Equipment and method for preparing graphene by plasma-assisted flash Joule heat

Abstract

The invention discloses equipment and a method for preparing graphene by plasma-assisted flash Joule heat. The equipment comprises a central control system, a vacuum system, a signal acquisition system, a power supply system and a tubular rotary reaction device, the central control system is mainly used for issuing and controlling instructions of each area of the equipment; the vacuum system is used for controlling the vacuum degree required by the reaction and is monitored by a vacuum meter in real time; the signal acquisition system acquires temperature, voltage and current during reaction in real time and inputs the temperature, voltage and current to the central control system; the power supply system provides electric energy for the tubular rotary reaction device; the tubular rotary reaction device is used for placing a sample and generating plasma, so that the sample is subjected to uninterrupted plasma treatment and flash Joule heat treatment. According to the equipment, plasma-Joule heat is continuously carried out, a powdery sample can be fully treated, and the problem that the purity of a product after flash evaporation is too poor due to excessive material impurities before heating of traditional Joule heat equipment is remarkably solved.

Description

Technical Field

[0001] The invention belongs to the field of composite material manufacturing, and in particular relates to the preparation of flash vaporized graphene. Background Art

[0002] Graphene is a carbon atom in the form of sp 2 The special structure of the two-dimensional material composed of hybrid orbitals makes it exhibit excellent mechanical, electrical and chemical properties. These properties give it broad prospects in the fields of materials science, energy, biomedicine, etc. The traditional synthesis methods of graphene are divided into top-down exfoliation and bottom-up growth. The high defects caused by the top-down method and the high cost required by the bottom-up method limit the large-scale production of graphene. Flash Joule heating technology is an innovative technology that directly synthesizes large-scale graphene from low-cost carbon sources. It can convert various carbon sources into high-purity graphene in less than 100 milliseconds. This technology is highly efficient, pollution-free, and has high product purity, and is hailed as a revolutionary technology.

[0003] The carbon source selected by the flash Joule heating device usually contains many impurities. The traditional impurity removal method is low-voltage discharge pretreatment. Although this method can quickly remove most of the impurities in the carbon source, it still has the following shortcomings: First, the resistance value of the sample after low-voltage discharge pretreatment is significantly lower than that before pretreatment. Too low resistance value will make it difficult for the sample to rise to the corresponding temperature during the flash Joule heating process, making it difficult to convert the selected carbon source into graphene; second, the energy generated by low-voltage discharge is relatively low, which may lead to incomplete impurity removal, especially for those impurities that are tightly bound to the sample or difficult to decompose. Low voltage may not provide enough energy to decompose or separate from the sample.

[0004] Plasma technology is an applied science involving the fourth state of matter - plasma. Plasma is composed of ions, electrons and neutral particles, is highly active, and can produce various impurity removal effects under the action of electromagnetic fields.

[0005] Compared with the traditional low-voltage discharge pretreatment for impurity removal, plasma impurity removal has high efficiency, does not cause surface damage, and does not change the resistance value of the sample. Therefore, it is proposed to use plasma impurity removal instead of traditional low-voltage discharge pretreatment. However, plasma impurity removal technology is limited to the sample surface. For some powdered or granular samples, it is difficult for plasma to effectively remove impurities from the sample. In addition, if the plasma impurity removal treatment is carried out separately from the flash Joule heat, the more complicated operation process and long-term contact with air will have a negative impact on the purity of the final graphene.

[0006] Therefore, this patent abandons the traditional graphene preparation method and innovatively improves the flash Joule heat equipment to combine it with plasma technology, overcoming the problem that plasma impurity removal technology cannot effectively remove impurities from powdered samples, and designs a device that directly synthesizes high-purity graphene from a carbon source with more impurities. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a device and method for preparing graphene by using Joule heat of plasma-assisted flash evaporation, which can utilize plasma to fully contact with powdered samples without changing the resistance value of the initial samples, effectively remove impurities in the samples, and achieve an ideal pretreatment effect. At the same time, the device can continuously perform the flash evaporation step after plasma treatment, so that the sample is in a vacuum state during the reaction stage, effectively isolated from the external environment, and ensure the purity and preparation efficiency of the sample. In addition, the tubular rotary reaction device used in the present invention has the characteristics of simple structure and easy manufacture, and can be modified as required.

[0008] The present invention is achieved through the following technical solutions:

[0009] A device and method for preparing graphene by plasma-assisted flash evaporation Joule heat, characterized in that: it includes a central control system, a vacuum system, a signal acquisition system, a power supply system, and a tubular rotating reaction device;

[0010] The central control system plays the role of transmitting commands, real-time monitoring, signal acquisition, and alarm processing in the entire equipment, connecting the spectrometer of the signal acquisition system, the voltage and current sensors of the signal acquisition system, and the power supply system;

[0011] The vacuum system includes a vacuum box, a vacuum pump, and a vacuum gauge; the vacuum box is used to place the tubular rotary reaction device, and two exhaust valves are provided on the outer wall, which can adjust the atmospheric pressure in the box to balance with the external atmospheric pressure after the reaction. The good airtightness of the vacuum box can isolate the atmosphere in the box from the external atmosphere, avoiding the introduction of external impurity gases; the vacuum pump is connected to an exhaust valve on one side of the outer wall of the vacuum box, which is used to remove the impurity gases in the box and maintain the required vacuum degree during the reaction; the vacuum gauge is located above the vacuum box, which is used to provide real-time feedback on the vacuum degree in the box;

[0012] The signal acquisition system is used to collect temperature, voltage, and current signals during the reaction process and transmit them to the central control system. The signal acquisition system includes an infrared thermometer, a voltage and current sensor, and the infrared thermometer is embedded in the top groove of the vacuum box in the vacuum system and is connected to the central control system. The voltage and current sensor can measure the voltage on both sides of the sample and the current passing through the sample, and then measure the resistance value of the sample. The voltage and current sensor simultaneously connects the two copper electrodes of the tubular rotating reaction device and the central control system.

[0013] The power supply system is used to provide electric energy to the tubular rotating reaction device, and the power supply system is connected to the tubular rotating reaction device and the central control system;

[0014] The tubular rotary reaction device comprises a bottom plate, a slide rail, a stud, a stud fixing device, an electrode fixing device, a copper electrode, a transmission fixing device, an inner and outer tube fixing device, an inner tube, an outer tube, an inductor coil, and an inductor coil fixing device;

[0015] The bottom plate is used to carry other components in the tubular rotary reaction device, and is bonded to the slide rail, stud fixing device, transmission fixing device, and inner and outer tube fixing devices. The bottom plate is made of wood, and the material can also be selected according to actual needs;

[0016] The slide rail enables the electrode fixing device to slide within a certain range, so that the electrode fixing device cannot fall off the slide rail and cannot collide with the transmission fixing device and the inner and outer tube fixing devices;

[0017] The stud is used to control the position of the electrode fixture. The geometric orientation of the stud is fixed by the stud fixture. Both ends of the stud have threads with different directions, which are engaged with the left and right electrode fixtures respectively, and can rotate under the drive of the motor inside the transmission fixture.

[0018] The electrode fixing device is used to fix the copper electrode, and is composed of a trapezoidal bracket, a sector-shaped chuck, a handle, and a spring. By turning the handle, the precise height of the copper electrode can be adjusted to keep the copper electrode and the inner tube coaxial;

[0019] The transmission fixture is composed of a fixing bracket, a motor, and a bearing. The bearing is embedded in the circular hole on the upper part of the fixing bracket. The motor is located inside the fixing bracket. The transmission fixture can completely fix the outer tube and make the inner tube rotate along the axial direction driven by the motor.

[0020] The inner and outer tube fixtures are composed of a fixing bracket and a bearing. The bearing is embedded in the circular hole on the upper part of the fixing bracket. The bearing in the inner and outer tube fixtures is at the same height and coaxial with the bearing of the transmission fixture. The inner tube is used to place the sample and is the actual reaction site of the sample. The material is quartz. The two ends of the inner tube are embedded in two horizontal bearings on both sides, and the two ends of the outer tube are respectively embedded in the arc grooves of the transmission fixture and the inner and outer tube fixture.

[0021] The inductor coil is used to generate plasma, and the inductor coil fixing device is used to fix the inductor coil, and two ends of the inductor coil are respectively connected to the transmission fixing device and the inner and outer tube fixing devices.

[0022] A device and method for preparing graphene by plasma-assisted flash evaporation Joule heat, characterized by adopting the following steps:

[0023] Step 1: Select a suitable carbon source, such as carbon black, anthracite, metallurgical coke, biomass;

[0024] Step 2: placing the carbon source in the middle of the inner tube of the tubular rotating reaction device;

[0025] Step 3: Move the electrode fixture to both sides, place the copper electrode into the electrode fixture, and adjust the height of the copper electrode by rotating the handle to make it coaxial with the inner tube;

[0026] Step 4: Place the tubular rotary reaction device in a vacuum box, turn on the infrared thermometer, and adjust the position of the tubular rotary reaction device so that the light spot of the infrared thermometer passes through the outer tube and irradiates the middle position of the inner tube to measure the temperature of the reaction sample;

[0027] Step 5: Open the exhaust valve connected to the vacuum pump on the outer wall of the vacuum box, close the exhaust valve connected to the outside world on the outer wall of the vacuum box, close and lock the door of the vacuum box, start the vacuum pump, turn off the vacuum pump when the vacuum reaches about 10 mmHg, and close the exhaust valve connected to the vacuum pump;

[0028] Step 6: applying commands through the central control system, using the power supply system to provide high-frequency alternating current to the inductor coil in the tubular rotating reaction device to generate plasma;

[0029] Step 7: A command is applied through the central control system, and the power supply system is used to power the motor of the tubular rotating reaction device, so that the inner tube containing the powder sample rotates for a period of time, and the powder sample can be fully in contact with the plasma;

[0030] Step 8: Stop supplying power to the inductor of the tubular rotary reaction device, use the power supply system to supply power to the motor of the tubular rotary reaction device, push the pressing device to press the electrodes at both ends, and stop supplying power to the motor when the resistance is adjusted to 1 ohm by controlling the pressure;

[0031] Step 9: Input the corresponding parameters of flash Joule heat into the central control system, and apply commands to the power supply system through the central control system, so that the power supply system supplies power to the copper electrode in the tubular rotary reaction device, and performs instantaneous Joule heating on the sample at a voltage of 120V, so that the sample is heated to a high temperature of about 3000°C within 0.1 seconds, and then cooled to room temperature at an extremely fast speed;

[0032] Step 10: Turn off the power supply system and observe the sample temperature measured by the infrared thermometer. When the temperature reaches about 25°C, open the exhaust valve on one side of the vacuum box connected to the outside world. When the air pressure inside the vacuum box is balanced with the outside air pressure, open the vacuum box door and then take out the sample.

[0033] The present invention has at least the following advantages and effects over the prior art:

[0034] The present invention combines plasma technology with flash evaporation Joule heat technology, so that the reaction raw materials are first subjected to plasma treatment and then subjected to Joule heat reaction, replacing the traditional low-voltage discharge pretreatment process, making impurity removal more thorough, and effectively improving the problem of uncontrollable sample resistance value before flash evaporation;

[0035] The present invention makes the whole reaction process in a vacuum state, so that the reaction sample is effectively isolated from the outside world, avoiding the influence of external conditions on the purity of the product;

[0036] The present invention utilizes a transmission fixing device to rotate the inner tube, so that the sample in the inner tube is continuously turned over, thereby achieving the effect of full contact with the plasma;

[0037] The present invention uses a pressing device to press the copper electrode against the sample, and adjusts the resistance by applying pressure, so that the subsequent flash Joule heating step can be carried out uninterruptedly after the plasma treatment, thereby realizing the continuous progress of the reaction process and significantly improving the experimental efficiency.

[0038] The invention has a relatively simple structure, simple and easy technical means, and has outstanding substantial progress compared with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the overall structure of a device for preparing graphene by plasma-assisted flash evaporation Joule heat;

[0040] Figure 1 Numbers indicate: 1-central control system; 2-1-vacuum box; 2-2-vacuum pump; 2-3-vacuum gauge; 2-4-exhaust valve; 3-1-infrared thermometer; 3-2-voltage and current sensor; 4-power supply system; 5-tubular rotary reaction device;

[0041] Figure 2 It is a process flow chart of equipment and method for preparing graphene by plasma-assisted flash evaporation Joule heat;

[0042] Figure 3 It is a cross-sectional view of a tubular rotary reaction device of an apparatus and method for preparing graphene by plasma-assisted flash evaporation Joule heat;

[0043] Figure 3 The numbers represent: 5-1-base plate, 5-2-slide rail, 5-3-stud, 5-4-stud fixture, 5-5-electrode fixture, 5-6-copper electrode, 5-7-transmission fixture, 5-8-inner and outer tube fixture, 5-9-inner tube, 5-10-outer tube, 5-11-inductor coil, 5-12-inductor coil fixture;

[0044] Figure 4An enlarged view and a cross-sectional view of an electrode fixing device in a tubular rotary reaction device are provided for a device and method for preparing graphene by using Joule heat of plasma-assisted flash evaporation;

[0045] Figure 4 The numbers in the figure represent: 5-5-1-trapezoidal bracket, 5-5-2-sector chuck, 5-5-3-handle, 5-5-4-spring;

[0046] Figure 5 An enlarged view and a cross-sectional view of a transmission fixture in a tubular rotary reaction device of a device and method for preparing graphene by plasma-assisted flash evaporation Joule heat;

[0047] Figure 5 The numbers in the figure represent 5-7-1-fixed bracket, 5-7-2-motor, and 5-7-3-bearing. DETAILED DESCRIPTION

[0048] The technical solution of the embodiment of the present invention will be further described in detail below with reference to the accompanying drawings.

[0049] like Figure 1 As shown, the present invention discloses a device and method for preparing graphene by plasma-assisted flash evaporation Joule heat, comprising a central control system 1, a vacuum system 2, a signal acquisition system 3, a power supply system 4, and a tubular rotating reaction device 5;

[0050] The central control system 1 plays the role of transmitting commands, real-time monitoring, signal acquisition, and alarm processing in the entire device, and is connected to the spectrometer 3-1 of the signal acquisition system, the voltage and current sensor 3-2 of the signal acquisition system, and the power supply system 4;

[0051] The vacuum system includes a vacuum box 2-1, a vacuum pump 2-4, and a vacuum gauge 2-3; the vacuum box 2-1 is used to place a tubular rotary reaction device 5, and two exhaust valves 2-4 are provided on the outer wall, which can adjust the atmospheric pressure in the box to be balanced with the external atmospheric pressure after the reaction. The good airtightness of the vacuum box 2-1 can isolate the atmosphere in the box from the external atmosphere, thereby avoiding the introduction of external impurity gases; the vacuum pump 2-2 is connected to the vacuum box 2-1, and is used to remove the impurity gases in the box and maintain the required vacuum degree during the reaction; the vacuum gauge 2-3 is connected to the vacuum box 2-1, and is used to provide real-time feedback of the vacuum degree in the box;

[0052] The signal acquisition system 3 is used to collect temperature, voltage and current signals during the reaction process and transmit them to the central control system 1. The signal acquisition system 3 includes an infrared thermometer 3-1 and a voltage and current sensor 3-2. The infrared thermometer 3-1 is embedded in the top groove of the vacuum box 2-1 in the vacuum system and is connected to the central control system 1. The voltage and current sensor 3-2 can measure the voltage on both sides of the sample and the current passing through the sample, and then measure the resistance value of the sample. The voltage and current sensor 3-2 is simultaneously connected to the two copper electrodes 5-6 of the tubular rotating reaction device and the central control system 1;

[0053] The power supply system 4 is used to provide electric energy to the tubular rotary reaction device 5, and the power supply system 4 is connected to the tubular rotary reaction device 5 and the central control system 1;

[0054] The tubular rotary reaction device 5 includes a bottom plate 5-1, a slide rail 5-2, a stud 5-3, a stud fixing device 5-4, an electrode fixing device 5-5, a copper electrode 5-6, a transmission fixing device 5-4, an inner and outer tube fixing device 5-8, an inner tube 5-9, an outer tube 5-10, an inductor 5-11, and an inductor fixing device 5-12;

[0055] The bottom plate 5-1 is used to carry other components in the tubular rotary reaction device 5, and is bonded to the slide rail 5-2 and the stud fixing device 5-4. The bottom plate 5-1 is made of wood, and the material can also be selected according to actual needs;

[0056] The slide rail 5-2 enables the electrode fixing device 5-5 to slide within a certain range, so that the electrode fixing device 5 cannot fall off the slide rail 5-2 and cannot collide with the transmission fixing device 5-7 and the inner and outer tube fixing devices 5-8;

[0057] The stud 5-3 is used to control the position of the electrode fixture 5-5. The geometric orientation of the stud 5-3 is fixed by the stud fixture 5-4. The two ends of the stud 5-3 have threads with different directions, which are respectively engaged with the left and right electrode fixtures 5-5, and can rotate under the drive of the motor 5-7-2 inside the transmission fixture.

[0058] The electrode fixing device 5-5 is used to fix the copper electrode 5-6, and is composed of a trapezoidal bracket 5-5-1, a sector-shaped chuck 5-5-2, a handle 5-5-3, and a spring 5-5-4. By turning the handle 5-5-3, the precise height of the copper electrode 5-6 can be adjusted so that the copper electrode 5-6 and the inner tube 5-9 remain coaxial;

[0059] The transmission fixture 5-7 is composed of a fixing bracket 5-7-1, a motor 5-7-2, and a bearing 5-7-3. The bearing 5-7-3 is embedded in the round hole on the upper part of the fixing bracket. The motor 5-7-2 is located inside the fixing bracket 5-7-1. The transmission fixture 5-7 can completely fix the outer tube 5-10 and make the inner tube 5-9 rotate along the axial direction driven by the motor 5-7-2.

[0060] The inner and outer tube fixture 5-8 is composed of a fixing bracket 5-7-1 and a bearing 5-7-3. The bearing 5-7-3 is embedded in the circular hole on the upper part of the fixing bracket 5-7-1. The bearing 5-7-3 in the inner and outer tube fixture is at the same height and coaxial with the bearing 5-7-3 of the transmission fixture. The inner tube 5-9 is used to place the sample as the actual reaction site of the sample. The material is quartz. The two ends of the inner tube 5-9 are embedded in two horizontal bearings 5-7-3 on both sides. The two ends of the outer tube 5-10 are respectively embedded in the arc grooves of the transmission fixture 5-7 and the inner and outer tube fixture 5-8;

[0061] The inductor coil 5-11 is used to generate plasma, and the inductor coil fixing device 5-12 is used to fix the inductor coil 5-11, and its two ends are respectively connected to the transmission fixing device 5-7 and the inner and outer tube fixing devices 5-8.

[0062] A specific process of a device and method for preparing graphene by plasma-assisted flash evaporation Joule heat includes the following steps:

[0063] Step 1: Weigh 0.1g of carbon black.

[0064] Step 2: Place carbon black into the middle of the inner tube of the tubular rotating reactor.

[0065] Step 3: Move the electrode fixture to both sides, place the copper electrode into the electrode fixture, and adjust the height of the copper electrode by rotating the handle to make it coaxial with the inner tube.

[0066] Step 4: Place the tubular rotating reaction device in a vacuum box, turn on the infrared thermometer, and adjust the position of the tubular rotating reaction device so that the light spot of the infrared thermometer passes through the outer tube and shines on the middle position of the inner tube to measure the temperature of the reaction sample.

[0067] Step 5: Open the exhaust valve connected to the vacuum pump on the outer wall of the vacuum box, close the exhaust valve connected to the outside world on the outer wall of the vacuum box, close and lock the door of the vacuum box, start the vacuum pump, turn off the vacuum pump when the pressure reaches about 10 mmHg, and close the exhaust valve connected to the vacuum pump.

[0068] Step 6: A command is issued through the central control system, and a power supply system is used to provide high-frequency alternating current to the inductor coil in the tubular rotating reaction device to generate plasma.

[0069] Step 7: A command is applied through the central control system, and the power supply system is used to power the motor of the tubular rotating reaction device, so that the inner tube containing the powder sample rotates for a period of time, and the powder sample can be fully in contact with the plasma.

[0070] Step 8: Stop supplying power to the inductor coil of the tubular rotary reaction device, use the power supply system to supply power to the motor of the tubular rotary reaction device, push the clamping device to clamp the electrodes at both ends, and stop supplying power to the motor when the resistance is adjusted to about 1 ohm by controlling the pressure.

[0071] Step nine: Input the corresponding parameters of flash Joule heat into the central control system, and apply commands to the power supply system through the central control system, so that the power supply system supplies power to the copper electrodes in the tubular rotating reactor, and performs instantaneous Joule heating on the sample at a voltage of 120V, so that the sample is heated to a high temperature of about 3000°C within 0.1 seconds, and then cooled to room temperature at an extremely fast speed.

[0072] Step 10: Turn off the power supply system and observe the sample temperature measured by the infrared thermometer. When the temperature reaches about 25°C, open the exhaust valve on one side of the vacuum box connected to the outside world. When the air pressure inside the vacuum box is balanced with the outside air pressure, open the vacuum box door and then take out the sample.

Claims

1. A device and method for preparing graphene by plasma-assisted flash evaporation Joule heat, comprising a central control system, a vacuum system, a signal acquisition system, a power supply system, and a tubular rotating reaction device; The central control system plays the role of transmitting commands, real-time monitoring, signal acquisition, and alarm processing in the entire device, and is connected to the spectrometer of the signal acquisition system, the voltage and current sensors of the signal acquisition system, and the power supply system; The vacuum system includes a vacuum box, a vacuum pump, and a vacuum gauge; the vacuum box is used to place a tubular rotary reaction device, and two exhaust valves are provided on the outer wall, which can adjust the atmospheric pressure in the box to be balanced with the external atmospheric pressure after the reaction. The good airtightness of the vacuum box can isolate the atmosphere in the box from the external atmosphere, thereby avoiding the introduction of external impurity gases; the vacuum pump is connected to an exhaust valve on one side of the outer wall of the vacuum box, and is used to remove the impurity gases in the box and maintain the required vacuum degree during the reaction; the vacuum gauge is located above the vacuum box, and is used to provide real-time feedback on the vacuum degree in the box; The signal acquisition system is used to collect temperature, voltage, and current signals during the reaction process and transmit them to the central control system. The signal acquisition system includes an infrared thermometer, a voltage and current sensor, the infrared thermometer is embedded in the top groove of the vacuum box in the vacuum system, and is connected to the central control system. The voltage and current sensor can measure the voltage on both sides of the sample and the current passing through the sample, and then can measure the resistance value of the sample. The voltage and current sensor simultaneously connects the two copper electrodes of the tubular rotating reaction device and the central control system; The power supply system is used to provide electric energy to the tubular rotary reaction device, and the power supply system is connected to the tubular rotary reaction device and the central control system; The tubular rotary reaction device comprises a bottom plate, a slide rail, a stud, a stud fixing device, an electrode fixing device, a copper electrode, a transmission fixing device, an inner and outer tube fixing device, an inner tube, an outer tube, an inductor coil, and an inductor coil fixing device; The bottom plate is used to carry other components in the tubular rotary reaction device, and is bonded to the slide rail, stud fixing device, transmission fixing device, and inner and outer tube fixing devices. The bottom plate is made of wood, and the material can also be selected according to actual needs; The slide rail enables the electrode fixing device to slide within a certain range, so that the electrode fixing device cannot fall off the slide rail and cannot collide with the transmission fixing device and the inner and outer tube fixing devices; The stud is used to control the position of the electrode fixture. The geometric orientation of the stud is fixed by the stud fixture. Both ends of the stud have threads with different directions, which are engaged with the left and right electrode fixtures respectively, and can rotate under the drive of the motor inside the transmission fixture. The electrode fixing device is used to fix the copper electrode, and is composed of a trapezoidal bracket, a sector-shaped chuck, a handle, and a spring. By turning the handle, the precise height of the copper electrode can be adjusted to keep the copper electrode and the inner tube coaxial; The transmission fixture is composed of a fixing bracket, a motor, and a bearing. The bearing is embedded in the circular hole on the upper part of the fixing bracket. The motor is located inside the fixing bracket. The transmission fixture can completely fix the outer tube and make the inner tube rotate along the axial direction driven by the motor. The inner and outer tube fixtures are composed of a fixing bracket and a bearing. The bearing is embedded in the circular hole on the upper part of the fixing bracket. The bearing in the inner and outer tube fixtures is at the same height and coaxial with the bearing of the transmission fixture. The inner tube is used to place the sample and is the actual reaction site of the sample. The material is quartz. The two ends of the inner tube are embedded in two horizontal bearings on both sides, and the two ends of the outer tube are respectively embedded in the arc grooves of the transmission fixture and the inner and outer tube fixture. The inductor coil is used to generate plasma, and the inductor coil fixing device is used to fix the inductor coil, and two ends of the inductor coil are respectively connected to the transmission fixing device and the inner and outer tube fixing devices.

2. The device and method for preparing graphene by plasma-assisted flash evaporation Joule heat according to claim 1, characterized in that: A novel tubular rotating reaction device was designed, which rotates repeatedly when the powder sample is treated with plasma, so that the powder sample is fully in contact with the plasma, improving the problem of insufficient and uneven powder sample treatment in traditional plasma treatment.

3. The device and method for preparing graphene by plasma-assisted flash evaporation Joule heat according to claim 1, characterized in that: In the tubular rotary reaction device, the electrode fixing device can move the copper electrodes connected to the wires closer to each other to press the sample after plasma treatment, and adjust the resistance by setting the pressure of compression. This device can make the sample realize uninterrupted plasma treatment and flash Joule heat under vacuum conditions, improving efficiency while avoiding the influence of the external environment on the purity of the product.

4. The device and method for preparing graphene by plasma-assisted flash evaporation Joule heat according to claim 1, characterized in that Take the following steps: Step 1: Select a suitable carbon source, such as carbon black, anthracite, metallurgical coke, biomass; Step 2: placing the carbon source in the middle of the inner tube of the tubular rotating reaction device; Step 3: Move the electrode fixture to both sides, place the copper electrode into the electrode fixture, and adjust the height of the copper electrode by rotating the handle to make it coaxial with the inner tube; Step 4: Place the tubular rotary reaction device in a vacuum box, turn on the infrared thermometer, and adjust the position of the tubular rotary reaction device so that the light spot of the infrared thermometer passes through the outer tube and irradiates the middle position of the inner tube to measure the temperature of the reaction sample; Step 5: Open the exhaust valve connected to the vacuum pump on the outer wall of the vacuum box, close the exhaust valve connected to the outside world on the outer wall of the vacuum box, close and lock the door of the vacuum box, start the vacuum pump, turn off the vacuum pump when the vacuum reaches about 10 mmHg, and close the exhaust valve connected to the vacuum pump; Step 6: applying commands through the central control system, using the power supply system to provide high-frequency alternating current to the inductor coil in the tubular rotating reaction device to generate plasma; Step 7: A command is applied through the central control system, and the power supply system is used to power the motor of the tubular rotating reaction device, so that the inner tube containing the powder sample rotates for a period of time, and the powder sample can be fully in contact with the plasma; Step 8: Stop supplying power to the inductor of the tubular rotary reaction device, use the power supply system to supply power to the motor of the tubular rotary reaction device, push the pressing device to press the electrodes at both ends, and stop supplying power to the motor when the resistance is adjusted to 1 ohm by controlling the pressure; Step 9: Input the corresponding parameters of flash Joule heat into the central control system, and apply commands to the power supply system through the central control system, so that the power supply system supplies power to the copper electrode in the tubular rotary reaction device, and performs instantaneous Joule heating on the sample at a voltage of 120V, so that the sample is heated to a high temperature of about 3000°C within 0.1 seconds, and then cooled to room temperature at an extremely fast speed; Step 10: Turn off the power supply system and observe the sample temperature measured by the infrared thermometer. When the temperature reaches about 25°C, open the exhaust valve on one side of the vacuum box connected to the outside world. When the air pressure inside the vacuum box is balanced with the outside air pressure, open the vacuum box door and then take out the sample.

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