CN110294468B

CN110294468B - Device and method for preparing fullerene by using compressed arc

Info

Publication number: CN110294468B
Application number: CN201910716764.3A
Authority: CN
Inventors: 李雪霏; 邹科
Original assignee: Beijing Three Arc Technology Co ltd
Current assignee: Beijing Three Arc Technology Co ltd
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2024-05-17
Anticipated expiration: 2039-08-05
Also published as: CN110294468A

Abstract

The invention provides a device for preparing fullerene by using compressed electric arc, which can increase the temperature and power of the electric arc by using an electromagnet in an electric arc reaction chamber and react to obtain fullerene carbon clusters. The invention also provides a method for preparing fullerene by using the device, which comprises the steps of gasifying a carbon rod in an arc reaction chamber by using a plasma generator to obtain soot containing fullerene, cooling and filtering the soot, and collecting the soot. The invention solves the problem of low yield of fullerene, and can automatically collect the fullerene in a vacuum environment, thereby avoiding pollution to the air environment and damage to the health of operators.

Description

Device and method for preparing fullerene by using compressed arc

Technical Field

The invention relates to the technical field of carbon nanomaterial preparation, in particular to a device for preparing fullerene by using a compressed arc and a method for preparing fullerene by using the device.

Background

Currently, carbon nanomaterials including fullerenes have been prepared by various methods for obtaining energy. These methods include: coal combustion, benzene combustion, laser evaporation, beam bombardment, ion implantation, chemical passage, arc discharge, high temperature and high pressure, and nuclear reaction. The arc discharge method is easy to operate and low in cost, and people commonly select the method at present. But the yield of fullerenes is severely limited due to the lower power of the arc discharge process.

After the two parallel graphite electrodes establish an arc channel, the generated arc is not compressed by the outside, the section of the arc column is increased along with the increase of power, the current density in the arc column is nearly constant, and the arc generated in the mode is free arc. At present, a free arc method is generally adopted to prepare the carbon nanomaterial and the fullerene.

The free arc method working conditions include: the distance between the two carbon rods is about 20mm, free electric arc is obtained under the actions of micro negative pressure, helium atmosphere and gravity field, the voltage of the electric arc is about 40V, the power is about 4-10Kw, and the electric arc temperature is about 6000 ℃. Because the minimum gasification temperature of graphite is about 5100 ℃, and the arc temperature just exceeds the minimum temperature condition required for gasifying graphite, the generated cathode arc root and anode arc root are unstable. The arc root is smaller in the anode arc root area, and the arc root always jumps on the end face of the graphite electrode instantaneously. The gasification rate of graphite is almost independent of the diameter of graphite electrode, so even if the volume of graphite electrode is increased, carbon nanomaterial and fullerene cannot be efficiently prepared.

In view of this, the present invention has been made.

Disclosure of Invention

A first object of the present invention is to provide an apparatus for preparing fullerenes using a compressed arc.

A second object of the present invention is to provide a method for preparing fullerenes using the apparatus.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

the invention relates to a device for preparing fullerene by using compressed arc, which comprises an arc reaction chamber for preparing soot containing fullerene, wherein a cathode electrode, an anode electrode, a power supply, an electromagnet and a water-cooled wall are arranged inside the arc reaction chamber,

The water cooling wall is of a cylindrical structure with an interlayer cavity, the water cooling wall is provided with a water inlet and a water outlet which are communicated with the interlayer cavity, the interlayer cavity is used for providing a cooling water circulation space to enable cooling water to absorb and take away reaction heat,

The cathode electrode and the anode electrode are oppositely arranged in the water-cooled wall with a certain distance, the anode of the power supply is connected with the anode electrode, the cathode of the power supply is connected with the cathode electrode, an electric arc can be generated between the cathode electrode and the anode electrode,

The electromagnet is an electrified coil which is sleeved outside the water-cooled wall and is positioned between the cathode electrode and the anode electrode and used for generating a magnetic field to compress the electric arc,

The arc reaction chamber is provided with an inert gas inlet, an inert gas outlet and a collecting port, wherein the inert gas inlet and the inert gas outlet are respectively used for leading in and leading out inert gas into the arc reaction chamber, and the collecting port is used for leading out reacted gas-phase products from the arc reaction chamber.

Preferably, the cathode electrode is made of red copper, and the inside of the cathode electrode contains a tungsten cerium electrode core.

Preferably, the anode electrode is made of graphite.

Preferably, an insulating layer is arranged outside the energizing coil.

Preferably, an electrode moving mechanism is further provided in the arc reaction chamber, for moving the anode electrode in the direction of the cathode electrode. When the anode electrode is observed to be shortened due to evaporation, the cathode electrode and the anode electrode can be maintained at a proper distance by manipulating the electrode moving mechanism, which may be a known screw moving mechanism or a pneumatic moving mechanism.

Preferably, the device also comprises a cooling bin, a filtering bin and a tail gas treatment bin which are sequentially connected with the arc reaction chamber, wherein,

The cooling bin is connected with a collecting port of the arc reaction chamber and is used for cooling gas-phase products output from the arc reaction chamber and inputting the cooled gas-phase products into the filtering bin,

The filtering bin is used for filtering out solids in the gas phase product and inputting the gas phase product without the solids into the tail gas treatment bin,

The tail gas treatment bin is used for treating the gas-phase product output from the filtering bin to enable the gas-phase product to meet the emission standard.

The invention also relates to a method for preparing fullerene by using the device, which comprises the following steps: and (3) introducing inert gas into the arc reaction chamber, and introducing cooling water into the water cooling wall to discharge the cathode electrode and the anode electrode to generate a compressed arc, so as to obtain the soot containing fullerene.

Preferably, the soot is cooled and then added with an organic solvent for thorough mixing, and insoluble matters in the soot are removed, so that the carbon nanomaterial containing fullerene is obtained.

Preferably, the inert gas is helium alone, argon alone, or a mixture of helium and argon.

Preferably, the power source used between the cathode electrode and the anode electrode is a direct current power source, the power source current is 100-500 a, and the voltage is 10-400 v.

Preferably, the arc temperature generated in the discharging process is 5000-20000 ℃, and the diameter of the arc column is 5-20 mm.

The invention has the beneficial effects that:

The invention provides a device for preparing fullerene by using compressed electric arc, which compresses the electric arc by using an electromagnet to centralize and control an electric arc column. Therefore, the gasification anode carbon rod has high speed, and the defect of low gasification speed in the traditional method is overcome.

In the preferred scheme, the cyclone air inlet is carried out by using a plurality of air inlets, so that the temperature of the interlayer cavity is reduced, heat exchange by using high-purity helium is not needed, and the problem that soot containing fullerene can be prepared only by using high-purity helium in the traditional method is solved. The soot containing fullerenes can be made in the present invention using helium, argon, or a mixture of both inert gases.

In addition, due to the heat exchange of the flowing gas, the generated soot particles can flow along with the gas and convey the product into the cooling bin, so that the collection of the product is facilitated. Whereas in the prior art the gas in the reaction chamber is stationary, so that only the product can be collected in the reaction chamber. Therefore, the invention solves the problem that soot containing fullerene can be obtained only by gasifying a carbon rod in a static environment.

Drawings

Fig. 1 is a schematic diagram of a structure of an apparatus for preparing fullerenes using a compressed arc.

Fig. 2 is a cross-sectional view of the arc generating device body.

Fig. 3 is a cross-sectional view of an arc generating device (power supply).

Fig. 4 is a sectional view in the direction a of fig. 2.

Fig. 5 is a schematic diagram of a compressed arc using an electromagnet.

FIG. 6 is a chromatogram of an organic solvent with a product dissolved therein.

Wherein, 1-an arc reaction chamber;

11-a cathode electrode; 12-an anode electrode; 121-an auxiliary anode;

13-an electromagnet;

131-an insulating layer;

14-water cooling walls;

141-anode cooling water inlet; 142-anode cooling water outlet;

143-auxiliary anode cooling water inlet; 144-auxiliary anode cooling water outlet;

15-inert gas inlet; 16-inert gas outlet; 17-a collection port;

18-a power supply; 19-arc;

2-cooling bin; 3-a filter bin; 4-a tail gas treatment bin.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, based on the examples herein, which are within the scope of the invention as defined by the claims, will be within the scope of the invention as defined by the claims.

[ Arc reaction chamber ]

The embodiment of the invention relates to a device for preparing fullerene by using a compressed arc. As shown in fig. 1, the apparatus comprises an arc reaction chamber 1, the arc reaction chamber 1 functioning to produce soot containing fullerenes. Inside the arc reaction chamber, there are cathode 11, anode 12, power source 18, electromagnet 13 and water cooled wall 14.

The water-cooled wall 14 has a cylindrical structure with an interlayer cavity, and a water inlet and a water outlet (not shown in the figure) are arranged on the water-cooled wall 14 and are communicated with the interlayer cavity, and the number of the water inlet and the water outlet can be more than one. The interlayer cavity is used for providing a cooling water circulation space so that cooling water absorbs and takes away reaction heat, and the device is maintained to stably run.

The cathode 11 and the anode 12 are disposed in the water wall 14 with a certain distance therebetween, which may be 10-45 mm. The power supply 18 may be provided inside or outside the arc reaction chamber, the anode of the power supply 18 is connected to the anode electrode 12 through a wire, the cathode of the power supply 18 is connected to the cathode electrode 11 through a wire, and an arc 19 may be generated in a passage between the cathode electrode 11 and the anode electrode 12. The high temperature region generated by the arc 19 forms a plurality of fullerene cages, and under the action of flowing gas, the fullerene cages formed in the high temperature region can rapidly leave the reaction zone and enter the subsequent cooling bin 2, so that the yield and the output of fullerene can be improved compared with those of the prior art in which non-flowing inert gas is used in the arc reaction chamber.

The electromagnet 13 is an energizing coil, and the energizing coil is sleeved outside the water-cooled wall 14 and is positioned between the cathode electrode 11 and the anode electrode 12, and is used for generating a magnetic field to compress the electric arc 19. Fig. 5 is a schematic diagram of compression arc using an electromagnet, namely ampere rule in energized solenoid (ampere rule two): the energized solenoid is held in the right hand and the four fingers are pointed in the direction of the current, so that the end pointed by the thumb is the N pole of the energized solenoid. It can be seen that the passage of current into the energized coil creates a magnetic field that can direct and compress the arc, further controlling the shape and path of the arc 19 such that the arc 19 is centered in the passage. Since the generated arc 19 is a plasma arc, the power of the arc 19 does not change after being compressed, but the shape of the arc 19 changes, which is specifically represented by a taper of the arc column, and the energy per unit area increases after the taper.

The arc reaction chamber 1 is provided with an inert gas inlet 15, an inert gas outlet 16 and a collecting port 17, wherein the inert gas inlet 15 and the inert gas outlet 16 are respectively used for leading in and leading out inert gas into the arc reaction chamber 1 to provide inert atmosphere for the reaction. The collecting port 17 is used for guiding out the gas-phase product after the reaction from the arc reaction chamber 1, and the gas-phase product needs to be cooled and collected later.

In one embodiment of the present invention, the cathode 11 is made of red copper, and has a tungsten cerium electrode core therein. Since the heat conductivity of red copper is superior to that of other metals, the use of red copper as the cathode electrode 11 can reduce the cathode temperature and has good electrical conductivity.

In one embodiment of the present invention, the anode electrode 12 is graphite. Further, a carbon rod can be used as the anode electrode 12, and graphene and other carbon nanomaterial can be generated by evaporation during the arc reaction.

In one embodiment of the invention, an insulating layer 131 is provided outside the energized coil to prevent the arc 19 from being energy dispersed, creating a double or series arc. Specifically, during the arc 19, a circuit is formed between the cathode electrode 11 and the anode electrode 12, and the flowing inert gas is capable of forming a gaseous insulating layer between the cathode electrode 11 and the anode electrode 12. Since the insulating layer formed by the inert gas is occasionally broken, double arcs or so-called cross arcs may occur at the time of the breaking. When a double arc occurs, some of the current on the original arc 19 will be distributed to the other arcs that occur, and such arcs will not be constrained, and thus the arc energy will be distributed and the power will be reduced. The insulating layer 131 outside the energizing coil is an insulating layer for preventing cold air, that is, when the aforementioned gaseous insulating layer is broken, a current flow is formed from the cathode electrode 11 to the auxiliary anode 121 and then to the anode electrode 12. After the insulating layer 131 is added outside the energizing coil, such a situation can be effectively prevented.

[ Arc generator ]

The specific structure of the arc generating device is shown in fig. 2 and 3. The device is located inside the arc reaction chamber 1 and comprises a cathode electrode 11, an auxiliary anode 121, an anode electrode 12 and a power supply 18.

A water-cooled wall 14 is provided on the outer periphery of the cathode 11, and a certain gap is provided between the water-cooled wall 14 and the cathode 11 to form an inert gas circulation space. The water-cooling wall 14 is provided with a water inlet and a water outlet, and a cooling water circulation space is arranged inside the water-cooling wall 14. Specifically, an anode cooling water inlet 141 and an anode cooling water outlet 142 are provided outside the anode electrode 12, and an auxiliary anode cooling water inlet 143 and an auxiliary anode cooling water outlet 144 are provided outside the auxiliary anode 121. The inert gas inlets 15 may adopt the mode shown in fig. 4, that is, the water-cooled wall 14 is simultaneously provided with a plurality of inert gas inlets 15, each inert gas inlet 15 is a tangential air inlet, so that inert gas swirl flow can enter the gap between the water-cooled wall 14 and the cathode electrode 11, and the reaction heat can be rapidly taken away.

Outside the water-cooled wall 14, an electromagnet 13 is arranged between the cathode electrode 11 and the anode electrode 12. The auxiliary anode 121 is located in the gap between the water-cooled wall 14 and the cathode electrode 11 and extends to the position of the electromagnet 13 until entering the inner ring of the electromagnet 13. An insulating layer 131 is provided on the side of the electromagnet 13 adjacent to the anode electrode 12.

The negative electrode of the power supply 18 is connected to the cathode electrode 11, and the positive electrode of the power supply 18 is connected to the anode electrode 12 and the auxiliary anode 121, respectively. An anode control switch K1 is provided on a connection lead between the positive electrode of the power supply 18 and the anode electrode 12, and an auxiliary anode control switch K2 is provided on a connection lead between the positive electrode of the power supply 18 and the auxiliary anode 121.

When the arc generating device needs to be started, the auxiliary anode control switch K2 is first closed, inert gas is introduced into the inert gas inlet 15, and an inert gas protective film is formed on the surface of the cathode electrode 11. Electrons emitted from the cathode electrode 11 fall on the auxiliary anode 121 to form an auxiliary arc. When the auxiliary arc reaches a certain power and length, the anode control switch K1 is closed, the anode arc root is transferred to the anode electrode 12, a main arc between the cathode electrode 11 and the anode electrode 12 is formed, the auxiliary anode control switch K2 is opened at the moment, and the auxiliary arc is automatically extinguished. The auxiliary arc is formed first and then turned into the main arc.

The arc 19 is turned to a position where the distance from the cathode electrode 11 to the auxiliary anode 121 is shortest, then the arc is sent to the anode electrode 12 by flowing inert gas, and then the auxiliary anode 121 is disconnected, so that a loop is formed between the cathode electrode 11 and the anode electrode 12, and a main arc 19 is formed. The flowing inert gas can form an insulating layer between the cathode electrode 11 and the anode electrode 12. Since the insulating layer formed by the inert gas is occasionally broken, double arcs or so-called arcing occurs at the time of breaking, the arc energy is dispersed, and the power is reduced, so that the insulating layer 131 needs to be provided outside the energizing coil.

In summary, the present invention prevents double arcs from occurring by: (1) an insulating layer 131 is provided outside the energizing coil; (2) The temperature of the cooling water of the auxiliary anode 121 is reduced to make the temperature of the inert gas as low as possible; (3) increasing the flow rate of the inert gas; (4) A plurality of inert gas inlets 15 are provided for swirling the inert gas.

[ Other device Structure ]

Further, an electrode moving mechanism (not shown in the figure) is provided inside the arc reaction chamber 1. When it is observed that the anode electrode 12 (typically a carbon rod) is shortened due to evaporation, the anode electrode 12 can be moved toward the cathode electrode 11 by manipulating the electrode moving mechanism so that the cathode electrode 11 and the anode electrode 12 are maintained at a proper distance. The electrode moving mechanism may be a known screw moving mechanism or a pneumatic moving mechanism, for example, a cylinder is used to reciprocate the anode electrode 12.

Further, the device also comprises a cooling bin 2, a filtering bin 3 and a tail gas treatment bin 4 which are sequentially connected with the arc reaction chamber 1. Wherein the cooling bin 2 is connected with a collecting port 17 of the arc reaction chamber 1 and is used for cooling gas-phase products output from the arc reaction chamber 1 and inputting the cooled gas-phase products into the filtering bin 3; the filtering bin 3 is used for filtering out solids in the gas-phase product and inputting the gas-phase product without the solids into the tail gas treatment bin 4; the tail gas treatment bin 4 is used for treating the gas-phase product output from the filter bin 3 so as to enable the gas-phase product to meet the emission standard.

The arc reaction chamber 1, the cooling chamber 2 and the filter chamber 3 were all operated under vacuum. Specifically, since the fullerene-containing carbon nanoparticles are collected by filtration using the filter bag, the gas-phase product output from the arc reaction chamber 1 needs to be cooled to a temperature acceptable to the filter bag. The filtered soot remains in the bottom of the filter house 3, and a vacuum valve is installed in the bottom of the filter house 3. When in collection, the collecting container is connected with the valve, and the valve is directly opened, so that the soot can be prevented from contacting with air and water vapor in the air. The gas phase product without solid matter enters the tail gas treatment bin 4 for purification and filtration, and can be compressed for secondary use when the purity reaches 99.99% or 99.999%.

[ Method for producing Fullerene ]

The invention also relates to a method for preparing fullerene by using the device, which comprises the following steps: inert gas is introduced into the arc reaction chamber 1, cooling water is introduced into the water cooling wall 14, and the cathode electrode 11 and the anode electrode 12 are discharged to generate a compressed arc 19, thereby obtaining soot containing fullerene.

In one embodiment of the invention, soot is collected after cooling and filtering, and organic solvent is added to the collection to thoroughly mix, and insoluble materials therein are removed to obtain fullerene-containing carbon nanomaterial. The organic solvent added may be toluene or o-xylene. If the product contains fullerene, the organic solvent is changed from colorless transparent to wine red to black.

In one embodiment of the invention, the inert gas is helium alone, argon alone, or a mixture of helium and argon. Because helium has a small molecular weight, the helium can quickly enter a fullerene ball cage for cooling, and single helium is usually used in the prior art. Helium is typically extracted from natural gas at a relatively high content. Although natural gas fields are numerous, the fields from which helium can be produced have no tendency to increase significantly. Since helium is difficult to replace with other gases, the supply of helium is still limited and can be consumed after 25 years if consumption is continued at the current rate. In the invention, the spiral inlet air is adopted, and the cooling effect can be enhanced through the air flow, so that mixed inert gas can be used, the ratio of helium to argon in the introduced mixed gas is not required, and the mixed gas only contains trace helium.

Further, the power supply 18 used between the cathode electrode 11 and the anode electrode 12 in the present invention is a direct current power supply. The dc power supply is a constant current power supply, and can supply current to generate an arc between the cathode electrode 11 and the anode electrode 12. Since it is a constant current power supply, the current is a set value, the voltage is a variable value, and the variation of the voltage varies with the variation of the distance between the cathode electrode 11 and the anode electrode 12, and the variation of the gas flow rate. Preferably, the power supply 18 has a current of 100 to 500 amps and a voltage of 10 to 400 volts.

The reaction time of the carbon rod as the anode electrode 12 is determined by the current set point and the gas flow value. The greater the current, the faster the vaporization rate, and the greater the gas flow, the faster the vaporization rate. However, the reaction rate cannot be increased at the same time, and the reaction rate needs to be adjusted according to specific experimental conditions.

Further, the arc temperature generated during the discharge is 5000-20000 ℃, and the arc column diameter is 5-20 mm, preferably 8-9 mm. The diameter of the arc column generated in the prior art is 2-3 mm, and the arc temperature is below 6000 ℃. Compared with the prior art, the electric arc column generated by the device provided by the invention is thickened, the size is controllable, and the temperature is also increased. The applicant found that about 40 to 60 minutes consumed a graphite rod 300mm long and 8mm in diameter using existing fullerene preparing apparatus. By adopting the device provided by the invention, the carbon rods with the same size can be consumed within 5-15 minutes, so that the yield of the fullerene can be obviously improved.

Example 1

The cathode electrode 11 in the arc reaction chamber 1 is a red copper electrode containing a tungsten cerium core, the anode electrode 12 is a carbon rod, and cooling water is introduced into the water-cooled wall 14 under the inert gas atmosphere (the volume ratio of helium to argon is 1:5), so that the cathode electrode 11 and the anode electrode 12 discharge to generate a compression arc. The direct current power supply 18 is adopted to supply power to the cathode electrode 11 and the anode electrode 12, the current of the power supply 18 is 200 amperes, and the voltage is 50-200 volts. The temperature of the cooling water is 18-20 ℃.

The temperature of the arc 19 generated in the discharging process is 5000-20000 ℃, and the diameter of the arc column is 8-9 mm. And outputting the gas phase product of the reaction from the arc reaction chamber 1, cooling by the cooling bin 2 and collecting by the filtering bin 3 to obtain the soot containing fullerene.

Adding o-xylene into the soot for dissolution, centrifuging to separate insoluble substances to obtain reddish brown solution, and carrying out liquid chromatography detection on the reddish brown solution, wherein the chromatogram is shown in figure 6, and the characteristic peak of C60 appears when the retention time is 7.449 seconds, the characteristic peak of C70 appears when the retention time is 11.954 seconds, and the product is proved to contain fullerene.

The supply voltage was adjusted from 40V to 110V at a current of 100A, and the fullerene yield variation is shown in table 1.

TABLE 1

	40V	50V	60V	70V	80V	90V	100V	110V
									C60 yield (%)	0.31	0.58	0.82	2.31	2.76	2.43	2.11	1.85
C70 yield (%)	0.08	0.09	0.266	0.68	0.93	0.79	0.68	0.62
									Yield of C80 (%)	0.001	0.003	0.003	0.021	0.027	0.02	0.018	0.006
Yield of metal fullerene (%)	0	0	0	0	0.0006	0	0	0

* The meaning of a metal fullerene is that the C82 ball cage contains one metal atom inside, e.g. gd@c82.

The supply voltage was also varied at a current of 200A, and the fullerene yield variation is shown in table 2.

TABLE 2

	40V	50V	60V	70V	80V	90V	100V	110V
									C60 yield (%)	1.28	1.96	2.73	3.27	4.16	4.91	5.24	5.38
C70 yield (%)	0.43	0.63	0.94	1.11	1.37	1.61	1.76	1.75
									Yield of C80 (%)	0.041	0.061	0.091	0.107	0.134	0.148	0.152	0.149
Yield of metal fullerene (%)	0	0.002	0.003	0.0011	0.004	0.005	0.0052	0.0054

The change in fullerene yield is shown in table 3 by changing the supply voltage when the current was 300A.

TABLE 3 Table 3

	40V	50V	60V	70V	80V	90V	100V	110V
									C60 yield (%)	2.53	3.26	5.19	6.44	7.88	8.43	7.63	7.25
C70 yield (%)	0.85	1.07	1.73	2.11	2.63	2.81	2.44	2.39
									Yield of C80 (%)	0.082	0.108	0.169	0.199	0.232	0.259	0.211	0.113
Yield of metal fullerene (%)	0.0022	0.0031	0.0049	0.0057	0.0081	0.0084	0.0069	0.0068

The change in fullerene yield is shown in table 4 by changing the supply voltage at a current of 400A.

TABLE 4 Table 4

	40V	50V	60V	70V	80V	90V	100V	110V
									C60 yield (%)	2.85	3.71	5.31	6.76	8.25	8.42	8.35	8.33
C70 yield (%)	0.92	1.22	1.78	2.24	2.39	2.79	2.87	2.79
									Yield of C80 (%)	0.074	0.115	0.163	0.212	0.236	0.258	0.273	0.268
Yield of metal fullerene (%)	0.0027	0.0036	0.0051	0.0059	0.0078	0.0075	0.0079	0.0084

The supply voltage was varied at a current of 500A and the fullerene yield variation is shown in table 5.

TABLE 5

	40V	50V	60V	70V	80V	90V	100V	110V
									C60 yield (%)	2.15	2.91	4.87	5.63	7.54	8.26	7.92	7.16
C70 yield (%)	0.83	0.96	1.63	1.88	2.53	2.74	2.63	2.37
									Yield of C80 (%)	0.077	0.081	0.099	0.182	0.249	0.271	0.258	0.231
Yield of metal fullerene (%)	0.0019	0.0027	0.0046	0.0055	0.0074	0.0086	0.0078	0.0068

As can be seen in combination with the data in tables 1 to 5, the yield of C60 showed a tendency to increase and decrease after increasing the current value from 100A to 500A, reaching a maximum at 400A.

Example 2

The cathode electrode was replaced with a carbon rod, the current value was 400A, the voltage value was 100V, and the same as in example 1 was repeated.

Example 3

The inert gas was replaced with a single helium gas, the current value was 400A, and the voltage value was increased to 170V (this is a voltage change by changing the inert gas, not actively changing the voltage), otherwise the same as in example 1.

Example 4

The inert gas was replaced with argon alone, the current value was 400A, the voltage value was 100V, and the same as in example 1 was repeated.

Example 5

The electromagnet in the arc reaction chamber was removed, the current value was 400A, the voltage value was 100V, and the same as in example 1 was repeated.

The yields of fullerenes (C60) for examples 1-5 are shown in Table 6.

TABLE 6

	Example 1	Example 2	Example 3	Example 4	Example 5
						C60 yield (%)	8.35	7.46	8.21	8.30	6.15

As can be seen from the data in table 6, the use of a single or mixed inert gas has little effect on fullerene yield. However, the productivity is reduced by changing the cathode electrode material and removing the electromagnet. Particularly, when the electromagnet is not used, a compression arc cannot be generated, and the influence on the yield is large.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An apparatus for preparing fullerene using compressed arc, characterized in that the apparatus comprises an arc reaction chamber for preparing soot containing fullerene, a cathode electrode, an anode electrode, a power source, an electromagnet and a water-cooled wall are arranged inside the arc reaction chamber,

The cathode electrode and the anode electrode are oppositely arranged in the water-cooled wall, a certain distance is reserved between the cathode electrode and the anode electrode, the anode of the power supply is respectively connected with the anode electrode and the auxiliary anode, the cathode of the power supply is connected with the cathode electrode, an electric arc can be generated between the cathode electrode and the anode electrode, an anode control switch is arranged on a connecting lead of the anode of the power supply and the anode electrode, an auxiliary anode control switch is arranged on a connecting lead of the anode of the power supply and the auxiliary anode,

The arc reaction chamber is provided with an inert gas inlet, an inert gas outlet and a collecting port, the inert gas inlet and the inert gas outlet are respectively used for leading in and leading out inert gas into the arc reaction chamber, the collecting port is used for leading out gas phase products after reaction from the arc reaction chamber,

The cathode electrode is made of red copper, and the inside of the cathode electrode contains a tungsten cerium electrode core.

2. The device of claim 1, wherein the anode electrode is graphite.

3. The apparatus of claim 1, wherein an insulating layer is disposed outside the energized coil.

4. The apparatus of claim 1, wherein an electrode moving mechanism is further provided in the arc reaction chamber for moving the anode electrode in the direction of the cathode electrode.

5. The apparatus according to any one of claims 1 to 4, further comprising a cooling chamber, a filtering chamber and an exhaust gas treatment chamber connected in sequence to the arc reaction chamber, wherein,

6. A method of preparing fullerenes, characterized in that it uses the device according to any one of claims 1 to 5, comprising: and (3) introducing inert gas into the arc reaction chamber, and introducing cooling water into the water cooling wall to discharge the cathode electrode and the anode electrode to generate a compressed arc, so as to obtain the soot containing fullerene.

7. The method of claim 6, wherein the inert gas is helium alone, argon alone, or a mixture of helium and argon.

8. The method of claim 6, wherein the power source used between the cathode electrode and the anode electrode is a direct current power source, the power source current is 100 to 500 amps, and the voltage is 10 to 400 volts.

9. The method according to claim 6, wherein the arc temperature generated during the discharge is 5000-20000 ℃ and the arc column diameter is 5-20 mm.