阅读说明：本技术 二维钛化碳在生成大气压均匀介质阻挡放电中的应用 (Application of two-dimensional titanized carbon in generating atmospheric pressure uniform dielectric barrier discharge ) 是由 王任衡 崔伟胜 钱正芳 林俏露 孙一翎 范姝婷 于 2021-01-14 设计创作，主要内容包括：本发明公开了一种二维材料Ti-3C-2T-x在大气压空气条件下生成均匀介质阻挡放电中的应用。基于Ti-3C-2T-x在生成均匀介质阻挡放电中的应用还公开了一种介质阻挡放电装置和方法。所述介质阻挡放电装置内表面设置有Ti-3C-2T-x。Ti-3C-2T-x表面存在Ti空位并分布有官能团,可以形成弱电子束缚态。弱电子束缚态的存在可以增大种子电子密度,从而在低频电源的条件下提升大气压空气介质阻挡放电的均匀性。(The invention discloses a two-dimensional material Ti 3 C 2 T x The application in generating uniform dielectric barrier discharge under the atmospheric pressure air condition. Based on Ti 3 C 2 T x The application in generating uniform dielectric barrier discharge also discloses a dielectric barrier discharge device and a method. The inner surface of the dielectric barrier discharge device is provided with Ti 3 C 2 T x 。Ti 3 C 2 T x Ti vacancies exist on the surface and are distributed with functional groups, so that a weak electron bound state can be formed. The existence of weak electron bound state can increase the electron density of the seed, thereby improving the uniformity of the barrier discharge of the atmospheric air dielectric under the condition of a low-frequency power supply.)

1. Two-dimensional material Ti₃C₂T_xThe application in generating uniform dielectric barrier discharge under the atmospheric pressure air condition; wherein, the Ti₃C₂T_xHas Ti vacancies and functional groups.

2. Use according to claim 1, characterized in that: the Ti₃C₂T_xIn atmospheric pressure air dielectric barrier discharge for increasing seed electron density.

3. Use according to claim 1 or 2, characterized in that: the Ti₃C₂T_xT in (1) is at least one of-OH, O and-F, and x is 0-2.

4. Use according to claim 3, characterized in that: the Ti₃C₂T_xThe material is prepared by HF solution to MAX phase Ti₃Al₂C₂And etching to form the mask.

5. Use according to any one of claims 1, 2, 4, characterized in that: the discharge power supply that produces the uniform dielectric barrier discharge is a <50kHz low frequency power supply.

6. Use according to any one of claims 1, 2, 4, characterized in that: the Ti₃C₂T_xIs arranged on the inner surface of the insulating medium of the discharge device.

7. A dielectric barrier discharge device comprises a ground electrode, a high-voltage electrode and an insulating dielectric layer arranged between the ground electrode and the high-voltage electrode in a stacked mode, a discharge space is formed by wrapping the insulating dielectric layer, and Ti is arranged on the surface of the insulating dielectric layer of the discharge space₃C₂T_xLayer of the Ti₃C₂T_xTi vacancies and functional groups are present.

8. The dielectric barrier discharge device according to claim 7, wherein: the ground electrodes comprise a first ground electrode and a second ground electrode, and the first ground electrode and the second ground electrode are oppositely arranged;

the insulating medium layer is arranged between the first ground electrode and the second ground electrode in a stacked mode;

the high-voltage electrode is arranged in the insulating medium layer and penetrates through the discharge space; and an insulating medium coating layer is also coated on at least the outer surface of the high-voltage electrode.

9. A method for generating a uniform dielectric barrier discharge comprises the following steps:

providing a dielectric barrier discharge device according to claim 7 or 8;

connecting a high-voltage electrode of the dielectric barrier discharge device with a high-voltage end of a discharge power supply, grounding a ground electrode of the dielectric barrier discharge device, and setting the frequency of output voltage;

and starting a discharge power supply by taking air as working gas under atmospheric pressure, and increasing the voltage between electrodes until uniform dielectric barrier discharge is generated in the discharge space.

10. The method of claim 9, wherein: a low frequency power supply with a pulse frequency of <50kHz for the discharge power supply.

Technical Field

The invention relates to an atmospheric pressure low-temperature plasma generation technology, in particular to a two-dimensional material Ti₃C₂T_xIn the generation of uniform dielectric barrier dischargeTo a discharge device and to a method of generating a uniform dielectric barrier discharge.

Background

The atmospheric pressure low-temperature plasma macroscopically represents room temperature, contains various high-energy active particles, and can be effectively applied to material surface treatment, nano material synthesis, biomedical application and the like. Dielectric Barrier Discharge (DBD) is a low-temperature plasma generation method with great industrial application prospects due to its characteristics of simplicity, effectiveness, and scalability. However, since air contains electronegative oxygen molecules, it can reduce the content of metastable nitrogen molecules, and adsorb free electrons, resulting in a decrease in the electron density of the discharge space seed. Generally, the DBD discharge in the atmospheric air condition is expressed as a filament discharge mode, which affects the treatment effect and even affects the treated object.

To improve the uniformity of the plasma, DBDs are mostly operated at low pressure or relying on a rare gas. This entails some limitations such as high economic cost and the necessity of the treatment object to be applicable to a vacuum environment. Many studies have been conducted in order to obtain a uniform DBD under atmospheric pressure air conditions. It was found that the discharge characteristics of the atmospheric pressure DBD mainly depend on the development of electron avalanches, which is determined by its time scale and spatial scale. In recent years, the use of nanosecond pulse power supply can control the occurrence time of electron avalanche, and thus, dispersion discharge with better uniformity is realized. However, nanosecond pulsed power supplies are expensive and power limited, which affects their industrial applications. In addition, due to capacitive load and nanosecond level voltage rise time, the discharge characteristics of the nanosecond pulse power supply are easily affected by specific electrode structures, and are not suitable for high-power industrial application.

Low frequency power supplies (e.g., less than 50kHz) are a possible choice for large-scale applications of atmospheric air DBDs. However, the voltage pulse of the low-frequency power supply cannot suppress excessive development of electron avalanche on a time scale, and the discharge easily converts into a filament-like discharge. The mean free path of collision between electrons and gas molecules in air is only 68 nm, and most atmospheric air DBDs exhibit an obvious filament-like discharge form.

It has been found that the formation of the non-uniform electric field distribution is advantageous to adjust the uniformity of the DBD. In addition, under low frequency power conditions, increasing the seed electron density has been shown to greatly improve the atmospheric air DBD uniformity. The "shallow well" of the dielectric surface plays a key role in the generation of an atmospheric air uniform DBD. On the basis of this result, Luo uses a special alumina ceramic to provide seed electrons, achieving a weaker uniform Thomson discharge under air conditions. However, shallow traps on the surface of dielectric barrier materials (e.g., ceramic, Polytetrafluoroethylene (PTFE), quartz) may degrade and be affected by other factors during discharge, failing to maintain a stable uniform discharge for industrial applications.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned disadvantages of the prior art and providing a Ti under low frequency power supply condition₃C₂T_xApplication in generating uniform DBD (direct double-diffused metal) of atmospheric air and based on Ti₃C₂T_xThe uniform DBD generation device and method solve the technical problem that the uniform DBD is relatively difficult to realize in the existing atmospheric air.

In order to achieve the above object, one aspect of the present invention provides a two-dimensional material Ti₃C₂T_xThe application in generating uniform dielectric barrier discharge under the atmospheric pressure air condition; wherein, the Ti₃C₂T_xHas Ti vacancies and functional groups.

In another aspect, a dielectric barrier discharge device is provided. The dielectric barrier discharge device comprises a ground electrode, a high-voltage electrode and an insulating dielectric layer arranged between the ground electrode and the high-voltage electrode in a laminated manner, a discharge space is formed by wrapping the insulating dielectric layer, and Ti is further arranged on the surface of the insulating dielectric layer of the discharge space₃C₂T_xLayer of the Ti₃C₂T_xTi vacancies and functional groups are present on the surface.

In yet another aspect of the present invention, a method for generating a uniform dielectric barrier discharge is provided. The generation method of the uniform dielectric barrier discharge comprises the following steps:

providing a dielectric barrier discharge device of the present invention;

connecting a high-voltage electrode of the dielectric barrier discharge device with a high-voltage end of a discharge power supply, grounding a ground electrode of the dielectric barrier discharge device, and setting the frequency of output voltage;

and starting a discharge power supply by taking air as working gas under atmospheric pressure, and increasing the voltage between electrodes until uniform dielectric barrier discharge is generated in the discharge space.

Compared with the prior art, the Ti of the invention₃C₂T_xThe method is used for increasing the electron density of the seeds when uniform dielectric barrier discharge is generated in atmospheric air, so that the discharge uniformity is improved. In addition, the inventors found, through their studies, that Ti₃C₂T_xThe discharge voltage can be reduced when the uniform dielectric barrier discharge is generated in atmospheric pressure air. The method overcomes the defect that the existing filament discharge under the atmospheric pressure air dielectric barrier discharge influences the processed object, and has important application value in the aspect of industrial application.

The invention relates to a dielectric barrier discharge device and a method for generating uniform dielectric barrier discharge, because Ti is arranged in a discharge space of the dielectric barrier discharge device₃C₂T_xTherefore, the dielectric barrier discharge device and the uniform dielectric barrier discharge generation method can generate atmospheric pressure air uniform dielectric barrier discharge under the condition of low-frequency power supply.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a DBD device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the electric field distribution and the electron avalanche development of the DBD device(ii) a Wherein FIG. 2(a) is Ti-free₃C₂T_xAn electric field distribution condition and an electron avalanche development diagram of the layered DBD device; FIG. 2(b) is a schematic view of a structure provided with Ti₃C₂T_xAn electric field distribution condition and an electron avalanche development diagram of the DBD device of the embodiment of the present invention of the layer;

fig. 3 is a discharge phenomenon diagram of the DBD device during a discharge process; wherein FIG. 3(a) is Ti-free₃C₂T_xA discharge phenomenon pattern of the DBD device of the layer during a discharge process; FIG. 3(b) is a schematic view of a film formed with Ti₃C₂T_xA discharge phenomenon diagram of the DBD device of the embodiment of the present invention in a discharge process;

fig. 4 is a voltage-current waveform diagram of a DBD device during a discharge process; wherein FIG. 4(a) is Ti-free₃C₂T_xA voltage-current waveform diagram of the DBD device of the layer during discharge; FIG. 4(b) is a schematic view of a film formed with Ti₃C₂T_xA voltage-current waveform diagram of a DBD device of an embodiment of the present invention during a discharge process;

FIG. 5 is Ti₃C₂T_xXPS profile of (a);

FIG. 6 is Ti₃C₂T_xTi having vacancies and functional groups on the surface₃C₂T_xElectron density of state distribution;

FIG. 7 is Ti having vacancies and functional groups on the surface₃C₂T_xAnd the bound electrons in the medium and weak electron bound state are released under the action of external ions.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In one aspect, embodiments of the present invention provide Ti₃C₂T_xThe method is applied to uniform dielectric barrier discharge (hereinafter, the dielectric barrier discharge is also referred to as DBD), in particular to the application of generating atmospheric pressure air uniform DBD under the condition of low-frequency power supply.

The inventor finds that Ti₃C₂T_xThe method is applied to the DBD, and is beneficial to generating uniform DBD of atmospheric air, thereby effectively overcoming the phenomenon that the existing atmospheric air DBD generally has filiform discharge. Meanwhile, the rare gas and the low-pressure environment are not needed any more, so that the defects of higher cost and limitation of industrial application are avoided. The atmospheric-pressure air uniform DBD described in the embodiments of the present invention is represented by atmospheric-pressure air uniform dielectric barrier discharge.

In addition, the inventors have further studied and found that Ti₃C₂T_xWhen the method is applied to the DBD, the electron density of the seeds can be effectively increased, the discharge voltage is reduced, and the uniformity of the DBD under the condition of a low-frequency power supply can be improved. As is experimentally found, in the examples, the DBD device shown in FIG. 1 was used for discharging (i.e., containing Ti)₃C₂T_xDielectric barrier discharge device) at a discharge voltage of 5.2kV, when the discharge voltage rises to 5.8kV, the diffuse discharge filled the entire discharge space, and the discharge current waveform did not have any filiform current spike, as shown in fig. 3(b) and fig. 4 (b). Without Ti₃C₂T_xWhen the DBD device shown in FIG. 1 was used, the discharge was started at a discharge voltage of 5.5kV, and when the discharge voltage was increased to 7kV, a sharp filiform current peak was observed in the voltage-current waveform at the discharge voltage,that is, the wire discharge phenomenon still occurs, as shown in fig. 3(a) and 4 (a). That is, in Ti₃C₂T_xEnabling uniform discharge at a relatively low voltage.

Further measured, Ti₃C₂T_xWhen the method is applied to the DBD for uniform DBD, the pulse frequency can be set to be<A low frequency power supply of 50kHz performs a uniform DBD.

Next, the above-mentioned Ti₃C₂T_xIn each of the examples of application, Ti₃C₂T_xIs arranged on the discharge side of the dielectric barrier discharge of the electrodes, in particular in the discharge space 5 of the DBD device as shown in fig. 1 hereinafter. Ti₃C₂T_xHas Ti vacancies and functional groups. In the examples, Ti having Ti vacancies and functional groups on the surface₃C₂T_xWherein T is at least one of-F, O and-OH, and x has a value range of 0-2.

In the specific examples, Ti₃C₂T_xThe MAX phase Ti can be treated by HF solution₃Al₂C₂And etching to form the mask. Etching with HF solution can be performed on Ti₃C₂T_xThe surface generates abundant Ti vacancies and functional groups, and the Ti vacancies and the functional groups can form a weak electron bound state, thereby achieving the effect of increasing the electron density of the seeds.

Further, based on Ti described above₃C₂T_xApplication to the generation of uniform DBDs in atmospheric air. The method has the advantages that the method has the advices on the application of other two-dimensional nano materials in generating uniform DBD in atmospheric pressure air, for example, the two-dimensional nano materials comprise more than twenty kinds of simple substances, inorganic compounds, metal compounds, salts, organic frameworks and the like, and hundreds of two-dimensional nano materials with different characteristics can be further obtained through surface modification, doping and the like. These two-dimensional nanomaterials may have a similar "weak electron beam binding state" that may have a great influence on the discharge characteristics of the DBD. The mechanism can be further expanded to more nano materials such as zero-dimensional nano dots, one-dimensional nano wires (rods) and the like.

On the other hand, based on T abovei₃C₂T_xThe embodiment of the invention also provides a DBD device. The DBD device comprises a ground electrode, a high-voltage electrode and an insulating medium layer arranged between the ground electrode and the high-voltage electrode in a laminated manner, a discharge space is formed by wrapping the insulating medium layer, and Ti is further arranged in the discharge space₃C₂T_xLayer of and Ti₃C₂T_xTi vacancies and functional groups are present on the surface.

The ground electrode, the high-voltage electrode and the insulating medium layer may be arranged according to the ground electrode, the high-voltage electrode and the insulating medium layer included in the conventional DBD device₃C₂T_xAnd (3) a layer. The Ti₃C₂T_xThe layer is arranged on an inner wall of the discharge space, such as on an inner wall of an insulating dielectric layer present in the discharge space.

In a preferred embodiment, a DBD device according to an embodiment of the present invention is configured as shown in fig. 1, and ground electrodes included in the DBD device include a first ground electrode 1 and a second ground electrode 2, and the first ground electrode 1 and the second ground electrode 2 are disposed opposite to each other.

The included insulating medium layer 3 is arranged between the first ground electrode 1 and the second ground electrode 2 in a laminated manner, and a discharge space 4 is formed in the insulating medium layer 3, namely the insulating medium layer 3 wraps the discharge space 4; ti is also provided in the discharge space 4₃C₂T_xA layer 5; in the specific examples, Ti₃C₂T_xThe layer 5 is arranged on the inner wall of the discharge space 4.

The contained high-voltage electrode 6 is arranged in the insulating medium layer 3 and penetrates through the discharge space 4; and an insulating medium coating layer 7 is coated on at least the outer surface of the high-voltage electrode 6 penetrating the discharge space 4.

The ground electrodes, such as the first ground electrode 1 and the second ground electrode 2, may be conventional metal electrodes, such as two copper sheets arranged oppositely, and the specific size may be 20 × 30 × 0.2mm, and the opposite arrangement may be specifically attached to two opposite outer surfaces of the insulating medium layer 3.

The insulating dielectric layer 3 is arranged between the first ground electrode 1 and the second ground electrode 2 as shown in fig. 1 to function as an insulating dielectric barrier. In an embodiment, the insulating medium layer 3 shown in fig. 1 is formed by splicing and stacking a first insulating medium layer 31 and a second insulating medium layer 32, a groove 41 is formed in an edge region of the first insulating medium layer 31 away from the first ground electrode 1, a groove 42 is formed in an edge region of the second insulating medium layer 32 away from the second ground electrode 2, and the groove 41 and the groove 42 enclose to form the discharge space 4. The first insulating medium layer 31 and the second insulating medium layer 32 may be separated to facilitate the separation of Ti₃C₂T_xThe layer 5 is placed in the discharge space 4 or removed from the discharge space 4. In a particular embodiment, the insulating dielectric layer 3 may be a conventional dielectric barrier material, such as, but not limited to, PTFE.

In an embodiment, the discharge space 4 may be a cylindrical cavity, such as a cylinder with a height of 20mm and a diameter of 3 mm. At this time, the grooves 41 and 42 are respectively cylindrical grooves with a semicircular cross section, a depth of 20mm and a diameter of 3 mm. The discharge space 4 may be directly connected to the atmosphere, or may be connected to the atmosphere by a pipe or the like.

Ti₃C₂T_xA layer 5 of Ti arranged on the inner wall surface of the discharge space 4₃C₂T_xThe electron density of the seeds in the discharge space can be effectively increased, and uniform DBD can be generated under the atmospheric pressure air condition. In the examples, Ti₃C₂T_xThe layer 5 may be Ti₃C₂T_xPressing the formed film. In the specific examples, Ti₃C₂T_xThe thin film is attached to the inner wall of the upper or lower part of the discharge space 4. In the specific examples, Ti₃C₂T_xThe thickness of the film may be equal to 0.2mm or less.

The high voltage electrode 6 shown in fig. 1 is arranged through the discharge space 4 and in the insulating dielectric layer 3. In the embodiment, when the insulating medium layer 3 is formed by splicing and stacking the first insulating medium layer 31 and the second insulating medium layer 32 as described above, the high-voltage electrode 6 is disposed at the interface where the first insulating medium layer 31 and the second insulating medium layer 32 are spliced and stacked. In the embodiment, the high-voltage electrode 6 is wrapped by the insulating medium coating 7, and the insulating medium coating 7 has the same function as the insulating medium layer 3 and plays an insulating role. The material may be a conventional dielectric barrier material, such as but not limited to PTFE, having a thickness of 0.1mm or less. The high voltage electrode may comprise three of the aforementioned insulated coated conductors, preferably with the high voltage electrode 6 being arranged parallel to the first and second ground electrodes 1, 2.

Of course, the DBD device according to an embodiment of the present invention further includes other components necessary and supplementary to the DBD device, such as a discharge power supply (not shown in fig. 1) for supplying a high voltage to the high voltage electrode 6, and in an embodiment of the present invention, the discharge power supply is a low frequency power supply.

Ti is provided in the discharge space 4 of the DBD device₃C₂T_xLayer 5. The DBD device can generate uniform DBD of atmospheric pressure air under a low-frequency power supply, and can improve the application value of low-temperature plasma in the industrial aspect.

In another aspect, an embodiment of the present invention further provides a method for generating a uniform DBD under a low-frequency power condition. The method of uniform DBD generation includes the steps of:

s01: providing a DBD device;

s02: connecting a high-voltage electrode of the DBD device with a high-voltage end of a discharge power supply, grounding a ground electrode of the DBD device, and setting the frequency of output voltage;

s03: starting a discharge power supply with air as a working gas at atmospheric pressure, and increasing an inter-electrode voltage until a uniform DBD is generated in the discharge space.

In step S01, the DBD device is the DBD device according to the embodiment of the present invention, as described above, and specifically, is the DBD device shown in fig. 1. For the sake of saving the description space of the present application, the DBD device in step S01 will not be described herein.

In step S02, the high voltage electrode, specifically, the high voltage electrode 6 of the DBD device shown in fig. 1, is electrically connected to the high voltage end of the discharge power supply, and the ground electrode is connected to the ground end.

In step S03, since the discharge space can be directly connected to the atmosphere, there is no need to set the air parameter during the discharge voltage.

The above-described method of uniform DBD generation can generate a uniform DBD under a low frequency power and atmospheric air.

The Ti will be further explained by taking the above method of uniform DBD generation as an example in the above DBD device (shown in FIG. 1)₃C₂T_xApplication in generating an atmospheric air homogeneous DBD.

A DBD device:

the structure is shown in fig. 1, the first ground electrode 1 and the second ground electrode 2 are uniform copper sheets, and the sizes of the uniform copper sheets are 20 multiplied by 30 multiplied by 0.2 mm.

The insulating medium layer 3 is formed by splicing and overlapping an upper first insulating medium layer 31 and a lower second insulating medium layer 32 which are the same, and the insulating medium layer 3 is made of PTFE and has the size of 20 multiplied by 30 multiplied by 3 mm.

The discharge space 4 is a cylindrical discharge cavity with a length of 20mm and a diameter of 3mm, and is formed by enclosing semi-cylindrical grooves formed in the first insulating medium layer 31 and the second insulating medium layer 32.

Ti₃C₂T_xA layer 5 of Ti is arranged at the bottom of the discharge space 4₃C₂T_xLayer 5 is Ti₃C₂T_xA film formed by pressing and adhered on the inner wall of the discharge space 4.

The high-voltage electrode 6 is composed of 3 copper wires which are arranged side by side and have the diameter of 0.25mm, and is arranged at the joint and overlapped interface of the first insulating medium layer 31 and the second insulating medium layer 32, and the insulating medium coating layer 7 coated on the surface is a PTFE coating layer with the thickness of 0.1 mm.

A discharge power supply: CTP-2000K produced by Nanjing Suman company is adopted, the output voltage is sine alternating current, and the frequency is 5-20 kHz.

The discharge voltage was measured by a built-in capacitive voltage divider of VD305A manufactured by Pearson.

The discharge current is measured by a built-in 50 Ω non-inductive resistor in series with the discharge system.

The discharge voltage and current were displayed and stored using a tek oscilloscope TBS 1102B.

The discharge experiment adopts air as working gas, and the ambient pressure, temperature and humidity are respectively 1.02 multiplied by 10 during discharge⁵Pa, 20 ℃ and 90%.

2. With respect to Ti₃C₂T_xTi of layer 5₃C₂T_xSurface defect and functional group analysis:

for two-dimensional nano material Ti₃C₂(Ti₃C₂T_x) XPS characterization was performed and the spectrum of XPS is shown in FIG. 5. From Ti of FIG. 5₃C₂T_xCan find the F1s, O1 s, Ti 2p and C1s orbital peaks in the broad spectrum. The presence of F1s at binding energies 686eV and 530eV, and O1 s indicates the presence of-F and-OH functional groups, respectively. Meanwhile, when the mass concentration of the HF acid exceeds 7%, Ti obtained by etching is obtained₃C₂T_xTi vacancies will form at the surface and the resulting Ti vacancy density is directly proportional to the HF acid concentration.

Further by DFT to Ti₃C₂Ti having vacancies and functional groups on the surface₃C₂T_xThe electron density of states distribution was calculated as shown in fig. 6. Pure Ti can be obtained by DFT calculation₃C₂The electron state density is not zero near the near fermi level, and thus metalloid conductivity can be exhibited. However, Ti vacancies and surface functional groups, when present, are Ti₃C₂The electron density of states of (a) is greatly changed. As shown in FIG. 6, pure Ti₃C₂The peak of the electron density of the surface C atoms at the fermi level occurs at-0.09 eV. When Ti is present₃C₂When Ti vacancies exist on the surface, the electron state density peak is shown at-0.3 eV below the Fermi level. Ti₃C₂When the functional groups are-F, -OH and-O, a peak in the density of electron states also appears at about-1 eV below the Fermi level.

As can be seen from FIGS. 5 to 6, Ti₃C₂T_xThe local defect state is represented as an n-type defect state, and the density peak value of the electronic state is within 1eV below the Fermi levelThe peak value of the electron state density can form a weak electron beam binding state, and can form a weak binding effect on free electrons. As shown in fig. 7. Ti₃C₂T_xThe weak electron beam binding state can form the effect similar to a shallow well on the surface of a bulk medium. The difference is that the shallow well number on the surface of the bulk medium is less, and Ti₃C₂T_xHas extremely high specific surface area, so that the weak electron bound state far exceeds the shallow trap on the surface of bulk medium in quantity. From the above analysis, it can be concluded that Ti₃C₂T_xDue to the two-dimensional nano-structure characteristics, the state density distribution similar to a shallow bit well can be formed, the electron density of the seeds is greatly increased, and the DBD uniformity of atmospheric air is further improved.

In addition, Ti₃C₂T_xThe release of the bound electrons in the weak electron beam bound state by external ions is schematically shown in fig. 7.

DBD experimental results and analysis:

in the discharge space 4 of the above DBD device, Ti is not placed₃C₂T_xLayer 5 was used as a comparative experiment.

3.1 about Ti₃C₂T_xInfluence of layer 5 on the electric field distribution in the uniform discharge:

the voltage of 7.0kV is set between the electrodes, and the electric field distribution parameters of the electrode structure are simulated by using ANSYS Maxwell 3D software, and the result is shown in FIG. 2. As can be seen from fig. 2(a) and 2(b), relatively uneven electric field distributions which are vertically symmetrical can be formed in the discharge space 4 of the DBD device, and the electric field intensity in the discharge space 4 and in the narrow gap regions on both sides of the high voltage electrode 6 is significantly larger than that in the middle region. According to the electron avalanche development path schematic diagram drawn by the electric field vector, the development path length of the electron avalanche (areas 1-4) in the two narrow areas is far shorter than that of the electron avalanche (areas 5-8) in the middle area. By comparison of FIG. 2, it is found that Ti₃C₂T_xThe presence of (a) has little effect on the distribution of the electric field parameters.

3.2 about Ti₃C₂T_xInfluence of layer 5 on discharge voltage and discharge phenomena:

ti-containing by the DBD device shown in FIG. 1₃C₂T_xLayer 5 and Ti-free₃C₂T_xThe discharge phenomenon of the discharge test of the layer 5 is shown in fig. 3. Ti is not provided in the discharge space 4₃C₂T_xIn the case of the layer 5, the small areas in the discharge space 4 and on both sides of the high voltage electrode 6 are first discharged at 5.5kV, and when the applied voltage reaches 7kV, DBD discharges visible to the naked eye are formed on both upper and lower sides of the discharge space, as shown in fig. 3 (a). When Ti is arranged at the bottom of the electrode₃C₂T_xLayer 5, the discharge phenomena are clearly distinguished: when the applied voltage reaches 5.2kV, the electrode starts to discharge, and when the voltage reaches 5.8kV, the upper side and the lower side inside the electrode form macroscopic dispersion discharge, as shown in fig. 3 (b).

3.3 about Ti₃C₂T_xEffect of layer 5 on current waveform in uniform discharge:

ti-containing by the DBD device shown in FIG. 1₃C₂T_xLayer 5 and Ti-free₃C₂T_xIn the discharge experiment of the layer 5, the discharge voltage current waveform when the DBD device is completely discharged in both cases is shown in fig. 4. As can be seen from fig. 4(a), when the DBD discharge phenomenon visible to the naked eye occurs, a few filiform current spikes still occur in the actual discharge current. When Ti is provided in the DBD device₃C₂T_xAfter layer 5, the filamentary current spikes in the voltage positive half cycle current waveform completely disappeared as shown in fig. 4 (b).

As is clear from the discharge phenomenon and the voltage-current waveform, when the DBD device generates a macroscopic atmospheric pressure DBD discharge, a pulse current having a pulse width of 1 to 2 μ s still appears in an actual discharge current waveform. Ti is arranged in the discharge space 4 without affecting the parameters of the electric field₃C₂T_xThe DBD device discharge voltage is significantly reduced after layer 5 and the pulse current in the current waveform almost completely disappears.

Through experiments, Ti₃C₂T_xA large influence is exerted on the discharge characteristics of the atmospheric air DBD. Under low frequency power supply, Ti₃C₂T_xBy passingThe electron density of the seeds is increased, so that the development of filiform discharge is effectively inhibited, and the uniformity of the atmospheric air DBD is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.