Intrinsic defect graphene and preparation method thereof

Abstract

The invention relates to the technical field of preparation of nano carbon materials, in particular to intrinsic defect graphene and a preparation method thereof.The preparation method comprises the steps that high-purity graphite powder and benzoyl peroxide are mixed and ground, and gray powder is obtained; calcining the gray powder at a constant temperature under an air atmosphere condition, and naturally cooling to room temperature to obtain black expansion powder; calcining the black expanded powder at a constant temperature under an ammonia atmosphere condition, and naturally cooling to room temperature to obtain nitrogen-doped graphite; and pressing the nitrogen-doped graphite into a rod, taking the rod as an anode of an electric arc furnace, taking a high-purity graphite rod as a cathode of the electric arc furnace, carrying out arc discharge under the atmosphere conditions of hydrogen and protective gas, and collecting soot generated in a furnace chamber after the anode rod is completely consumed, so as to obtain the intrinsic defect graphene. According to the invention, graphene or heteroatom-doped graphene is not needed as a premise, high-purity graphene can be directly used as a precursor, and the problems of high cost and low efficiency in the existing intrinsic defect graphene preparation method are solved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of nano carbon materials, and in particular to intrinsic defect graphene and a preparation method thereof. Background Art

[0002] Studies have shown that the structure of graphene is composed of sp 2 It is composed of carbon atoms, has good conductivity and high stability, but has no catalytic / energy storage activity. Intrinsic defects help to regulate the energy band structure of graphene, increase reactive sites, and improve its surface electron transport process, thereby giving it higher electrochemical activity. Therefore, introducing intrinsic defects into the structure of graphene, that is, preparing intrinsic defect graphene, has attracted widespread attention from scientists in the field of catalysis / energy storage.

[0003] The existing methods for preparing intrinsic defect graphene mainly include the following: 1) using plasma equipment to etch milligram-level graphene (Appl. Catal. A-Gen., 2017, 529: 127-133); 2) treating heteroatom-doped graphene at high temperature (≥1100°C) and inert atmosphere (Jia et al, Adv. Mater., 2016, 28, 9532); 3) using CVD method, using calcium oxide as template and catalyst, to prepare a small amount of intrinsic defect graphene with a layered structure under high temperature conditions (Tang et al, Adv. Funct. Mater., 2016, 26(4): 577-585); 4) using scanning electron microscopy to photoetch trace graphene nanosheets (O'Hem et al, Nano Letters, 2014, 14(3): 1234-1241).

[0004] In summary, it can be seen that the existing technical means need to use graphene or heteroatoms as precursors when preparing intrinsic defect graphene, and some methods also require the use of plasma equipment or scanning electron microscopes, which are costly. In addition, the single product preparation amount of the existing technology is low, and the output can only reach the milligram level, which is inefficient and cannot meet the needs of large-scale actual production and application. Therefore, seeking a low-cost and high-efficiency method for preparing intrinsic defect graphene is still an important problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide an intrinsic defect graphene and a preparation method thereof. The present invention does not require graphene or heteroatom-doped graphene as a prerequisite, and can directly use high-purity graphene as a precursor, thereby solving the problems of high cost and low efficiency in the existing preparation methods of intrinsic defect graphene.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A preparation method of intrinsic defect graphene, comprising the following steps:

[0008] Mix high-purity graphite powder with benzoyl peroxide and grind to obtain a gray powder. Calcinate the gray powder at a constant temperature under an air atmosphere. After benzoyl peroxide is uniformly mixed with the graphite powder, calcination in air can turn the graphite powder into expanded graphite, increasing the spacing of the graphite and providing a better doping path for the subsequent doping of nitrogen atoms. It is easier for nitrogen atoms to be doped into the graphite layer or surface. Naturally cool to room temperature to obtain a black expanded powder.

[0009] Calcinate the black expanded powder at a constant temperature under an ammonia atmosphere to dope nitrogen atoms into the graphite layer or surface. Naturally cool to room temperature to obtain nitrogen-doped graphite.

[0010] Press the nitrogen-doped graphite into a rod and use it as the anode of an arc furnace. Use a high-purity graphite rod as the cathode of the arc furnace. Under a hydrogen and protective gas atmosphere, perform arc discharge. During the process of exfoliating graphite by arc discharge, use the high temperature during arc discharge to remove the nitrogen atoms between the graphite layers, forming vacancies, thereby creating intrinsic defects. After the anode rod is consumed, collect the soot generated in the furnace cavity to obtain intrinsic defect graphene.

[0011] The present invention does not require graphene or heteroatom-doped graphene as a precursor. It can directly use high-purity graphite powder as a precursor and first uses an arc furnace to prepare intrinsic defect graphene. Press the nitrogen-doped graphite into a rod and use it as an electrode. By means of a one-step rapid arc discharge, when obtaining graphene, synchronously and selectively remove the nitrogen atoms in its structure to form vacancies and convert it into intrinsic defect graphene. It is fast, efficient, and has a high single-product preparation amount. The output can reach the gram level, solving the problems of high cost and low efficiency in the existing preparation methods of intrinsic graphene.

[0012] In a preferred embodiment of the present invention, the arc discharge voltage is 12V - 20V and the current is 110A - 130A.

[0013] In a preferred embodiment of the present invention, the mass ratio of high-purity graphite powder to benzoyl peroxide is 1 - 3:1.

[0014] In a preferred embodiment of the present invention, the constant temperature calcination temperature of the gray powder under an air atmosphere is 120°C - 150°C, and the calcination time is 20min - 30min.

[0015] In a preferred embodiment of the present invention, the constant temperature calcination temperature of the black expanded powder under an ammonia atmosphere is 800°C - 900°C, and the calcination time is 1h - 3h.

[0016] In a preferred embodiment of the present invention, the diameter of the high-purity graphite rod is 8mm - 12mm.

[0017] In a preferred embodiment of the present invention, the protective gas is one or a mixture of nitrogen, argon, and helium.

[0018] In a preferred embodiment of the present invention, the grinding time is 30 min to 40 min.

[0019] In a preferred embodiment of the present invention, the purity of the graphite powder is ≥99.9%.

[0020] Another object of the present invention is to provide an intrinsic defect graphene prepared by the preparation method described in any one of the above.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. In the present invention, high-purity graphite powder is mixed with benzoyl peroxide to obtain a gray powder. The gray powder is calcined at a constant temperature in an air atmosphere. After benzoyl peroxide is uniformly mixed with graphite, calcination in air can turn the graphite powder into expanded graphite, increasing the distance between the graphite layers, providing a better doping path for the subsequent doping of nitrogen atoms, making it easier for nitrogen atoms to be doped into the graphite interlayer or surface, and obtaining a black expanded powder. The black expanded powder is calcined at a constant temperature in an ammonia atmosphere to dope nitrogen atoms into the graphite interlayer or surface, obtaining nitrogen-doped graphite. The nitrogen-doped graphite is pressed into a rod and used as the anode of an electric arc furnace, and a high-purity graphite rod is used as the cathode of the electric arc furnace. Under the atmosphere of hydrogen and protective gas, arc discharge is carried out. During the arc discharge, while exfoliating the graphite, the nitrogen atoms between the graphite layers are removed by the high temperature during the arc discharge to form vacancies, thereby creating intrinsic defects. After the anode rod is consumed, the soot generated in the furnace cavity is collected to obtain intrinsic defect graphene. The present invention does not require graphene or heteroatom-doped graphene as a precursor, can directly use high-purity graphite powder as a precursor, and for the first time uses an electric arc furnace to prepare intrinsic defect graphene. The nitrogen-doped graphite is pressed into a rod and used as an electrode. By means of one-step rapid arc discharge, when obtaining graphene, the nitrogen atoms in its structure are synchronously selectively removed to form vacancies, and it is transformed into intrinsic defect graphene. The speed is fast, the efficiency is high, the single-product preparation amount is high, and the output can reach the gram level, solving the problems of high cost and low efficiency in the existing preparation methods of intrinsic graphene.

[0023] 2. The raw materials such as benzoyl peroxide involved in the preparation process of the present invention are cheap and easily available, and the cost is low. In addition, by adjusting the calcination time under the ammonia atmosphere to adjust the nitrogen content of the nitrogen-doped graphite, the beneficial effect of controlling the defect content in the intrinsic defect graphene can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 1 of the present invention.

[0025] Figure 2 This is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 2 of the present invention.

[0026] Figure 3 This is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 3 of the present invention.

[0027] Figure 4 This is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 4 of the present invention.

[0028] Figure 5 This is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 5 of the present invention.

[0029] Figure 6 In it, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 1, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene.

[0030] Figure 7 In it, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 2, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene.

[0031] Figure 8 In it, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 3, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene.

[0032] Figure 9 In it, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 4, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene.

[0033] Figure 10 In it, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 5, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. Detailed implementation manners

[0034] Next, in combination with the embodiments of the present invention, with the help of preferred embodiments and accompanying drawings, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] It should be noted that all the professional terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be obtained through market purchase or prepared by existing methods.

[0036] Example 1

[0037] A preparation method of intrinsic defect graphene includes the following steps:

[0038] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 3:1, and grind for 30 min to obtain a gray powder.

[0039] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 120 °C in an air atmosphere for 20 min, and then naturally cool it to room temperature to obtain black expanded graphite.

[0040] (3) Calcinate the black expanded graphite at a constant temperature of 800 °C in an ammonia atmosphere for 2 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0041] (4) Press the nitrogen-doped graphite into a rod with a diameter of 6 mm as the anode of the arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, carry out arc discharge. The volume ratio of hydrogen to protective gas is 1:3, the arc discharge voltage is 15 V, and the current is 120 A until the anode rod is consumed. After the furnace body is cooled to room temperature, collect the soot generated in the furnace cavity. This soot is the intrinsic defect graphene.

[0042] Figure 1 The transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 1 is shown. It can be seen that the intrinsic graphene is sheet-shaped and the edges are curled, and the sheet size is between 200 nm and 500 nm.

[0043] Figure 6 In the figure, A is the high-resolution N 1s spectrum of nitrogen-doped graphite of the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 1, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. Through the N 1s spectra before and after the arc in the XPS spectrum, it can be seen that before and after the introduction of the intrinsic defect, the nitrogen content decreases from 5.47 at.% to 0.16 at.%, indicating that the method of the present invention can remove the nitrogen atoms between the graphite layers by the high temperature (4000 K - 6000 K) during the arc discharge while peeling the graphite by the arc discharge method, thereby creating intrinsic defects. These results show that the present invention can successfully prepare graphene with intrinsic defects.

[0044] Example 2

[0045] A preparation method of intrinsic defect graphene, comprising the following steps:

[0046] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 3:1, and grind for 40 min to obtain a gray powder.

[0047] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 130 °C in an air atmosphere for 20 min, and then naturally cool it to room temperature to obtain black expanded graphite.

[0048] (3) Calcine the black expanded graphite at a constant temperature of 850 °C in an ammonia atmosphere for 2 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0049] (4) Press the nitrogen-doped graphite into a rod with a diameter of 7 mm as the anode of an arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and a protective gas, perform arc discharge. The volume ratio of hydrogen to the protective gas is 1:3, the arc discharge voltage is 15 V, and the current is 120 A until the anode rod is consumed. Wait for the furnace body to cool to room temperature, and collect the soot generated in the furnace cavity. This soot is the intrinsic defect graphene.

[0050] Figure 2 It is the transmission electron microscope photo of the intrinsic defect graphene prepared in Example 2. It can be seen that the intrinsic defect graphene prepared in Example 2 has a sheet structure with curled edges, and the average size is between 200 nm and 500 nm. Figure 7 In it, A is the high-resolution N 1s spectrum of the nitrogen-doped graphite of the X-ray photoelectron energy spectrum of the intrinsic defect graphene prepared in Example 2, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. It can be seen from the N 1s spectra before and after the arc in the XPS spectrum that the nitrogen content decreases from 6.05 at.% to 0.19 at.% before and after the introduction of the intrinsic defect.

[0051] Example 3

[0052] A preparation method of intrinsic defect graphene, comprising the following steps:

[0053] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 3:1, and grind for 40 min to obtain a gray powder.

[0054] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 150 °C in an air atmosphere for 20 min, and then naturally cool it to room temperature to obtain black expanded graphite.

[0055] (3) Calcine the black expanded graphite at a constant temperature of 900 °C in an ammonia atmosphere for 1 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0056] (4) Press the nitrogen-doped graphite into a rod with a diameter of 8 mm as the anode of the arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, perform arc discharge. The volume ratio of hydrogen to the protective gas is 1:3, the arc discharge voltage is 15 V, and the current is 120 A until the anode rod is consumed. After the furnace body cools to room temperature, collect the soot generated in the furnace cavity. This soot is the intrinsic defect graphene.

[0057] Figure 3 It is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 3. It can be seen that the intrinsic defect graphene prepared in Example 3 has a lamellar structure with curled edges, and the average size is between 200 nm and 500 nm. Figure 8 In it, A is the high-resolution N 1s spectrum of the X-ray photoelectron spectroscopy nitrogen-doped graphite of the intrinsic defect graphene prepared in Example 3, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. It can be seen from the N 1s spectra before and after the arc in the XPS spectrum that the nitrogen content decreases from 6.02 at.% to 0.14 at.% before and after the introduction of the intrinsic defect.

[0058] Example 4

[0059] A preparation method of intrinsic defect graphene includes the following steps:

[0060] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 3:1, and grind for 30 min to obtain a gray powder.

[0061] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 150 °C in an air atmosphere for 30 min, and then naturally cool it to room temperature to obtain black expanded graphite.

[0062] (3) Calcinate the black expanded graphite at a constant temperature of 900 °C in an ammonia atmosphere for 2 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0063] (4) Press the nitrogen-doped graphite into a rod with a diameter of 8 mm as the anode of the arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, perform arc discharge. The volume ratio of hydrogen to the protective gas is 1:3, the arc discharge voltage is 15 V, and the current is 120 A until the anode rod is consumed. After the furnace body cools to room temperature, collect the soot generated in the furnace cavity. This soot is the intrinsic defect graphene.

[0064] Figure 4 It is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 4. It can be seen that the intrinsic defect graphene prepared in Example 4 has a lamellar structure with curled edges, and the average size is between 200 nm and 500 nm.Figure 9 Among them, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 4, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. It can be seen from the N 1s spectra before and after the arc in the XPS spectrum that the nitrogen content decreases from 6.93 at.% to 0.22 at.% before and after the introduction of the intrinsic defect.

[0065] Example 5

[0066] A preparation method of intrinsic defect graphene includes the following steps:

[0067] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 3:1, and grind for 40 min to obtain a gray powder.

[0068] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 150 °C in an air atmosphere for 30 min, and then naturally cool it to room temperature to obtain black expanded graphite.

[0069] (3) Calcinate the black expanded graphite at a constant temperature of 900 °C in an ammonia atmosphere for 3 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0070] (4) Press the nitrogen-doped graphite into a rod with a diameter of 8 mm as the anode of the arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, carry out arc discharge. The volume ratio of hydrogen to the protective gas is 1:3, the arc discharge voltage is 15 V, and the current is 120 A until the anode rod is consumed. Wait for the furnace body to cool to room temperature, and collect the soot generated in the furnace cavity. This soot is the intrinsic defect graphene.

[0071] Figure 5 is the transmission electron microscope photograph of the intrinsic defect graphene prepared in Example 5. It can be seen that the intrinsic defect graphene prepared in Example 5 has a lamellar structure with curled edges, and the average size is between 200 nm and 500 nm. Figure 10 Among them, A is the high-resolution N 1s spectrum of nitrogen-doped graphite in the X-ray photoelectron spectrum of the intrinsic defect graphene prepared in Example 5, and B is the high-resolution N 1s spectrum of the intrinsic defect graphene. It can be seen from the N 1s spectra before and after the arc in the XPS spectrum that the nitrogen content decreases from 8.43 at.% to 0.27 at.% before and after the introduction of the intrinsic defect.

[0072] Example 6

[0073] A preparation method of intrinsic defect graphene includes the following steps:

[0074] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 1:1, and grind for 35 min to obtain a gray powder.

[0075] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 120 °C in an air atmosphere for 25 min, and then naturally cool it to room temperature to obtain expanded graphite.

[0076] (3) Calcinate the expanded graphite at a constant temperature of 800 °C in an ammonia atmosphere for 2 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0077] (4) Press the nitrogen-doped graphite into a rod with a diameter of 6 mm as the anode of an arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, carry out arc discharge. The volume ratio of hydrogen to protective gas is 1:3, the arc discharge voltage is 12 V, and the current is 130 A until the anode rod is consumed. After the furnace body is cooled to room temperature, collect the soot generated in the furnace cavity, and this soot is the intrinsic defect graphene.

[0078] Example 7

[0079] A method for preparing intrinsic defect graphene, comprising the following steps:

[0080] (1) Mix high-purity graphite powder with a purity of 99.9% and benzoyl peroxide in a mass ratio of 2:1, and grind for 35 min to obtain a gray powder.

[0081] (2) Place the gray powder in a crucible, and calcine it at a constant temperature of 120 °C in an air atmosphere for 20 min, and then naturally cool it to room temperature to obtain expanded graphite.

[0082] (3) Calcinate the expanded graphite at a constant temperature of 800 °C in an ammonia atmosphere for 2 h, and then naturally cool it to room temperature to obtain nitrogen-doped graphite.

[0083] (4) Press the nitrogen-doped graphite into a rod with a diameter of 6 mm as the anode of an arc furnace, and use a high-purity graphite rod as the cathode. Under the condition of a mixed atmosphere of hydrogen and protective gas, carry out arc discharge. The volume ratio of hydrogen to protective gas is 1:3, the arc discharge voltage is 20 V, and the current is 110 A until the anode rod is consumed. After the furnace body is cooled to room temperature, collect the soot generated in the furnace cavity, and this soot is the intrinsic defect graphene.

[0084] In summary, the present invention does not require graphene or heteroatom-doped graphene as a precursor, and can directly use high-purity graphite powder as a precursor. For the first time, intrinsic defective graphene is prepared by an electric arc furnace. Nitrogen-doped graphite is pressed into a rod as an electrode, and through a one-step rapid arc discharge, when graphene is obtained, nitrogen atoms in its structure are synchronously and selectively removed to form vacancies, converting it into intrinsic defective graphene. This method is fast, efficient, and has a high single-product preparation amount, with the output reaching the gram level, solving the problems of high cost and low efficiency in the existing preparation methods of intrinsic graphene.

[0085] It should be noted that when the present invention involves a numerical range, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the adopted step methods are the same as those in the embodiments, to prevent repetition, the present invention describes preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0086] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A method for preparing intrinsic defect graphene, characterized in that: The following steps are involved: Mixing graphite powder and benzoyl peroxide, grinding to obtain mixed powder, calcining the mixed powder at a constant temperature under air atmosphere to convert the graphite powder into expanded graphite, increasing the interlayer spacing of the graphite, and naturally cooling to room temperature to obtain expanded graphite; The expanded graphite is calcined at a constant temperature under an ammonia atmosphere to allow nitrogen atoms to be doped into the interlayers or surface of the graphite, and then naturally cooled to room temperature to obtain nitrogen-doped graphite; The nitrogen-doped graphite is pressed into a rod as the anode of an electric arc furnace, and the graphite rod is used as the cathode of the electric arc furnace. Arc discharge is performed under hydrogen and protective gas atmosphere conditions, and nitrogen atoms between graphite layers are removed to form vacancies. After the anode rod is consumed, soot generated in the furnace chamber is collected to obtain intrinsic defect graphene.

2. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The arc discharge voltage is 12V~20V, and the current is 110A~130A.

3. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The mass ratio of graphite powder to benzoyl peroxide is 1 to 3:

1.

4. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The mixed powder is calcined at a constant temperature of 120° C. to 150° C. in an air atmosphere, and the calcination time is 20 min to 30 min.

5. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The expanded graphite is calcined at a constant temperature of 800°C to 900°C under an ammonia atmosphere, and the calcination time is 1h to 3h.

6. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The diameter of the grinding rod is 8mm to 12mm.

7. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The shielding gas is a mixture of one or more of nitrogen, argon and helium.

8. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The grinding time is 30min to 40min.

9. The method for preparing intrinsic defect graphene according to claim 1, characterized in that: The purity of graphite powder is ≥99.9%.

10. Intrinsic defect graphene obtained by the preparation method according to any one of claims 1 to 9.

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