Device for reducing graphene oxide by chemical method
By designing a horizontal heating tank and related components for the chemical reduction of graphene oxide, the problem of low reduction efficiency of graphene oxide in existing technologies has been solved, achieving efficient and low-cost graphene preparation that is suitable for industrial production.
Patent Information
- Application Number
- CN202422144234.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-09-02
AI Technical Summary
The lack of existing technology for chemical reduction of graphene oxide has resulted in high costs, low efficiency, and unstable product quality during the preparation of graphene oxide, making it difficult to achieve industrial mass production.
A chemical reduction device for graphene oxide, including a horizontal heating tank, was designed. The device is equipped with components such as a screw feeder, a feed hopper, a stirrer, an air inlet, and an air outlet. By controlling the gas flow rate and temperature, the rapid reduction of graphene oxide is achieved.
It enables rapid reduction of graphene oxide, reduces production costs, improves product quality, is suitable for industrial mass production, and reduces the risk of secondary pollution from graphene materials.
Smart Images
Figure CN223659843U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of graphene preparation, specifically to a device for the chemical reduction of graphene oxide. Background Technology
[0002] Graphene, as the most representative and important two-dimensional material, has been widely used in industries such as electronic heat dissipation, fibers, and lithium batteries due to its excellent mechanical, thermal, electrical, and magnetic properties. Graphene is a single-atom-thick layer of graphite with a two-dimensional honeycomb network structure. Graphene oxide sheets are produced by adding oxygen-containing functional groups to increase hydrophilicity, making them easily deformable in water. After expansion, post-processing such as heating and ultrasound completes layer separation. In addition, the interlayer interactions of graphite change the hybridization state. Because the finished products are mostly mixtures of single, double, or even multiple layers, the number of layers is difficult to control precisely. Furthermore, the graphene oxide prepared by processes such as ultrasound has many defects, resulting in thermal and electrical conductivity that cannot reach their optimal performance. The oxygen-containing functional groups in graphene oxide destroy the structure and conjugated π bonds, making the graphene's conductivity poor or even non-conductive. To restore the excellent conductivity of graphene, it is necessary to remove the oxygen-containing functional groups in graphene oxide, repair defects, and rebuild the structure and conjugated π bonds to obtain graphene with excellent conductivity. Graphene possesses structural ductility, and its electrical, optical, and acoustic properties can be significantly adjusted through stress and deformation, even altering its bandwidth structure. Graphene exhibits ultra-high strength and high electron mobility; the charge mobility in graphene can reach 200,000 cm² / Vs, exceeding that of silicon by more than 100 times. Furthermore, graphene possesses high thermal conductivity (5000 W / mK). These advantages make graphene poised to replace silicon as a crucial material for future ultra-high-frequency transistors, and it will be used in high-performance integrated circuits. Graphene oxide is produced by reacting natural graphite with strong oxidizing agents in a strong acid environment. After ultrasonic dispersion, graphene oxide can be produced. Adding a reducing agent removes oxygen-containing functional groups such as hydroxyl, carboxyl, and epoxy groups from its surface, yielding reduced graphene oxide. The redox method is currently the main method for mass-producing graphene powder due to its simplicity and low production requirements.
[0003] Chemical reduction involves reacting graphene oxide with a reducing agent, such as hydrogen, ammonia, hydrazine hydrate, phenylhydrazine, potassium hydroxide, sulfoxide, ascorbic acid, hydroiodic acid, NaBH4, and hydroquinone. Hydrogen reduction is one of the most common chemical methods. Reacting graphene oxide with hydrogen at high temperatures, with the heater temperature controlled between 300-800℃, reduces oxygen atoms in the graphene oxide to oxygen gas. This allows oxygen-containing functional groups to rapidly move out of the carbon atom layers, thus reducing the graphene oxide. The reduced graphene exhibits excellent thermal and electrical conductivity. However, currently, there is no equipment specifically designed for the chemical reduction of graphene oxide. Utility Model Content
[0004] To address the shortcomings of existing technologies, this invention provides a device for the chemical reduction of graphene oxide.
[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:
[0006] This utility model discloses a chemical reduction device for graphene oxide, comprising a cylindrical horizontal heating tank, wherein a spiral feeder is provided inside the horizontal heating tank, a feed hopper is provided at one end of the horizontal heating tank, and an agitator is provided inside the feed hopper, and an auxiliary ventilation pipe is provided on the discharge pipe at the bottom of the feed hopper; a collection tank is provided at the other end of the horizontal heating tank, and a first pressure gauge and a pressure relief valve are provided on the collection tank.
[0007] The front section of the horizontal heating tank is provided with an inlet for injecting hydrogen and inert gas into the horizontal heating tank, and the rear section of the horizontal heating tank is provided with an outlet for discharging waste gas after the reaction; and the outlet is provided with a filter device for filtering graphene.
[0008] As a preferred embodiment of this invention, the reaction temperature of the horizontal heating tank is 600-800℃.
[0009] As a preferred technical solution of this utility model, the horizontal heating tank is provided with a driving device for driving the spiral pusher to rotate.
[0010] As a preferred embodiment of this utility model, the horizontal heating tank is equipped with a second pressure gauge for detecting the air pressure inside the horizontal heating tank.
[0011] As a preferred embodiment of this utility model, the inner wall of the horizontal heating tank is provided with a heat insulation layer.
[0012] As a preferred embodiment of this utility model, the bottom of the horizontal heating tank is provided with supporting feet.
[0013] As a preferred embodiment of this utility model, the horizontal heating tank is provided with a waste outlet at the bottom of its end.
[0014] The beneficial effects of this utility model are:
[0015] This chemical reduction device for graphene oxide can rapidly reduce graphene oxide, saving costs, facilitating operation, lowering the production threshold for graphene materials, reducing the probability of secondary contamination of graphene, and producing graphene oxide with excellent thermal and electrical conductivity. This invention can be used for industrial mass production. The front end of the horizontal heating tank is connected to a feeding funnel; the center of the horizontal heating tank has a heating device to raise the temperature to the reaction temperature of 600℃. An air inlet is located at the front of the horizontal heating tank to inject hydrogen and inert gases. A mass flow controller is installed at the air inlet to control the flow rate of the gases participating in the reaction. An air outlet is located at the rear to discharge waste gases after the reaction, while waste materials can be discharged through the waste outlet. A collection pipe is used to collect the graphene. This allows for rapid reduction of graphene oxide, and the gases released during the reduction reaction can be discharged promptly, thus enabling continuous sample preparation. Attached Figure Description
[0016] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:
[0017] Figure 1 This is a schematic diagram of the interior of a horizontal heating tank in a chemical reduction device for graphene oxide according to this utility model.
[0018] Figure 2 This is a schematic diagram of the structure of a chemical method for reducing graphene oxide according to this utility model.
[0019] In the diagram: 1. Horizontal heating tank; 2. Screw feeder; 3. Feed hopper; 4. Agitator; 5. Ventilation pipe; 6. Collection tank; 7. First pressure gauge; 8. Pressure relief valve; 9. Air inlet; 10. Air outlet; 11. Filter device; 12. Second pressure gauge; 13. Insulation layer; 14. Support legs; 15. Waste outlet. Detailed Implementation
[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0021] Example: Figure 1 and Figure 2As shown, this utility model discloses a chemical reduction device for graphene oxide, comprising a cylindrical horizontal heating tank 1, with a spiral feeder 2 inside the horizontal heating tank 1. A feed hopper 3 is located at one end of the horizontal heating tank 1, and a stirrer 4 is installed inside the feed hopper 3. An air inlet 9 for facilitating airflow into the heating tank 1 is also provided on the discharge pipe at the bottom of the feed hopper 3. An air pipe 5 is located at the tail end of the horizontal heating tank 1. A collection tank 6 is located at the other end of the horizontal heating tank 1, and a first pressure gauge 7 and a pressure relief valve 8 are installed on the collection tank 6. The air pressure inside the collection tank 6 is always controlled between 0.01-0.11 MPa, with 0.1 MPa being optimal in actual operation. The collection tank 6 can be equipped with a backflow air pipe, which is also equipped with a switch valve to prevent negative pressure from forming in the collection tank 6 when the pressure relief valve 8 is open, thus preventing the risk of backflow.
[0022] The horizontal heating tank 1 is equipped with a horizontal outlet 10 at the front for injecting hydrogen and inert gas, which is used to discharge waste gas after the reaction. The outlet 10 also contains a filter device 11 for filtering graphene. This invention can rapidly reduce graphene oxide, saving costs, is easy to operate, lowers the production threshold for graphene materials, reduces the probability of secondary contamination of graphene, and the reduced graphene oxide has excellent thermal and electrical conductivity. This invention can be used for industrial mass production.
[0023] This invention relates to a method for feeding graphene oxide into a feed hopper, where it is initially crushed and stirred by a stirrer, and then fed into a horizontal heating tank via an auxiliary venting pipe. The top of a collection tank is connected to the tail of the heater, and the collection tank is equipped with a first pressure gauge 7 and a pressure relief valve to discharge residual waste gas from the reduced graphene oxide material.
[0024] The front end of the horizontal heating vessel is connected to the feeding funnel. The interior of the horizontal heating vessel has a heating device at its center to raise the temperature to the reaction temperature of 600℃. An air inlet is located at the front of the horizontal heating vessel to inject hydrogen and inert gases into it. A mass flow controller is installed at the air inlet to control the flow rate of the gases participating in the reaction. An air outlet is located at the rear to discharge the waste gas after the reaction, while the waste material can be discharged through the waste outlet. A collection pipe is used to collect graphene, enabling conditions for rapid reduction of graphene oxide. The gases released during the reduction reaction can be discharged in a timely manner, thus achieving continuous sample preparation.
[0025] The temperature inside the horizontal heating vessel was maintained at a constant 600℃. After the reduction reaction had been underway for 4 hours, heating and hydrogen supply were stopped, and inert gas was introduced for another 2 hours. Then, the inert gas supply was stopped, and the vessel was allowed to cool naturally to room temperature to obtain reduced graphene oxide.
[0026] The horizontal heating tank 1 has a reaction temperature of 600-800℃ and is equipped with a heating device to raise the temperature inside the chamber to the reaction temperature of 600℃.
[0027] The horizontal heating tank 1 is equipped with a drive device that drives the spiral pusher 2 to rotate. Power can be transmitted to the driven gear of the horizontal heating tank 1 using gears, and a hydraulic coupling can be installed to buffer the huge torque during instantaneous start-up. Furthermore, the drive device can be a driving pulley, but is not limited to having a driven pulley. The driving pulley is connected to the driven pulley via a belt, and the drive device drives the spiral pusher to rotate.
[0028] The horizontal heating tank 1 is equipped with a second pressure gauge 12 for detecting the air pressure inside the horizontal heating tank 1. The inner wall of the horizontal heating tank 1 is provided with a heat insulation layer 13.
[0029] The horizontal heating tank 1 is provided with support feet 14 at its bottom. The horizontal heating tank 1 is provided with a waste outlet 15 at its end bottom.
[0030] During operation, this chemical reduction graphene oxide apparatus, with a stirrer and helium continuously introduced through the inlet, raises the temperature of the horizontal heating tank 1 to 600°C. Helium supply is then stopped, and hydrogen is introduced instead, with a pressure of 0.1 MPa and a flow rate of 250 ml / min. After 4 hours of reduction reaction, heating in the horizontal heating tank 1 is stopped, hydrogen supply is shut off, and helium is introduced through the inlet 9 for another 2 hours before helium supply is stopped. The process is then allowed to cool naturally to room temperature, thus producing the chemically reduced graphene oxide product.
[0031] Graphene oxide raw material can be continuously added to the horizontal heating tank 1 to react with hydrogen, so as to ensure continuous production and processing. After initial crushing and stirring by the agitator, the reaction can be made uniform by two stirrings by the screw feeder. Secondly, the horizontally set cylinder of the horizontal heating tank 1 is equipped with a drive device for its screw feeder, so that during the operation of the horizontal heating tank 1, the product after the reduction reaction of graphene oxide and hydrogen gradually moves to the rear end of the horizontal heating tank 1. The generated graphene material enters the collection tank through the tail end. When entering the collection tank in a helium atmosphere, it is cooled to room temperature. Helium is continuously introduced to prevent the high-temperature graphene generated during the reaction from being re-oxidized in the collection tank. Since the gas flow rate is 250ml / min, the gas easily carries graphene powder. This technical solution is equipped with a filter to prevent graphene from being carried out.
[0032] The collection tank can be equipped with active heat dissipation, such as air cooling or water cooling. Furthermore, the tilt angle and length of the horizontal heating tank 1 can be optimized based on the movement speed of graphene oxide within the tank, the heating temperature, and the reaction time, ensuring continuous and uninterrupted graphene production. This means that graphene oxide particles move and react within the horizontal heating tank 1 to generate graphene. If effective control is not possible, the temperature of the horizontal heating tank 1 can be appropriately increased, but not exceeding 800℃ (600-800℃ is the optimal reaction temperature). The tilt angle of the horizontal heating tank 1 can also be adjusted to a head-lower-tail-higher configuration, allowing the reaction to proceed fully. In the presence of reducing hydrogen, graphene is prepared via a highly efficient chemical reduction pathway. As the concentration of graphene oxide gradually increases, the final conversion efficiency of the monomer gradually decreases. In particular, when 10 wt% graphene oxide is added to the horizontal heating tank 1, the monomer conversion rate decreases by approximately 25%.
[0033] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A chemical reduction of graphene oxide apparatus, characterized by, The application relates to a horizontal heating tank (1) in a cylindrical type, wherein a screw propeller (2) is arranged in the horizontal heating tank (1), one end of the horizontal heating tank (1) is provided with a feeding hopper (3), a stirrer (4) is arranged in the feeding hopper (3), a ventilation assisting pipe (5) is further arranged on a discharging pipe at the bottom of the feeding hopper (3); the other end of the horizontal heating tank (1) is provided with a collecting tank (6), a first pressure gauge (7) and a pressure relief valve (8) are arranged on the collecting tank (6). A gas inlet (9) for injecting hydrogen and inert gas into the horizontal heating tank (1) is arranged at the front section of the horizontal heating tank (1), a gas outlet (10) is arranged at the tail section of the horizontal heating tank (1) and is used for discharging waste gas after reaction; and a filtering device (11) for filtering graphene is arranged in the gas outlet (10).
2. The apparatus for chemical reduction of graphene oxide according to claim 1, wherein, The reaction temperature of the horizontal heating tank (1) is 600-800 DEG C.
3. The apparatus for reducing graphene oxide chemically according to claim 1, wherein, A driving device for driving the rotation of the screw propeller (2) is arranged on the horizontal heating tank (1).
4. The apparatus for chemical reduction of graphene oxide according to claim 2, wherein, A second pressure gauge (12) for detecting the air pressure in the horizontal heating tank (1) is arranged on the horizontal heating tank (1).
5. The apparatus for reducing graphene oxide chemically according to claim 1, wherein, A heat preservation layer (13) is arranged on the inner wall of the horizontal heating tank (1).
6. The apparatus for chemically reducing graphene oxide according to claim 5, wherein Supporting legs (14) are arranged at the bottom of the horizontal heating tank (1).
7. The apparatus for chemically reducing graphene oxide of claim 5, wherein, A waste material outlet (15) is arranged at the bottom of the tail end of the horizontal heating tank (1).