Graphene preparation device

Abstract

The utility model relates to the technical field of graphene production equipment, in particular to a graphene preparation device which comprises a microwave source, a waveguide chamber and a reaction chamber. The microwave source is used for emitting microwaves into the waveguide cavity; the waveguide chamber is fixedly connected with the reaction chamber, and the waveguide chamber is communicated with the reaction chamber; the cross section of the waveguide cavity is rectangular, and the projection of the cavity wall of the reaction cavity in a set plane coincides with the projection of the cavity wall of the waveguide cavity in the set plane. Graphene oxide is placed in a reaction area with the strongest microwave capacity in a reaction chamber, a rectangular waveguide chamber is adopted as a microwave transmission module, and meanwhile, due to the fact that the projection of the chamber wall of the reaction chamber in a set plane coincides with the projection of the chamber wall of the waveguide chamber in the set plane, microwaves are transmitted in the reaction area in a single mode; the energy is concentrated in the reaction area, the electric field intensity is improved, and the graphene oxide is instantly radiated by a high-strength microwave field, so that the deoxidation reaction and defect repair can be completed in a relatively short time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of graphene production equipment, and particularly to a graphene preparation device. Background Art

[0002] Graphene is a material composed of single-layer sp 2 hybridized carbon atoms arranged in a honeycomb lattice, and has excellent mechanical, electrical and thermal properties. The ability to mass-produce high-quality graphene is crucial for its widespread adoption in industrial applications. Currently, graphene oxide has become a key precursor for preparing graphene. However, during the preparation of graphene oxide, the oxidation reaction introduces a large number of oxygen-containing functional groups (such as hydroxyl, carbonyl and carboxyl groups, etc.) on the surface of graphene, destroying the π-π conjugate structure of graphene. Therefore, a reduction step is required to remove or partially remove the oxygen atoms in graphene oxide and restore its conjugate properties.

[0003] In the related art, when graphene oxide is irradiated by microwaves in the reaction zone with the strongest microwave energy, its temperature will rise. During the high-temperature process, the oxygen-containing functional groups are thermally decomposed, and part of the carbon repairs its own structural defects. However, the electric field intensity in the reaction zone of the existing multimode microwave oven cavity is insufficient, resulting in a long time for the deoxidation reaction and defect repair of graphene oxide and high energy consumption. Summary of the Utility Model

[0004] The purpose of the present disclosure is to provide a graphene preparation device to shorten the time for the deoxidation reaction and defect repair of graphene oxide and reduce energy consumption.

[0005] Based on the above purpose, the present disclosure provides a graphene preparation device, including a microwave source, a waveguide chamber and a reaction chamber; the microwave source is used to emit microwaves into the waveguide chamber; the waveguide chamber is fixedly connected to the reaction chamber and the waveguide chamber communicates with the reaction chamber; the cross-sectional shape of the waveguide chamber is rectangular, and the projection of the chamber wall of the reaction chamber in a set plane coincides with the projection of the chamber wall of the waveguide chamber in the set plane, where the set plane is perpendicular to the transmission direction of the microwaves.

[0006] In an embodiment of the present disclosure, the shape of the projection of the chamber wall of the reaction chamber in the set plane is rectangular, the rectangle has a long side and a short side, the long side extends in the horizontal direction, the short side extends in the vertical direction, and the ratio of the length of the long side to the length of the short side is 1.5:1 to 2.5:1.

[0007] In one embodiment of the present disclosure, the graphene preparation device also includes a lifting device; the reaction chamber includes a box body and a base, and an opening is provided at the bottom of the box body; the base is connected to the lifting device, and the lifting device can drive the base to rise so that the base blocks the opening, and the lifting device can also drive the base to descend so that the base is separated from the box body.

[0008] In one embodiment of the present disclosure, a stage is disposed in the reaction chamber, and the stage is fixedly mounted on the base.

[0009] In one embodiment of the present disclosure, the reaction chamber is further provided with an air inlet pipe and a sealing sleeve, wherein the air inlet pipe is installed on the base; the sealing sleeve is fixedly installed in the reaction chamber to enclose with the base and the top plate of the reaction chamber to form a closed chamber; the stage is provided with an air outlet channel, one end of the air outlet channel is connected to the air inlet pipe, and the other end of the air outlet channel is connected to the closed chamber.

[0010] In one embodiment of the present disclosure, the graphene preparation device further includes a mounting frame, which is connected to a side of the base facing away from the stage, and the mounting frame is provided with an escape space for avoiding the air inlet pipe.

[0011] In one embodiment of the present disclosure, the stage is cylindrical, and a plurality of air outlet holes are arranged at intervals on the circumferential surface of the stage, and the air outlet holes are connected to the air outlet channel.

[0012] In one embodiment of the present disclosure, a side wall of the reaction chamber is provided with an observation window.

[0013] In one embodiment of the present disclosure, the top plate of the reaction chamber is provided with an exhaust pipe, and the exhaust pipe is used to discharge gas, or the exhaust pipe is used to connect to a vacuum pump.

[0014] In one embodiment of the present disclosure, a first flange is provided at one end of the waveguide chamber close to the reaction chamber, and a second flange is provided at one end of the reaction chamber close to the waveguide chamber, and the first flange is fixedly connected to the second flange by fasteners.

[0015] The beneficial effects of the present disclosure are mainly:

[0016] The graphene preparation device provided by the present disclosure, when in use, places graphene oxide in the reaction area with the strongest microwave ability in the reaction chamber, and uses a rectangular waveguide chamber as the microwave transmission module. At the same time, since the projection of the chamber wall of the reaction chamber on the set plane coincides with the projection of the chamber wall of the waveguide chamber on the set plane, the microwave is transmitted in a single mode (such as TE10) in the reaction area, the energy is concentrated in the reaction area, and the electric field strength is increased. Graphene oxide can be instantaneously irradiated by a high-strength microwave field, so that the deoxidation reaction and defect repair can be completed in a relatively short time. Description of the Drawings

[0017] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 Structural schematic diagram of the graphene preparation device provided by the embodiment of the present disclosure;

[0019] Figure 2 Structural schematic diagram of the reaction chamber in the embodiment of the present disclosure;

[0020] Figure 3 Exploded view of the reaction chamber in the embodiment of the present disclosure;

[0021] Figure 4 Front view of the reaction chamber in the embodiment of the present disclosure;

[0022] Figure 5 For Figure 4 Cross-sectional view along line A-A;

[0023] Figure 6 Left view of the reaction chamber in the embodiment of the present disclosure;

[0024] Figure 7 For Figure 6 Cross-sectional view along line B-B;

[0025] Figure 8 Side view of the chamber wall of the reaction chamber in the embodiment of the present disclosure;

[0026] Figure 9 Temperature-time curve during the preparation of graphene in Example 1;

[0027] Figure 10 Raman spectrogram of the graphene prepared in Example 1;

[0028] Figure 11X-ray photoelectron spectroscopy (XPS) spectrum of the graphene prepared in Example 1;

[0029] Figure 12 Thermogravimetric analysis graph of the graphene prepared in Example 1;

[0030] Figure 13 Raman statistical chart of the graphene prepared under different microwave input powers;

[0031] Figure 14 Transmission electron microscope characterization of the graphene prepared in Example 1 Figure 1 ;

[0032] Figure 15 Transmission electron microscope characterization of the graphene prepared in Example 1 Figure 2 ;

[0033] Figure 16 Electric field simulation diagram of the reaction chamber in Example 1;

[0034] Figure 17 Electric field simulation diagram of the multimode microwave reaction equipment in the comparative example.

[0035] Explanation of the reference numerals is as follows:

[0036] 1 - Microwave source; 2 - Waveguide chamber; 21 - First flange; 3 - Reaction chamber; 31 - Box body; 311 - Second flange; 32 - Base; 321 - Annular groove; 33 - Carriage; 331 - Air outlet; 34 - Inlet pipe; 35 - Sealing sleeve; 36 - Observation window; 37 - Exhaust pipe; 4 - Circulator water load; 5 - Three-pin adjuster; 6 - Short-circuit breaker; 7 - Lifting device; 8 - Mounting frame; 81 - Mounting plate; 82 - Support plate. Detailed implementation manners

[0037] Next, the technical solutions of the present disclosure will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0038] In the description of the present disclosure, it should be noted that when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present disclosure. In addition, when terms such as "first", "second", "third" appear, they are only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and limited, when terms such as "installation", "connection", "linkage" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0040] See Figures 1 to 8 As shown, this embodiment provides a graphene preparation device, which includes a microwave source 1, a waveguide chamber 2, and a reaction chamber 3. The microwave source 1 is used to emit microwaves into the waveguide chamber 2; the waveguide chamber 2 is fixedly connected to the reaction chamber 3, and the waveguide chamber 2 communicates with the reaction chamber 3; the cross-sectional shape of the waveguide chamber 2 is rectangular, and the projection of the chamber wall of the reaction chamber 3 in the set plane coincides with the projection of the chamber wall of the waveguide chamber 2 in the set plane, where the set plane is perpendicular to the transmission direction of the microwaves.

[0041] In this embodiment, taking the waveguide chamber 2 as an example, the waveguide chamber 2 can be a straight-through tube body, and the shape of its cross-section is rectangular. The inner wall of the straight-through tube body is the chamber wall of the waveguide chamber 2. In this embodiment, the wall thickness of the waveguide chamber 2 and the wall thickness of the reaction chamber 3 can be equal. In other embodiments, when the wall thicknesses of the waveguide chamber 2 and the reaction chamber 3 are not equal, as long as the inner walls of the two coincide, the outer walls may not coincide.

[0042] When the graphene preparation device provided in this embodiment is in use, the graphene oxide is placed in the reaction area with the strongest microwave ability in the reaction chamber 3, and the rectangular waveguide chamber 2 is used as the microwave transmission module. At the same time, since the projection of the chamber wall of the reaction chamber 3 in the set plane coincides with the projection of the chamber wall of the waveguide chamber 2 in the set plane, the microwaves are transmitted in a single mode (such as TE10) in the reaction area, the energy is concentrated in the reaction area, and the electric field intensity is increased. The graphene oxide can be instantaneously irradiated by the high-strength microwave field, so that the deoxidation reaction and defect repair can be completed in a relatively short time.

[0043] It should be noted that the graphene preparation device provided in this embodiment can be used to prepare graphene powder, and can also be used to prepare graphene fibers, etc.

[0044] Exemplarily, the microwave source 1 can be enclosed to avoid leakage, such as being wrapped with a stainless steel housing. The power of the microwave source 1 can be in any suitable range, for example, it can be 1 - 20 kW. Appropriately increasing the power can effectively improve the production efficiency.

[0045] In one embodiment, referring to Figure 1 As shown, the graphene preparation device further includes a circulator water load 4, a three - pin regulator 5, and a short - circuit breaker 6. One end of the circulator water load 4 is connected to the microwave source 1, the other end of the circulator water load 4 is connected to one end of the three - pin regulator 5, and the other end of the three - pin regulator 5 is connected to the waveguide chamber 2. The circulator water load 4 includes a water load and a circulator. The water load acts as a terminal load to absorb the reflected energy guided from the third port of the circulator, preventing the energy from reflecting back to the microwave source 1; the three - pin regulator 5 is used to adjust the impedance of the microwave transmission line or the waveguide chamber 2 to achieve the best match with the microwave source 1 or the water load, thereby minimizing reflection and standing waves; the short - circuit breaker 6 is used to adjust the impedance of the transmission line or the waveguide chamber 2. By adjusting the position of the short - circuit breaker 6, the standing - wave ratio and matching characteristics of the system can be changed to achieve the best match with the microwave source 1 or the water load. In addition, the position of the reaction zone can also be adjusted by adjusting the short - circuit breaker 6 and the three - pin regulator 5 so that the reaction zone corresponds to the placement position of the graphene oxide.

[0046] It should be noted that the structures and working principles of the circulator water load 4, the three - pin regulator 5, and the short - circuit breaker 6 should be understandable to those skilled in the art, and are well - known and easy to implement for those skilled in the art. Therefore, they will not be described in detail in this embodiment.

[0047] In one embodiment, referring to Figure 1 As shown, one end of the waveguide chamber 2 close to the reaction chamber 3 is provided with a first flange 21, and one end of the reaction chamber 3 close to the waveguide chamber 2 is provided with a second flange 311. The first flange 21 and the second flange 311 are fixedly connected by fasteners.

[0048] Exemplarily, the fasteners can include bolts and nuts.

[0049] It should be noted that the waveguide chamber 2 and the three - pin regulator 5, as well as the reaction chamber 3 and the short - circuit breaker 6, are also connected by flanges.

[0050] In one embodiment, referring to Figure 8As shown, the shape of the projection of the chamber wall of the reaction chamber 3 in the set plane is rectangular. The rectangle has a long side and a short side. The long side extends in the horizontal direction, and the short side extends in the vertical direction. The ratio of the length L1 of the long side to the length L2 of the short side is 1.5:1 to 2.5:1.

[0051] In this embodiment, the shape and size of the projection of the chamber wall of the waveguide chamber 2 in the set plane are the same as those of the projection of the chamber wall of the reaction chamber 3 in the set plane, which is equivalent to directly integrating the reaction chamber and the waveguide chamber. Thus, the microwave is transmitted in a single mode (such as TE10) in the reaction region, the electric field in the reaction region is more concentrated, the energy is concentrated in the reaction region and the electric field strength is increased. Graphene oxide can be irradiated by more microwave energy in a short time, reaching an ultra-high reaction temperature, so that the deoxidation reaction and defect repair can be completed within 5 seconds.

[0052] In one embodiment, as shown in Figure 1 、 Figure 2 and Figure 5 the graphene preparation device further includes a lifting device 7; the reaction chamber 3 includes a box body 31 and a base 32. An opening is provided at the bottom of the box body 31; the base 32 is connected to the lifting device 7. The lifting device 7 can drive the base 32 to rise so that the base 32 seals the opening, and the lifting device 7 can also drive the base 32 to descend so that the base 32 is separated from the box body 31.

[0053] After the lifting device 7 drives the base 32 to descend, the sample can be placed on the base 32, and then the lifting device 7 drives the base 32 to rise until the base 32 seals the opening, so that the box body 31 and the base 32 are sealed to form a complete reaction chamber 3. After the reaction is completed, the lifting device 7 drives the base 32 to descend again to facilitate the removal of the reacted sample.

[0054] Exemplarily, the sample can be graphene oxide powder. Usually, the graphene oxide powder is loaded into a sample box, and then the sample box is placed on the base 32.

[0055] Exemplarily, the lifting device 7 can be an electric cylinder, a pneumatic cylinder or a hydraulic cylinder.

[0056] In this embodiment, a groove is provided on the upper surface of the base 32, and a sealing member (not shown in the figure) is provided in the groove. The base 32 seals the opening through the sealing member. Exemplarily, the sealing member can be a sealing ring.

[0057] Exemplarily, as shown in Figure 3 the base 32 is in a disc shape, and two annular grooves 321 are provided on the upper surface of the base 32. Sealing members are provided in both of the two annular grooves 321.

[0058] It should be understood that the graphene preparation device further includes a frame (not shown in the figure), which can be used to install and fix the box body 31 of the reaction chamber 3. Of course, when necessary, it can also be used to support and fix at least one of the microwave source 1, the circulator water load 4, the three-pin regulator 5, the waveguide chamber 2, and the short-circuit breaker 6.

[0059] In one embodiment, a carrier table 33 is arranged in the reaction chamber 3, and the carrier table 33 is fixedly installed on the base 32.

[0060] In this embodiment, the carrier table 33 and the base 32 are integrally formed. The sample box is placed on the carrier table 33. The position of the reaction zone is adjusted to a position corresponding to the carrier table 33, so that the graphene oxide powder in the sample box can receive the strongest microwave energy radiation.

[0061] In one embodiment, referring to Figure 3 and Figure 5 as shown, the reaction chamber 3 is further provided with an air inlet pipe 34 and a sealing sleeve 35. The air inlet pipe 34 is installed on the base 32; the sealing sleeve 35 is fixedly installed in the reaction chamber 3 to enclose a sealed chamber with the base 32 and the top plate of the reaction chamber 3; the carrier table 33 is provided with an air outlet channel, one end of the air outlet channel is communicated with the air inlet pipe 34, and the other end of the air outlet channel is communicated with the sealed chamber.

[0062] By providing the air inlet pipe 34, a protective gas or other reaction gas can be introduced into the sealed chamber. Since the carrier table 33 is provided with an air outlet channel, the introduced protective gas or other reaction gas can fill the sealed space through the air outlet channel, and the pressure adjustment during the graphene preparation process can be realized. The material of the sealing sleeve 35 can be quartz, which will not affect the entry of microwaves into the sealed chamber.

[0063] It should be understood that the cross-sectional shape of the sealing sleeve 35 can be, but is not limited to, circular, elliptical or rectangular.

[0064] Through simulation calculation and practical verification, the carrier table 33 can, while supporting the sample, ensure the entry of gas at the bottom and will not reduce the microwave intensity in the reaction zone.

[0065] In one embodiment, referring to Figure 3 and Figure 7 as shown, the carrier table 33 is cylindrical, and a plurality of air outlet holes 331 are spaced apart on the circumferential surface of the carrier table 33, and the air outlet holes 331 are communicated with the air outlet channel.

[0066] Exemplarily, the plurality of air outlet holes 331 are evenly spaced along the circumferential surface of the carrier table 33. In this embodiment, the number of the air outlet holes 331 can be four.

[0067] It should be noted that the shape of the stage 33 may also be a rectangular parallelepiped.

[0068] In one embodiment, see Figure 1 and Figure 7 As shown, the graphene preparation device further includes a mounting frame 8 , which is connected to a side of the base 32 facing away from the stage 33 , and the mounting frame 8 is provided with an escape space for evading the air inlet pipe 34 .

[0069] For example, see Figure 2 As shown, the mounting frame 8 includes a mounting plate 81 and two support plates 82, the two support plates 82 are arranged opposite to each other, and an escape space is formed between the two support plates 82 for escaping the air intake pipe 34; one end of the support plate 82 is fixedly connected to the base 32, and the other end of the support plate 82 is fixedly connected to the mounting plate 81, and the mounting plate 81 is connected to the lifting device 7. The lifting device 7 drives the support frame to move, and then drives the base 32 to move.

[0070] In one embodiment, see Figure 4 As shown, the side wall of the reaction chamber 3 is provided with an observation window 36. Optical instruments and equipment are used to monitor the microwave reaction in real time through the observation window 36 to help control the reaction process and products. For example, a linear infrared colorimeter can be used to record the temperature of the reaction system in real time, and an optical emission spectrometer can be used to detect the generation, concentration and reaction of related chemically active substances in the reaction.

[0071] The size of the observation window 36 is relatively small, and transparent glass is installed on the observation window 36 .

[0072] In one embodiment, see Figure 2 As shown, the top plate of the reaction chamber 3 is provided with an exhaust pipe 37, and the exhaust pipe 37 is used to discharge gas, or the exhaust pipe 37 is used to connect with a vacuum pump.

[0073] The exhaust pipe 37 is in communication with the reaction chamber 3. Under normal pressure, the gas in the reaction chamber 3 can be discharged from the exhaust pipe 37. A vacuum pump can also be connected to the exhaust pipe 37 to provide vacuum or low pressure conditions for the reaction.

[0074] The application effect of the graphene preparation device provided by the embodiment of the present disclosure will be explained below through specific examples.

[0075] Example 1

[0076] The graphene oxide powder is reduced using the graphene preparation device provided in this embodiment.

[0077] Under the condition of not connecting the vacuum pump, the pressure in the reaction chamber 3 is normal pressure. The sample box containing graphene oxide powder is placed on the stage 33, and then the lifting device 7 automatically rises to the preset position, and the reaction chamber 3 is closed as a whole. Carrier gas argon is introduced into the inlet pipe 34, and the carrier gas flow rate is 1 SLM. After the argon gas is introduced for 2 - 5 minutes to expel the residual air in the sealing sleeve 35, the microwave power is set to 1.0 kW, and the microwave source 1 is turned on. Through the observation window 36 of the reaction chamber 3, it can be seen that there is an instant fire accompanied by the white argon plasma glow. After the reaction for 10 seconds, the microwave source 1 is turned off, the lifting device 7 descends, the graphene powder is collected, and relevant characterizations are carried out. The results are as follows:

[0078] See Figure 9 As shown, the single-mode cavity refers to the reaction chamber in this embodiment, and the multi-mode cavity refers to the conventional microwave oven cavity. After the microwave is turned on, the temperature of graphene oxide under the single-mode microwave condition rises sharply, and the highest temperature reaches above 3000 °C within 3 seconds, proving that after microwave radiation, graphene oxide reaches an ultra-high reaction temperature, so that the deoxidation reaction and defect repair can be completed within 5 seconds.

[0079] However, the temperature of graphene oxide under the multi-mode microwave condition rises slowly, and the highest temperature is only about 1100 °C after 7 seconds, and the deoxidation reaction and defect repair cannot be completed in a short time.

[0080] See Figure 10 As shown, for the graphene prepared by the graphene preparation device provided in this embodiment, the ratio of I D / I G is 0.1, and the ratio of I 2D / I G is 2.2, indicating that the prepared graphene has ultra-high crystallinity and high quality.

[0081] See Figure 11 As shown, for the graphene prepared by the graphene preparation device provided in this embodiment, most of the oxygen-containing groups have been removed, and it has an ultra-high carbon-oxygen ratio. Exemplarily, the carbon-oxygen ratio is greater than 1000.

[0082] See Figure 12 As shown, the maximum decomposition temperature of the graphene prepared by the graphene preparation device provided in this embodiment in an air atmosphere is 520 °C, while the maximum decomposition temperature of graphene oxide is 220 °C, indicating that the graphene has high structural stability, low impurity content, and purity > 99.9%.

[0083] See Figure 13 As shown, graphene of different qualities can be prepared by controlling the microwave input power. For example, when the input power is 200 W, the I D / I Gis 1.1, when the input power is 600 W, I of graphene D / I G is 0.7, when the input power is 1000 W, I of graphene D / I G is 0.1.

[0084] See Figure 14 and Figure 15 As shown, the graphene prepared by the graphene preparation device provided in this embodiment has the characteristic of thin layers, and the number of layers is 1-2 layers.

[0085] See Figure 16 As shown, the microwave electric field of the reaction cavity corresponding to the stage 33 at the center of the reaction cavity is the maximum value, up to 7.4×10 4 V / m. The single-mode microwave energy is stronger here, which is more conducive to the reduction and structure repair of graphene oxide.

[0086] Comparative example

[0087] A conventional multi-mode microwave reaction device (such as a microwave oven) is used to reduce graphene oxide powder. Among them, the microwave power is 1.0 Kw. It does not reach the maximum value, and there are problems of incomplete reduction and uneven effect.

[0088] The multi-mode microwave resonance cavity used in the multi-mode microwave reaction device has microwaves reflecting back and forth in the furnace cavity, and there are various transmission modes of microwaves in the multi-mode resonance cavity, which results in less energy absorbed by graphene oxide during actual reaction. See Figure 17 As shown, the region with the maximum electric field in the reaction cavity of the microwave oven is the starting area of the microwave source 1, and its electric field strength is relatively low, about 0.7×10 4 V / m, and the microwave energy provided in the graphene oxide reaction is relatively low. See Figure 9 As shown, the maximum reaction temperature in the multi-mode cavity is only about 1100℃, which cannot reach the high temperature required for reduction, resulting in low-quality and poor uniformity of the prepared graphene.

[0089] In summary, the graphene preparation device provided in this embodiment can realize the rapid and convenient preparation of high-quality graphene. The obtained graphene powder has the characteristics of high quality, high conductivity, high crystallinity, high purity, and low oxygen content, which is conducive to the batch preparation of graphene powder and has broad application prospects.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A graphene preparation device, characterized in that: The invention comprises a microwave source, a waveguide chamber and a reaction chamber; the microwave source is used to emit microwaves into the waveguide chamber; the waveguide chamber is fixedly connected to the reaction chamber, and the waveguide chamber is communicated with the reaction chamber; the cross-sectional shape of the waveguide chamber is rectangular, and the projection of the cavity wall of the reaction chamber in a set plane coincides with the projection of the cavity wall of the waveguide chamber in the set plane, wherein the set plane is perpendicular to the transmission direction of the microwave.

2. The graphene preparation device according to claim 1, characterized in that: The projection of the chamber wall of the reaction chamber in the set plane is in the shape of a rectangle, the rectangle having a long side and a short side, the long side extending in the horizontal direction, the short side extending in the vertical direction, and the ratio between the length of the long side and the length of the short side is 1.5:1 to 2.5:

1.

3. The graphene preparation device according to claim 1, characterized in that: It also includes a lifting device; the reaction chamber includes a box body and a base, and the bottom of the box body is provided with an opening; the base is connected to the lifting device, and the lifting device can drive the base to rise so that the base blocks the opening, and the lifting device can also drive the base to descend so that the base is separated from the box body.

4. The graphene preparation device according to claim 3, characterized in that: A stage is arranged in the reaction chamber, and the stage is fixedly mounted on the base.

5. The graphene preparation device according to claim 4, characterized in that: The reaction chamber is also provided with an air inlet pipe and a sealing sleeve, wherein the air inlet pipe is installed on the base; the sealing sleeve is fixedly installed in the reaction chamber to enclose with the base and the top plate of the reaction chamber to form a closed chamber; the stage is provided with an air outlet channel, one end of the air outlet channel is connected to the air inlet pipe, and the other end of the air outlet channel is connected to the closed chamber.

6. The graphene preparation device according to claim 5, characterized in that: It also includes a mounting frame, which is connected to a side of the base away from the loading platform, and the mounting frame is provided with an escape space for evading the air intake pipe.

7. The graphene preparation device according to claim 5, characterized in that: The stage is cylindrical, and a plurality of air outlet holes are arranged at intervals on the circumferential surface of the stage, and the air outlet holes are communicated with the air outlet channel.

8. The graphene preparation device according to any one of claims 1 to 7, characterized in that: The side wall of the reaction chamber is provided with an observation window.

9. The graphene preparation device according to any one of claims 1 to 7, characterized in that: The top plate of the reaction chamber is provided with an exhaust pipe, and the exhaust pipe is used to discharge gas, or the exhaust pipe is used to connect with a vacuum pump.

10. The graphene preparation device according to any one of claims 1 to 7, characterized in that: A first flange is disposed at one end of the waveguide chamber close to the reaction chamber, and a second flange is disposed at one end of the reaction chamber close to the waveguide chamber. The first flange is fixedly connected to the second flange by fasteners.

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