A graphene preparation device and method using a high-voltage pulse power supply

Abstract

This invention discloses a graphene preparation apparatus and method using a high-voltage pulse power supply. The preparation apparatus includes a sliding track, a fixed outer shell and a movable outer shell disposed on the sliding track, and a four-way tube disposed between the fixed and movable outer shells. The four-way tube is fixedly disposed on the sliding track, with its upper port connected to a nitrogen source, its left port connected to a conductor, and its right port connected to another conductor. The two conductors are respectively connected to a test current source, and the positive terminal of the high-voltage pulse power supply is applied to the same side of the conductors and the positive terminal of the test current source. This invention has the advantages of stable and rapid preparation, high-quality graphene, and simple operation, and can effectively solve the problems of long preparation time and unstable graphene quality in traditional methods. At the same time, it saves energy and raw materials, improves preparation efficiency and performance indicators, and has high practical value.

Description

Technical Field

[0001] This invention belongs to the field of graphene preparation technology, and in particular relates to a graphene preparation device and preparation method using a high-voltage pulse power supply. Background Technology

[0002] Graphene, as an innovative material, possesses excellent electrical conductivity, thermal conductivity, mechanical strength, and chemical stability, making it a promising candidate for applications in biomedicine, electronic devices, sensors, and energy storage. However, its mass production still faces many technical challenges, such as long preparation cycles, high costs, and low efficiency.

[0003] Currently, the main methods for preparing graphene include chemical vapor deposition (CVD), chemical reduction, and mechanical exfoliation. However, traditional methods for preparing graphene have limitations, namely: firstly, traditional CVD requires high temperatures and complex equipment, resulting in long preparation cycles and high costs, which limits the large-scale application of graphene; secondly, chemical reduction methods require the use of toxic reducing agents such as hydrazine hydrate and sodium borohydride, which have poor safety and adverse environmental impacts; and finally, while mechanical exfoliation can obtain monolayer graphene, it has low production efficiency and high costs.

[0004] In summary, there is an urgent need for an efficient and low-cost method for preparing graphene in order to achieve stable, rapid, and efficient graphene production. Summary of the Invention

[0005] To overcome the problems existing in the prior art, the present invention provides a graphene preparation device and preparation method using a high-voltage pulse power supply.

[0006] As a first aspect of the present invention, a graphene preparation apparatus employing a high-voltage pulse power supply is provided, comprising a sliding track, a fixed housing and a movable housing disposed on the sliding track, and a four-way pipe disposed between the fixed housing and the movable housing. The four-way pipe is fixedly disposed on the sliding track, with its upper port connected to a nitrogen source, its left port connected to a conductor, and its right port connected to another conductor. The two conductors are respectively connected to a test current source, and the positive electrode of the high-voltage pulse power supply is applied to the same side of the conductor and the positive electrode of the test current source.

[0007] In this embodiment of the invention, both the fixed outer shell and the movable outer shell are glass shells, which are respectively fixed and movable components arranged on the sliding track.

[0008] Furthermore, both the fixed outer shell and the movable outer shell are made of plexiglass.

[0009] In this embodiment of the invention, the four-way tube is a four-way glass tube with four ports: top, bottom, left, and right, and a sealing plug is provided at the bottom port of the four-way glass tube.

[0010] In this embodiment of the invention, the conductors at both ends of the four-way pipe are copper conductors.

[0011] Furthermore, one end of each conductor passes through a fixed or movable housing on the same side and is electrically connected to a terminal block, thereby connecting to a test current source or a high-voltage pulse power supply, while the other end is embedded in a four-way tube.

[0012] In this embodiment of the invention, a container for storing graphene products is also included, connected to the lower port of the four-way pipe, wherein the container is a glass bottle.

[0013] Furthermore, it also includes an ultrasonic vibrator connected to the lower port of the four-way tube. The ultrasonic vibrator generates vibrations that cause the graphene attached to the inner wall of the four-way glass tube to be stored in the glass bottle connected to the lower port of the four-way glass tube.

[0014] In this embodiment of the invention, the glass shell is made of plexiglass, which has good transparency, chemical stability, mechanical properties and weather resistance, making it easy to directly observe the experimental phenomena, improve the understanding of the experimental data and increase the safety of the experiment.

[0015] Furthermore, the high-voltage pulse power supply uses a relay to control the on / off state of the high-voltage current.

[0016] As a second aspect of the present invention, a method for preparing graphene using a high-voltage pulsed power supply is provided. Based on the aforementioned graphene preparation apparatus using a high-voltage pulsed power supply, the preparation method includes the following steps:

[0017] Step 1: Place the graphite powder in the middle of the four-way tube, and at the same time adjust the movable outer shell to move the conductor towards the center, so that it can work together with the conductor at the other end to press the graphite powder tightly in the four-way tube.

[0018] Step 2: Adjust the nitrogen flow controller to fill the four-way glass tube with nitrogen;

[0019] Step 3: Connect the test current source to the conductors on the left and right sides respectively through the left and right terminals, and at the same time apply the positive terminal of the high voltage pulse power supply to the same side of the copper conductor and the positive terminal of the test current source.

[0020] Step 4: Wrap the surface of the glass tube connecting the conductor on the other side of the four-way tube with copper foil, and connect the other side of the high-voltage pulse power supply to the copper foil;

[0021] Step 5: Keep the test current source on and apply current to both sides of the graphite powder;

[0022] Step 6: By setting the control circuit in the relay to conduct for a certain period of time, the high-voltage pulse power supply is turned on, so that the high voltage is applied instantaneously to both sides of the graphite powder.

[0023] Step 7: When the high-voltage current passes through the graphite powder, the high temperature causes the graphite powder to expand in volume.

[0024] Step 8: Under the promotion of high temperature and high voltage current, graphite powder gradually transforms into graphene and adheres to the inner wall of the four-way glass tube.

[0025] Step 9: Control the high-voltage pulse power supply to shut down by setting the relay's circuit-breaking time, so that the high voltage disappears instantly, the circuit is broken, the current disappears, and the temperature drops instantly.

[0026] Step 10: The graphene attached to the inner upper wall of the four-way tube is stored in the glass bottle connected to the lower opening of the four-way tube by the vibration of the ultrasonic vibrator.

[0027] This invention has the following characteristics:

[0028] 1. Fast and efficient: Precise control of the graphene preparation process is achieved through relay control, enabling rapid and stable production of high-quality graphene. Compared to traditional methods, this reduces preparation time and the need for manual operation, thus improving production efficiency.

[0029] 2. High stability: The use of a sliding track and copper conductor structure ensures the device's structural stability and reliability, making it less susceptible to external interference. Furthermore, the use of a nitrogen cylinder and nitrogen flow controller eliminates oxygen in the preparation environment, preventing graphene oxidation.

[0030] 3. High flexibility: By adjusting parameters such as nitrogen flow rate, current magnitude, and energizing time, the number and quality of the prepared graphene layers can be controlled. It is suitable for preparing graphene samples with different requirements and has a wide range of applications.

[0031] 4. Energy-saving and environmentally friendly: Using nitrogen as a protective gas reduces graphene oxidation, improving yield and purity. Furthermore, the device is rationally designed, consumes little energy, and saves raw materials and energy.

[0032] 5. Simple operation: Simplified operation steps and reduced complexity. No high temperature conditions or toxic reducing agents are required, making operation safer and more convenient.

[0033] 6. High controllability: By using a high-voltage pulse power supply as a switch, the duration of voltage and current applied across the graphite powder can be precisely controlled, thereby precisely controlling the number of graphene layers prepared.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. The preparation apparatus and method provided by the present invention can realize efficient, low-cost and environmentally friendly graphene production. Moreover, the preparation process of this method does not produce graphene oxide and does not require the use of chemical reagents, thereby completely solving the problems of long cycle, high cost, low efficiency and environmental pollution in graphene preparation.

[0036] 2. This invention introduces a transient discharge method, providing a device and method for rapidly and stably preparing graphene with up to four layers. Attached Figure Description

[0037] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0038] Figure 1 The present invention provides an overall structural diagram of a graphene preparation device using a high-voltage pulse power supply.

[0039] Figure 2 This is a front view of a graphene preparation device using a high-voltage pulse power supply provided by the present invention.

[0040] Figure 3 This is a partial structural cross-sectional view of a graphene preparation device using a high-voltage pulse power supply provided by the present invention.

[0041] Figure 4 The present invention provides a schematic diagram of the working principle of a graphene preparation device using a high-voltage pulse power supply.

[0042] Figure 5 The present invention provides a circuit diagram of a relay-controlled high-voltage pulse in a graphene preparation device employing a high-voltage pulse power supply.

[0043] Figure 6 This is a result from a scanning electron microscope (SEM).

[0044] Figure 7 This is an X-ray photoelectron spectroscopy (XRD) image.

[0045] Among them, 1-graphite powder, 2-four-way glass tube, 3-copper conductor, 4-sliding rail, 5-left terminal, 6-nitrogen flow controller, 7-nitrogen cylinder, 8-ultrasonic vibrator, 9-glass bottle, 10-glass shell, 11-test current source, 12-high voltage pulse power supply, 13-nut, 14-right terminal, 15-sealing plug. Detailed Implementation

[0046] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] Example: A graphene preparation device using a high-voltage pulse power supply

[0049] like Figures 1-3 As shown, the system includes a glass housing 10, a sliding track 4, a copper conductor 3, four-way glass tubes 2 of different capacities, an ultrasonic vibrator 8, a nitrogen cylinder 7, a nitrogen flow controller 6, a glass bottle 9, a test current source 11, a high-voltage pulse power supply 12, a left terminal block 5, and a right terminal block 14. The sliding track 4 is placed horizontally. The glass housing 10 consists of two parts, mounted on the sliding track. One end of the glass housing is a fixed part, fixed to the sliding track, while the other end is a movable part, moving left and right along the sliding track. The four-way glass tubes 2 are fixedly mounted on the sliding track 4. The upper part is located between two glass shells 10; two copper conductors 3 are respectively set inside the glass shell at each end, one end of each copper conductor 5 passes through the glass shell 10 on the same side and is electrically connected to the left terminal 5 or the right terminal 14, and the other end is embedded in the four-way glass tube 2; the upper port of the four-way glass tube 2 is connected to the nitrogen cylinder 7 through the nitrogen flow controller 6, and the lower outlet is connected to the glass bottle 9. The vibrating head of the ultrasonic vibrator 8 is fixedly connected to the lower outlet of the four-way glass tube 2. When the ultrasonic vibrator 8 is turned on, it drives the four-way glass tube 2 to vibrate. The ultrasonic vibrator 8 can be any device that can generate vibration that is well known to those skilled in the art, and there are no special limitations.

[0050] The movable part on the right end of the glass shell can be driven to reciprocate by means of a screw or cylinder, and there is no limitation here.

[0051] Nitrogen cylinder 7 and nitrogen flow controller 6, as sources of nitrogen, can adopt structures familiar to those skilled in the art and are not subject to any special restrictions.

[0052] The high-voltage pulse power supply 12 adopts a structure well known to those skilled in the art. It adds a switching circuit to the high-voltage DC power supply and is used as a high-voltage power supply that can output adjustable pulse amplitude, width, frequency and number.

[0053] The copper conductor 3 at one end of the fixed glass shell is connected to the test current source 11, and the copper conductor 3 at one end of the movable glass shell is connected to the high-voltage pulse power supply 12.

[0054] Select a four-way glass tube 2 of appropriate capacity according to the desired graphene mass. Connect the copper conductor 3 to the left and right ports of the four-way glass tube 2 respectively. Simultaneously connect the nitrogen cylinder 7 to the nitrogen flow controller 6, which is connected to the upper port of the four-way glass tube 2 via a pipe. Install the ultrasonic vibrator 8 at the lower outlet of the four-way glass tube, and connect the lower outlet of the four-way glass tube to the glass bottle 9. Place the graphite powder 1 in the center of the four-way glass tube 2, and place a sealing plug 15 at the lower port of the four-way glass tube 2.

[0055] The copper conductor 3 is provided with threads that mate with the nut 13, thereby fixing it to the glass housing 10.

[0056] As a typical embodiment, the glass shell 10 is made of plexiglass, which has good transparency, chemical stability, mechanical properties and weather resistance, making it easy to directly observe the test phenomena, improve the understanding of the test data and increase the safety of the test.

[0057] Experimental example: A graphene preparation device using a high-voltage pulse power supply

[0058] I. Material Preparation:

[0059] 1. Glass housing: Select an appropriate size glass housing, install it on the sliding track, fix the left end and move the right end.

[0060] 2. Copper conductors: Prepare two copper conductors and fix them to the inside of the acrylic glass shell.

[0061] 3. Four-way glass tube: Select a four-way glass tube with an appropriate capacity according to the mass of graphene to be prepared.

[0062] 4. Terminal blocks: Connected to copper conductors.

[0063] 5. Nitrogen and flow controller: Connects the nitrogen source to the upper end of the four-way glass tube.

[0064] 6. Ultrasonic vibrator: Connected to the lower outlet of the four-way glass tube.

[0065] 7. Graphite powder: Place it in the center of the four-way glass tube.

[0066] 8. Test current source and high voltage pulse power supply: Prepare and connect to the copper conductors on both sides.

[0067] 9. High-voltage pulse power supply: It consists of a relay, a high-voltage transformer (flyback transformer, used to output high-voltage pulses) and a DC power supply. The relay includes control circuit and working circuit.

[0068] II. Equipment Connection and Debugging

[0069] 1. Install the glass housing on the sliding track, with the left end of the housing fixed on the sliding track and the right end of the housing able to move left and right on the sliding track;

[0070] 2. Two copper conductors are fixed inside the left and right sides of the acrylic shell, respectively, passing through the glass shell and connected to the terminals. The left and right copper conductors are connected by two sides of a four-way glass tube.

[0071] 3. Connect the copper conductor to the left and right ends of the four-way glass tube, and connect the nitrogen gas to one end of the nitrogen flow controller and the other end to the upper end of the four-way glass tube.

[0072] 4. Connect the ultrasonic vibrator to the lower side of the four-way glass tube, and connect the lower end of the four-way glass tube to the glass bottle.

[0073] III. Experimental Procedures

[0074] Step 1: Place the graphite powder in the middle of the four-way glass tube, and at the same time adjust the movable outer shell to move the conductor towards the center, so that it can work together with the copper conductor at the other end to press the graphite powder tightly in the four-way glass tube.

[0075] Step 2: Adjust the nitrogen flow controller to fill the four-way glass tube with nitrogen;

[0076] Step 3: Connect the test current source to the copper conductors on the left and right sides respectively through the left and right terminals. Simultaneously, apply the positive terminal of the high-voltage pulse power supply to the same side of the copper conductors as the positive terminal of the test current source. The working principle and circuit connection diagram are shown below. Figure 4 and Figure 5 As shown.

[0077] Step 4: Wrap the surface of the glass tube connected to the copper electrode (copper conductor) on the other side of the four-way glass tube with copper foil, and connect the other side of the high-voltage pulse power supply to the copper foil.

[0078] Step 5: Keep the test current source on and apply a current of 1000A to both sides of the graphite powder.

[0079] Step 6: By setting the control circuit in the relay to conduct for 1ms, the high-voltage pulse power supply is turned on for 1ms, so that 2000V voltage is applied instantaneously to both sides of the graphite powder.

[0080] Step 7: When a large current passes through the graphite powder, the internal temperature of the graphite powder reaches as high as 3000K, causing the graphite powder to expand in volume.

[0081] Step 8: Under the influence of high temperature and high current, graphite powder gradually transforms into graphene and adheres to the inner wall of the four-way glass tube.

[0082] Step 9: By setting the relay's circuit-breaking time, the high-voltage pulse power supply is controlled to shut down, causing the high voltage to disappear instantly, the circuit to break, the current to disappear, and the temperature to drop instantly.

[0083] Step 10: The graphene attached to the inner wall of the four-way glass tube is stored in the glass bottle connected to the lower opening of the four-way glass tube by the vibration of the ultrasonic vibrator.

[0084] The following parameters were used in the experiment:

[0085]

[0086] Note: The specific heat of graphite powder is 710 J / (kg·K), and its electrical conductivity is 0.061 × 10⁻⁶. -6 / (meter ohm), thermal conductivity 129 W / (m·K).

[0087] As a result, the monolayer graphene produced in experiments 1-3 using the above parameters was 10 mg, 120 mg, and 1 g, respectively.

[0088] As one implementation method, the preparation conditions for four-layer graphene are as follows:

[0089]

[0090] Note: The specific heat of graphite powder is 710 J / (kg·K), and its electrical conductivity is 0.061 × 10⁻⁶. -6 / (meter ohm), thermal conductivity 129 W / (m·K).

[0091] By changing the current applied across the conductor and the duration of the current flow, graphene with different numbers of layers can be prepared.

[0092] Product performance evaluation includes the following aspects:

[0093] 1. Graphene was observed using a scanning electron microscope (SEM), such as... Figure 6 As shown, the prepared graphene exhibits hexagonal monolayer graphene under a scanning electron microscope. This demonstrates that the method can effectively prepare monolayer graphene, and graphene with different numbers of layers can be prepared by adjusting the loading current and time.

[0094] 2. The purity and crystallinity of the prepared graphene were observed using X-ray diffraction (XPS), such as... Figure 7 As shown, the X-ray diffraction (XPS) spectrum exhibits a well-defined (002) peak, indicating that the spatial arrangement of the graphite crystal sheets is very regular and that there is no graphene oxide present.

[0095] Current technologies use a reduction method to prepare graphene. This method not only requires a long preparation time (5 to 7 days to prepare 10g), but also produces low-purity graphene with uncontrollable graphene layers. Compared with traditional methods, the method used in this patent allows for control over the number of graphene layers, and the average preparation time is 2 hours, far shorter than traditional methods. Furthermore, it produces higher purity and better crystallinity. This patent enables a stable and rapid graphene preparation process, greatly improving preparation efficiency.

[0096] In summary, this invention offers advantages such as stable and rapid preparation, high-quality graphene, and simple operation, effectively solving problems such as long preparation time and unstable graphene quality in traditional methods. Furthermore, it saves energy and raw materials, improves preparation efficiency and performance indicators, and possesses high practical value.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A graphene preparation apparatus employing a high-voltage pulse power supply, characterized in that, The device includes a sliding track, a fixed housing and a movable housing mounted on the sliding track, and a four-way pipe positioned between the fixed housing and the movable housing. The four-way pipe is fixedly mounted on the sliding track, with its upper port connected to a nitrogen source, its left port connected to a conductor, and its right port connected to another conductor. The two conductors are respectively connected to a test current source, and the positive terminal of a high-voltage pulse power supply is applied to the same side of the conductors as the positive terminal of the test current source. The conductors at both ends of the four-way pipe are copper conductors. An ultrasonic vibrator is connected to the lower port of the four-way pipe. The four-way tube is a four-way glass tube with four ports: top, bottom, left, and right. A sealing plug is installed at the bottom port of the four-way glass tube. A container for storing graphene products is connected to the bottom port of the four-way tube. Graphite powder is placed in the middle of the four-way glass tube. At the same time, the movable outer shell is adjusted to move the conductor towards the center, which, together with the copper conductor at the other end, presses the graphite powder tightly, making the graphite powder as compact as possible in the four-way glass tube. By adjusting the nitrogen flow controller, nitrogen is made to fill the four-way glass tube; The high-voltage pulse power supply uses a relay to control the on / off of the high-voltage current. Keep the test current source on and apply current to both sides of the graphite powder; By setting the control circuit in the relay to conduct for a certain period of time, the high-voltage pulse power supply is turned on, so that the high voltage is applied instantaneously to both sides of the graphite powder. By setting the relay's circuit-breaking time to control the high-voltage pulse power supply to shut down, the high voltage disappears instantly, the circuit is broken, the current disappears, and the temperature drops instantly.

2. The preparation apparatus according to claim 1, characterized in that, Both the fixed outer shell and the movable outer shell are glass shells, serving as the fixed component and the movable component respectively, which are mounted on the sliding track.

3. The preparation apparatus according to claim 1, characterized in that, Both the fixed and movable outer shells are made of plexiglass.

4. The preparation apparatus according to claim 1, characterized in that, One end of each conductor passes through a fixed or movable housing on the same side and is electrically connected to a terminal block, thereby connecting to a test current source or a high-voltage pulse power supply, while the other end is embedded in a four-way tube.

5. The preparation apparatus according to claim 1, characterized in that, The container is a glass bottle.

6. A method for preparing graphene using a high-voltage pulse power supply, characterized in that, Based on the preparation apparatus according to any one of claims 1-5, the preparation method comprises the following steps: Step 1: Place the graphite powder in the middle of the four-way tube, and at the same time adjust the movable outer shell to move the conductor towards the center, so that it can work together with the conductor at the other end to press the graphite powder tightly in the four-way tube. Step 2: Adjust the nitrogen flow controller to fill the four-way glass tube with nitrogen; Step 3: Connect the test current source to the conductors on the left and right sides respectively through the left and right terminals, and at the same time apply the positive terminal of the high voltage pulse power supply to the same side of the copper conductor and the positive terminal of the test current source. Step 4: Wrap the surface of the glass tube connecting the conductor on the other side of the four-way tube with copper foil, and connect the other side of the high-voltage pulse power supply to the copper foil; Step 5: Keep the test current source on and apply current to both sides of the graphite powder; Step 6: By setting the control circuit in the relay to conduct for a certain period of time, the high-voltage pulse power supply is turned on, so that the high voltage is applied instantaneously to both sides of the graphite powder. Step 7: When the high-voltage current passes through the graphite powder, the high temperature causes the graphite powder to expand in volume. Step 8: Under the promotion of high temperature and high voltage current, graphite powder gradually transforms into graphene and adheres to the inner wall of the four-way glass tube. Step 9: Control the high-voltage pulse power supply to shut down by setting the relay's circuit-breaking time, so that the high voltage disappears instantly, the circuit is broken, the current disappears, and the temperature drops instantly. Step 10: The graphene attached to the inner wall of the four-way tube is stored in the glass bottle connected to the lower opening of the four-way tube by the vibration of the ultrasonic vibrator.

Images