Preparation Method and Growth Device of Graphene Powder

Abstract

This application relates to the technical field of carbon materials, and particularly to a method for preparing graphene powder and a growth device. The method includes: introducing a carbon source gas into a molten first liquid metal placed in an inert atmosphere environment to form carbon-containing bubbles in the liquid metal, causing the carbon-containing bubbles to generate graphene under the action of the first liquid metal, and carrying the generated graphene to the liquid surface of the first liquid metal through the carbon-containing bubbles; collecting the graphene and tail gas rising to the liquid surface of the first liquid metal by using an air flow, and introducing them into a molten second liquid metal placed in an inert atmosphere environment to purify the graphene in the bubbles by the second liquid metal until the bubbles carrying graphene rise to the liquid surface of the second liquid metal; collecting the graphene and tail gas rising to the liquid surface of the second liquid metal by using an air flow into a powder collection device to obtain purified graphene powder. This application can achieve continuous production, purification, and collection of graphene powder.

Description

Technical Field

[0001] The present application relates to the technical field of carbon materials, and particularly relates to a preparation method and a growth device for graphene powder. Background Art

[0002] Graphene is one of the most potential carbon materials today, with excellent physical, chemical, and electrical properties, and is widely used in many fields such as optoelectronics and energy. Existing graphene is usually prepared by the oxidation-reduction method, physical method, and chemical vapor deposition (CVD) method. Among them, the oxidation-reduction method uses strong acids and strong oxidants during the preparation process, which will cause a large number of crystal defects in graphene, and the waste liquid pollution is serious. The graphene prepared by the physical method has too thick layers, is more inclined to graphite microflakes rather than graphene, and the sheet diameter is also very small. The graphene grown by the CVD method has few defects and the number of layers is controllable, which has received wide attention. However, the existing CVD synthesis method usually uses sputtering catalyst particles, and then grows graphene on the substrate. This method has a very low single synthesis output, cannot be continuously produced on a large scale, and the preparation cost is also relatively high, which is not conducive to industrial large-scale application. Summary of the Invention

[0003] In view of the above problems in the prior art, the present application provides a preparation method and a growth device for graphene powder, and the specific technical solutions are as follows:

[0004] On the one hand, the present application provides a preparation method for graphene powder, and the method includes:

[0005] S11: Introduce a carbon source gas into a molten first liquid metal placed in an inert atmosphere environment to form carbon-containing bubbles in the liquid metal, generate graphene under the action of the liquid metal, and carry the generated graphene to the liquid surface of the first liquid metal through the carbon-containing bubbles;

[0006] S12: Use air flow to collect the graphene and tail gas rising to the liquid surface of the first liquid metal, and introduce them into a molten second liquid metal placed in an inert atmosphere environment to form bubbles carrying graphene in the second liquid metal, so as to purify the graphene in the bubbles through the second liquid metal until the bubbles carrying graphene rise to the liquid surface of the second liquid metal;

[0007] S13: Use air flow to collect the graphene and tail gas rising to the liquid surface of the second liquid metal into a powder collection device (28) to obtain purified graphene powder.

[0008] Specifically, the metal materials of the first liquid metal and the second liquid metal are the same.

[0009] Specifically, the first liquid metal may include copper, an alloy composed of one or more of copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, and palladium, and the second liquid metal may include copper, an alloy composed of one or more of copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, and palladium.

[0010] Specifically, the temperature of the first liquid metal is 1100 - 1500 °C, and the temperature of the second liquid metal is T - (T + 100 °C), where T is the melting point temperature of the metal used for the second liquid metal.

[0011] Specifically, the carbon source gas is a mixture of a hydrocarbon gas and an inert gas, and the volume ratio between the hydrocarbon gas and the inert gas is 1:(5 - 30).

[0012] Specifically, the pressure of the inert gas atmosphere where the first liquid metal is located is normal pressure, and the pressure of the inert gas atmosphere where the second liquid metal is located is normal pressure.

[0013] Specifically, before the S11, the preparation method further includes:

[0014] Adding the metal solid used for the first liquid metal into a reaction vessel, and placing the reaction vessel in a heating furnace;

[0015] Adding the metal solid used for the second liquid metal into a purification vessel, and placing the purification vessel in a heating furnace;

[0016] Sealing the heating furnaces of the reaction vessel and the purification vessel, performing gas replacement on the heating furnaces through an inert gas, and forming an inert gas atmosphere in the heating furnaces of the reaction vessel and the purification vessel;

[0017] Heating the reaction vessel until the metal solid in the reaction vessel melts and reaches the target growth temperature; heating the purification vessel until the metal solid in the purification vessel melts.

[0018] On the other hand, the present application provides a graphene powder growth device, which is applied to the above-mentioned graphene powder preparation method. The growth device includes a reaction vessel, a purification vessel, a powder collection device, and at least one heating furnace;

[0019] The reaction vessel and the purification vessel are arranged in the heating furnace. The reaction vessel is communicated with a carbon source gas inlet pipe. The reaction vessel is communicated with the purification vessel through a first collection pipe, and the purification vessel is communicated with the powder collection device through a second collection pipe;

[0020] The reaction vessel is used to hold the first liquid metal, and the purification vessel is used to hold the second liquid metal.

[0021] Specifically, the powder collection device includes a powder collection vessel and a filter element. The powder collection vessel is provided with a powder inlet and an exhaust port of the collection device. The powder inlet is communicated with the second collection pipeline.

[0022] The filter element is hermetically connected to the inner wall of the powder collection vessel, and the filter element is located between the powder inlet and the exhaust port of the collection device.

[0023] Specifically, the at least one heating furnace includes a first heating furnace and a second heating furnace. The reaction vessel is arranged in the inner cavity of the first heating furnace, and the purification vessel is arranged in the inner cavity of the second heating furnace.

[0024] Based on the above technical solutions, the present application has the following beneficial effects:

[0025] In the present application, a carbon source gas is introduced into molten first liquid metal placed in an inert gas atmosphere environment to form carbon-containing bubbles in the liquid metal, so that the carbon-containing bubbles generate graphene under the action of the first liquid metal, and the generated graphene is carried to the liquid surface of the first liquid metal by the carbon-containing bubbles. The bubbles are broken by the air pressure to form floating graphene powder. The produced graphene has few defects, controllable number of layers, and large sheet diameter, and has excellent physical and chemical properties. Further, the graphene and tail gas rising to the liquid surface of the first liquid metal are collected by air flow and introduced into molten second liquid metal placed in an inert gas atmosphere environment to form bubbles carrying graphene in the second liquid metal, so as to purify the graphene in the bubbles by the second liquid metal. Since during the process of growing graphene powder by bubbles in the liquid metal, the surface of the graphene powder will adhere to the metal, but when the grown graphene powder leaves the reactor, the interfacial force between the graphene powder and the adhered metal weakens. The device of the present invention enables the weakly adhered metal in the graphene powder to remain in the second liquid metal until the bubbles carrying graphene rise to the liquid surface of the second liquid metal, and high-purity graphene powder is obtained. The automatic collection of graphene powder is realized through air flow and the powder collection device, which is beneficial to realizing the batch, continuous and large-scale production and purification of graphene, simplifying the transfer link and saving costs. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1: Schematic flow chart of the method for preparing graphene powder provided by the embodiment of the present application;

[0028] Figure 2 : Schematic structural diagram of the growth device for graphene powder provided by the embodiment of the present application;

[0029] Figure 3 : Raman diagram of the graphene powder generated in the reaction vessel provided by the embodiment of the present application;

[0030] Figure 4 : Raman diagram of the graphene powder collected in the powder collection device (28) provided by the embodiment of the present application;

[0031] Reference numerals: 1 - first heating furnace, 2 - furnace cover, 3 - first driving device, 4 - air inlet interface, 5 - carbon source gas inlet pipe, 6 - exhaust interface, 7 - first collection section, 8 - insulating base, 9 - induction heating device, 10 - bottom heat insulation member, 11 - refractory material, 12 - vessel body, 13 - flange, 14 - vessel cover, 15 - third collection section, 16 - flange exhaust interface, 17 - exhaust hole, 18 - second driving device; 19 - transmission rod; 20 - vessel heat insulation member; 21 - air inlet hole; 22 - first outer pipe section; 23 - first collection pump, 24 - second outer pipe section; 25 - second heating furnace; 26 - fifth collection section, 27 - sixth collection section; 28 - powder collection device; 29 - filter element, 30 - tail gas pipeline, 31 - second collection pump, 32 - fourth collection section. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0033] For the following defined terms, unless a different definition is given elsewhere in the claims or in this specification, these definitions shall apply. All numerical values, whether or not explicitly indicated, are hereby defined as being modified by the term "about". The term "about" generally refers to a numerical range that a person of ordinary skill in the art would consider equivalent to the stated value to produce substantially the same properties, functions, results, etc. A numerical range indicated by a low value and a high value is defined to include all the numerical values included in the numerical range and all the sub-ranges included in the numerical range.

[0034] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0035] The following introduces the growth device for graphene powder provided by the embodiments of this application. Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of a growth device for graphene powder. It can be understood that the structural diagram of the growth device in the drawings is only the technical solution of a specific embodiment of this application. The growth device of this application may include fewer or more structural features, and is not limited to Figure 2 the proposed device structure described therein.

[0036] The growth device includes a reaction vessel, a purification vessel, a powder collection device 28 and at least one heating furnace. The reaction vessel and the purification vessel are arranged in the heating furnace. The reaction vessel is connected to a carbon source gas inlet pipe 5, the reaction vessel and the purification vessel are connected through a first collection pipe, and the purification vessel and the powder collection device 28 are connected through a second collection pipe; the reaction vessel is used to hold a first liquid metal, and the purification vessel is used to hold a second liquid metal.

[0037] Specifically, the heating furnace includes a matching furnace lid 2 and a furnace body. The furnace lid 2 and the furnace body are sealed by a sealing member and are tightly connected, such as being tightly sealed by a sealing gasket and fastening bolts.

[0038] Specifically, the carbon source gas inlet pipe 5 includes a connected first inlet section and a second inlet section. The first inlet section is a flexible pipe, such as a stainless steel flexible pipe, and the second inlet section can be a graphite straight pipe; the first inlet section is arranged outside the inner cavity of the reaction vessel, and the second inlet section is arranged inside the inner cavity of the reaction vessel.

[0039] Specifically, the first collection pipe includes a first collection section 7, a second collection section, a third collection section 15 and a fourth collection section 32 that are connected in sequence; the first collection section 7 is connected to the reaction vessel, the second collection section is arranged outside the furnace body, and a first collection pump 23, such as a diaphragm pump, can be arranged in the pipeline of the second collection section; the third collection section 15 is connected to the purification vessel and is arranged outside the purification vessel, the fourth collection section 32 is arranged inside the purification vessel, the first collection section 7 and the third collection section 15 can be flexible pipes, such as stainless steel flexible pipes, and the fourth collection section 32 can be a graphite straight pipe.

[0040] Specifically, the second collection pipeline includes a connected fifth collection section 26 and a sixth collection section 27; the fifth collection section 26 is connected to the purification vessel, the fifth collection section 26 is a flexible hose, such as a stainless steel hose, and the sixth collection section 27 is arranged outside the furnace body and connected to the powder collection device 28. Specifically, the first collection pump 23 can adjust the pipeline pressure in the first collection pipeline.

[0041] In some embodiments, at least one heating furnace includes a first heating furnace 1 and a second heating furnace 25. The reaction vessel is arranged in the inner cavity of the first heating furnace 1, and the purification vessel is arranged in the inner cavity of the second heating furnace 25.

[0042] Further, both the first heating furnace 1 and the second heating furnace 25 are provided with an air inlet interface 4 and an exhaust interface 6. The air inlet interface 4 of the first heating furnace 1 is used to introduce a mixed gas of gaseous carbon source / inert gas, and the exhaust interface 6 is used to discharge the grown graphene powder and tail gas; the air inlet interface 4 of the second heating furnace 25 is used to introduce graphene powder / reaction tail gas, and the exhaust interface 6 is used to discharge the purified graphene powder and tail gas.

[0043] Further, the furnace cover 2 or the furnace body of the first heating furnace 1 is further provided with a first interface and a second interface. The first interface is used to communicate with the carbon source gas inlet pipe 5, and the second interface is used to pass through the first collection pipeline; the furnace cover 2 or the furnace body of the second heating furnace 25 is further provided with a third interface and a fourth interface. The third interface is used to pass through the first collection pipeline, and the fourth interface is used to pass through the second collection pipeline. A first collection pump 23 is arranged on the pipeline of the first collection pipeline. Specifically, the structures of the first heating furnace 1 and the second heating furnace 25 can be the same, so as to facilitate large-scale production and application.

[0044] Specifically, the first interface is hermetically connected to the first air inlet section, and the second interface is hermetically connected to the outlet end of the first collection section 7 and the inlet end of the second collection section respectively; the third interface is hermetically connected to the outlet end of the second collection section, and the fourth interface is hermetically connected to the outlet end of the fifth collection section 26 and the inlet end of the sixth collection section 27 respectively.

[0045] In other embodiments, the reaction vessel and the purification vessel are arranged in the inner cavity of the same heating furnace. The heating furnace is provided with an air inlet interface 4 and an exhaust interface 6 for passing out and discharging inert gas. Preferably, the position of the air inlet interface 4 is lower than the position of the exhaust interface 6.

[0046] Further, the furnace cover 2 or the furnace body is further provided with a first interface, a second interface, a third interface and a fourth interface. The connection manners between the first interface to the fourth interface and each pipeline are similar to those described above and will not be elaborated here. In this way, by providing one furnace body, the centralized arrangement of the reaction vessel and the purification vessel is realized, and the operation and equipment costs can be reduced.

[0047] Specifically, induction heating devices 9 are provided on the exteriors of both the reaction vessel and the purification vessel. The induction heating devices 9 are arranged inside the heating furnace. A refractory material 11, such as refractory sand, is provided between the reaction vessel or the purification vessel and the induction heating device 9 for heat insulation. An insulating base 8 is provided at the lower part of the induction heating device 9. A bottom heat insulation member 10, such as a ceramic plate, is provided between the reaction vessel or the purification vessel and the insulating base 8, which is not only used for heat insulation but also has excellent compressive properties. Specifically, the thickness of the insulating base 8 is 15 - 60 cm, and the thickness of the bottom heat insulation member 10 is 10 - 50 mm.

[0048] In some embodiments, both the reaction vessel and the purification vessel include a vessel body 12 and a vessel cover 14. The reaction vessel and the purification vessel can be crucibles, including a crucible body and a crucible cover, and the material can include one or several of graphite, silicon carbide, silicon carbide / graphite, and corundum.

[0049] Furthermore, an air inlet hole 21 and an exhaust hole 17 are provided on the vessel cover 14. For the vessel cover 14 of the reaction vessel, the air inlet hole 21 is arranged in the pipeline of the carbon source gas inlet pipe 5, and the exhaust hole 17 is hermetically communicated with the inlet end of the first collection pipeline. For the vessel cover 14 of the purification vessel, the air inlet hole 21 is arranged in the pipeline of the first collection pipeline, and the exhaust hole 17 is hermetically communicated with the inlet end of the second collection pipeline.

[0050] Specifically, for the vessel cover 14 of the reaction vessel, the air inlet hole 21 is hermetically communicated with the outlet end of the first inlet section and the inlet end of the second inlet section in the carbon source gas inlet pipe 5 respectively, and the exhaust hole 17 is hermetically communicated with the inlet end of the first collection section 7 of the first collection pipeline. For the vessel cover 14 of the purification vessel, the air inlet hole 21 is hermetically communicated with the outlet end of the third collection section 15 and the inlet end of the fourth collection section 32 in the carbon source gas inlet pipe 5 respectively, and the exhaust hole 17 is hermetically communicated with the inlet end of the fifth collection section 26 of the second collection pipeline.

[0051] Specifically, the outlet end of the carbon source gas inlet pipe 5 extends into the bottom of the vessel body 12, and the outlet end of the first collection pipeline extends into the bottom of the vessel body 12.

[0052] Specifically, a flange 13 can be provided on the vessel cover 14. The flange 13 is provided with a flange air inlet interface and a flange exhaust interface 16. The flange air inlet interface is communicated with the air inlet hole 21 on the vessel cover 14; preferably, they are concentrically arranged. The flange exhaust interface 16 is communicated with the exhaust hole 17 on the vessel cover 14; preferably, they are concentrically arranged. Specifically, the through-hole diameter of the flange air inlet interface is 1.1 - 2.0 times the diameter of the inlet end of the fourth collection section 32.

[0053] Further, for the vessel lid 14 of the reaction vessel, the outlet end of the first intake section is hermetically connected to the flange intake interface, and the intake end of the second intake section passes through the intake hole 21 and is hermetically connected to the flange intake interface; the intake end of the first collection section 7 of the first collection pipe is hermetically connected to the flange exhaust interface 16.

[0054] Further, for the vessel lid 14 of the purification vessel, the outlet end of the third collection section 15 of the first collection pipe is hermetically connected to the flange intake interface, and the intake end of the fourth collection section 32 passes through the intake hole 21 and is hermetically connected to the flange intake interface; the intake end of the fifth collection section 26 of the second collection pipe is hermetically connected to the flange exhaust interface 16.

[0055] Specifically, the growth device further includes a first driving device 3 and a second driving device 18. The first driving device 3 is in transmission connection with the vessel lid 14 of the reaction vessel, and is used to drive the vessel lid 14 to move towards the vessel body 12 until it is buckled with the vessel body 12, and the carbon source gas inlet pipe 5 extends into the bottom of the vessel body 12; the second driving device 18 is in transmission connection with the vessel lid 14 of the purification vessel, and is used to drive the vessel lid 14 to move towards the vessel body 12 until it is buckled with the vessel body 12, and the first collection pipe extends into the bottom of the vessel body 12.

[0056] Preferably, the first driving device 3 and the second driving device 18 can be oil cylinders, and the oil cylinder telescopic rods are fixedly connected to the flange 13 on the vessel lid 14.

[0057] In some embodiments, the powder collection device 28 includes a powder collection vessel and a filter element 29. The powder collection vessel is provided with a powder inlet and a collection device exhaust port, and the powder inlet is communicated with the second collection pipe; the filter element 29 is hermetically connected to the inner wall of the powder collection vessel, and the filter element 29 is located between the powder inlet and the collection device exhaust port, and is used to separate the powder from the tail gas. The tail gas passes through the filter element 29 and is discharged from the collection device exhaust port, and the graphene powder cannot pass through the filter element 29 and remains in the powder collection device 28. Specifically, the filter element 29 can be a dust filter, and the filter element 29 is tightly fixed to the inner wall of the powder collection device 28 without gaps.

[0058] Specifically, the powder inlet of the exhaust port is hermetically communicated with the outlet end of the sixth collection section 27 of the second collection pipe.

[0059] Preferably, the powder collection device 28 is a variable-diameter vessel, and its outer diameter gradually decreases from the bottom to the top. The lower part of the powder collection device 28 is a collection cavity, and its side interface is trapezoidal, and the included angle between the inclined plane and the bottom is 15-70°; the upper part of the powder collection device 28 is a convex platform type, and the top is provided with a collection device exhaust port.

[0060] Specifically, the exhaust port of the powder collection device 28 is communicated with the tail gas pipeline 30. A second collection pump 31, which can be a diaphragm pump, is provided on the tail gas pipeline 30 and is used to provide power for the second collection pipeline so as to form an air flow in the purification vessel to suck the graphene powder and the tail gas into the powder collection device 28.

[0061] Through the above growth device, it is possible to provide a sealed inert gas environment for the growth and purification of graphene powder, and at the same time provide an operating environment for the continuous synthesis, purification and collection of graphene powder, simplify the transfer link in the large-scale production of graphene powder, and save costs.

[0062] The following introduces the preparation method of the graphene powder provided by the embodiments of the present application in combination with the above growth device. Please refer to Figure 1 , Figure 1 which is a schematic flow chart of the preparation method. This specification provides the method operation steps such as in the embodiments or the flow chart, but based on routine or non-creative labor, it may include more or fewer operation steps. The step sequences listed in the embodiments are only one of the execution sequences of numerous steps and do not represent the only execution sequence. When the actual preparation method is executed, it can be executed in the method sequence shown in the embodiments or the drawings or executed in parallel. The method includes:

[0063] S11: Introduce a carbon source gas into the molten first liquid metal placed in an inert atmosphere environment to form carbon-containing bubbles in the liquid metal, generate graphene under the action of the first liquid metal, and carry the generated graphene to the liquid surface of the first liquid metal through the carbon-containing bubbles.

[0064] Specifically, the carbon source gas is a mixture of a hydrocarbon gas and an inert gas, and the volume ratio between the hydrocarbon gas and the inert gas is 1:(5-30). Preferably, the volume ratio between the hydrocarbon gas and the inert gas is 1:(5-20).

[0065] Specifically, the hydrocarbon gas may include but is not limited to at least one of methane, natural gas, ethane, propane, butane, ethylene, propylene, acetylene, liquefied petroleum gas, coalbed methane, and biogas. The inert gas may include but is not limited to nitrogen and / or helium, etc.

[0066] Specifically, the temperature of the first liquid metal is 1100-1500 °C. Preferably, the temperature of the first liquid metal is 1200-1400 °C.

[0067] Specifically, the air pressure of the inert atmosphere environment where the first liquid metal is located is normal pressure, that is, the air pressure in the reaction vessel is normal pressure.

[0068] After the carbon source gas is introduced into the first liquid metal at the above temperature, under the catalytic action and high temperature of the first liquid metal, it cracks to generate graphene powder. The graphene powder adheres to the inner wall of the carbon-containing bubbles, rises with the carbon-containing bubbles to the liquid surface of the first liquid metal, and breaks under the action of air pressure, so that the graphene powder floats above the liquid surface. It can be understood that this method will inevitably adhere to the metal powder of the first liquid metal in the graphene powder body. For example, a small amount of tar is generated during cracking, and then the technical powder of the first liquid metal will be adhered.

[0069] Based on the above graphene powder body growth device, the first liquid metal is placed in a reaction vessel, and the carbon source gas is introduced into the first liquid metal through the carbon source gas inlet pipe 5.

[0070] S12: Use air flow to collect the graphene and tail gas rising to the liquid surface of the first liquid metal, and introduce them into the molten second liquid metal placed in an inert atmosphere environment to form bubbles carrying graphene in the second liquid metal, so as to purify the graphene in the bubbles through the second liquid metal until the bubbles carrying graphene rise to the liquid surface of the second liquid metal.

[0071] Specifically, the metal materials of the first liquid metal and the second liquid metal are the same.

[0072] Specifically, the first liquid metal may include an alloy composed of one or several of copper, copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, palladium, and the second liquid metal may include an alloy composed of one or several of copper, copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, palladium.

[0073] Specifically, the temperature of the second liquid metal is T~(T + 100°C), where T is the melting point temperature of the metal used for the second liquid metal. In this way, making the heating temperature in the purification vessel slightly higher than the melting point of the corresponding metal can not only save energy consumption, but also enable the splashed metal to quickly condense and fall back into the second liquid metal again. For example, when the second liquid metal is copper, the temperature of the second liquid metal is 1100~1150°C.

[0074] Specifically, the air pressure in the inert atmosphere environment where the second liquid metal is located is normal pressure.

[0075] In practical applications, the air pressure in the purification vessel is 0.2~0.5 MPa, and the graphene powder body is introduced into the liquid surface of the liquid metal in the purification vessel through the suction force of the first collection pump 23. The pressure in the first collection pipeline is 0.2~0.5 MPa. In this way, the solid graphene powder and the tail gas can be smoothly introduced under the liquid surface through this internal pressure.

[0076] Further, on the first collection pipeline, the diameter of the first outer pipe section 22 of the second collection section is 30 - 50 mm, and the pipe diameters of the second outer pipe section 24, the third collection section 15, and the fourth collection section 32 are 10 - 15 mm, which can ensure the smooth exhaust of graphene powder and tail gas in the first reaction vessel. At the same time, the pressure of the second liquid metal under the liquid surface reaches the preset pressure, enabling the solid graphene powder and tail gas to smoothly enter under the liquid surface of the second liquid metal.

[0077] Based on the above graphene powder growth device, the second liquid metal is placed in the purification vessel and connected to the reaction vessel through the first collection pipeline; a suction air flow is formed in the first collection pipeline by the first collection pump 23 to form a purging air flow above the liquid surface of the first liquid metal in the reaction vessel, so that the graphene powder above the liquid surface is sucked into the first collection pipeline and discharged into the second liquid metal to form bubbles carrying graphene. Through the second liquid metal of the same metal material, due to the strong adhesion between the same metals and the heating effect of the molten second liquid metal, the weakly adhered metal powder in the graphene powder melts and merges with the second liquid metal, while the pure graphene powder does not melt in the metal and rises with the bubbles above the liquid surface of the second liquid metal, and then is collected into the second collection pipeline.

[0078] It can be understood that an inert gas atmosphere environment is formed in the reaction vessel through the inert gas flow. After the carbon-containing bubbles burst, a large amount of graphene powder is purged into the purification vessel by the inert gas. At this time, the main component of the formed bubbles is the inert gas.

[0079] S13: Use the air flow to collect the graphene and tail gas rising to the liquid surface of the second liquid metal into the powder collection device 28 to obtain the purified graphene powder.

[0080] Based on the above graphene powder growth device, the powder collection device 28 is connected to the purification vessel through the second collection pipeline, and the second collection pump 31 is used to provide power to form a suction force in the second collection pipeline, and then a purging air flow is formed above the second liquid metal in the purification vessel, so that the purified graphene powder is sucked into the second collection pipeline, and then enters through the powder inlet of the powder collection device 28. Under the blocking action of the filter element 29, the graphene powder remains in the inner cavity of the powder collection device 28, and the tail gas is discharged from the exhaust port of the collection device after passing through the filter element 29 for tail gas treatment or collection.

[0081] Specifically, before S11, the preparation method further includes:

[0082] S21: Add the metal solid of the first liquid metal into the reaction vessel, and place the reaction vessel in the heating furnace;

[0083] S22: Add the metal solid of the second liquid metal into the purification vessel, and place the purification vessel in the heating furnace;

[0084] S23: Seal the heating furnace of the reaction vessel and the heating furnace of the purification vessel, perform gas displacement on the heating furnace with an inert gas, and form an inert atmosphere environment in the heating furnace of the reaction vessel and the heating furnace of the purification vessel;

[0085] S24: Heat the reaction vessel until the metal solid in the reaction vessel melts and reaches the target growth temperature; heat the purification vessel until the metal solid state in the purification vessel melts.

[0086] Based on the foregoing growth device, the reaction vessel and the purification vessel can be placed in the same furnace body or in different furnace bodies. For the former method, add the same metal solid into the reaction vessel of the first heating furnace 1 and the lifting vessel of the second heating furnace 25 respectively; after sealing the first heating furnace 1 and the second heating furnace 25, evacuate the first heating furnace 1 and the second heating furnace 25, and then fill them with an inert gas. After repeating many times, the gas displacement is completed; continuously introduce an inert gas into the first heating furnace 1 and the second heating furnace 25 to form an inert atmosphere environment. Turn on the heating device to melt the metal solid in the reaction vessel and raise it to the reaction temperature, and melt the metal solid in the purification vessel. Use two driving devices to buckle the vessel cover 14 of the reaction vessel and the vessel cover 14 of the purification vessel respectively, so that the carbon source gas inlet pipe 5 extends below the liquid surface of the first liquid metal, and the exhaust end of the first collection pipeline extends below the liquid surface of the second liquid metal.

[0087] In summary, based on the above technical solutions, continuous production, purification and collection of graphene powder in liquid metal are realized, which is easy to scale up, simplifies the transfer link and saves costs; at the same time, using the same liquid metal as the growth catalyst and the purification metal liquid, the purified and separated liquid metal can be used for catalytic growth here, reducing costs; in addition, this application uses a pure physical method to purify graphene powder with a homogeneous metal, which will not introduce new metal impurities, and no chemical reagents are used throughout the process, which is environmentally friendly and pollution-free.

[0088] The following introduces the specific embodiments of this application in combination with the above purification method, growth device and preparation method of graphene powder.

[0089] Example 1

[0090] Please refer to Figure 2, this embodiment provides a growth device for graphene powder. The growth device includes a reaction vessel, a purification vessel, a first heating furnace 1, a second heating furnace 25, an induction heating device 9, a powder collection device 28, a first driving device 3, and a second driving device 18. The reaction vessel is arranged in the first heating furnace 1, the purification vessel is arranged in the second heating furnace 25. The reaction vessel is communicated with a carbon source gas inlet pipe 5, and the reaction vessel and the purification vessel are communicated through a first collection pipeline. The purification vessel and the powder collection device 28 are communicated through a second collection pipeline. The reaction vessel is used for containing a first liquid metal, and the purification vessel is used for containing a second liquid metal.

[0091] Both the reaction vessel and the purification vessel include a vessel body 12 and a vessel cover 14. The vessel body 12 is a crucible body, and the vessel cover 14 is a crucible cover. The materials of both the reaction vessel and the purification vessel are graphite. The induction heating device 9 is arranged outside the vessel body 12 of the reaction vessel and the purification vessel, and a refractory material 11 is arranged between the induction heating device 9 and the vessel body 12. The induction heating device 9 is an induction coil, and an insulating base 8 is arranged at its lower part. A bottom heat insulation member 10 is arranged between the reaction vessel and the corresponding insulating base 8, and between the purification vessel and the corresponding insulating base 8. The bottom heat insulation member 10 is a ceramic plate. Specifically, the thickness of the insulating base 8 is 15 - 60 cm, and the thickness of the bottom heat insulation member 10 is 2 - 15 cm.

[0092] An air inlet hole 21 and an exhaust hole 17 are arranged on the vessel cover 14 of both the reaction vessel and the purification vessel, and a flange 13 is arranged. The flange 13 is provided with a flange air inlet interface and a flange exhaust interface 16. The flange air inlet interface is communicated with the air inlet hole 21 on the vessel cover 14, and the flange exhaust interface 16 is communicated with the exhaust hole 17 on the vessel cover 14. A vessel heat insulation member 20 is also arranged between the flange 13 and the vessel cover 14. The vessel heat insulation member 20 is a ceramic plate with a thickness of 10 - 70 mm, preferably 50 mm. The vessel heat insulation member 20 is provided with a first through hole and a second through hole. Preferably, the first through hole is the same size as and in position matching with the air inlet hole 21 of the vessel cover 14, and the second through hole is the same size as and in position matching with the exhaust hole 17 of the vessel cover 14. Preferably, the first through hole, the flange air inlet interface, and the air inlet hole 21 are concentrically arranged, and the second through hole, the flange exhaust interface 16, and the exhaust hole 17 are concentrically arranged. The surfaces of the vessel cover 14, the vessel heat insulation member 20, and the flange 13 are closely fitted and fixed.

[0093] Both the first heating furnace 1 and the second heating furnace 25 include a furnace body and a furnace cover 2. A sealing gasket is provided at the sealing and fitting position between the furnace body and the furnace cover 2, and the furnace body and the furnace cover 2 are hermetically connected by bolts surrounding the furnace body. Intake interfaces 4 and exhaust interfaces 6 are provided on the furnace bodies of the first heating furnace 1 and the second heating furnace 25. The intake interface 4 is used to introduce a mixed gas of a gaseous carbon source / inert gas, and the exhaust interface 6 is used to discharge the grown graphene powder and tail gas. Further, a first interface and a second interface are also provided on the furnace cover 2 of the first heating furnace 1, and a third interface and a fourth interface are also provided on the furnace cover 2 of the second heating furnace 25.

[0094] The first driving device 3 is arranged on the furnace cover 2 of the first heating furnace 1 and is in transmission connection with the flange 13 on the cover of the reaction vessel 14. The second driving device 18 is arranged on the furnace cover 2 of the second heating furnace 25 and is in transmission connection with the flange 13 on the cover of the purification vessel 14. Specifically, the connection can be achieved through a transmission rod 19, such as the telescopic rod of an oil cylinder.

[0095] The powder collection device 28 includes a powder collection vessel and a filter element 29. A powder inlet and an exhaust port of the collection device are provided on the powder collection vessel. The powder inlet is communicated with the second collection pipeline. The filter element 29 is hermetically and tightly fixed to the inner wall of the powder collection vessel and is located between the powder inlet and the exhaust port of the collection device. The pores of the filter element 29 are smaller than the sheet diameter of the graphene powder. Specifically, the filter element 29 is a dust filter. The upper part of the powder collection device 28 is convex, and the exhaust port of the collection device is arranged at the top of the convex platform. The exhaust port of the collection device is communicated with the tail gas pipeline 30, and a second collection pump 31 is arranged in the tail gas pipeline 30.

[0096] The carbon source gas inlet pipe 5 includes a connected first intake section and a second intake section. The first intake section is a stainless steel hose, and the second intake section is a graphite straight pipe. The first collection pipeline includes a first collection section 7, a second collection section, a third collection section 15, and a fourth collection section 32 that are connected in sequence. The first collection section 7 and the third collection section 15 are stainless steel hoses, the fourth collection section 32 is a graphite straight pipe, and a first collection pump 23 is arranged on the second collection section. The first collection pump 23 is a diaphragm pump. The second collection pipeline includes a connected fifth collection section 26 and a sixth collection section 27, and the fifth collection section 26 is a stainless steel hose.

[0097] One end of the first air inlet section of the carbon source gas inlet pipe 5 is sealed and connected to the first interface of the first heating furnace 1, and the other end of the first air inlet section is sealed and connected to the flange air inlet interface. One end of the second air inlet section passes through the air inlet hole 21 of the vessel cover 14 and is sealed and connected to the flange air inlet interface of the reaction vessel, and the other end can extend into the bottom of the vessel body 12 of the reaction vessel; one end of the first collecting section 7 of the first collecting pipeline is sealed and connected to the flange exhaust interface 16 of the reaction vessel, and the other end is sealed and connected to the second interface of the first heating furnace 1; one end of the second collecting section is sealed and connected to the second interface of the first heating furnace 1, and the other end is sealed and connected to the third interface of the second heating furnace 25; the second collecting section includes a first outer pipe section 22 and a second outer pipe section 24, the first outer pipe section 22 is arranged between the first collecting pump 23 and the first heating furnace 1, and the second outer pipe section 24 is arranged between the first collecting pump 23 and the first heating furnace 1, and the second outer pipe section 24 is arranged between the first collecting pump 23 and the first heating furnace 1. The collecting pump 23 is connected to the second heating furnace 25; one end of the third collecting section 15 is sealed and connected to the third interface of the second heating furnace 25, and the other end is sealed and connected to the flange exhaust interface 16 of the purification vessel; one end of the fourth collecting section 32 passes through the air inlet 21 of the vessel cover 14 of the purification vessel and is sealed and connected to the flange air inlet interface, and the other end can extend into the bottom of the vessel body 12 of the purification vessel; one end of the fifth collecting section 26 of the second collecting pipeline is sealed and connected to the flange exhaust interface 16 of the purification vessel, and the other end is sealed and connected to the fourth interface of the second heating furnace 25; one end of the sixth collecting section 27 is sealed and connected to the fourth interface, and the other end is sealed and connected to the powder inlet of the powder collecting device 28, thereby forming a carbon source gas intake passage, an exhaust pipeline from graphene powder to the purification vessel, and an exhaust pipeline from the purified graphene powder to the powder collecting device 28. Specifically, the connection method from the first interface to the fourth interface can be screwed.

[0098] Specifically, the diameter of the first outer tube section 22 of the second collecting section is 30-50 mm, and the diameters of the second outer tube section 24, the third collecting section 15 and the fourth collecting section 32 are 10-15 mm.

[0099] Under the driving action of the first driving device 3, the vessel cover 14 of the reaction vessel can cooperate with the first air inlet section and the second air inlet section of the carbon source gas inlet pipe 5 to move downward until the vessel cover 14 is engaged with the vessel body 12, and the second air inlet section extends into the bottom of the first liquid metal, or can move upward until the second air inlet section is separated from the liquid surface of the first liquid metal; similarly, under the driving action of the second driving device 18, the vessel cover 14 of the purification vessel can cooperate with the third collecting section 15 and the fourth collecting section 32 of the first collecting pipe to move downward until the vessel cover 14 is engaged with the vessel body 12, and the fourth collecting section 32 extends into the bottom of the second liquid metal, or can move upward until the fourth collecting section 32 is separated from the liquid surface of the second liquid metal.

[0100] The carbon source gas enters the first intake section of the carbon source gas inlet pipe 5 from the external pipeline through the first interface, and enters the first liquid metal through the second intake section to form carbon-containing bubbles, and graphene is formed on the liquid surface of the first liquid metal. Under the action of the first collection pump 23, the graphene enters the second liquid metal in the purification vessel through the first collection pipeline for purification, and then, under the action of the second collection pump 31, the graphene enters the powder collection device 28 through the second collection pipeline.

[0101] Example 2

[0102] This embodiment provides a method for preparing graphene powder, which is realized based on the above-mentioned graphene powder growth device. Specifically, the method may include the following steps:

[0103] 1. Add metallic copper into the reaction vessel and the purification vessel, cover the furnace lids 2 of the first heating furnace 1 and the second heating furnace 25, and seal the first heating furnace 1 and the second heating furnace 25;

[0104] 2. Pass nitrogen through the intake interface 4 and exhaust it through the exhaust interface 6 to replace the air in the inner cavities of the first heating furnace 1 and the second heating furnace 25 to achieve an inert atmosphere environment, and continuously pass in and out nitrogen;

[0105] 3. Turn on the induction heating device 9 to heat the reaction vessel and the purification vessel to melt the metallic copper therein. The temperature of the liquid metallic copper in the reaction vessel is 1280 °C, and the temperature of the metallic copper in the purification vessel is 1100 °C;

[0106] 4. Control the first driving device 3 to drive the vessel lid 14 of the reaction vessel to buckle, and at the same time, make the graphite straight pipe of the carbon source gas inlet pipe 5 extend to the bottom of the liquid metallic copper in the reaction vessel, and control the second driving device 18 to drive the vessel lid 14 of the purification vessel to buckle, so that the graphite straight pipe of the second collection pipeline extends to the bottom of the liquid metallic copper in the purification vessel;

[0107] 5. Pass CH4 and N2 with a flow ratio of 1:20 through the carbon source gas inlet pipe 5 to form carbon-containing bubbles in the liquid metallic copper. Under the action of high temperature and the catalysis of copper, CH4 cracks to form graphene and H2. After the bubbles rise to the liquid surface, they burst under the action of air pressure, and the graphene powder floats above the liquid surface;

[0108] 6. Under the action of the first collection pump 23, the graphene powder enters the bottom of the liquid metallic copper in the purification vessel through the first collection pipeline to form bubbles carrying graphene. During the rising process, the weakly adhered copper in the graphene powder melts into the liquid metallic copper to achieve purification;

[0109] Under the action of the second collection pump 31, the graphene that rises above the liquid level in the purification vessel is sucked into the second collection pipeline and introduced into the powder collection device 28. Blocked by the filter element 29, the graphene powder remains in the collection device, and the tail gas enters the tail gas pipeline after passing through the filter element 29.

[0110] Combined Figure 3 with Figure 4 It can be seen that the quality of graphene is not reduced during the purification process; moreover, for the graphene powder grown in the first heating furnace 1 that has not been purified by the second heating furnace 25, it is corroded with an aqueous solution of FeCl3 / HCl with an excessive molar concentration ratio of 3:1 to remove possible residual copper powder impurities, and then washed 3 times with pure water and dried at 120 °C / 15 h. The graphene powder before and after corrosion and impurity removal is weighed, and the purity of the graphene powder before purification with the second heating furnace 25 is calculated to be 10.1 wt%. The graphene powder obtained in this example is corroded with an excessive aqueous solution of FeCl3 / HCl with a molar concentration ratio of 3:1 to remove possible residual copper powder impurities, and then washed 3 times with pure water and dried at 120 °C / 15 h. The graphene powder before and after corrosion and impurity removal is weighed, and the purity of the graphene powder obtained in this example is calculated to be 100 wt%.

[0111] Example 3

[0112] This example provides a method for preparing graphene powder. The difference between this example and Example 1 is that in step 1, the metal added to the reaction vessel and the purification vessel is a copper-nickel alloy containing 2% nickel; in step 3, the temperature of the liquid metal copper-nickel alloy in the reaction vessel is 1240 °C, and the temperature of the metal copper-nickel alloy in the purification vessel is 1150 °C; in step 5, CH4 and N2 with a flow ratio of 1:16 are introduced through the carbon source gas inlet pipe 5.

[0113] Based on Raman characterization of the graphene powder before and after purification, it is found that the quality of graphene is not reduced during the purification process; moreover, the purity of the graphene powder before purification with the second heating furnace 25 is 11%, and the purity of the graphene powder obtained after purification in this example is 100 wt%.

[0114] Example 4

[0115] This example provides a method for preparing graphene powder. The difference between this example and Example 1 is that in step 1, the metal added to the reaction vessel and the purification vessel is a copper-cobalt alloy containing 2.5% cobalt; in step 3, the temperature of the liquid metal cobalt in the reaction vessel is 1260 °C, and the temperature of the metal copper-cobalt alloy in the purification vessel is 1130 °C; in step 5, CH4 and N2 with a flow ratio of 1:10 are introduced through the carbon source gas inlet pipe 5.

[0116] Based on the Raman characterization of the graphene powder before and after purification, it is found that the quality of graphene is not reduced during the purification process; moreover, the purity of the graphene powder before purification in the second heating furnace 25 is 11.4%, and the purity of the graphene powder obtained after purification in this example is 100 wt%.

[0117] Example 5

[0118] This example provides a method for preparing graphene powder. The difference between this example and Example 1 is that in step 1, the metal added to the reaction vessel and the purification vessel is a copper-chromium alloy containing 4.5% chromium; in step 3, the temperature of the liquid metal copper-chromium in the reaction vessel is 1400 °C, and the temperature of the metal copper-chromium in the purification vessel is 1140 °C; in step 5, CH4 and N2 with a flow ratio of 1:5 are introduced through the carbon source gas inlet pipe 5.

[0119] Based on the Raman characterization of the graphene powder before and after purification, it is found that the quality of graphene is not reduced during the purification process; moreover, the purity of the graphene powder before purification in the second heating furnace 25 is 9.6%, and the purity of the graphene powder obtained after purification in this example is 100 wt%.

[0120] Example 6

[0121] This example provides a method for preparing graphene powder. The difference between this example and Example 1 is that in step 1, the metal added to the reaction vessel and the purification vessel is a copper-lead alloy containing 1% lead; in step 3, the temperature of the liquid metal copper-lead alloy in the reaction vessel is 1200 °C, and the temperature of the metal copper-lead in the purification vessel is 1090 °C; in step 5, CH4 and N2 with a flow ratio of 1:8 are introduced through the carbon source gas inlet pipe 5.

[0122] Based on the Raman characterization of the graphene powder before and after purification, it is found that the quality of graphene is not reduced during the purification process; moreover, the purity of the graphene powder before purification in the second heating furnace 25 is 10.5%, and the purity of the graphene powder obtained after purification in this example is 100 wt%.

[0123] It can be understood that since side reactions occur during the process of growing graphene powder by bubbling a carbon-containing gas into liquid copper, a small amount of tar and the like will adhere the copper powder to the graphene. The graphene powder carrying the copper powder is transported to the molten copper liquid in the purification vessel through the first collection pump 23, and the copper powder attached to the graphene powder will dissolve in the copper liquid. The graphene powder floats to the copper liquid surface and then enters the powder collection device 28 through the second collection pipeline with the gas flow. The tar content of the copper powder adhering to the grown graphene powder is low, and the influence on the quality of the graphene powder during the purification process is minimal, obtaining pure and high-quality graphene powder.

[0124] In summary, the present application has the following beneficial effects: The growth device of the present application can achieve continuous production, purification, and collection of graphene powder in liquid metal, is easy to scale up, simplifies the transfer link, and saves costs; the powder collection device 28 is equipped with a filter element 29 and the first collection pump 23 and the second collection pump 31 are installed, which not only enables the graphene powder to be completely collected in the powder collection device 28 but also makes the air flow of the whole system smooth; moreover, by using the same metal as the catalyst for growing graphene powder as the purification metal liquid, the purified metal can be reused for catalytic growth of graphene powder by liquid copper bubbling. The heating temperature in the purification heating furnace is slightly higher than the melting point of the metal, which can not only save energy consumption but also enable the splashed metal to quickly condense and fall back into the metal liquid again; in addition, strong acids and strong oxidants are not required during the preparation, purification, and collection of graphene powder, and there is no need to add a wastewater treatment system, which simplifies the process flow and reduces environmental pollution.

[0125] The above description has fully disclosed the specific embodiments of the present application. It should be noted that any modification made by those skilled in the art to the specific embodiments of the present application does not depart from the scope of the claims of the present application. Accordingly, the scope of the claims of the present application is not limited solely to the foregoing specific embodiments.

Claims

1. A preparation method of graphene powder, characterized in that, Using the same liquid metal as the growth catalyst and the purification metal liquid, through a pure physical method, the purification of graphene powder is realized by using a homogeneous metal; the method includes: S11: Introduce a carbon source gas into the molten first liquid metal placed in an inert atmosphere environment to form carbon-containing bubbles in the liquid metal, so that the carbon-containing bubbles generate graphene under the action of the first liquid metal, and carry the generated graphene to the liquid surface of the first liquid metal through the carbon-containing bubbles; S12: Use air flow to collect the graphene and tail gas rising to the liquid surface of the first liquid metal and introduce them into the molten second liquid metal placed in an inert atmosphere environment to form bubbles carrying graphene in the second liquid metal, so as to purify the graphene in the bubbles through the second liquid metal until the bubbles carrying graphene rise to the liquid surface of the second liquid metal; the metal materials of the first liquid metal and the second liquid metal are the same; S13: Use air flow to collect the graphene and tail gas rising to the liquid surface of the second liquid metal into a powder collection device (28) to obtain the purified graphene powder.

2. The preparation method according to claim 1, wherein The first liquid metal includes copper, an alloy composed of one or more of copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, and palladium, and the second liquid metal includes copper, an alloy composed of one or more of copper and iron, nickel, cobalt, gallium, tin, chromium, lead, germanium, antimony, bismuth, silver, and palladium.

3. The preparation method according to claim 1, wherein The temperature of the first liquid metal is 1100 - 1500 °C, and the temperature of the second liquid metal is T - (T + 100 °C), where T is the melting point temperature of the metal used for the second liquid metal.

4. The preparation method according to claim 1, wherein The carbon source gas is a mixture of a hydrocarbon gas and an inert gas, and the volume ratio between the hydrocarbon gas and the inert gas is 1:(5 - 30).

5. The preparation method according to claim 1, characterized in that, The air pressure of the inert atmosphere environment where the first liquid metal is located is normal pressure, and the air pressure of the inert atmosphere environment where the second liquid metal is located is normal pressure.

6. The preparation method according to claim 1, wherein Before the S11, the preparation method further includes: Add the metal solid used for the first liquid metal into a reaction vessel, and place the reaction vessel in a heating furnace; Add the metal solid used for the second liquid metal into a purification vessel, and place the purification vessel in a heating furnace; Seal the heating furnaces of the reaction vessel and the purification vessel, perform gas replacement on the heating furnaces through an inert gas, and form an inert atmosphere environment in the heating furnaces of the reaction vessel and the purification vessel; Heat the reaction vessel until the metal solid in the reaction vessel melts and reaches the target growth temperature; heat the purification vessel until the metal solid in the purification vessel melts.

7. A growth device for graphene powder, characterized in that, Applied to the preparation method of graphene powder according to any one of claims 1 - 6, the growth device includes a reaction vessel, a purification vessel, a powder collection device (28), and at least one heating furnace; The at least one heating furnace includes a first heating furnace (1) and a second heating furnace (25), the reaction vessel is disposed in the inner cavity of the first heating furnace (1), and the purification vessel is disposed in the inner cavity of the second heating furnace (25); The reaction vessel is communicated with a carbon source gas inlet pipe (5), the reaction vessel is communicated with the purification vessel through a first collection pipeline, and the purification vessel is communicated with the powder collection device (28) through a second collection pipeline; The reaction vessel is used for containing a first liquid metal, and the purification vessel is used for containing a second liquid metal.

8. The growth device according to claim 7, wherein The powder collection device (28) includes a powder collection vessel and a filter element (29), the powder collection vessel is provided with a powder inlet and an exhaust port of the collection device, and the powder inlet is communicated with the second collection pipeline; The filter element (29) is hermetically connected to the inner wall of the powder collection vessel, and the filter element (29) is located between the powder inlet and the exhaust port of the collection device.

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