Method for desorbing gas from two-dimensional crystals and applications thereof

Abstract

This invention belongs to the field of gas storage technology and relates to a method for desorbing gas from a two-dimensional crystal, comprising: 1) selecting a two-dimensional crystal material adsorbing the gas to be desorbed; 2) placing the two-dimensional crystal material from step 1) in a gas desorption chamber; 3) processing the two-dimensional crystal material from step 1); the processing method is heating treatment, light radiation treatment, plasma treatment, and / or treatment by an external electric field; 4) under the action of the processing method in step 3), reducing the interaction force between the adsorbed gas adsorbed on the two-dimensional crystal material and the two-dimensional crystal, thereby completing the desorption of the adsorbed gas from the two-dimensional crystal. This invention provides a method and application for adsorbing gas from a two-dimensional crystal that is easy to operate, has strong adsorption stability, and is easy to control.

Description

Technical Field

[0001] This invention belongs to the field of gas storage technology and relates to a method and application for desorbing gases from two-dimensional crystals. This invention is a divisional application of application number 2023105534184, entitled "Method and Application of Gas Adsorption on Two-Dimensional Crystals". Background Technology

[0002] Adsorption processes at solid-gas interfaces have long been a focus of scientific attention. These processes form the basis of many important phenomena and applications, such as gas capture and conversion, gas storage and separation, surface catalysis based on gas adsorption, material growth processes following source gas adsorption, and changes in the physical and chemical properties of adsorbents caused by adsorbed gases. Therefore, researching and exploring the adsorption behavior at solid-gas interfaces is of great significance in related fields.

[0003] Generally speaking, solid-gas interface adsorption processes can be divided into two types based on whether chemical bonds are formed between gas molecules and solid surface atoms: chemisorption and physisorption. In chemisorption gas-solid systems, the interaction energy between gas molecules and solid atoms is very high, even reaching hundreds of kJ / mol. Due to the formation of chemical bonds, the system exhibits strong stability. However, the strong bond energies in chemisorption generally make this process irreversible, making it difficult to achieve repetitive gas capture and release, thus greatly limiting related applications. Conversely, physisorption, where gas molecules interact with the solid surface through van der Waals forces, hydrogen bonds, or electrostatic attraction, is considered reversible, with low regeneration energy consumption, and its interaction energy is typically below 30 kJ / mol. However, due to the weak charge transfer between the solid adsorbent and gas molecules, especially for molecules with stable closed-shell layers, such as common nonpolar gas molecules like hydrogen, Ar, carbon dioxide, nitrogen, helium, and methane, adsorption is difficult to occur. Currently, to achieve physical adsorption and storage of gases, low temperature and high pressure conditions are often required, and once removed from this environment, the adsorbed gas will spontaneously desorb. These phenomena have hindered experimental research on adsorption performance and industrial applications in gas storage. Therefore, how adsorbents can capture and preserve molecules under mild conditions (such as room temperature and atmospheric pressure) remains an open question.

[0004] Numerous attempts have been made to improve the adsorption capacity of physical adsorption. For example, adsorbents with high specific surface area and porosity, such as 2D materials like MOFs, COMs, and graphene, have been employed. However, the adsorption capacity of these materials has not been significantly enhanced, mainly because the process remains limited to low-temperature adsorption. To date, stable adsorption of gas molecules under normal conditions has not been experimentally achieved. Exploring and developing methods to achieve stable, high-density adsorption of gases at room temperature and pressure is of significant research importance.

[0005] It is also important to note that since solid-gas interface behavior is fundamental to many phenomena, studying the adsorption behavior of solid adsorbents on gas molecules has significant potential application value. For example, it holds promise for developing new technologies to achieve gas separation. Currently, gas separation technologies mainly include pressure swing adsorption (PSA), hydrate gas separation, cryogenic distillation, cryogenic gas separation, and membrane separation. Among these, the hydrate method requires low temperature and high pressure to form hydrates, resulting in low reaction selectivity and slow hydrate formation efficiency; cryogenic distillation requires stringent operating conditions, including high pressure and low temperature; cryogenic separation consumes a large amount of refrigeration energy during the separation process, leading to high investment costs and demanding reaction conditions; and membrane separation has poor processing capacity and high energy consumption for pressurization. Currently, the most mature separation method is pressure swing adsorption (PSA). The principle of PSA is based on the differences in the adsorption characteristics of gas components in solid materials and the characteristic that the adsorption amount changes with pressure. It utilizes periodic pressure changes to complete the corresponding gas separation and purification. The separation technology generally includes three stages: gas adsorption, gas desorption and regeneration, and pressurization. Gas adsorption involves the adsorption of gases by an adsorbent. Desorption and regeneration are the processes by which the adsorbent is regenerated, allowing it to continue its adsorption function. Pressurization, on the other hand, involves increasing the gas pressure after desorption and regeneration, which not only achieves gas separation and improves gas purity but also prepares the gas for the next adsorption and purification process. The gas adsorption process is fundamental, and traditional adsorption processes are based on the principle of concentration reactions. Therefore, utilizing different methods to achieve the adsorption of gases by solid adsorbents plays a crucial role in gas production and separation. It is essential to strengthen the research and application of related technologies to achieve continuous innovation and improvement, ultimately promoting the development of gas separation technology.

[0006] Using two-dimensional materials such as graphene as adsorbents in gas adsorption studies holds promise for simultaneously modifying the adsorbents. The enormous specific surface area of ​​two-dimensional materials like graphene makes them susceptible to the influence of surface-adsorbed impurity atoms during production and use, leading to significant changes in their intrinsic physical and chemical properties. For example, when each carbon atom adjacent to a hydrogen atom in graphene forms a stable covalent bond, graphene transforms into a two-dimensional alkane, and the highly conductive graphene becomes a novel graphane material with insulating properties. If the hydrogenation of graphene surface atoms is incomplete, partially hydrogenated graphene will exhibit ferromagnetism and show a band structure that is adjustable with the degree of hydrogenation. Besides covalent bonds, graphene can also be modified through non-covalent interactions such as π-π interactions, hydrogen bonds, and ionic bonds, achieving surface functionalization. Furthermore, doping and ion bombardment are also important methods for altering graphene properties. Doping can change the fundamental characteristics of semiconductors, effectively controlling optical, electrical, and magnetic properties, thereby promoting the realization of high-efficiency novel optoelectronic devices. For example, nitrogen-doped graphene prepared by CVD exhibits the characteristics of an n-type semiconductor. Ion bombardment, using ions with a certain initial energy to bombard graphene targets, leads to the generation of defects such as vacancies, atomic deficiencies, and atomic substitutions. The presence of defects greatly affects the electron mobility of graphene. For example, graphene bombarded with Ar+ can exhibit wrinkled structures with different amplitudes and periodicities, thus affecting its electronic properties. Crucially, graphene modification is an important means of realizing graphene applications. For instance, graphene's unique mechanical, thermal, optical, and electrical properties, as well as its excellent barrier properties, have great potential application value in the coating field. By combining graphene with organic resins, not only can the overall performance of the coating be greatly improved, but it can also endow the coating with special properties such as corrosion resistance, thermal conductivity, electrical conductivity, and flame retardancy. Developing novel methods to achieve the controllable and stable adsorption of gas molecules by two-dimensional materials such as graphene will lay a solid foundation for improving the intrinsic properties of two-dimensional materials such as graphene and for the subsequent development and application of modified two-dimensional materials.

[0007] Solid adsorbents (or catalysts) enable the adsorption and catalytic decomposition of gas molecules. This process forms the basis for the chemical vapor deposition (CVD) method in preparing graphene and other low-dimensional materials. Therefore, studying the adsorption behavior of solid adsorbents on gas molecules has significant potential value in the field of CVD growth. Taking the CVD preparation of graphene as an example, and using methane as the carbon source and copper as the growth substrate, the process is simple: during growth, methane needs to be adsorbed onto the copper metal surface and undergoes catalytic cracking under the catalytic action of the copper substrate, resulting in a dehydrogenation reaction and ultimately the growth of a graphene film on the copper substrate. Therefore, in the CVD material preparation process, in addition to traditional parameter control such as pressure, gas flow rate, atmosphere composition ratio, growth temperature, growth time, and temperature and cooling process regulation, developing novel methods to control the adsorption process of solid adsorbents on gases is an important means of achieving target material control. Summary of the Invention

[0008] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for adsorbing gases using two-dimensional crystals that is easy to operate, has strong adsorption stability, and is easy to control.

[0009] Another technical problem that this invention aims to solve is to provide a method for desorbing gases onto a two-dimensional crystal.

[0010] Another technical problem that this invention aims to solve is to provide a method for separating gases.

[0011] Another technical problem that this invention aims to solve is to provide a method for modifying two-dimensional crystals.

[0012] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A method for adsorbing gas using a two-dimensional crystal, the method comprising the following steps:

[0014] 1) Select a two-dimensional crystal material;

[0015] 2) Place the two-dimensional crystal material in the gas adsorption chamber;

[0016] 3) Introduce the gas to be adsorbed into the gas adsorption chamber;

[0017] 4) Injecting charges into the two-dimensional crystal material placed in the gas adsorption chamber causes the surface of the two-dimensional crystal material to discharge, forming an external electric field;

[0018] 5) The gas placed around the two-dimensional crystal material is polarized under the action of the external electric field in step 4), generating a dipole moment and attracting the two-dimensional crystal material to form a stable structure, thus completing the adsorption of gas by the two-dimensional crystal material.

[0019] Preferably, the two-dimensional crystal material used in this invention includes two-dimensional crystals, which are layered sheet materials or layered materials with cavity structures; the two-dimensional crystals are one or a combination of graphene, hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2 and WTe2.

[0020] Preferably, when the two-dimensional crystal used in this invention is a layered sheet material, the two-dimensional crystal is a single-layered material, a double-layered material, or a few-layered material that is bonded together by van der Waals forces; when the two-dimensional crystal is a layered sheet material, the two-dimensional crystal is one or a combination of graphene sheets, MoS2 sheets, MoSe2 sheets, MoTe2 sheets, NbS2 sheets, NbSe2 sheets, NbTe2 sheets, WS2 sheets, WSe2 sheets, and WTe2 sheets.

[0021] Preferably, when the two-dimensional crystal used in this invention is a layered material with a cavity structure, the two-dimensional crystal is a layered material with a cavity structure formed by rolling up a single layer, double layer or multiple layers of layered material; when the two-dimensional crystal is a layered material with a cavity structure, the two-dimensional crystal is one or a combination of single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene tubes, boron nitride nanotubes and carbon fibers.

[0022] Preferably, the two-dimensional crystal material used in this invention further includes a substrate; the two-dimensional crystal is placed on the substrate; the substrate is an insulating non-metallic material or a non-insulating metallic material; when the substrate is an insulating non-metallic material, the substrate is sapphire, silicon carbide and / or silicon oxide; when the substrate is a non-insulating metallic material, the substrate is copper, nickel and / or platinum.

[0023] Preferably, the gas adsorption chamber in step 2) of the present invention is capable of introducing various gases and adjusting and detecting relevant experimental parameters, such as adjusting and measuring gas pressure, and adding voltage, current and electric field. It can be a sealed quartz tube or a reaction vessel.

[0024] Preferably, in step 3) of this invention, the gas to be adsorbed is one or a combination of an energy gas, an inert gas, nitrogen, or oxygen; when the gas to be adsorbed is an energy gas, it is one or a combination of hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; when the gas to be adsorbed is an inert gas, it is Ar and / or helium. The pressure of the gas to be adsorbed is 0.1 Pa - 10 Pa. 5 Pa; the temperature inside the gas adsorption chamber is T, and the liquefaction temperature of the gas to be adsorbed is T1; T1 < T < 200℃.

[0025] Preferably, in step 4) of the present invention, the charge is injected into the two-dimensional crystal material placed in the gas adsorption chamber by means of electrostatic generator injection, plasma injection and / or high voltage injection by high voltage power supply, and the electric field strength of the external electric field is 75V / mm to 350V / mm.

[0026] An application of a gas adsorption method based on two-dimensional crystals as described above in gas separation, two-dimensional crystal modification, and graphene growth.

[0027] A gas separation method includes the following steps:

[0028] a1) Select a two-dimensional crystal material for gas adsorption;

[0029] a2) Place the two-dimensional crystal material into the gas adsorption chamber;

[0030] a3) Introduce the mixed gas to be separated into the gas adsorption chamber;

[0031] a4) Injecting charges into the two-dimensional crystal material placed in the gas adsorption chamber causes the surface of the two-dimensional crystal material to discharge, forming an external electric field;

[0032] a5) Adjust the intensity of the external electric field and the discharge time to selectively adsorb the mixed gas to be separated in step a3) and separate the target gas from the mixed gas to be separated.

[0033] Preferably, the target gas used in this invention is a gas adsorbed on a two-dimensional crystal material or the gas remaining after adsorption by the two-dimensional crystal material in the mixed gas to be separated.

[0034] Preferably, the gas separation method used in this invention further includes the following after step a5):

[0035] a6) Repeat step a5) until the target gas is purified from the mixed gas to be separated.

[0036] A method for modifying two-dimensional crystals includes the following steps:

[0037] S1) Select a two-dimensional crystal;

[0038] S2) Place the two-dimensional crystal into the gas adsorption chamber;

[0039] S3) Introduce gas into the gas adsorption chamber;

[0040] S4) Injecting charge into the two-dimensional crystal placed in the gas adsorption cavity causes the surface of the two-dimensional crystal to discharge, forming an external electric field;

[0041] S5) Under the action of an external electric field, the two-dimensional crystal adsorbs the gas in the gas adsorption chamber, thereby completing the modification of the two-dimensional crystal; preferably, the method for modifying the two-dimensional crystal provided by the present invention is to modify the physical and / or chemical properties of the two-dimensional crystal, especially the mechanical, thermal, optical and / or electrical properties.

[0042] This invention provides a method for adsorbing gases from two-dimensional crystals, and also a method for desorbing gases from two-dimensional crystals. This method utilizes light energy, thermal energy, and plasma techniques, and employs electron injection to activate the two-dimensional material, thereby catalytically decomposing the adsorbed gases on its surface and achieving desorption. This method can serve as an efficient and effective means of desorbing gases. Specifically, the method for desorbing gases from two-dimensional crystals provided by this invention includes the following steps:

[0043] 1) Select a two-dimensional crystal material that adsorbs the gas to be desorbed;

[0044] 2) Place the two-dimensional crystal material from step 1) into the gas desorption chamber;

[0045] 3) Process the two-dimensional crystal material in step 1); the processing method is heat treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field;

[0046] 4) Under the action of the treatment method in step 3), the interaction force between the adsorbed gas adsorbed on the two-dimensional crystal material and the two-dimensional crystal is reduced, and the adsorbed gas is desorbed from the two-dimensional crystal.

[0047] Preferably, the two-dimensional crystal material used in this invention includes two-dimensional crystals, which are layered sheet materials or layered materials with cavity structures; the two-dimensional crystals are one or a combination of graphene, hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2 and WTe2.

[0048] Preferably, when the two-dimensional crystal used in this invention is a layered sheet material, the two-dimensional crystal is a single-layered material, a double-layered material, or a few-layered material that is bonded together by van der Waals forces; when the two-dimensional crystal is a layered sheet material, the two-dimensional crystal is one or a combination of graphene sheets, MoS2 sheets, MoSe2 sheets, MoTe2 sheets, NbS2 sheets, NbSe2 sheets, NbTe2 sheets, WS2 sheets, WSe2 sheets, and WTe2 sheets.

[0049] Preferably, when the two-dimensional crystal used in this invention is a layered material with a cavity structure, the two-dimensional crystal is a layered material with a cavity structure formed by rolling up a single layer, double layer or multiple layers of layered material; when the two-dimensional crystal is a layered material with a cavity structure, the two-dimensional crystal is one or a combination of single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene tubes, boron nitride nanotubes and carbon fibers.

[0050] Preferably, the gas desorption chamber in step 2) of the present invention is a closed quartz tube or a reaction vessel.

[0051] Preferably, in step 3) of this invention, when the treatment method is heating, the heating temperature is 200℃~800℃, preferably 300℃~500℃. When the treatment method is light radiation treatment, the light is human illumination and / or laser illumination, and the wavelength range of the light used in the light radiation treatment is less than 1000nm; the temperature of the light radiation treatment is 200℃~800℃, preferably 300℃~500℃. When the treatment method is plasma treatment, the plasma treatment uses a plasma generator, the plasma generator is an inductively coupled plasma generator, the controllable power range of the plasma generator is preferably 200W-500W, the plasma generator pressure is preferably 0.1Pa-10Pa, the plasma generator reaction temperature is 20℃~800℃, preferably 100℃~500℃, and the plasma treatment time is preferably 10s-30min. When the treatment method is through an external electric field, the external electric field is an external electric field formed by charge injection or charge; when the external electric field is through charge injection, the charge injection method is through an electrostatic generator and / or through a high-voltage power supply; the charge injection time is 10s-10min; the preferred strength of the external electric field is 500V / mm to 1000V / mm.

[0052] Preferably, in step 4) of this invention, the adsorbed gas adsorbed on the two-dimensional crystal material is one or a combination of an energy gas, an inert gas, nitrogen, or oxygen; when the gas to be adsorbed is an energy gas, it is one or a combination of hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; when the gas to be adsorbed is an inert gas, it is Ar and / or helium.

[0053] Preferably, the method for desorbing gas from a two-dimensional crystal provided by the present invention further includes, after step 4), the following:

[0054] 5) Detect the desorbed gas to verify the type and amount of gas desorbed.

[0055] Preferably, the instrument used for detecting the desorbed gas in step 5) of the present invention is a thermogravimetric analyzer or a mass spectrometer.

[0056] The present invention also includes the application of a method for desorbing gases from two-dimensional crystals as described above in gas separation or two-dimensional crystal modification.

[0057] The present invention also includes a gas separation method, the gas separation method comprising the following steps:

[0058] b1) Select a two-dimensional crystal material that adsorbs the gas to be desorbed;

[0059] b2) Place the two-dimensional crystal material obtained in step b1) into the gas desorption chamber;

[0060] b3) Process the two-dimensional crystal material in step b1); the processing method is heat treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field.

[0061] b4) Adjust the processing parameters of step b3) to selectively release the gas adsorbed by the two-dimensional crystal material in step b3), thereby completing the desorption of the target gas from the two-dimensional crystal; the processing parameters include heating temperature, heating time, light intensity, light wavelength, plasma processing intensity, plasma processing time, electric field intensity and / or external electric field processing time.

[0062] Preferably, the gas separation method further includes, after b4):

[0063] b5) Detect the target gas obtained in step b4) to verify the gas type and the amount of gas desorbed.

[0064] Preferably, when the treatment in b3) is a heating treatment, the heating temperature is 200℃~500℃ and the heating time is 10min-60min; when the treatment in b3) is a light radiation treatment, the light is artificial light and / or laser light, the wavelength of the light used in the light radiation is less than 1000nm, the applicable temperature of the light radiation is 200℃~500℃, and the light radiation time is 10min-60min.

[0065] Preferably, when the treatment in b3) is plasma treatment, the plasma treatment uses a plasma generator, the plasma generator is an inductively coupled plasma generator, the controllable power range of the plasma generator is preferably 200W-500W, the plasma generator pressure is preferably 0.1Pa-10Pa, the plasma generator reaction temperature is 20℃~800℃, preferably 100℃~500℃, and the plasma treatment time is preferably 10s-30min.

[0066] Preferably, when the treatment in b3) is performed by an external electric field, the external electric field is an external electric field formed by charge injection or charge; when the external electric field is performed by charge injection, the charge injection is performed by an electrostatic generator and / or by a high-voltage power supply; the charge injection time is 10s-10min; and the preferred strength of the external electric field is 500V / mm to 1000V / mm.

[0067] The present invention also includes a method for modifying a two-dimensional crystal, the method comprising the following steps:

[0068] S1) Select a two-dimensional crystal for adsorbing gas;

[0069] S2) Place the two-dimensional crystal from step S1) into the gas desorption chamber;

[0070] S3) Process the two-dimensional crystal from step S1); the processing method is heating treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field.

[0071] S4) Under the action of the treatment method in step S3), the interaction force between the adsorbed gas adsorbed on the two-dimensional crystal and the two-dimensional crystal is reduced, and the two-dimensional crystal of the adsorbed gas is desorbed.

[0072] Preferably, the method for modifying the two-dimensional crystal further includes the following steps after step S4):

[0073] S5) Adjust the processing parameters of the Sb3) processing method to achieve partial or complete gas desorption of the two-dimensional crystals of the adsorbed gas.

[0074] Preferably, in step S3), when the treatment method is external electric field treatment, the field strength of the external electric field is greater than 1000V / mm; in step S3), when the treatment method is plasma treatment, the reaction temperature of the plasma generator used for plasma treatment is 20℃~300℃.

[0075] Preferably, the two-dimensional crystal is a layered material or a layered material with a cavity structure; the layered material is a single-layered material, a double-layered material, or a few-layered material bonded together by van der Waals forces; the single-layered material, double-layered material, or few-layered material may or may not contain defects, the defects being atomic absence, atomic substitution, and / or atomic doping; the layered material is one or a combination of graphene, hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, and WTe2.

[0076] When the two-dimensional crystal is a layered material with a cavity structure, the layered material with a cavity structure is one or a combination of single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene tubes, boron nitride nanotubes, and carbon fibers.

[0077] Preferably, the two-dimensional crystal further includes a substrate, and the layered material or the layered material with a cavity structure is disposed on the substrate; the substrate is an insulating non-metallic material, and the substrate is sapphire, silicon carbide and / or silicon oxide.

[0078] Preferably, the method for modifying two-dimensional crystals provided by the present invention is to modify the physical and / or chemical properties of two-dimensional crystals, especially the mechanical, thermal, optical and / or electrical properties.

[0079] Beneficial Effects: The novel method for gas adsorption using two-dimensional crystals provided by this invention is based on the principle of electrostatic adsorption and employs a polarization enhancement strategy. By injecting a certain amount of charge into a two-dimensional crystal (such as graphene) in a gas environment, a surface discharge process is achieved. This causes the intrinsic gas molecules surrounding the crystal to polarize under the influence of an external electric field, generating dipole moments. Simultaneously, the atoms on the two-dimensional crystal surface undergo lattice distortion, exhibiting a piezoelectric effect. Gas molecules are attracted to the two-dimensional crystal material, and further discharge processes lead to the formation of a stable structure between the two-dimensional crystal and gas molecules. This structure is maintained by the dipole (electrostatic) interaction between the polarized molecules and the two-dimensional crystal. Even after further removal of the injected charge, the graphene remains stable. Ultimately, the interaction between the out-of-plane displacement atoms of the two-dimensional crystal material and the polarized gas molecules is greatly enhanced, enabling the controllable and stable adsorption of various types of gases on the surface of the two-dimensional crystal. This method can serve as an efficient method for adsorbing and storing various types of gases, providing technical support for gas storage, development, and industrial applications. Specifically, this invention has the following advantages: 1) This invention develops a novel gas adsorption method. Based on the principle of electrostatic adsorption, it employs charge injection to achieve the adsorption process of various types of gases, including energy, greenhouse, and inert gases, by two-dimensional crystalline materials such as graphene under normal temperature and pressure conditions, opening a new door for gas storage and development. 2) The adsorbed gases achieved by this invention have the characteristics of high stability, large adsorption capacity, and diverse types. The solid adsorbent two-dimensional crystalline material used has advantages such as large specific surface area and easy availability. 3) The charge injection method introduced in this invention is characterized by simple process, easy operation, and strong universality, making it suitable for large-scale applications. Furthermore, the adsorbed gases exhibit high stability, large adsorption capacity, and diverse types. This invention will provide technical support for gas storage and development, accelerate future applications, and promote social progress.

[0080] The method for desorbing gases from two-dimensional crystals provided by this invention comprehensively utilizes light energy, heat energy, and plasma technologies, as well as employing electron injection to activate the two-dimensional material and catalytically decompose the adsorbed gases on its surface, thereby achieving desorption. This method enables the release of multiple gases from the two-dimensional crystal, laying a technological foundation for future gas development and accelerating future applications, thus promoting social progress. Compared with existing technologies, this invention has the following advantages: 1. This invention develops a novel gas desorption method that comprehensively utilizes heating, light irradiation, plasma, and the injection of a large amount of charge to achieve a stable and controllable desorption process for various types of gases adsorbed on two-dimensional crystal materials such as graphene. This invention, combined with the gas adsorption process, opens new doors for gas storage and development. 2. The gas desorption method of this invention is characterized by its simple process, ease of operation, and strong universality, making it suitable for large-scale applications.

[0081] This invention provides a gas separation method based on either gas adsorption or desorption from a two-dimensional crystal. The principle is based on the difference in polarization of gas molecules; under the same field strength, gases with higher polarization adsorb faster, while those with lower polarization adsorb slower. It also considers the differences in thermodynamic and other stability of the adsorbed gases after adsorption; heavier gas molecules are more stable in their unbonded state. The method involves a cyclical process of adsorption and desorption of the mixed gas, ultimately achieving separation. This invention can achieve different degrees of spontaneous adsorption and desorption of gases on the adsorbent surface by simply controlling the charge density and injection time. In the future, this method is expected to become a core technology for gas separation, with potential for further expansion of applications, breakthroughs in process flow, and simplification of different types of gas recovery and extraction processes based on the properties of the gas and the properties of the two-dimensional crystal material itself. This invention, by separating multiple mixed gases, has enormous potential applications in future aerospace and fuel cells. Furthermore, it provides technical support for achieving the "dual-carbon goal." Compared with existing technologies, this invention has the following advantages: 1. Based on novel theories and inventions of gas adsorption and desorption, this invention develops a completely new method for gas separation. By comprehensively utilizing heating, light, plasma, and the injection of a large amount of charge, and taking into account the ease with which different gas molecules polarize and the difficulty of polarization-induced adsorption of different gas molecules by two-dimensional crystal materials such as graphene, and further considering the differences in the stability of different gas molecules after adsorption, it achieves controllable selective adsorption and desorption of different types of gas molecules, thus achieving gas separation. This application invention will open new doors for gas storage and development. 2. The gas separation method of this invention is characterized by simple process, low cost, ease of operation, low energy consumption, intelligence, and strong universality, making it suitable for large-scale applications.

[0082] This invention leverages the enormous specific surface area of ​​two-dimensional crystals and the ease with which their physical and chemical properties are influenced by surface-adsorbed atoms. It proposes a novel method to study and explore the effects of different gas molecules on the properties of graphene materials, thereby modifying graphene and related two-dimensional crystals to meet their application needs in various fields. This invention explores the effects of different adsorption degrees, types, and structures of gas molecules on graphene and other two-dimensional crystals based on the covalent and non-covalent adsorption processes of gas molecules on the graphene surface. By implementing the process of gas adsorption on two-dimensional crystal materials and further adjusting experimental parameters, this invention delves into and develops methods to alter the physical and chemical properties of two-dimensional crystals and other adsorbents based on different adsorbed gases and concentrations. This invention provides an important means for the physicochemical surface modification of two-dimensional crystals. Attached Figure Description

[0083] Figure 1 This is a schematic diagram of the method for adsorbing gas using two-dimensional crystals provided by the present invention;

[0084] Figure 2 It describes the adsorption behavior of gases by graphene with different numbers of layers on a silicon oxide substrate;

[0085] Figure 3 These are atomic images of gas adsorbed on graphene; (c) shows a typical gas molecule height distribution, with positions derived from Figures (a) and (b).

[0086] Figure 4 It is the threshold for field strength breakdown under different pressures;

[0087] Figure 5 These are AFM images and corresponding height information of single-walled carbon nanotubes after adsorbing Ar gas.

[0088] Figure 6 It is a Raman comparison of graphene before and after gas adsorption on a metal substrate;

[0089] Figure 7 These are the conditions under which gas adsorption occurs at different pressures;

[0090] Figure 8 It uses plasma to achieve gas adsorption, and the Raman data are obtained before and after adsorption.

[0091] Figure 9 This is a characterization of the gas before and after desorption. After desorption, the D peak of graphene disappears, indicating no damage.

[0092] Figure 10 This is a comparison of Raman data before and after the desorption of gas from a single layer of graphene on a silicon oxide substrate.

[0093] Figure 11This is a comparison of Raman data before and after the desorption of gas in four layers of graphene on a silicon oxide substrate.

[0094] Figure 12 These are AFM images and corresponding height information of single-walled carbon nanotubes before and after gas desorption.

[0095] Figure 13 These are Raman data for niobium diselenide before and after adsorption and desorption of the gas;

[0096] Figure 14 These are Ar atoms remaining on the surface after the adsorption of the mixed gas and selective desorption.

[0097] Figure 15 It is a comparison of the adsorption stability of three different gases;

[0098] Figure 16 It is an electrical characterization of monolayer graphene before and after gas adsorption and after gas desorption;

[0099] Figure 17 It involves controlling the adsorption time to achieve different degrees of gas adsorption, thereby regulating the performance of graphene.

[0100] Figure 18 It is a temperature-varying resistor that adsorbs gases to varying degrees on a single layer of graphene;

[0101] Figure 19 The superconducting properties of non-layered materials remain unchanged before and after gas adsorption, while non-layered materials cannot adsorb gases.

[0102] Figure 20 It is the temperature-dependent resistance of a single layer of graphene after it adsorbs gas;

[0103] Figure 21 These are the optical properties of monolayer molybdenum sulfide samples that have adsorbed gases to varying degrees.

[0104] Figure 22 It is the change in graphene stress caused by the adsorption of different degrees of gas;

[0105] Figure 23 It refers to the change in the electrical properties of graphene after covalent adsorption of hydrogen gas. Detailed Implementation

[0106] Invention A)

[0107] First, this invention provides a method for adsorbing gas using a two-dimensional crystal, the method comprising the following steps:

[0108] 1) Select a two-dimensional crystal material;

[0109] 2) Place the two-dimensional crystal material in the gas adsorption chamber;

[0110] 3) Introduce the gas to be adsorbed into the gas adsorption chamber;

[0111] 4) Injecting charges into the two-dimensional crystal material placed in the gas adsorption chamber to induce surface discharge and form an external electric field; the charge injection methods are charge injection, electrostatic generator charge injection, high voltage charge injection, and plasma generator charge injection.

[0112] 5) The gas placed around the two-dimensional crystal material is polarized under the action of the external electric field in step 4), generating a dipole moment and attracting the two-dimensional crystal material to form a stable structure, thus completing the adsorption of gas by the two-dimensional crystal material.

[0113] The principle of the two-dimensional crystal gas adsorption method provided by this invention is as follows: Figure 1 Taking Ar atom adsorption as an example, after injecting negative charge, graphene will polarize the surrounding Ar gas atoms. The polarized Ar atoms and charged graphene attract each other and eventually combine together, causing the graphene lattice distortion in the bonding region. The polarized Ar atoms and charged graphene undergo charge transfer. After further removing the external negative charge, the state of the adsorbed gas remains unchanged.

[0114] The technical solution provided by the present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0115] Example 1

[0116] Using monolayer graphene grown on a copper / nickel single-crystal alloy substrate as raw material, the adsorption of Ar gas by graphene was achieved by charge injection using an electrostatic generator. The specific operation is as follows:

[0117] First, a monolayer of graphene grown on a copper / nickel single-crystal alloy substrate is placed in a gas adsorption chamber (a sealed quartz tube at room temperature). Ar is introduced, and the gas pressure is adjusted to 500 Pa via a pressure valve. Using an electrostatic generator, negative charges are generated at a potential of -1.0 kV. The emitted negative charges are transferred to the monolayer graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the detected current density is approximately 1 nA / mm². 2 At this point, the electric field strength due to the accumulated charge on the surface is greater than 75 V / mm (calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 5 minutes. Typical morphology after gas adsorption is shown in [reference needed]. Figure 3 a. STM images characterize the distribution of Ar atoms adsorbed on the graphene sample, and the height distribution of gas molecules is as follows: Figure 3 As shown in Figure c, the height distribution of argon gas is the same as the diameter of the atoms, indicating that the adsorbed gas molecules are argon atoms.

[0118] Example 2

[0119] The procedure is basically the same as in Example 1, except that the type of gas adsorbed is different. The specific operation is as follows:

[0120] First, the monolayer graphene on the metal substrate is placed in a gas adsorption chamber (the gas adsorption chamber is a sealed quartz tube, and the ambient temperature is room temperature). In this embodiment, helium gas is introduced (in addition to helium, gases treated in the same way as in this embodiment can also include energy gases such as hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; inert gases such as helium; and one or more other types of gas molecules such as nitrogen and oxygen). The gas pressure is adjusted to 500 Pa. Using an electrostatic generator, a negative charge is generated under a potential of -1.0 KV. The emitted negative charge is transferred to the monolayer graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the detected current density is ~1 nA / mm. 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 5 minutes. Typical morphology after helium adsorption is shown in [reference needed]. Figure 3 b, STM image characterizing the distribution of helium atoms adsorbed on the graphene sample. The gas molecule height distribution is as follows... Figure 3 As shown in c. Figure 3 c is Figure 3 a and Figure 3 The corresponding height profiles of Ar and He atoms in b are shown, and Cu atom steps are drawn for comparison. The thickness of Ar and He is equal to their atomic diameter, and the Cu atoms are approximately spaced perpendicular to the plane of Cu(111).

[0121] Example 3

[0122] The procedure is basically the same as in Example 1, except that the substrate on which the graphene is placed is different. The specific operation is as follows:

[0123] First, a monolayer of graphene on a silicon oxide substrate (similar to this embodiment, the graphene can be on various types of substrates, including insulating non-metallic substrates such as sapphire, silicon carbide, and silicon oxide, or non-insulating metallic substrates such as copper, nickel, and platinum, as well as suspended substrates without contact. In this embodiment, a copper-nickel alloy substrate and a silicon oxide substrate were selected as the substrates on which the monolayer graphene is located) is placed in a gas adsorption chamber (the gas adsorption chamber can be a sealed quartz tube). Ar is introduced and the gas pressure is adjusted to 500 Pa. A negative charge is generated using an electrostatic generator under a potential of -1.0 KV. The emitted negative charge is transferred to the monolayer graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the current density is detected to be ~1 nA / mm². 2At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 5 minutes. Typical Raman spectra of graphene adsorbed on a silicon oxide substrate are shown below. Figure 2 .

[0124] Example 4

[0125] The process is basically the same as in Example 3, except that the thickness of the graphene is different. The specific operation is as follows:

[0126] First, graphene (the thickness of graphene can be single-layer, double-layer, triple-layer, or more, with a thickness of 1-10 nm. In this embodiment, double-layer, triple-layer, and quadruple-layer graphene are selected) is placed in a gas adsorption chamber (the gas adsorption chamber must be able to allow the introduction of various gases and to measure relevant experimental parameters during the adsorption process, such as adjusting and measuring gas pressure, detecting current, electric field, etc., and can be a sealed quartz tube reactor, etc. In this embodiment, the gas adsorption chamber is a sealed reactor). Ar is introduced and the gas pressure is adjusted to 500 Pa. Using an electrostatic generator, negative charges are generated under a potential of -1.0 KV. The emitted negative charges are transferred to the graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the detected current density is ~1 nA / mm². 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 5 minutes. Typical Raman spectra of graphene of different thicknesses on a silicon oxide substrate after adsorption are shown below. Figure 2 .

[0127] Example 5

[0128] The procedure is basically the same as in Example 1, except that the conditions for adsorbing the gas are changed, including changes in gas pressure and the rate of injection of charge. The specific operation is as follows:

[0129] First, the graphene on the copper-nickel alloy metal substrate is placed in the gas adsorption chamber (the gas adsorption chamber is a closed quartz tube), Ar is introduced, and the gas pressure is adjusted to 10 Pa (in other embodiments similar to this one, the gas pressure range is 0.1 Pa-10 Pa). 5 Using an electrostatic generator, negative charges are generated (Pa). These negative charges are then transferred to the graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter; note that the current density is approximately 2 nA / mm². 2 (In this embodiment, the current density is adjusted to <10nA / mm) 2To avoid damaging the graphene sample, the surface electric field strength generated by the accumulated charge must reach a sufficient threshold. Once the threshold is reached, it is used to release static electrons, i.e., the surface discharge process. In this embodiment, the threshold is 125V / mm. For details on the field strength thresholds of the breakdown gas under different pressures, please refer to [link to relevant documentation]. Figure 4 The injection time is approximately 5 minutes.

[0130] Example 6

[0131] The procedure is basically the same as in Example 1, except that the type of two-dimensional crystal is different. The specific operation is as follows:

[0132] First, single-walled carbon nanotubes (in this embodiment, two-dimensional crystals are limited to layered materials bonded together by van der Waals forces, whose surface atoms must have out-of-plane displacement capability, and whose thickness is 1-10 nm, including but not limited to single-layer, double-layer, and few-layered hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, WTe2, etc., and allotropes of two-dimensional crystals, such as single-walled and multi-walled carbon nanotubes, carbon fibers, etc.) are placed in a gas adsorption chamber (the gas adsorption chamber can be a sealed quartz tube). Ar is introduced and the gas pressure is adjusted to 500 Pa. Using an electrostatic generator, negative charges are generated. The emitted negative charges are transferred to the graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter. Note that the current density is ~2 nA / mm². 2 (In this embodiment, the current density is adjusted to <10nA / mm) 2 To avoid damaging the single-walled carbon nanotube sample and ensure that the surface field strength generated by the accumulated charge reaches a sufficient threshold, the typical morphology after gas adsorption was observed after an injection time of approximately 5 minutes. A comparison of the AFM height before and after Ar gas adsorption in single-walled nanotubes is shown in the figure. Figure 5 The height before gas adsorption was about 1.86 nm, and the height at the same position increased to 2.11 nm after adsorption of Ar gas.

[0133] Example 7

[0134] This example is basically the same as Example 1, except for the method of charge implantation into the graphene. In this example, a high-voltage implantation method is used, and the specific operation is as follows:

[0135] First, graphene on a metal substrate is placed in a gas adsorption chamber (which can be a sealed quartz tube). Ar is introduced and the gas pressure is adjusted to 66.5 Pa. A high-voltage power supply is directly contacted with the graphene sample, applying a high voltage of 5000 V. At this point, surface charge accumulates, generating an electric field strength >80 V / m. The gas to be adsorbed is then broken down under this high voltage. When the voltage of the graphene exceeds the breakdown voltage threshold, the discharge process helps the graphene capture and retain gas molecules by transforming them into a stable structure. This structure is maintained by the dipole interaction between the gas molecules and the graphene, and the graphene remains stable even after the injected charge is removed. A typical Raman spectrum of graphene after gas adsorption is shown below. Figure 6 After graphene adsorbs gas, a distinct D peak appears.

[0136] Example 8

[0137] This is basically the same as Example 7, except that the conditions have changed. The specific operation is as follows:

[0138] First, the graphene on the metal substrate is placed in a gas adsorption chamber (which can be a sealed quartz tube), Ar is introduced, and the gas pressure is adjusted to 1000 Pa (in other embodiments similar to this one, the pressure range can be 0.1 Pa-10 Pa). 5 A high-voltage power supply (Pa) was directly applied to the graphene sample, generating an electric field strength >80V / m. Under this high voltage, the gas was broken down, polarized, and produced a weak glow, subsequently adsorbing onto the sample surface. The effect of gas pressure on the adsorption results is discussed in [reference needed]. Figure 7 The ratio of the D peak to the G peak of graphene under different pressures indicates the amount of gas adsorbed and the ease of adsorption. The larger the ratio, the easier the adsorption and the greater the amount of gas adsorbed.

[0139] Example 9

[0140] This example is basically the same as Example 1, except that the method of charge implantation into the graphene is different. In this example, plasma implantation is used, and the specific operation is as follows:

[0141] First, the graphene on the metal substrate is placed in the gas adsorption chamber (which can be a sealed quartz tube). Ar is introduced and the gas pressure is adjusted to 1 Pa (in this embodiment, the pressure is 1 Pa; in other embodiments similar to this embodiment, the range can be 1-10 Pa). 2Pa (this pressure range easily generates plasma glow), set the temperature to 100℃ (in this embodiment, the temperature range is room temperature to 200℃); turn on the inductively coupled plasma generator, specifically with a power of 20W (in other embodiments similar to this embodiment, the power range can be 5-100W). In this embodiment, the electric field strength generated by the accumulated surface charge should reach 100V / m. The sample is generally processed for 60s (in other embodiments similar to this embodiment, the processing time can range from 10s to 600s). Typical Raman spectra after Ar gas adsorption are shown in [reference needed]. Figure 8 The curve after gas adsorption shows a peak on the far left, known as peak D, which is produced by the adsorbed gas.

[0142] Invention B)

[0143] This invention provides a method for adsorbing gases from two-dimensional crystals, and also provides a method for desorbing gases from two-dimensional crystals with a similar concept. This method includes the following steps:

[0144] 1) Select a two-dimensional crystal material for the gas to be desorbed;

[0145] 2) Place the material to be desorbed into the gas desorption chamber;

[0146] 3) The desorption chamber is cleaned to remove residual gas;

[0147] 4) Heating the two-dimensional crystalline material containing the gas to be desorbed, and / or irradiating the two-dimensional crystalline material containing the gas to be desorbed with light, and / or subjecting the two-dimensional crystalline material containing the gas to be desorbed with plasma, and / or injecting reverse charge into the two-dimensional crystalline material containing the gas to be desorbed. Among these methods, light irradiation mainly activates the catalytic function of graphene, while plasma treatment accelerates the bombardment effect of electrons.

[0148] 5) Under the action of step 3), the two-dimensional crystal material for desorbing the gas reduces the interaction force between the adsorbed gas and the two-dimensional crystal, thereby completing the desorption process of the gas adsorbed on the surface of the two-dimensional crystal.

[0149] 6) Use mass or thermogravimetric analysis to detect the desorbed gas and verify the type and amount of gas desorbed.

[0150] The technical solution provided by the present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0151] Example 10

[0152] Using Ar-adsorbed graphene as raw material, the adsorption surface is desorbed by heating. The specific operation is as follows:

[0153] First, monolayer graphene (grown on a copper / nickel single-crystal alloy substrate) adsorbed with Ar gas was placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber was then evacuated and cleaned with hydrogen three or more times to remove oxygen and moisture. Next, the sample (monolayer graphene adsorbed with Ar gas) was heated to 400°C for approximately 10 minutes. Typical Raman spectroscopy results for monolayer graphene before and after complete Ar gas desorption are shown in [reference needed]. Figure 9 After the adsorbed gas is removed, the graphene adsorbed with the gas exhibits a typical D peak ( Figure 9 The leftmost peak of the bottom curve disappears. Vacuuming is used to obtain a higher purity of the desorbed gas, removing residual gas from the adsorption chamber first. Furthermore, it prevents water and oxygen in the adsorption chamber from damaging two-dimensional crystals such as graphene during the desorption process.

[0154] Example 11

[0155] The procedure is basically the same as in Example 10, except that the type of gas to be desorbed is different. The specific operation is as follows:

[0156] First, monolayer graphene (grown on a copper / nickel single-crystal alloy substrate) adsorbed with He gas was placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber was then evacuated and cleaned with hydrogen gas three or more times to remove oxygen and moisture. The sample was then heated to 400℃ for approximately 10 minutes. After complete He gas desorption, the monolayer graphene exhibited typical Raman characteristics and... Figure 9 Similar, will not be provided again.

[0157] Example 12

[0158] The procedure is basically the same as in Example 10, except that the substrate on which the graphene is placed is different. The specific operation is as follows:

[0159] First, monolayer graphene adsorbed with Ar gas (graphene can be placed on various types of substrates, including insulating non-metallic substrates such as sapphire, silicon carbide, and silicon oxide, or non-insulating metallic substrates such as copper, nickel, and platinum, as well as suspended substrates without contact. In this embodiment, a silicon oxide substrate was selected as the substrate for the monolayer graphene) was placed in a gas desorption chamber (the gas adsorption chamber is a sealed quartz tube that can be vacuumed and heated). The gas desorption chamber was then evacuated and cleaned with hydrogen gas three or more times to remove oxygen and moisture. The sample was then heated to 400°C for approximately 10 minutes. Typical Raman spectroscopy of the monolayer graphene on the silicon oxide substrate before and after gas desorption is shown in [reference needed]. Figure 10 After the adsorbed gas is removed, the typical D peak of the graphene disappears.

[0160] Example 13

[0161] The process is basically the same as in Example 12, except that the thickness of the graphene is different. The specific operation is as follows:

[0162] First, graphene (with a thickness of 1-10 nm, which can be single-layer, double-layer, triple-layer, or more, and four layers thick) adsorbed with Ar gas is placed in a gas desorption chamber (a sealed quartz tube that can be evacuated and heated). The chamber is then evacuated and cleaned with hydrogen three or more times to remove oxygen and moisture. The sample is then heated to 400°C for approximately 10 minutes. Typical Raman spectroscopy of the four-layer graphene after complete gas desorption is shown in [reference needed]. Figure 11 .

[0163] Example 14

[0164] The process is basically the same as in Example 10, except that the desorption conditions are changed, including the heating temperature and desorption time. The specific operation is as follows:

[0165] First, monolayer graphene (grown on a copper / nickel single-crystal alloy substrate) adsorbed with Ar gas is placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber is then evacuated and cleaned three or more times with hydrogen to remove oxygen and moisture. Next, the sample is heated to 300°C (the temperature range for complete gas desorption is 300-800°C; in this embodiment, 300°C is used, as temperatures exceeding 800°C will damage the intrinsic lattice structure of the graphene), for approximately 30 minutes (the desorption time is set between 10 minutes and 2 hours; higher temperatures result in faster desorption, while lower temperatures require longer desorption times).

[0166] Example 15

[0167] The procedure is basically the same as in Example 10, except that the type of two-dimensional crystal used to adsorb Ar gas is different. The specific operation is as follows:

[0168] First, single-walled carbon nanotubes (in this embodiment, two-dimensional crystals, limited to layered materials bound together by van der Waals forces, whose surface atoms must have out-of-plane displacement capability, and a thickness of 1-10 nm, including but not limited to single-layer, double-layer, and few-layered hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, WTe2, etc., and allotropes of two-dimensional crystals, such as single-walled and multi-walled carbon nanotubes, carbon fibers, etc.) adsorbed with Ar gas were placed in a gas desorption chamber (the gas adsorption chamber was a sealed quartz tube, which could be vacuumed and heated). The gas desorption chamber was then evacuated and cleaned with hydrogen gas three or more times to remove oxygen and moisture. The sample was then heated to 400°C for approximately 10 minutes. An AFM image of the same location after gas desorption is shown below. Figure 12 The height of the single-walled tube for adsorbing gas is 2.11 nm, and the height of the sample after desorbing the gas is 1.76 nm.

[0169] Example 16

[0170] This example is basically the same as Example 10, except that the desorption method is different. In this example, light radiation is used to achieve gas desorption, and the specific operation is as follows:

[0171] First, monolayer graphene (grown on a copper / nickel single-crystal alloy substrate) adsorbed with Ar gas was placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber was then evacuated and cleaned three or more times with hydrogen to remove oxygen and moisture. Next, the sample was subjected to light irradiation, using human illumination and / or laser light. In this embodiment, the wavelength was 488 nm (typically less than 1000 nm), the irradiation power was 10 mW, and the irradiation time was 60 min. Irradiation not only generates a certain amount of heat but also stimulates the catalytic performance of the graphene, thereby desorbing the gas. Raman characteristics before and after gas desorption were observed. Figure 9 Similar, will not be provided again.

[0172] Example 17

[0173] This is basically the same as Example 16, except that the two-dimensional crystal used for gas desorption is different, and the specific operation is as follows:

[0174] First, NbSe2 (a two-dimensional crystal defined as a layered material bound together by van der Waals forces, with surface atoms capable of out-of-plane displacement and a thickness of 1-10 nm, including but not limited to single-layer, double-layer, and few-layered hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, WTe2, etc., and allotropes of two-dimensional crystals, such as single-walled and multi-walled carbon nanotubes, carbon fibers, etc. In this embodiment, single-layered MoS2 is used) adsorbed with Ar gas is placed in a gas desorption chamber (the gas adsorption chamber is a sealed quartz tube that can be vacuumed and heated). Then, the gas desorption chamber is evacuated and cleaned with hydrogen gas three or more times to remove oxygen and moisture. The sample was then subjected to light irradiation, using human illumination and / or laser light. In this embodiment, the wavelength used was 488 nm, typically within the range of less than 1000 nm. The irradiation power was 10 mW, and the irradiation time was 60 min. Irradiation not only generates a certain amount of thermal effect but also stimulates the catalytic performance of the two-dimensional crystal, thereby desorbing the gas. Intrinsic NbSe2 Raman data before and after gas desorption are shown in [link to relevant documentation]. Figure 13 Raman data showed that after gas adsorption, the peak positions of NbSe2 and other peaks exhibited a significant blue shift, and after desorption, the peak positions basically returned to their initial levels.

[0175] Example 18

[0176] This example is basically the same as Example 10, except that the desorption method is different. In this example, plasma bombardment is used to achieve gas desorption, and the specific operation is as follows:

[0177] First, monolayer graphene (grown on a copper / nickel single-crystal alloy substrate) adsorbed with Ar gas was placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber was then evacuated and cleaned three or more times with hydrogen to remove oxygen and moisture. Next, the sample underwent plasma treatment with another gas. In this embodiment, helium plasma technology was used. Because excessive plasma during helium plasma treatment can easily replace adsorbed helium while desorbing Ar, and can further damage the graphene, the sample needed to be appropriately heated before helium plasma treatment. The heating temperature was set to 200℃, and the plasma power and treatment time were strictly controlled. The plasma power was set to 100W, and the treatment time to 10 minutes. Raman characteristics before and after plasma treatment and... Figure 9 Similar, will not be provided again.

[0178] Example 19

[0179] This example is essentially the same as Example 10, except that the desorption method is different. In this example, the two-dimensional crystal material containing the gas to be desorbed is injected with a reverse charge to achieve gas desorption. The specific operation is as follows:

[0180] First, monolayer graphene containing Ar gas, which is adsorbed via charge adsorption, is placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating) as described in Example 1 (the graphene is grown on a copper / nickel single-crystal alloy substrate). The chamber is then evacuated and cleaned with hydrogen three or more times to remove oxygen and moisture. Next, the sample is subjected to an equal amount of reverse charge treatment. During this process, the polarized gas molecules return to their original state under the influence of the reverse charge, thus achieving the desorption of Ar gas. Raman characteristics before and after gas desorption are then analyzed. Figure 9 Similar, will not be provided again.

[0181] Invention C)

[0182] Based on the foregoing content (methods for adsorbing gases from two-dimensional crystals and methods for desorbing gases from two-dimensional crystals), a novel gas separation technology is provided. The gas separation method includes the comprehensive use of two means: a) selective gas adsorption to achieve gas separation, and b) selective gas desorption to achieve gas separation.

[0183] a) Gas separation is achieved using selective gas adsorption, including the following steps:

[0184] 1) Select a two-dimensional crystal material for gas adsorption;

[0185] 2) Place the two-dimensional crystal material into the gas adsorption chamber;

[0186] 3) Introduce the mixed gas to be separated into the gas adsorption chamber;

[0187] 4) Injecting charges into the two-dimensional crystal material placed in the gas adsorption chamber causes the surface of the two-dimensional crystal material to discharge, forming an external electric field;

[0188] 5) Adjust the intensity of the external electric field and the discharge time to achieve selective adsorption of different gases based on the differences in the polarization intensity of gas molecules, thereby achieving the effect of gas separation;

[0189] b) Gas separation is achieved using selective gas desorption, including the following steps:

[0190] 6) Select a two-dimensional crystal material that has already adsorbed the mixed gas;

[0191] 7) Place the two-dimensional crystalline material that adsorbs the mixed gas in the gas desorption chamber;

[0192] 8) Heating the two-dimensional crystal material of the gas to be desorbed in the desorption chamber, and / or subjecting the two-dimensional crystal material of the gas to be desorbed to light radiation, and / or subjecting the two-dimensional crystal material of the gas to be desorbed to plasma treatment, and / or subjecting the two-dimensional crystal material of the gas to be desorbed to electric current treatment.

[0193] 9) By selecting the heating temperature, heating time, and / or light intensity, light wavelength, and / or plasma treatment intensity and time, and / or power treatment intensity and time, the selective release of different adsorbed gases can be achieved, thereby achieving the effect of gas separation.

[0194] 10) Detect the desorbed gas to verify the type and quantity of the gas.

[0195] The technical solution provided by the present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0196] Example 20

[0197] The basic operation involves precisely controlling the adsorption conditions in invention A) above, and controlling the adsorption of different gases to different degrees based on the differences in polarization ability of different gas molecules in the mixed gas, thus achieving preliminary gas separation. Then, precisely controlling the desorption conditions in invention B) above, and achieving further selective desorption of the gases based on the differences in stability of different gas molecules adsorbed on the two-dimensional crystal surface, and finally achieving gas separation through multiple cycles of selective adsorption and desorption processes.

[0198] Using monolayer graphene grown on a copper / nickel single-crystal alloy substrate as raw material, the separation of Ar / H2 gases by graphene was achieved. The specific operation is as follows:

[0199] Selective adsorption process: A monolayer of graphene grown on a copper / nickel single-crystal alloy substrate is placed in a gas adsorption chamber (a sealed quartz tube at room temperature). A mixture of Ar and H2 gas is introduced, and the gas pressure is adjusted to 500 Pa using a pressure valve. An electrostatic generator is used to generate negative charges at a potential of -1.0 kV. These negative charges are transferred to the monolayer graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter, with a detected current density of approximately 1 nA / mm². 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 1 minute. Due to the difference in the degree of gas polarization, hydrogen is more easily polarized; therefore, under these conditions, the material surface mainly adsorbs hydrogen.

[0200] Then, by combining selective desorption, since adsorbed Ar has better thermal stability, gas separation can be achieved through temperature gradient differences. Specifically, graphene adsorbed with an Ar / H2 mixture is placed in a gas desorption chamber, and the heating temperature is precisely controlled at 190℃ for 5 minutes. At this point, most of the hydrogen will be desorbed, while Ar remains in an adsorbed state. Desorption of argon requires a higher temperature; the heating temperature can be set to 500℃ for 5 minutes. The STM image showing the partially adsorbed Ar state after hydrogen desorption is shown below. Figure 14 By repeating the above process multiple times, the Ar / H2 mixture can be separated.

[0201] Example 21

[0202] This is basically the same as Example 20, except that the type of two-dimensional crystal used to separate the mixed gas is different. The specific operation is as follows:

[0203] Selective adsorption process: Two-dimensional crystal hBN (in this embodiment, two-dimensional crystal is limited to layered materials bonded together by van der Waals forces, whose surface atoms must have out-of-plane displacement capability, and a thickness of 1-10 nm, including but not limited to single-layer, double-layer, and few-layer hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, WTe2, etc. with layered structures) is placed in a gas adsorption chamber (the gas adsorption chamber can be a sealed quartz tube, and the ambient temperature is room temperature). A mixture of Ar and hydrogen gas is introduced, and the gas pressure is adjusted to 500 Pa by a pressure valve. Using an electrostatic generator, negative charges are generated under a potential of -1.0 KV. The emitted negative charges are transferred to the single-layer graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the detected current density is approximately 1 nA / mm. 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 1 minute. Due to the difference in the degree of gas polarization, hydrogen is more easily polarized, therefore, hydrogen is the main gas adsorbed on the hBN surface.

[0204] Then, by further combining the selective desorption process, since the thermal stability of adsorbed Ar is better, the gas can be separated by the difference in temperature gradient and time. Specifically, the graphene adsorbed with Ar / H2 mixture is placed in the gas desorption chamber, and the heating temperature is precisely controlled at 190℃ for 5 minutes. At this time, most of the hydrogen will be desorbed, while Ar will still be in the adsorbed state. Desorbing argon requires a higher temperature, so the heating temperature can be set to 500℃ for 5 minutes.

[0205] By repeating the above process multiple times, the Ar / H2 mixture can be separated.

[0206] Example 22

[0207] This is basically the same as Example 20, except that the types of gases to be separated are different; it is helium and hydrogen. The specific operation is as follows:

[0208] Selective adsorption process: A monolayer of graphene grown on a copper / nickel single-crystal alloy substrate is placed in a gas adsorption chamber (a sealed quartz tube at room temperature). A mixture of helium and hydrogen is introduced, and the gas pressure is adjusted to 500 Pa using a pressure valve. An electrostatic generator is used to generate negative charges at a potential of -1.0 kV. These negative charges are transferred to the monolayer graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter, with a detected current density of approximately 1 nA / mm². 2At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 1 minute. Due to the difference in the degree of gas polarization, hydrogen is more easily polarized, so the material surface mainly adsorbs hydrogen.

[0209] Then, by combining the selective desorption process, since the thermal stability of adsorbed helium is better, the gas can be separated by the difference in temperature gradient and time. Specifically, the graphene adsorbed with He / H2 mixture is placed in the gas desorption chamber, and the heating temperature is precisely controlled at 190℃ for 5 minutes. At this time, most of the hydrogen will be desorbed, while the helium will still be in the adsorbed state.

[0210] The above process is repeated multiple times to achieve the separation of the He / H2 mixture. Variation-temperature Raman data on the stability differences between hydrogen and helium can be found in [link to relevant documentation]. Figure 15 .

[0211] Example 23

[0212] This is basically the same as Example 20, except that the types of gases to be separated are different; this time it is carbon dioxide and hydrogen. The specific operation is as follows:

[0213] Selective adsorption process: A monolayer of graphene grown on a copper / nickel single-crystal alloy substrate is placed in a gas adsorption chamber (a sealed quartz tube at room temperature). A mixture of helium and hydrogen is introduced, and the gas pressure is adjusted to 500 Pa using a pressure valve. An electrostatic generator is used to generate negative charges at a potential of -1.0 kV. These negative charges are transferred to the monolayer graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter, with a detected current density of approximately 1 nA / mm². 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 1 minute. Due to the difference in the degree of gas polarization, hydrogen is more easily polarized, so the material surface mainly adsorbs hydrogen.

[0214] Then, by further combining the selective desorption process, since adsorbed carbon dioxide has better thermal stability, the gas can be separated by the difference in temperature gradient and time. Specifically, the graphene adsorbed with carbon dioxide / H2 mixture is placed in the gas desorption chamber, and the heating temperature is precisely controlled at 220℃ for 5 minutes. At this time, most of the hydrogen will be desorbed, while the carbon dioxide will still be in the adsorbed state.

[0215] The above process is repeated multiple times to achieve the separation of the carbon dioxide / H2 mixture. Variation-temperature Raman data on the stability differences between carbon dioxide and hydrogen can be found in [link to relevant documentation]. Figure 15 .

[0216] Example 24

[0217] The procedure is basically the same as in Example 20, except that the selective adsorption and selective desorption methods are different. The specific procedures are as follows:

[0218] Selective adsorption process: A single-layer graphene grown on a copper / nickel single-crystal alloy substrate is placed in a gas adsorption chamber (a sealed quartz tube at room temperature), and a mixture of Ar and H2 gases is introduced. In this embodiment, a high-voltage injection method is used, with a high-voltage power supply directly contacting the graphene sample. A high voltage of 5000V is applied to the sample, at which point surface charge accumulates, generating an electric field strength >80V / m. At this point, polarized hydrogen and argon gases are adsorbed on the graphene surface. Due to the difference in polarization, hydrogen gas is mainly adsorbed on the surface.

[0219] Then, a selective desorption process is further incorporated. In this embodiment, either light irradiation or plasma treatment is used. The light wavelength used in this embodiment is 488 nm, the light power is 7 mW, and the irradiation time is 60 min. Light irradiation not only generates a certain amount of heat but also excites the catalytic performance of the two-dimensional crystal, thereby desorbing the gas. Alternatively, plasma treatment is performed with a heating temperature of 200°C, and the plasma power and treatment time are strictly controlled. The plasma power is set to 100 W, and the treatment time is 5 min. Because adsorbed Ar is more stable, it is easier to desorb hydrogen under the same conditions.

[0220] By repeating the above process multiple times, the Ar / H2 mixture can be separated.

[0221] Invention D)

[0222] This invention provides a two-dimensional crystal modification method based on gas adsorption, wherein the method for achieving gas adsorption includes:

[0223] 1) Gas adsorption is the same as the process of non-covalently bonded gas adsorption in invention A). Different degrees of gas adsorption can also be achieved by partial or complete desorption of the gas. The desorption process is the same as that in invention B).

[0224] 2) Gas adsorption is a gas adsorption process in which gas is bonded by covalent bonds. By injecting current, an external field strength greater than 1000V / mm is generated, or a plasma treatment process is used. The preferred treatment conditions are 20℃-300℃.

[0225] The technical solution provided by the present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0226] Example 25

[0227] Using monolayer graphene on a silicon oxide substrate as raw material, non-covalent Ar modification of graphene is achieved in accordance with the method described in invention A), as follows:

[0228] Taking electrostatic injection as an example, a monolayer of graphene on a silicon oxide substrate is first placed in a gas adsorption chamber (which can be a sealed quartz tube at room temperature). Ar is introduced, and the gas pressure is adjusted to 133 Pa using a pressure valve. An electrostatic generator is used to generate negative charges at a potential of -550 V. The emitted negative charges are transferred to the monolayer graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter, and the detected current density is approximately 0.55 nA / mm². 2 At this point, the electric field strength due to accumulated charge on the surface is greater than 75 V / mm (calculated by measuring the surface voltage with a voltmeter), and the injection time is approximately 7 minutes. Graphene with different degrees of Ar adsorption was characterized electrically. The curve of sample resistance versus gate voltage is shown below. Figure 16 The resistance of the modified graphene increased significantly, and the degree of P doping decreased.

[0229] Example 26

[0230] The method is basically the same as in Example 25, except that the amount of gas adsorbed on the graphene surface is controlled by adjusting the adsorption time, thereby controlling the properties of the graphene. The specific operation is as follows:

[0231] Taking electrostatic injection as an example, a monolayer of graphene on a silicon oxide substrate is first placed in a gas adsorption chamber (which can be a sealed quartz tube at room temperature). Ar is introduced, and the gas pressure is adjusted to 133 Pa using a pressure valve. An electrostatic generator is used to generate negative charges at a potential of -550 V. The emitted negative charges are transferred to the monolayer graphene through a metal conductor. The current at this point is characterized by a high-precision ammeter, and the detected current density is approximately 0.55 nA / mm². 2 At this point, the electric field strength of the accumulated charge on the surface is greater than 75V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter), and the injection time is 3 minutes. (In other embodiments similar to this one, the injection time can be between 1 second and 7 minutes). In this embodiment, the amount of gas adsorbed on the graphene is controlled by precisely controlling the injection time. Raman spectral data of different adsorption times for Ar graphene with varying degrees of adsorption are shown below. Figure 17 .

[0232] Example 27

[0233] This is basically the same as Example 25, except for the type of gas. The specific operation is as follows:

[0234] Taking electrostatic injection as an example, the monolayer graphene on the silicon oxide substrate is first placed in a gas adsorption chamber (which can be a sealed quartz tube at room temperature). Helium gas (which can also be one or more of the following: energy gases such as hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; inert gas helium; and various other types of gas molecules such as nitrogen and oxygen; in this embodiment, helium is selected) is introduced. The gas pressure is adjusted to 500 Pa using a pressure valve. A negative charge is generated using an electrostatic generator at a potential of -1.0 KV. The emitted negative charge is transferred to the monolayer graphene through a metal conductor. The current at this time is characterized by a high-precision ammeter, and the detected current density is approximately 1 nA / mm². 2 At this point, the electric field strength due to the accumulated charge on the surface is greater than 75 V / mm (the surface electric field strength is calculated by measuring the surface voltage with a voltmeter). The injection time is approximately 7 minutes. By precisely controlling the injection time, the amount of gas adsorbed on the two-dimensional crystal is controlled. Electrical characterization of the graphene with adsorbed helium is performed; the curve of sample resistance changing with temperature is shown below. Figure 18 .

[0235] Example 28

[0236] This is basically the same as Example 25, except that the type of two-dimensional crystal is different. The specific operation is as follows:

[0237] First, η-Mo3C2 (in this embodiment, although it is a thin layer, non-layered structural materials whose surface atoms do not have out-of-plane displacement capabilities are not included in this scope, such as η-Mo3C2, etc.) is introduced with Ar and the gas pressure is adjusted to 500 Pa. Using an electrostatic generator, negative charges are generated. The emitted negative charges are transferred to Mo3C2 through a metal conductor. The current at this time is characterized by a high-precision ammeter. Note that the current density is ~2 nA / mm². 2 (In this embodiment, the current density is adjusted to <10nA / mm) 2 To avoid damaging the Mo3C2 sample, and to ensure that the surface field strength generated by its accumulated charge reaches a sufficient threshold, the injection time was approximately 5 minutes. The results showed that, due to inherent limitations of the material, it cannot effectively adsorb gases, and the superconducting properties of Mo3C2 remained almost unchanged before and after treatment. (See...) Figure 19 .

[0238] Example 29

[0239] Using monolayer graphene on a silicon oxide substrate as raw material, non-covalent Ar modification of graphene is achieved in accordance with the method described in invention B). The specific operation is as follows:

[0240] Taking thermal annealing as an example, firstly, monolayer graphene (graphene on a silicon oxide substrate) adsorbed with Ar gas is placed in a gas desorption chamber (a sealed quartz tube capable of vacuuming and heating). The chamber is then evacuated and cleaned with hydrogen three or more times to remove oxygen and moisture. Next, the sample is heated for 10 minutes, with the temperature adjusted from room temperature to 300°C. The amount of gas adsorbed on the graphene is controlled by adjusting the annealing temperature. The graphene with different levels of Ar adsorption is then electrically characterized. The resistance curve of the sample versus temperature is shown in the figure. Figure 20 .

[0241] Example 30

[0242] This is basically the same as Example 28, except that the type of two-dimensional crystal is different. The specific operation is as follows:

[0243] Taking thermal annealing as an example, a monolayer MoS2 (in this embodiment, a two-dimensional crystal, limited to a layered material bound together by van der Waals forces, whose surface atoms must have out-of-plane displacement capability, and a thickness of 1-10 nm, including but not limited to monolayer, bilayer, and few-layered hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, WTe2, etc., and allotropes of two-dimensional crystals, such as single-walled and multi-walled carbon nanotubes, carbon fibers, etc.; in this embodiment, monolayer MoS2 is used) adsorbed with Ar gas is first placed in a gas desorption chamber (the gas adsorption chamber is a sealed quartz tube, which can be vacuumed and heated). The gas desorption chamber is then evacuated and cleaned with hydrogen gas three or more times to remove oxygen and moisture. The sample is then heated to 400°C, with heating times of 60 seconds and 10 minutes in this embodiment. The amount of gas adsorbed on the two-dimensional crystal was controlled by precisely controlling the annealing time. Photoluminescence (PL) characterization was performed on monolayer MoS2 with varying degrees of Ar adsorption. Figure 21 .

[0244] Example 31

[0245] This is basically the same as Example 28, except that the type of desorbed gas is different. The specific operation is as follows:

[0246] Taking thermal annealing as an example, firstly, a single-layer graphene (graphene on a silicon oxide substrate) adsorbed with helium (the gas can also be one or more of the following: energy gases such as hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; inert gas helium; and various other types of gas molecules such as nitrogen and oxygen; etc. In this embodiment, the gas used to modify the graphene is helium) is placed in a gas desorption chamber (the gas adsorption chamber is a sealed quartz tube that can be vacuumed and heated). Then, the gas desorption chamber is evacuated and cleaned with hydrogen three or more times to remove oxygen and moisture. Next, the sample is heated to 400℃ for approximately 10 seconds to 10 minutes. By precisely controlling the annealing time, the amount of gas adsorbed on the graphene is controlled. The change in graphene stress under different gas adsorption degrees is shown in [the figure]. Figure 22 .

[0247] Example 32

[0248] Using monolayer graphene on a silicon oxide substrate as raw material, the graphene is modified by covalently bonded hydrogen gas. The specific operation is as follows:

[0249] An external field strength greater than 1000 V / mm is generated by injecting current, or a plasma treatment process is performed, with the preferred processing conditions being 20℃-300℃. Taking the plasma process as an example, firstly, a single layer of graphene on a silicon oxide substrate is placed in a gas adsorption chamber (the gas adsorption chamber can be a sealed quartz tube, with the ambient temperature at room temperature). Ar is introduced and the gas pressure is adjusted to 1 Pa, with the temperature set at 100℃. An inductively coupled plasma generator is then activated, with a power of 20 W, and the plasma interaction time is 10 s-10 min. The electrical properties of the graphene chemically adsorbed with hydrogen are characterized, as shown in [the following section]. Figure 23 The figure shows how the resistance of graphene changes with the gate voltage under different magnetic fields after gas adsorption.

[0250] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for desorbing gases from a two-dimensional crystal, characterized in that: The method for desorbing gas from a two-dimensional crystal includes the following steps: 1) Select a two-dimensional crystal material that adsorbs the gas to be desorbed; 2) Place the two-dimensional crystal material from step 1) into the gas desorption chamber; 3) The desorption chamber is cleaned to remove residual gas; 4) Process the two-dimensional crystal material in step 1); the processing method is heat treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field; 5) Under the action of the treatment method in step 4), the interaction force between the adsorbed gas adsorbed on the two-dimensional crystal material and the two-dimensional crystal is reduced, and the process of desorbing the adsorbed gas from the two-dimensional crystal is completed, so that the peak position is restored to the initial level. The two-dimensional crystal material includes a two-dimensional crystal, which is a layered sheet material or a layered material with a cavity structure; the two-dimensional crystal is one or a combination of graphene, hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, and WTe2; when the two-dimensional crystal is a layered sheet material, it is a single-layered or few-layered material bonded together by van der Waals forces; when the two-dimensional crystal is a layered sheet material, it is MoS2. The two-dimensional crystal is one or a combination of thin sheets, MoSe2 thin sheets, MoTe2 thin sheets, NbS2 thin sheets, NbSe2 thin sheets, NbTe2 thin sheets, WS2 thin sheets, WSe2 thin sheets, and WTe2 thin sheets; when the two-dimensional crystal is a layered material with a cavity structure, the two-dimensional crystal is a layered material with a cavity structure formed by rolling up a single layer or multiple layers of layered material; when the two-dimensional crystal is a layered material with a cavity structure, the two-dimensional crystal is one or a combination of single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene tubes, boron nitride nanotubes, and carbon fibers. In step 4), when the treatment method is heating, the heating temperature is 300℃~500℃; when the treatment method is light radiation treatment, the light is human illumination and / or laser illumination, and the wavelength range of the light used in the light radiation treatment is less than 1000nm; the light power is 10mW, and the light time is 60min; when the treatment method is plasma treatment, the plasma treatment uses a plasma generator, the plasma generator is an inductively coupled plasma generator, the plasma generator power is 200W-500W, the plasma generator pressure is 0.1Pa-10Pa, the plasma generator reaction temperature is 100℃~500℃, and the plasma treatment time is 10s-30min; the external electric field is an external electric field formed by charge injection or charge; when the external electric field is formed by charge injection, the charge injection method is through electrostatic generator injection and / or through high-voltage power supply injection; the charge injection time is 10s-10min; the external electric field strength is 500V / mm~1000V / mm. V / mm; In step 5), the adsorbed gas adsorbed on the two-dimensional crystal material is one or a combination of energy gas, inert gas, nitrogen, or oxygen; when the gas to be adsorbed is an energy gas, it is one or a combination of hydrogen, methane, ethane, propane, butane, ethylene, propylene, butene, acetylene, and carbon monoxide; when the gas to be adsorbed is an inert gas, it is Ar and / or helium.

2. The method for desorbing gas from a two-dimensional crystal according to claim 1, characterized in that: The method for desorbing gas from a two-dimensional crystal further includes, after step 5): 6) Detect the desorbed gas to verify the type and amount of gas desorbed.

3. The method for desorbing gas from a two-dimensional crystal according to claim 2, characterized in that: The instrument used for detecting the desorbed gas in step 6) is a thermogravimetric analyzer or a mass spectrometer.

4. The application of a method for desorbing gases from a two-dimensional crystal as described in claim 1 in gas separation or two-dimensional crystal modification.

5. A gas separation method, characterized in that: Includes the following steps: b1) Select a two-dimensional crystal material that adsorbs the gas to be desorbed; b2) Place the two-dimensional crystal material obtained in step b1) into the gas desorption chamber; b3) Process the two-dimensional crystal material in step b1); The processing method is heating treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field; b4) Adjust the processing parameters of step b3) to selectively release the gas adsorbed by the two-dimensional crystal material in step b3), thereby completing the desorption of the target gas from the two-dimensional crystal; the processing parameters include heating temperature, heating time, light intensity, light wavelength, plasma processing intensity, plasma processing time, electric field intensity and / or external electric field processing time. The gas separation method further includes, after b4), the following: b5) Detect the target gas obtained in step b4) to verify the gas type and the amount of gas desorbed; when the treatment in b3) is heating treatment, the heating temperature is 200℃~500℃ and the heating time is 10min~60min; when the treatment in b3) is light radiation treatment, the light is artificial light and / or laser light, the wavelength of the light used in the light radiation is less than 1000nm, the applicable temperature of the light is 200℃~500℃, and the light time is 10min~60min; when the treatment in b3) is plasma treatment, the plasma treatment uses a plasma generator, the plasma generator is an inductively coupled plasma generator, the power of the plasma generator is 200W~500W, the pressure of the plasma generator is 0.1Pa~10Pa, the reaction temperature of the plasma generator is 100℃~500℃, and the plasma treatment time is 10s~30min. When the processing in b3) is performed by an external electric field, the external electric field is an external electric field formed by charge injection or charge; when the external electric field is performed by charge injection, the charge injection method is injection by an electrostatic generator and / or injection by a high-voltage power supply; the charge injection time is 10s-10min; and the external electric field strength is 500V / mm~1000V / mm.

6. A method for modifying two-dimensional crystals, characterized in that: The method for modifying two-dimensional crystals includes the following steps: S1) Select a two-dimensional crystal for adsorbing gas; S2) Place the two-dimensional crystal from step S1) into the gas desorption chamber; S3) Process the two-dimensional crystal from step S1); the processing method is heating treatment, light radiation treatment, plasma treatment and / or treatment by an external electric field. S4) Under the action of the treatment method in step S3), the interaction force between the adsorbed gas adsorbed on the two-dimensional crystal and the two-dimensional crystal is reduced, and the gas adsorption of the adsorbed gas is carried out on the two-dimensional crystal. The method for modifying two-dimensional crystals further includes, after step S4): S5) Adjust the processing parameters of the Sb3) processing method to achieve partial or complete gas desorption of the two-dimensional crystals of the adsorbed gas. In step S3), when the treatment method is external electric field treatment, the field strength of the external electric field is greater than 1000V / mm; in step S3), when the treatment method is plasma treatment, the reaction temperature of the plasma generator used for plasma treatment is 20℃~300℃. The two-dimensional crystal is a layered material or a layered material with a cavity structure; the layered material is a single-layered material or a few-layered material bonded together by van der Waals forces; the single-layered material or the few-layered material may or may not contain defects, the defects being atomic absence, atomic substitution, and / or atomic doping; the layered material is one or a combination of graphene, hBN, MoS2, MoSe2, MoTe2, NbS2, NbSe2, NbTe2, WS2, WSe2, and WTe2; When the two-dimensional crystal is a layered material with a cavity structure, the layered material with a cavity structure is one or a combination of single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene tubes, boron nitride nanotubes, and carbon fibers. The two-dimensional crystal further includes a substrate, and the layered material or the layered material with a cavity structure is disposed on the substrate; the substrate is an insulating non-metallic material, and the substrate is sapphire, silicon carbide and / or silicon oxide.

7. An application of the method for modifying two-dimensional crystals according to claim 6 to modify the physical and / or chemical properties of two-dimensional crystals, specifically the application to modify the mechanical, thermal, optical and / or electrical properties of two-dimensional crystals.

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