CN212832856U

CN212832856U - High-temperature reaction device for preparing graphene by electrifying carbon powder

Info

Publication number: CN212832856U
Application number: CN202021500006.2U
Authority: CN
Inventors: 吕海港
Original assignee: Shanxi University
Current assignee: Shanxi University
Priority date: 2020-07-27
Filing date: 2020-07-27
Publication date: 2021-03-30
Anticipated expiration: 2030-07-27

Abstract

The utility model belongs to the technical field of preparation nano-material device, concretely relates to carbon dust circular telegram preparation graphite alkene's high temperature reaction unit. The utility model aims at solving the technical problems of small production scale and low efficiency of the existing graphene production device. The utility model adopts the technical proposal that: the utility model provides a high temperature reaction unit of carbon dust circular telegram preparation graphite alkene, its includes one big one little two concentric drum electrodes, insulating ring lid and insulating bottom plate, the bottom of two concentric drum electrodes sets up on insulating bottom plate, insulating ring lid suit is between little drum electrode and big drum electrode. The utility model has the advantages of large production scale and high efficiency.

Description

High-temperature reaction device for preparing graphene by electrifying carbon powder

Technical Field

The utility model belongs to the technical field of preparation nano-material device, concretely relates to carbon dust circular telegram preparation graphite alkene's high temperature reaction unit.

Background

Graphene is a two-dimensional nano material composed of single-layer honeycomb-shaped carbon atoms, is the thinnest, lightest, strongest and hardest material, has excellent electric conduction and heat conduction performance, and is called as the king of materials. The current large-scale production of graphene is primarily a graphite redox process. In view of the problems of complex process technology, waste liquid treatment and the like, the production cost of the graphene is very high, the price of the graphene powder in the market is high, and the large-scale application of the graphene is limited. WO2020/051000(Flash Joule Heating Synthesis Method and composition theory) discloses a Method for preparing graphene by electric power Joule Heating Flash evaporation, wherein carbon powder such as carbon black, coke or anthracite is put in a quartz tube, large current is electrified for less than 1 second, the temperature is as high as about 3000 ℃, and the carbon powder is instantly changed into graphene. For the estimation of the power cost, only 2 degrees of electricity are needed for producing 1 kg of graphene, and the power cost is about 1 yuan. Although the graphene obtained by the method is low in cost. However, due to the limitation of the quartz tube reactor, the method can only produce about 1 gram of graphene at one time. The production process comprises the following steps: carbon powder is filled in a quartz tube, two sides of the quartz tube are plugged by a copper plug or a graphite plug, and a copper electrode props against the plug to supply power for heating so as to change the carbon powder into graphene. This reaction gives off a great deal of heat, which needs to be dissipated quickly by light radiation. In addition, the volume of the carbon powder can expand or contract in the reaction process, so that the electrode which is pressed against the plug needs to be padded with a rubber pad to provide certain elasticity, and the phenomenon that the quartz tube is broken due to the volume expansion of the carbon powder or the conductivity is suddenly reduced due to the volume contraction is avoided. From the above reaction process, it is not suitable for mass production. To enable the reaction to be applied to mass production, the reaction apparatus thereof needs to satisfy 6 conditions: (1) the reaction requires large current discharge, so the conductivity of the electrode is good; (2) the reaction produces high temperatures, so all parts are resistant to high temperatures; (3) the reaction needs rapid cooling, so the heat dissipation area of the reaction device is large; (4) the volume of the carbon powder in the reaction is changed, so that the volume of a reaction cavity in the reaction device can be automatically adjusted; (5) in order to continuously and automatically carry out the reaction, the reaction device is convenient to feed and discharge; (6) the device is easy to be enlarged in process. Therefore, in order to realize large-scale production, a new high-temperature reaction device for preparing graphene from carbon powder needs to be designed to meet the requirement of industrialization.

Disclosure of Invention

The utility model aims at solving the technical problems of small production scale and low efficiency of the existing graphene production device, and providing a high-temperature reaction device for preparing graphene by electrifying carbon powder.

In order to achieve the above object, the utility model adopts the following technical scheme:

the utility model provides a high temperature reaction unit of carbon dust circular telegram preparation graphite alkene, its includes one big one little two concentric drum electrodes, insulating ring lid and insulating bottom plate, the bottom of two concentric drum electrodes sets up on insulating bottom plate, insulating ring lid suit is between little drum electrode and big drum electrode.

Further, the optimal radial distance between the small cylinder electrode and the large cylinder electrode is 5-200 mm.

Further, the small cylinder electrode and the large cylinder electrode are both made of graphite, copper, iron, stainless steel, tungsten, chromium, nickel, silver or titanium.

Furthermore, the inner diameter of the insulating ring cover is 0.5-2.0 mm larger than the outer diameter of the small cylinder electrode, and the outer diameter of the insulating ring cover is 0.5-2.0 mm smaller than the inner diameter of the large cylinder electrode.

Furthermore, the insulating base plate is provided with a circular ring boss, the inner diameter and the outer diameter of the circular ring boss are the same as those of the insulating circular ring cover, and the outer diameter or the side length of the insulating base plate is larger than that of the large cylinder electrode.

Further, the insulating bottom plate and the insulating ring cover are made of quartz, alumina ceramic, zirconia ceramic, aluminum nitride ceramic, silicon nitride ceramic, boron nitride ceramic or silicon carbide ceramic.

The beneficial effects of the utility model reside in that:

(1) the cylinder electrode of the utility model is made of high-conductivity metal or graphite, and can meet the conductivity requirement.

(2) The utility model discloses a drum electrode, insulating ring lid and insulating bottom plate all adopt high temperature resistant material to make, can satisfy the high temperature resistant requirement.

(3) The utility model discloses a drum electrode's surface area is very big, and the heat conductivity is fine, can satisfy quick radiating requirement.

Compared with the background art, the utility model, have following advantage: (1) no elastic pads or springs need to be added to the electrodes. When the carbon powder is accumulated and shrunk, the upper insulating circular ring cover naturally descends due to gravity; when the carbon powder volume increases, the insulating ring cover can be automatically jacked up. (2) Easy feeding and discharging. The insulating circular ring cover on the upper part is opened, and then raw materials can be poured in; the prepared graphene can be released at one time by opening the lower insulating bottom plate. (3) The process scale-up is easy to perform. The difference in radius between the concentric cylinders can be small, suitable for small amounts of reactants; can also be large, has large volume for filling carbon powder, is suitable for large-scale production, and improves the production efficiency.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

fig. 2 is a scanning electron microscope image of graphene produced by an embodiment of the apparatus of the present invention;

fig. 3 is a raman spectrum of graphene produced by the device of the present invention.

Detailed Description

The invention is further described with reference to the following figures and examples.

The experimental methods described in the following examples are all conventional methods unless otherwise specified; the starting materials and materials used, if not specifically required, are commercially available. The power supply used was a 60 kilowatt dc power supply (300V max and 200A max current).

Example 1

As shown in fig. 1, the high-temperature reaction device for preparing graphene by electrifying carbon powder in the embodiment includes a large cylindrical electrode 1, a small cylindrical electrode 3, an insulating ring cover 2 and an insulating base plate 5, wherein the bottom ends of the small cylindrical electrode 1 and the large cylindrical electrode 3 are arranged on the insulating base plate 5, and the insulating ring cover 2 is sleeved between the small cylindrical electrode 1 and the large cylindrical electrode 3. The small cylindrical electrode 1 is made of copper, and the outer diameter of the small cylindrical electrode is 40 mm, and the height of the small cylindrical electrode is 60 mm; the large cylinder electrode 3 is made of copper, and the inner diameter of the large cylinder electrode is 80 mm, and the height of the large cylinder electrode is 40 mm; the insulating ring cover 2 is made of quartz, the inner diameter of the insulating ring cover is 0.5 mm larger than the outer diameter of the small cylinder electrode, the outer diameter of the insulating ring cover is 0.5 mm smaller than the inner diameter of the large cylinder electrode, and the thickness of the insulating ring cover is 10 mm; the insulating base plate 5 is made of quartz, the outer diameter of the insulating base plate is 120 mm, the thickness of the insulating base plate is 20 mm, a circular boss is arranged on the insulating base plate 5, the inner diameter and the outer diameter of the circular boss are the same as those of the insulating circular cover 2, and the height of the circular boss is 10 mm.

The utility model discloses a use method does: firstly, the insulating bottom plate 5 and the large cylinder electrode 3 are assembled, the small cylinder electrode 1 is inserted into a central circular groove of the insulating bottom plate 5, 5 g of conductive carbon black 4 is put into the central circular groove, the conductive carbon black is uniformly distributed between the large cylinder electrode and the small cylinder electrode, the insulating circular ring cover 2 is pressed on the conductive carbon black, and the height of the conductive carbon black is about 10 mm. The resistance across the measurement electrode was 1.0 ohm.

The whole reaction device is placed in a vacuum box, a discharge circuit is connected, and the reaction device is vacuumized to be lower than 0.1 atmosphere. The power is switched on, the voltage is selected to be 250V, the discharge is carried out for 500 milliseconds, the pause is carried out for 5 seconds, and the discharge is cycled for 5 times. Each discharge shines intense light in both the top and bottom directions. The power supply is cut off, the vacuum box is filled with gas, the vacuum box is opened, the reaction device is taken out, and the height of the conductive carbon black product is reduced to about 8 mm. It can be seen that the insulating ring cover 2 plays a role of automatically stretching along with the carbon powder volume. The quartz bottom plate of the reaction apparatus was opened, and the prepared product was poured out from the bottom. And grinding and crushing the product, dispersing by 3 kilowatt ultrasound, and centrifugally drying to obtain black powder. Scanning electron microscopy of these black powders (fig. 2) revealed that a lamellar structure had been produced. The black powders were examined by laser raman spectroscopy to obtain a raman spectrum (fig. 3). The black powder can be analyzed by a map, and is a graphene nano material with less than 10 layers. The G peak in fig. 3 is a main characteristic peak of graphene, and is caused by in-plane vibration of sp2 carbon atoms, and the peak can effectively reflect the number of layers of graphene; the D peak is a disordered vibration peak of the graphene and is used for representing structural defects or edges in the graphene sample; the 2D peak is a two-phonon resonance second-order Raman peak and is used for representing an interlayer stacking mode of carbon atoms in the graphene sample.

In addition, only one control device for automatically feeding from the top and automatically discharging from the bottom is needed to be added, the whole reaction can be automatically and continuously carried out, and the large-scale production of graphene is realized.

Example 2

By adopting the reaction device of the embodiment 1, coke, anthracite and charcoal powder of 800 meshes and conductive carbon black are respectively and uniformly mixed according to the proportion of 4:1 to obtain three kinds of carbon powder. After the three kinds of carbon powder are respectively filled between the small cylinder electrode and the large cylinder electrode and covered with the insulating circular cover 2 made of quartz and compacted, the heights of the coke powder, the anthracite powder and the charcoal powder are respectively 5.2 mm, 5.3 mm and 7.1 mm, and the resistances are respectively 3.2 ohm, 3.5 ohm and 4.1 ohm. The discharge was performed according to the energization step of example 1, and intense white light was emitted. The height of the product after reaction is about 7 mm. And (3) after the reaction product is subjected to ultrasonic dispersion, centrifugal separation and drying, the scanning electron microscope image and the Raman spectrogram are similar to those of the conductive carbon black.

This shows that the utility model is suitable for preparing graphene from coke, anthracite and charcoal powder, and is also suitable for preparing graphene from most types of carbon powder.

Example 3

The small cylinder electrode 1 and the large cylinder electrode 3 made of copper in example 1 were changed to the small cylinder electrode 1 and the large cylinder electrode 3 made of graphite, iron, stainless steel, tungsten, chromium, nickel, silver, and titanium, respectively, 5 g of conductive carbon black was filled between the small cylinder electrode and the large cylinder electrode made of the above materials and covered with the insulating ring cover 2 made of quartz to be compacted, and discharge was performed according to the energization step of example 1 to emit intense white light. After the reaction product is subjected to ultrasonic dispersion, centrifugal separation and drying, the scanning electron microscope image and the Raman spectrogram of the reaction product are completely the same as the results obtained by using the copper cylinder electrode.

This shows that the large and small cylindrical electrodes of the present invention can also be made of materials with high temperature resistance and good conductivity, such as graphite, copper, iron, stainless steel, tungsten, chromium, nickel, silver or titanium.

Example 4

The insulating ring cover and the insulating base plate made of quartz in the embodiment 1 are respectively made of alumina ceramic, zirconia ceramic, aluminum nitride ceramic, silicon nitride ceramic, boron nitride ceramic or silicon carbide ceramic. 5 g of conductive carbon black is filled between the small cylinder electrode and the large cylinder electrode, and the ceramic ring cover made of the material is covered on the conductive carbon black for compaction, and the discharge is carried out according to the electrifying step of the embodiment 1. Since the ceramic is opaque, the emission of intense white light is not seen. After the reaction product is subjected to ultrasonic dispersion, centrifugal separation and drying, the scanning electron microscope image and the Raman spectrum image of the reaction product are basically the same as the results of using the quartz insulating material electrode.

This shows the utility model discloses an insulating ring lid and insulating bottom plate can also use alumina ceramics, zirconia pottery, aluminium nitride pottery, silicon nitride pottery, boron nitride pottery or silicon carbide pottery preparation.

Example 5

The inner diameters of the large cylinder electrode 1 in the embodiment 1 are respectively changed into 45 mm, 50 mm, 440 mm and 480 mm, and are matched with the corresponding insulating circular ring cover and the insulating bottom plate, carbon powder of 0.1 g, 1.0 g, 1500 g and 2000 g are respectively filled between the small cylinder electrode and the large cylinder electrode and are covered with the insulating circular ring cover to be compacted, the height of the carbon powder is about 10 mm, and the resistance is respectively 0.1 ohm, 0.3 ohm, 25.3 ohm and 30.4 ohm. The voltage of 60, 120, 300 and 300V was chosen respectively, and the discharge was performed according to the power-on procedure of example 1, and the first 3 reaction devices all emitted intense white light, and the last one did not emit intense white light because the current was too small. And after multiple electrifying reactions, taking out the product, ultrasonically dispersing, centrifugally separating and drying. Wherein the scanning electron micrograph and the Raman spectrum of the product of the first 3 reaction apparatuses are substantially identical to those of example 1. When the inner diameter of the large cylinder electrode is 480 millimeters, the product is far away from graphene, and graphene cannot be prepared. In addition, when the inner diameter of the large cylindrical electrode is 45 mm, the gap between the two cylindrical electrodes is too small to be convenient for filling carbon powder. Therefore, graphene can only be obtained by matching a large cylinder electrode with a diameter of 50-440 mm with a small cylinder electrode with a diameter of 40 mm. Since the outer diameter of the small cylindrical electrode is 40 mm, the optimum radial distance between the large and small cylindrical electrodes is 5-200 mm.

From the above results, to prepare a certain amount of graphene, the radial distance between the concentric large and small cylindrical electrodes is 5 to 200 mm. In addition, the reaction device can be easily amplified by hundreds of times, and the large-scale graphene production is met.

The above is only the embodiment of the present invention, not limiting the scope of the present invention, all of which utilize the equivalent structure or equivalent flow transformation made by the content of the present invention, or directly or indirectly applied to other related technical fields, and all included in the same way in the protection scope of the present invention.

Claims

1. A high-temperature reaction device for preparing graphene by electrifying carbon powder is characterized in that: the electrode comprises a large cylinder electrode, a small cylinder electrode, an insulating ring cover and an insulating bottom plate, wherein the bottom ends of the two concentric cylinder electrodes are arranged on the insulating bottom plate, and the insulating ring cover is sleeved between the small cylinder electrode and the large cylinder electrode.

2. The high-temperature reaction device for preparing graphene by electrifying carbon powder according to claim 1, which is characterized in that: the optimal radial distance between the small cylinder electrode and the large cylinder electrode is 5-200 mm.

3. The high-temperature reaction device for preparing graphene by electrifying carbon powder according to claim 1, which is characterized in that: the small cylinder electrode and the large cylinder electrode are both made of graphite, copper, iron, stainless steel, tungsten, chromium, nickel, silver or titanium.

4. The high-temperature reaction device for preparing graphene by electrifying carbon powder according to claim 1, which is characterized in that: the inner diameter of the insulating ring cover is 0.5-2.0 mm larger than the outer diameter of the small cylinder electrode, and the outer diameter of the insulating ring cover is 0.5-2.0 mm smaller than the inner diameter of the large cylinder electrode.

5. The high-temperature reaction device for preparing graphene by electrifying carbon powder according to claim 1, which is characterized in that: the insulating bottom plate is provided with a circular ring boss, the inner diameter and the outer diameter of the circular ring boss are the same as those of the insulating circular ring cover, and the outer diameter or the side length of the insulating bottom plate is larger than that of the large cylinder electrode.

6. The high-temperature reaction device for preparing graphene by electrifying carbon powder according to claim 1, which is characterized in that: the insulating bottom plate and the insulating ring cover are made of quartz, alumina ceramics, zirconia ceramics, aluminum nitride ceramics, silicon nitride ceramics, boron nitride ceramics or silicon carbide ceramics.