, is placed on a monolayer graphene transfer station. At the single-layer graphene transfer station, a polymethyl methacrylate film support layer is used to support the single-layer graphene. A monolayer of graphene with a polymethyl methacrylate film support layer is coated on the substrate surface of the polarization interface, so that the monolayer of graphene is in direct contact with the oriented dipole molecule monolayer. The surface of the polarized interface substrate covered with monolayer graphene is subjected to solvent immersion treatment to remove the polymethyl methacrylate film support layer on the monolayer graphene, and the surface of the polarized interface substrate covered with monolayer graphene is subjected to heat treatment to generate a sensing structure with a stable interface electric field. The solvent used in the solvent immersion treatment is acetone solution.

4. The graphene-based gas detection method as described in claim 3, characterized in that: The specific steps for in-situ deposition of nanoscale catalytic clusters on the surface of a single-layer graphene to generate a sensing structure with a selective adsorption layer are as follows: The sensing structure with a stable interfacial electric field is fixed on the sample stage of the in-situ deposition site. Precursor gas is introduced into the in-situ deposition site, and the surface of the single-layer graphene of the sensing structure is brought into full contact with the precursor gas. Plasma is applied to the surface of monolayer graphene to decompose the precursor gas in situ on the surface of monolayer graphene, generating nanoscale catalytic clusters. By controlling the average particle size of the nanoscale catalytic clusters generated during the in-situ deposition process, a sensing structure with a stable interfacial electric field containing nanoscale catalytic clusters can be obtained. A selective adsorption layer with a specific adsorption potential well depth for the target gas is generated by thermally treating a sensing structure with a stable interfacial electric field containing nanoscale catalytic clusters. Among them, the precursor gas refers to platinum tetrachloride vapor; The method of controlling nanoscale catalytic clusters is to regulate the nucleation and growth process of nanoscale catalytic clusters by adjusting the plasma treatment time, adjusting the partial pressure of the precursor gas, and using short-time plasma pulse intermittents, so as to stabilize the average particle size at the nanoscale.

5. The graphene-based gas detection method as described in claim 4, characterized in that: The specific steps for applying a low-frequency stepped wave bias to the sensing structure in a zero-air environment are as follows: The sensing structure with a selective adsorption layer is placed in a zero-gas environment and the target gas is introduced. Connect the sensor structure electrode, which is in a zero-air environment, to a low-frequency stepped wave bias generator. Set the parameters of the low-frequency stepped wave bias generator to apply a low-frequency stepped wave bias to the electrodes of the sensing structure.

6. The graphene-based gas detection method as described in claim 5, characterized in that: The specific steps for collecting the resistance time series of graphene and establishing spectral reference features corresponding to the target gas concentration are as follows: When a low-frequency stepped wave bias is applied, the electrodes of the sensing structure are connected to a high-precision resistance measuring instrument. In a zero-gas environment, continuous resistance data is collected from the sensing structure to obtain the resistance time series of the target gas in a zero-gas environment. The resistance time series was subjected to short-time Fourier transform to obtain the spectral data of the target gas concentration in a zero-gas environment; Extract the peak frequency and peak amplitude of the spectral features corresponding to the target gas concentration from the spectral data to obtain the spectral feature parameters corresponding to the target gas concentration; The spectral characteristic parameters corresponding to the target gas concentration are used as spectral reference features to establish spectral reference features corresponding to the target gas concentration.

7. The graphene-based gas detection method as described in claim 6, characterized in that: The steps involve applying a low-frequency stepped wave bias to the sensing structure under the test environment to obtain the spectral characteristics of the target gas response, and correcting the main peak frequency and amplitude of the spectral characteristics based on simultaneously measured temperature and humidity data. The sensing structure is placed in the environment to be tested, and a low-frequency stepped wave bias with the same settings as in the zero gas environment is applied to the sensing structure. The resistance of the sensing structure is collected to obtain the resistance time series of the target gas response. Temperature and humidity data are collected simultaneously while the resistance of the sensing structure is being acquired. The resistance time series of the target gas response is subjected to short-time Fourier transform to obtain the spectral characteristics of the target gas response. The main peak frequency and main peak amplitude of the target gas response spectrum characteristics are corrected using the collected temperature and humidity data.

8. The graphene-based gas detection method as described in claim 7, characterized in that: The acquisition of the target gas concentration refers to the inversion calculation of the position and amplitude of the main peak of the corrected spectral features based on the stored spectral reference features using a multivariate nonlinear empirical inversion formula, thereby obtaining the target gas concentration.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the graphene-based gas detection method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the graphene-based gas detection method according to any one of claims 1 to 8.

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