Curved graphene and preparation method thereof

Abstract

The present invention provides curved graphene and a preparation method thereof, and relates to the technical field of carbon material preparation. The preparation method of curved graphene comprises the following steps: providing a graphite carbon material, placing the graphite carbon material in pure water, bombarding the surface of the graphite carbon material with an electron beam to form a colloidal suspension; and alternately emitting a combination of low-frequency, medium-frequency, and high-frequency ultrasonic waves into the colloidal suspension to obtain a curved graphene aqueous solution. The prepared curved graphene aqueous solution has good dispersibility.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon material preparation, and in particular to curved graphene and a preparation method thereof. Background Art

[0002] Carbon has five unique crystal structures, including diamond, fullerene (0-D nanographite material), carbon nanotube (1-D nanographite material), graphene (2-D nanographite material) and curved graphene (3-D graphite material).

[0003] Curved graphene is a thermodynamically unstable but kinetically stable metastable substance of carbon. Its structure is a graphene sheet with a certain curvature, which makes the carbon atoms in equilibrium have a certain stress and can be in a higher energy state.

[0004] Curved graphene, as a three-dimensional material composed of a single layer of carbon atoms, has unique physical and chemical properties and has important application value in the fields of electronic devices, energy storage, biology and life sciences. However, there is currently no report on the preparation method of carbon single-element monodisperse functional curved graphene structures. Therefore, how to prepare curved graphene has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a curved graphene and a preparation method thereof, which solves the technical problem of how to prepare curved graphene.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for preparing curved graphene comprises the following steps:

[0010] S1. Preparation of colloidal suspension

[0011] Providing a graphite carbon material, placing the graphite carbon material in pure water, and bombarding the surface of the graphite carbon material with an electron beam to form a colloidal suspension;

[0012] S2. Preparation of curved graphene

[0013] A combination of low-frequency, medium-frequency and high-frequency ultrasonic waves is alternately emitted into the colloidal suspension to obtain curved graphene.

[0014] Preferably, the voltage between the electrode plate and the graphite carbon material plate during electron beam bombardment is 2-100 volts, and the current density is 0.02-200 mA / cm2 , bombardment time is 158-178 hours.

[0015] Preferably, the graphite carbon material is selected from any one of crystalline and amorphous carbon materials.

[0016] Preferably, the graphite carbon material is selected from single crystal graphite, polycrystalline graphite or graphene.

[0017] Preferably, the pure water is selected from any one of deionized water, distilled water or ultrapure water, and the resistivity of the pure water is greater than 18 MΩ·cm.

[0018] Preferably, the ultrasonic combination has a low frequency of 20-40 kHz, a medium frequency of 60-100 kHz, and a high frequency of 120-200 kHz.

[0019] On the other hand, there is provided a curved graphene prepared by the preparation method, wherein the curved graphene is an aqueous solution.

[0020] Preferably, the mass concentration of the curved graphene aqueous solution is 0.1%-0.45%, and the pH value is 1.5-3.2.

[0021] Preferably, the ORP of the curved graphene aqueous solution is 280mv-380mv.

[0022] Preferably, the conductivity σ of the curved graphene aqueous solution is 1-5 ms / cm.

[0023] Preferably, the electromotive force E of the curved graphene aqueous solution is 280mv-380mv.

[0024] (III) Beneficial effects

[0025] The present invention provides a curved graphene and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0026] The method for preparing curved graphene provided by the present invention comprises providing a graphite carbon material, wherein the graphite carbon material is selected from single crystal graphite, polycrystalline graphite or graphene; placing the graphite carbon material in pure water; bombarding the surface of the graphite carbon material with an electron beam, so that the carbon atom layer on the surface of the graphite carbon material is peeled off and dispersed in the pure water to form a colloidal suspension; and alternately emitting a low-frequency, medium-frequency and high-frequency ultrasonic combination into the colloidal suspension, wherein the low frequency in the ultrasonic combination is 20-40 kHz, the medium frequency is 60-100 kHz and the high frequency is 120-200 kHz, so as to obtain a curved graphene aqueous solution.

[0027] Under the bombardment of electron beams, pure water produces hydrogen and oxygen, which further produce -COOH, -OH, H + , O 2-etc., -COOH, -OH, H + , O 2- The groups bond with the carbon atom layer stripped off by the electron beam, thereby modifying the stripped carbon atom layer; the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 2-100 volts, and the current density is 0.02-200 mA / cm 2 Under the condition of continuous bombardment for 158-178 hours, the peeled carbon atom layers will be peeled off layer by layer and modified layer by layer to form a curved graphene structure. Since the particles of the modified curved graphene structure have the same potential, they repel each other, so that the prepared colloidal suspension has better dispersibility. Then, a combination of low-frequency, medium-frequency and high-frequency ultrasonic waves is alternately emitted into the colloidal suspension. The low frequency of the ultrasonic wave combination is 20-40 kHz, the medium frequency is 60-100 kHz, and the high frequency is 120-200 kHz. When the ultrasonic wave changes, the pure water in the colloidal suspension is compressed and rarefied, resulting in rapid movement, thereby generating cavitation, so that the unstable microbubbles will generate shock waves when they grow and suddenly burst. The shock waves generate a large amount of vibration energy, which further breaks the bonds and generates a large amount of -COOH, -OH, H + , O 2- Groups such as these are used to modify the curved graphene structure, so that the prepared curved graphene aqueous solution still has good dispersibility after standing for 24 hours.

[0028] In addition, the modified curved graphene structure has certain functionality, so the prepared curved graphene has certain functionality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a schematic diagram of the preparation process of curved graphene in Example 1;

[0031] Figure 2 This is a morphology diagram of the curved graphene prepared in Example 1;

[0032] Figure 3 This is a morphological diagram of the curved graphene prepared in Example 2;

[0033] Figure 4 This is a morphological diagram of the curved graphene prepared in Example 3;

[0034] Figure 5This is a morphological diagram of the curved graphene prepared in Example 4;

[0035] Figure 6 Schematic diagram of the carbon-oxygen single bond structure and carbon-oxygen double bond structure contained in the curved graphene prepared in Example 1;

[0036] Figure 7 This is a TEM test photograph of the curved graphene aqueous solution prepared in Example 1 after being left to stand for 24 hours;

[0037] Figure 8 The AFM analysis results of the curved graphene aqueous solution prepared in Example 1 after being left to stand for 24 hours;

[0038] Fig. 9 This is the normal distribution diagram of the curved graphene particle size prepared in Example 1;

[0039] Fig.10 This is the infrared spectrum IR of the curved graphene aqueous solution prepared in Example 1;

[0040] Fig.11 It is a schematic diagram of electron beam bombarding graphite carbon material in the method for preparing curved graphene of the present invention;

[0041] Fig.12 It is a schematic diagram of the effect of ultrasonic changes on the colloidal suspension in the method for preparing curved graphene of the present invention;

[0042] Fig.13 Schematic diagram of the process of functional group modification of the peeled carbon atom layer;

[0043] Fig.14 This is a schematic diagram of the principle of the method for preparing curved graphene of the present invention;

[0044] Fig.15 This is an electron microscope image of the graphite layer of the three-high graphite plate of Example 1 formed under electron beam bombardment and exfoliated into flake graphene;

[0045] Fig.16 This is an electron microscope image of the curved graphene formed by the flaky graphene peeled off in Example 1;

[0046] Fig.17 This is an electron microscope image of the circular or hemispherical curved graphene of Example 1;

[0047] Fig.18 This is an electron microscope image of a partial onion-shaped curved graphene in Example 1. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The embodiments of the present application solve the technical problem of how to prepare curved graphene by providing a curved graphene and a preparation method thereof.

[0050] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0051] Curved graphene is a thermodynamically unstable but kinetically stable metastable substance of carbon. Its structure is that the graphene sheets have a certain curvature, so that the carbon atoms in equilibrium have a certain stress energy and are in a higher energy state. 2-D nanographite material graphene is a planar material and belongs to a stable substance. Therefore, curved graphene is different from 2-D nanographite material graphene. In addition, the curved graphene aqueous solution is very easy to agglomerate due to the strong intermolecular force and has poor dispersibility.

[0052] The energy of carbon in different carbon allotropes is different. The energy of carbon atoms in graphite is zero, which is the most stable state. 60 The maximum energy of carbon atoms in the 240 About 0.15eV, the energy of carbon atoms in carbon nanotubes and diamonds is 0.02-0.03eV. To overcome the stress energy of the graphene bending structure, different carbon allotropes have different formation heats. The most stable graphite has a formation heat of zero Hf(g·c); diamond is 1.67KJ / mol; C 60 is 42.51KJ / mol; C 70 To make graphite change into a curved structure and form different carbon allotropes, higher energy must be applied from the outside to form monodisperse carbon atoms or carbon atom clusters with higher energy in an excited state.

[0053] Based on the above analysis, if Figure 11-14As shown, the present invention suspends a plate-like graphite carbon material (which can be any crystalline, amorphous, natural, or artificial carbon material) in pure water to completely immerse it, and uses an electron beam device to bombard the suspended plate-like graphite carbon material. Under the action of the electric field and electrochemical oxidation, a DC voltage is added to the pure water and the current is gradually increased. With 50A as the limit (the voltage varies with the distance between the electrodes), a carbon atom layer around the anode is precipitated like fog, and the precipitate is suspended in the water in a colloidal state to form a colloidal suspension. At the same time, when the ultrasonic wave changes, the pure water in the colloidal suspension is compressed and rarefied, resulting in rapid movement, thereby generating cavities, so that the unstable microbubbles generate shock waves when they grow and suddenly burst. The shock waves generate a large amount of vibration energy, which further breaks the bonds of pure water molecules and generates a large amount of -COOH, -OH, H + , O 2- Plasma and free radical groups are used to modify the curved graphene structure. During the ultrasonic action, not only can the luminescence phenomenon be observed, but also when the microbubbles burst, up to 10 11 Pa pressure, the center temperature can reach 10 4 -10 6 The inventors have found that the combination of three ultrasonic waves, namely, low frequency 20-40 kHz, medium frequency 60-100 kHz, and high frequency 120-200 kHz, can be alternately emitted into the colloidal suspension to break the bonds of pure water molecules and generate a large number of free radicals (such as -COOH, -OH, H + , O 2- On the other hand, the plane graphene is stretched or compressed by the vibration energy of ultrasonic shock waves and the mechanical stress energy of electron beam bombardment, so that the plane graphene introduces bending strain to form a curved structure. At the same time, by utilizing the characteristics of atomic structure and molecular structure, different resonance energies are input to chemically modify the surface of the curved graphene structure, and the preparation of curved graphene is achieved through controllable resonance energy to obtain a single substance or single functional curved graphene structure.

[0054] Specifically, Figure 1 As shown, a method for preparing curved graphene comprises the following steps: Figure 1 Graphitization is the process of converting any crystalline, amorphous, natural, artificial carbon material or high-purity graphene powder (purity 99.999%; 300-500 mesh) into graphite plates (average particle size 3-20um; volume density 1.70-1.90g / cm 3 ; resistivity 10-16μΩm; compressive strength 80-180MPa thermal expansion coefficient 20-200℃ range 3-510-6 / K), placed in a pretreatment container, and 18MΩ ultrapure water is prepared by a non-ion water purifier and transported to the pretreatment container, and the graphite plate is immersed in ultrapure water for 24h.

[0055] In the electron beam unit, ultrapure water is used as the fluid medium. The electric control device applies a voltage of 2-100 volts between the electrode plate (negative electrode, pure titanium metal plate) and the prepared graphite plate (positive electrode). The negative electrode releases an electron beam to continuously bombard the positive graphite plate for 158-178 hours. The current density generated by the electron beam is 0.01-300mA / cm 2 The bombarded carbon atoms are peeled off layer by layer and suspended in the fluid medium. The suspension is processed by the physical treatment device, sonochemical treatment device and quality monitoring device at a rate of 6.4 m / h. 3 -8.9m 3 In this process, a combination of low-frequency 20-40KHz, medium-frequency 60-100KHz, and high-frequency 120-200KHz ultrasonic waves are alternately emitted into the suspension through high-shear homogenization physical treatment and sonochemical treatment devices. The combined ultrasonic waves compress and rarefy the pure water of the fluid medium and cause strong and rapid movement, thereby generating cavitation of the holes. The shock wave generates a large amount of vibration energy, which further breaks the OH2 bond and produces a large amount of -COOH, -OH, H + , O 2- The groups are used to surface modify the graphite particles peeled off layer by layer to form a curved graphene structure. Since the modified curved graphene structure particles have the same potential, they repel each other, so the prepared curved graphene structure aqueous solution has good dispersibility.

[0056] The electron beam bombardment lasts for 158-178 hours, and the circulating aqueous solution containing the curved graphene particles is detected online by a quality monitoring device. When the mass concentration of the curved graphene aqueous solution is 0.1%-0.45%; the pH value is 1.5-3.2; the ORP is 280mv-380mv; and the conductivity σ is 1-5ms / cm, the aqueous solution of the curved graphene particles meets the standards and enters the liquid carbon solution unit for high-speed centrifugal classification to obtain single-layer curved graphene. At the same time, solid powder, paste and highly concentrated liquid products are prepared by the concentration device.

[0057] The prepared curved graphene has a large specific surface area and good electrical conductivity, and is suitable for use in electronic devices and other fields.

[0058] The graphite carbon material of the present application can also be selected as a graphite plate. Preferably, the graphite plate adopts high-strength, high-density, and high-purity graphite (referred to as "three-high graphite"). The "three-high" graphite material adopts isotropic and isostatically pressed special graphite with ultra-fine particle structure. The "three-high" graphite plate requires precise external dimensions and surface finish processing to improve the electron beam bombardment effect.

[0059] The resistivity of the pure water is greater than 18 MΩ·cm, thereby ensuring that the conductive medium in the water is almost completely removed, and at the same time, the undissociated colloidal substances, gases and organic matter in the water are all removed, and the electron beam is transmitted through the pure water to prepare impurity-free curved graphene.

[0060] The preparation method of the present invention also includes treating and separating the formed curved graphene aqueous solution to obtain a curved graphene product.

[0061] The preparation method of the present invention also includes surface treatment of the plate-like graphite carbon material to improve the electron beam bombardment effect.

[0062] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0063] Embodiment 1:

[0064] This embodiment provides a method for preparing curved graphene, comprising the following steps:

[0065] S1. Preparation of colloidal suspension

[0066] Provide a three-high graphite plate, place the three-high graphite plate in deionized water, the resistivity of the deionized water is 20MΩ·cm, use an electron beam to bombard the surface of the three-high graphite plate, the voltage between the electrode plate and the three-high graphite plate is 2 volts, and the current density is 0.02mA / cm 2 , the bombardment time was 158 h, and a colloidal suspension was formed;

[0067] S2. Preparation of curved graphene

[0068] A combination of low-frequency, medium-frequency and high-frequency ultrasonic waves is alternately emitted into the colloidal suspension, with the low frequency being 20 kHz, the medium frequency being 60 kHz and the high frequency being 120 kHz, to obtain a homogeneous curved graphene aqueous solution.

[0069] The graphite layer of the three-high graphite plate is formed under electron beam bombardment and peeled off into flake graphene. The electron microscope image is as follows Fig.15 As shown in the figure, the peeled graphene flakes are stretched or compressed under the vibration energy of ultrasonic shock waves and the mechanical stress energy of electron beam bombardment to form curved graphene, as shown in the electron microscope image. Fig.16 As shown; the graphene sheet forms a disc or hemisphere during bending, and its electron microscope image is as follows Fig.17 As shown; the curved graphene partially shows an onion-like graphene morphology, and its electron microscope image is as follows Fig.18 shown.

[0070] The prepared curved graphene aqueous solution was tested, with a mass concentration of 0.1%, a pH value of 1.5, an ORP of 280 mv, a conductivity σ of 1 ms / cm, and an electromotive force E of 280 mv.

[0071] The morphology of the prepared curved graphene is shown in the figure Figure 2 shown.

[0072] The prepared curved graphene contains carbon-oxygen single bond structure and carbon-oxygen double bond structure, and its structural schematic diagram is shown in Figure 6 shown.

[0073] After the prepared curved graphene aqueous solution was left to stand for 24 hours, TEM analysis and AFM analysis were performed. The analysis results are shown in Figure 7 and Figure 8 .Depend on Figure 7 and Figure 8 It can be seen that the curved graphene particles have good dispersibility in their aqueous solution, and the results of TEM and AFM analysis are basically consistent.

[0074] The normal distribution diagram of the prepared curved graphene particle size is shown in Fig. 9 shown.

[0075] The curved graphene aqueous solution was analyzed by infrared spectroscopy IR, and the results are as follows Fig.10 .Depend on Fig.10 It can be seen that the infrared spectrum is basically consistent with the spectrum of pure water, and the matching pair reaches 90%, which indicates that the carbon nanoparticle water suspension does not contain any other solvent except water. -1 The peak at 1701cm should be the hydroxyl absorption peak, which is mainly the absorption peak of hydroxyl groups and adsorbed water in the carboxyl groups on the surface of the curved graphene particles; -1 The more obvious absorption peak is the characteristic absorption peak of the C=O group on the surface carboxyl group; 1449cm -1 and 861cm -1 It is the absorption region of carbon-carbon double bonds of condensed aromatic hydrocarbons on the surface of carbon nanoparticles; 1232cm -1 It is the -OH deformation vibration absorption peak of the surface carboxyl group.

[0076] Embodiment 2:

[0077] The difference between this embodiment and embodiment 1 is that the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 5 volts and the current density is 10 mA / cm 2 The bombardment time is 162 hours. The low frequency, medium frequency and high frequency of the ultrasonic combination are 30 kHz, 80 kHz and 150 kHz, and the rest are the same as in Example 1.

[0078] The morphology of the prepared curved graphene is shown in the figure Figure 3 shown.

[0079] The prepared curved graphene aqueous solution has a mass concentration of 0.2%, a pH value of 2.0, an ORP of 250 mv, a conductivity σ of 2 ms / cm, and an electromotive force E of 300 mv.

[0080] Embodiment 3:

[0081] The difference between this embodiment and embodiment 1 is that the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 40 volts and the current density is 50 mA / cm 2 The bombardment time is 170 hours. The low frequency, medium frequency and high frequency of the ultrasonic combination are 35 kHz, 90 kHz and 180 kHz, and the rest are the same as in Example 1.

[0082] The morphology of the prepared curved graphene is shown in the figure Figure 4 shown.

[0083] The prepared curved graphene aqueous solution has a mass concentration of 0.3%, a pH value of 2.5, an ORP of 300 mv, a conductivity σ of 4 ms / cm, and an electromotive force E of 350 mv.

[0084] Embodiment 4:

[0085] The difference between this embodiment and embodiment 1 is that the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 100V and the current density is 200mA / cm 2 The bombardment time is 178 hours. The low frequency of the ultrasonic combination is 40 kHz, the medium frequency is 100 kHz, and the high frequency is 200 kHz. Others are the same as in Example 1.

[0086] The morphology of the prepared curved graphene is shown in the figure Figure 5 shown.

[0087] The mass concentration of the prepared curved graphene aqueous solution is 0.45%, the pH value is 3.2, the ORP is 380mv, the conductivity σ is 5ms / cm, and the electromotive force E is 380mv.

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 1 is that S2 is not included, and the rest is the same as Example 1. The prepared graphene is heterogeneous. It can be seen that the graphite carbon material is first bombarded with an electron beam, and under the field-induced action of the electric field and the electrochemical oxidation, a colloidal suspension is formed when a DC voltage is added to pure water and the current is gradually increased, and then a low-frequency, medium-frequency, and high-frequency ultrasonic combination is alternately emitted. The mechanical stress energy of the electron beam bombardment and the stretching or compression of the changing ultrasonic shock wave vibration energy introduce bending strain into the planar graphene, thereby forming a curved structure. Therefore, the alternating emission of a low-frequency, medium-frequency, and high-frequency ultrasonic combination is a key step in preparing curved graphene.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is that, in electron beam bombardment, the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 1V, and the rest is the same as Example 1. The prepared graphene is heterogeneous.

[0092] Comparative Example 3

[0093] The difference between this comparative example and Example 1 is that, in electron beam bombardment, the voltage between the electrode plate (negative electrode) and the graphite carbon material plate (positive electrode) is 105 V, and the rest is the same as Example 1. The prepared graphene is heterogeneous.

[0094] Comparative Example 4

[0095] The difference between this comparative example and Example 1 is that only low-frequency 20 kHz ultrasonic waves are emitted into the colloidal suspension, and the other conditions are the same as those in Example 1, thereby obtaining heterogeneous graphene.

[0096] Comparative Example 5

[0097] The difference between this comparative example and Example 1 is that only medium-frequency 60 kHz ultrasonic waves are emitted into the colloidal suspension, and the other conditions are the same as those in Example 1, thereby obtaining heterogeneous graphene.

[0098] Comparative Example 6

[0099] The difference between this comparative example and Example 1 is that only high-frequency 120 kHz ultrasonic waves are emitted into the colloidal suspension, and the other steps are the same as Example 1, thereby obtaining heterogeneous graphene.

[0100] Comparative Example 7

[0101] The difference between this comparative example and Example 1 is that air is used instead of pure water as the medium, and the other conditions are the same as Example 1, and the prepared graphene is heterogeneous.

[0102] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0103] First, the graphite carbon material is bombarded with an electron beam. Under the action of the electric field and electrochemical oxidation, a DC voltage is added to pure water and the current is gradually increased to form a colloidal suspension. Then, a combination of low-frequency, medium-frequency, and high-frequency ultrasonic waves is emitted alternately. The mechanical stress energy of the electron beam bombardment and the stretching or compression of the changing ultrasonic shock wave vibration energy introduce bending strain into the planar graphene, thereby forming a curved structure and preparing curved graphene.

[0104] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing curved graphene, characterized in that: The steps include: S1. Preparation of colloidal suspension Providing a graphite carbon material, placing the graphite carbon material in pure water, and bombarding the surface of the graphite carbon material with an electron beam to form a colloidal suspension; S2. Preparation of curved graphene Alternately emitting a combination of ultrasonic waves of 20-40 kHz, 60-100 kHz, and 120-200 kHz into the colloidal suspension to obtain curved graphene; The electron beam bombardment, the voltage between the electrode plate and the graphite carbon material plate is 2-100 volts, and the current density between the electrode plate and the graphite carbon material plate is 0.02-200 mA / cm 2 , bombardment time is 158-178 hours; The curved graphene is an aqueous solution; the mass concentration of the curved graphene aqueous solution is 0.1%-0.45%, and the pH value is 1.5-3.

2.

2. The preparation method according to claim 1, characterized in that The graphite carbon material is selected from any one of crystalline and amorphous carbon materials.

3. The preparation method according to claim 1, characterized in that: The pure water is selected from any one of deionized water, distilled water or ultrapure water, and the resistivity of the pure water is greater than 18 MΩ•cm.

4. The preparation method according to claim 1, characterized in that: The ORP of the curved graphene aqueous solution is 280mv-380mv.

5. The preparation method according to claim 1, characterized in that: The conductivity σ of the curved graphene aqueous solution is 1-5 ms / cm.

6. The preparation method according to claim 1, characterized in that: The electromotive force of the curved graphene aqueous solution is 280mv-380mv.

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