High-quality graphene powder growth method and equipment based on solid-phase catalysis

Abstract

The present application relates to the technical field of carbon materials, and in particular to a method and apparatus for growing high-quality graphene powder based on solid-phase catalysis. The growth method comprises: providing a prefabricated three-dimensional metal foil in a three-dimensional form, wherein the material of the prefabricated three-dimensional metal foil comprises a catalyst metal; blowing the prefabricated three-dimensional metal foil from a feed port of a reactor into a reactor by an airflow, and while the prefabricated three-dimensional metal foil rises in the reactor with the airflow, heating the prefabricated three-dimensional metal foil and bringing it into contact with a carbon source gas introduced into the reactor, so as to grow graphene on the prefabricated three-dimensional metal foil; cooling the prefabricated three-dimensional metal foil with graphene grown thereon output from the discharge port of the reactor, so as to separate the graphene and the prefabricated three-dimensional metal foil, and thereby obtaining graphene powder. This method avoids subsequent complex purification processes and achieves continuous growth of high-quality graphene.

Description

Technical Field

[0001] The present application relates to the field of carbon material technology, and in particular to a method and apparatus for growing high-quality graphene powder based on solid-phase catalysis. Background Art

[0002] Currently, the main methods for growing graphene powder include physical mechanical exfoliation, redox exfoliation, and electrolytic exfoliation. While physical exfoliation does not destroy the graphene microstructure, the layers are generally thicker. Electrolytic exfoliation is similar to physical exfoliation, but it can also damage the graphene microstructure and produce thicker layers. While redox exfoliation can produce graphene with fewer layers, it severely damages the graphene crystal structure and produces large amounts of wastewater containing strong oxidants and strong acids during the preparation process. Given that the quality of graphene powder is crucial to product application development and directly determines product performance, there is an urgent need to find a high-quality, low-cost, and pollution-free graphene growth method.

[0003] Patent CN112919453 discloses a method for growing a graphene powder material. The method comprises growing a vertical graphene array on a copper foil using a roll-to-roll plasma chemical vapor deposition device. An appropriate amount of PMMA solution is then dripped onto the surface of the copper foil with the grown vertical graphene array and evenly spin-coated, followed by heating and curing in an oven. Taking advantage of the poor bonding between the vertical graphene array and the copper foil, a mechanical stripping method is used to directly and completely peel off the cured vertical graphene PMMA polymer layer from the copper foil. The peeled polymer layer is immersed in acetone to completely dissolve the PMMA, thereby obtaining a graphene sheet suspension. Finally, the graphene suspension is separated by filtration and placed in a ball mill or sand mill to obtain a graphene powder material. Although this method reduces environmental pollution to a certain extent, the thickness of the graphene material grown is still relatively thick and has many defects. The process is complicated and the efficiency is very low, making it impossible to achieve large-scale production. Patent CN110803696A discloses a method for making graphene powder in one step using chemical vapor deposition. The method places a carrier in a quartz tube, and after heating, a carbon source is introduced into the quartz tube to grow graphene in the carrier. After removing the carrier, graphene powder is obtained. In this method, the graphene powder is grown without using any substrate. Under negative pressure conditions, the carbon source gas introduced diffuses between the carrier and the cover plate sandwiched on both sides of the copper foil. The copper foil participates in the pyrolysis reaction of the carbon source gas. Since the copper foil is sandwiched between the carrier and the cover plate, only a small amount of carbon source gas can contact the copper foil, resulting in low catalytic efficiency and very low graphene production efficiency. Summary of the Invention

[0004] In response to the above-mentioned problems in the prior art, the present application provides a method and apparatus for growing high-quality graphene powder based on solid-phase catalysis. The specific technical solutions are as follows:

[0005] On the one hand, the present application provides a method for growing high-quality graphene powder based on solid-phase catalysis, using a high-quality graphene growth device based on solid-phase catalysis, the growth device including a reactor, and the method comprising:

[0006] Providing a prefabricated three-dimensional metal foil in a three-dimensional form, wherein the material of the prefabricated three-dimensional metal foil includes a catalyst metal;

[0007] The prefabricated three-dimensional metal foil is blown from a feed port of the reactor into the reactor by an airflow, and as the prefabricated three-dimensional metal foil rises in the reactor along with the airflow, the prefabricated three-dimensional metal foil is heated and contacts the carbon source gas introduced into the reactor, thereby growing graphene on the prefabricated three-dimensional metal foil;

[0008] The prefabricated three-dimensional metal foil with graphene grown thereon, which is output from the discharge port of the reactor, is cooled to separate the graphene from the prefabricated three-dimensional metal foil to obtain graphene powder.

[0009] In a possible implementation manner, the prefabricated three-dimensional metal foil is a ball-shaped object with wrinkles formed by metal foil.

[0010] In a possible implementation manner, the thickness of the metal foil used in the prefabricated three-dimensional metal foil is 35-50 um.

[0011] In a possible implementation manner, the single body diameter of the prefabricated three-dimensional metal foil is 3-6.5 cm.

[0012] In a possible embodiment, the bulk density of the prefabricated three-dimensional metal foil is 1.62-2.54 g / cm 3 .

[0013] In a possible embodiment, the inner cavity of the reactor has a heating zone, and as the prefabricated three-dimensional metal foil rises in the reactor with the airflow, the prefabricated three-dimensional metal foil is heated in the heating zone by induction heating, and the heating temperature is lower than the melting point of the prefabricated three-dimensional metal foil.

[0014] In a possible implementation manner, the heating temperature is less than or equal to 850°C.

[0015] In a possible implementation manner, the cooling treatment method for the prefabricated three-dimensional metal foil with grown graphene is rapid cooling.

[0016] In a possible implementation manner, the carbon source gas includes at least one of ethylene, propane, propylene, butane, butene, and acetylene.

[0017] In a possible implementation manner, along the blowing direction of the prefabricated three-dimensional metal foil, the length of the heating zone in the inner cavity of the reactor for heating the prefabricated three-dimensional metal foil is 6-8 m.

[0018] In a possible embodiment, the gaseous carbon source inlet for introducing the gaseous carbon source is located in the heating zone, and along the blowing direction of the prefabricated three-dimensional metal foil, the distance between the gaseous carbon source inlet and the interface of the heating zone close to the feed port is 4-5m.

[0019] In a possible implementation manner, the blowing speed of the prefabricated three-dimensional metal foil in the reactor is 1.5-2.5 m / s.

[0020] In a possible implementation manner, the gaseous carbon source inlet for introducing the gaseous carbon source is in the shape of a nozzle, including a plurality of nozzle holes, and the porosity of the gaseous carbon source inlet is 55%-65%.

[0021] In a possible implementation manner, the diameter of the nozzle is 3.5-5.5 cm.

[0022] In a possible implementation manner, the instantaneous velocity of the carbon source gas entering the reactor cavity is 6.5-8 m / s.

[0023] In a possible embodiment, the growth equipment includes a separation device for placing the prefabricated three-dimensional metal foil, the discharge port of the separation device is connected to the feed port pipe of the reactor, and the prefabricated three-dimensional metal foil enters the pipe through the discharge port of the separation device under the action of gravity, and the falling speed is 100-250 pieces / min.

[0024] In a possible implementation manner, the cavity diameter of the reactor is 18-25 cm.

[0025] In a possible implementation manner, the diameter of the pipe used to transport the prefabricated three-dimensional metal foil is 2-2.3 times the diameter of the prefabricated three-dimensional metal foil.

[0026] In a possible implementation manner, the diameter of the pipe used to transport the prefabricated three-dimensional metal foil is 6-15 cm.

[0027] In a possible implementation manner, the graphene separated from the prefabricated three-dimensional metal foil is blown into a powder collector of the growth device through a pipe, and the diameter of the pipe for transporting the graphene is 30-50 mm.

[0028] In a possible embodiment, the growth equipment includes a separation device for placing the prefabricated three-dimensional metal foil, the separation device includes a first separation kettle and a second separation kettle, one of the first separation kettle and the second separation kettle is used to transport the prefabricated three-dimensional metal foil into the reaction kettle, and the other is used to recover the prefabricated three-dimensional metal foil; the growth method further includes:

[0029] If it is detected that the remaining amount of the prefabricated three-dimensional metal foil in the target separation kettle currently used for conveying the prefabricated three-dimensional metal foil between the first separation kettle and the second separation kettle is low to a preset amount, the target separation kettle is switched to a separation kettle for recycling the prefabricated three-dimensional metal foil through pipeline control, and the separation kettle currently used for recycling the prefabricated three-dimensional metal foil between the first separation kettle and the second separation kettle is switched to a separation kettle for conveying the prefabricated three-dimensional metal foil.

[0030] On the other hand, the present application provides a high-quality graphene powder growth device based on solid-phase catalysis, which is applied to the above-mentioned growth method, wherein the growth device includes a reactor, a cooling device, a separation device and a powder collector; the reactor is connected to a carbon source air inlet pipe;

[0031] The reactor is provided with a first feed port, a first discharge port and a heating zone located between the first feed port and the first discharge port; the gaseous carbon source inlet is used to introduce the carbon source gas into the heating zone;

[0032] The discharge port of the separation device is connected to the first feed port through a breakable pipeline, and the feed port of the separation device is connected to the second feed port of the separation device through a breakable pipeline;

[0033] The cooling device is arranged on the pipeline between the reactor and the separation device, and is used to cool the conveyed material. The powder collector is communicated with the powder discharge port of the separation device.

[0034] In a possible embodiment, the separation device includes a first separation kettle and a second separation kettle, wherein the first separation kettle and the second separation kettle are respectively connected to the reaction kettle in a disconnectable manner and are also connected to the powder collector in a disconnectable manner;

[0035] When one of the first separation kettle and the second separation kettle is used to transport materials into the first feed port of the reactor, the other is used to recover materials output from the first discharge port of the reactor; the first separation kettle and the second separation kettle can switch functions by controlling the on-off of the pipeline.

[0036] In a possible embodiment, the first separation kettle is provided with a second feed port, a second discharge port and a first powder discharge port, and the second separation kettle is provided with a third feed port, a third discharge port and a second powder discharge port;

[0037] The second feed port and the third feed port are respectively connected to the first discharge port through a disconnectable pipeline, and the second discharge port and the third discharge port are respectively connected to the first feed port through a disconnectable pipeline;

[0038] The first powder discharge port and the second powder discharge port are respectively connected to the feed port of the powder collector through on-off pipelines.

[0039] On the other hand, the present application provides a graphene powder, which is prepared using the above-mentioned high-quality graphene powder growth method based on solid-phase catalysis.

[0040] On the other hand, the present application provides an application of the graphene powder as described above, wherein the graphene powder is used as a conductive material or a thermal conductive material.

[0041] Based on the above technical solution, this application has the following beneficial effects:

[0042] The present application provides a method for growing high-quality graphene powder, which uses a prefabricated three-dimensional metal foil as a growth catalytic substrate, and transports it to a reactor for heating by blowing airflow, so that it contacts with a carbon source gas and grows graphene during the rising process, and then separates the two under cooling to obtain high-quality graphene powder. The present application prefabricates the metal foil into a three-dimensional form, and the metal foil changes from a planar structure to a loose three-dimensional structure. The cross-section in any direction has a larger contact area with the gas than the vertical direction of the original planar structure, and is easily carried to the target position by the high-speed airflow; and the contact area between the three-dimensional metal foil monomers is very small. At a relatively low growth temperature, the three-dimensional metal foil is not easy to adhere to each other. It also has a certain rigidity and can better maintain the initial shape, so as to facilitate the stable growth of graphene and be able to be recycled. In addition, the carbon source gas and the inert gas intake are divided into two paths, one for transporting the metal foil, and the other for filling the heating zone at different positions of the reactor, so that the inert gas flow carries the three-dimensional metal foil through the reactor and is cooled. Due to the large difference in thermal expansion coefficient, the binding force between the two is weakened and separated, and they are collected separately when the mass and density differences are large. The operation is simple, and large-scale production can be achieved. High-quality graphene powder that does not require post-processing and purification is obtained. The preparation process does not involve acidic or alkaline solutions, which is green and environmentally friendly. The catalyst metal content in the graphene powder obtained by this application is less than 10ppm, the conversion rate of the gaseous carbon source reaches more than 92%, and the proportion of graphene within 5 layers is as high as more than 91%, with a specific surface area of ​​550m 2 / g or more. In addition, the I D / I G The value is below 0.135, there are fewer defects, and the conductivity can reach above 11550S / m. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] To more clearly illustrate the technical solution of this application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0044] Figure 1 : A schematic structural diagram of a high-quality graphene powder growth device based on solid-phase catalysis provided in an embodiment of the present application;

[0045] Figure 2 : Photos of the prefabricated three-dimensional metal foil provided in the examples of this application;

[0046] Figure numerals: 100-reactor, 101-heating zone, 102-first feed port, 103-second feed port, 201-carbon source gas inlet, 202-first air inlet pipe, 203-second air inlet pipe, 204-gas mixing device, 205-third air inlet pipe, 300-cooling device, 410-first separation kettle, 411-second discharge port, 412-second feed port, 413-first powder discharge port, 420-second separation kettle, 421-third discharge port, 422-third feed port, 423-second powder discharge port, 500-powder collector, 501-isolator, 601-first gas pipeline, 601-second gas pipeline, 701-vertical pipe section, 702-horizontal pipe section, 800-control valve, 10-prefabricated three-dimensional metal foil, 20-graphene powder. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification. All numerical values, whether or not explicitly indicated, are defined herein as being modified by the term "about". The term "about" generally refers to a numerical range that one 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 lower value and an upper value is defined to include all numerical values ​​included in the numerical range and all subranges included in the numerical range.

[0049] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0050] The following describes the high-quality graphene powder growth equipment based on solid phase catalysis provided in the embodiment of the present application. Figure 1 , Figure 1 It is a structural diagram of a high-quality graphene powder growth device based on solid-phase catalysis. It is understandable that the reaction device structure in the figure is only a technical solution of a specific embodiment of the present application. The reaction device of the present application may include fewer or more structural features. Figure 1 The device structure described in the present invention is limited.

[0051] The growth apparatus includes a reactor 100, a cooling device 300, a separation device, and a powder collector 500. The reactor 100 is connected to a carbon source air inlet pipe. The reactor 100 is provided with a first feed port 102, a first discharge port 103, and a heating zone 101 located between the first feed port 102 and the first discharge port 103. The first feed port 102 is used to introduce material, which is a catalytic metal material capable of growing graphene, such as a prefabricated three-dimensional metal foil. The first feed port 102 is connected to a vent pipe that provides a transport airflow, thereby forming an airflow in the pipe for transporting the material. Preferably, the first feed port 102 is located at the bottom of the reactor 100, and the first discharge port 103 is located at the top of the reactor 100. A material riser is formed between the first feed port 102 and the second feed port 412, and the heating zone 101 is located within this riser.

[0052] The carbon source air inlet pipe is connected to the carbon source gas inlet device, which is provided with a gaseous carbon source air inlet 201 for introducing the carbon source gas into the heating zone 101; preferably, the gaseous carbon source air inlet 201 is located in the heating zone 101 so that the carbon source gas can directly enter the heating zone 101.

[0053] The separation device is used to accommodate materials and transport them into the reactor 100. Preferably, the separation device is also used to recover materials output from the first discharge port 103 of the reactor 100. The discharge port of the separation device is connected to the first feed port 102 via a breakable pipeline, and the feed port of the separation device is connected to the second feed port 412 of the separation device via a breakable pipeline.

[0054] The cooling device 300 is installed in the pipeline between the reactor 100 and the separation device, and is used to cool the conveyed material. The powder collector 500 is connected to the powder discharge port of the separation device. The cooling device 300 is used to cool the graphene-grown material discharged from the first discharge port 103 to separate the graphene from the material. The graphene and material are blown into the separation device by the airflow. Due to the significant difference in mass, the material falls into the separation device cavity under the action of gravity, and the graphene powder is further blown into the powder collector 500 by the airflow.

[0055] In some embodiments, the discharge port of the separation device is connected to a vertical pipe section 701 so that the material in the separation device can enter the vertical pipe section 701 under the action of gravity and then be blown into the reactor 100 by the air flow.

[0056] Specifically, the carbon source gas inlet device includes a first inlet pipe 202, a second inlet pipe 203, a mixing device 204, and a third inlet pipe 205. The first inlet pipe 202 and the second inlet pipe 203 are respectively connected to the inlet end of the mixing device 204. The outlet end of the mixing device 204 is connected to the inlet end of the third inlet pipe 205. The outlet end of the third inlet pipe 205 is connected to the gaseous carbon source inlet port 201 (e.g., a nozzle). The first inlet pipe 202 is used to introduce an inert gas, and the second inlet pipe 203 is used to introduce a carbon-containing gas. The mixing device 204 is used to premix the introduced inert gas and carbon-containing gas to produce a carbon source gas, which then enters the heating zone 101 through the third inlet pipe 205 and the gaseous carbon source inlet port 201.

[0057] In some embodiments, the gaseous carbon source inlet 201 for introducing the gaseous carbon source is in the shape of a nozzle, including multiple nozzle holes. Exemplarily, the gaseous carbon source inlet 201 is a porous nozzle, such as a porous ceramic nozzle or a porous graphite nozzle. By using a porous material as the nozzle, the introduced carbon source gas is pre-mixed before entering the reaction chamber and enters the heating zone 101 of the reactor 100 at a constant speed, ensuring uniform distribution of the carbon source gas and the rising transport airflow in the reactor 100 chamber along the cross-sectional direction.

[0058] In some embodiments, the third air inlet pipe 205 at least partially extends into the heating zone 101 in the reactor 100, so that the carbon source gas is preheated in the pipeline. Since the carbon source gas has a very small specific heat capacity, it can instantly reach the preset catalytic reaction growth temperature.

[0059] In some embodiments, the porosity of the gaseous carbon source inlet 201 is 55%-65%. By setting a suitable porosity, it is possible to ensure uniform gas dispersion and control the concentration of the carbon-containing gas in the heating zone 101.

[0060] In some embodiments, the nozzle diameter is 3.5-5.5 cm. Setting an appropriate aperture helps control the velocity of the carbon source gas entering the reaction chamber. Combining the above-described nozzle aperture and porosity settings can further improve the uniformity of carbon source gas distribution within the heating zone 101 and facilitate concentration control.

[0061] In some embodiments, the instantaneous velocity of the carbon source gas entering the chamber of the reactor 100 is 6.5-8 m / s. By controlling the gas inlet velocity within the above range, the gas uniformity of the reaction chamber cross section is increased, thereby improving the graphene growth uniformity and product quality.

[0062] In some embodiments, the cavity diameter of the reactor 100 is 18-25 cm to provide a sufficient space for the material to pass through and to avoid slowing down the air flow velocity due to an excessively large diameter.

[0063] Specifically, the length of the heating zone 101 can be set based on the actual growth requirements of graphene, such as the preset growth temperature and the time required for the carbon source gas to decompose and grow graphene.

[0064] In some embodiments, the heating zone 101 in the inner cavity of the reactor 100 for heating the catalyst material (such as prefabricated three-dimensional metal foil) is 6-8 meters long to ensure that the catalyst material can be heated to a preset growth temperature and has sufficient graphene growth time.

[0065] When the gaseous carbon source inlet 201 is located within the heating zone 101, the distance between the gaseous carbon source inlet 201 and the interface of the heating zone 101 near the feed port is 4-5 meters along the blowing direction of the material (such as a prefabricated three-dimensional metal foil). For example, if the gas is blown vertically and from bottom to top, the distance between the gaseous carbon source inlet 201 and the bottom interface of the heating zone 101 is 4-5 meters. In this way, the heating zone 101 is divided into two sections: one section is used to heat the catalyst material blown into the heating zone 101, and the other section is used to grow graphene on the surface of the catalyst material heated to the preset growth temperature. This prevents graphene growth at excessively low temperatures and improves product quality.

[0066] In some embodiments, the heating device used in the reactor 100 is an induction heating device, and the reactor 100 cavity is made of insulating ceramic materials, including but not limited to silicon carbide, corundum, zirconium oxide, boron nitride, etc. The induction heating device generates eddy currents in the catalyst material rising to the heating zone 101 through an induction coil, thereby achieving induction heating of the catalyst material. This improves heating efficiency and ensures the accuracy of growth temperature control, while avoiding uneven heating of the catalyst in the cavity, low heating efficiency, and uneven growth temperature distribution caused by traditional heating methods, thereby reducing the impact on graphene growth quality.

[0067] In some embodiments, the cooling device 300 can be a heat exchanger, such as a circulating water heat exchanger. The cooling device 300 is arranged on the connecting pipe between the reactor 100 and the separation device, and then cools the catalyst material with graphene grown in the pipe. This method realizes the sudden cooling of the material. Due to the huge difference in thermal expansion coefficients between graphene and catalyst materials, the interfacial bonding force between graphene and catalyst materials is rapidly reduced. Under the scouring of high-speed airflow, graphene is quickly peeled off from the catalyst material to form powdered graphene.

[0068] In some embodiments, the inner cavity diameter of the separation device is much larger than the diameter of the pipe for transporting the material. Therefore, after the transported material enters the inner cavity of the separation device with the airflow, the airflow speed slows down, and the catalyst material falls to the bottom of the cavity due to its large mass. The graphene powder enters the powder collector 500 from the powder discharge port of the separation device with the airflow.

[0069] In some embodiments, the separation device includes a first separation kettle 410 and a second separation kettle 420, and the first separation kettle 410 and the second separation kettle 420 are respectively connected to the reactor 100 in an on-off manner and are connected to the powder collector 500 in an on-off manner; when one of the first separation kettle 410 and the second separation kettle 420 is used to transport materials into the first feed port 102 of the reactor 100, the other is used to recover materials output from the first discharge port 103 of the reactor 100; through the on-off control of the pipeline, the first separation kettle 410 and the second separation kettle 420 can switch functions, that is, the first separation kettle 410 is currently used to feed the first feed port 102 of the reactor 100 to the first discharge port 103 of the reactor 100. 2. When the second separation kettle 420 is used to receive the material output from the first discharge port 103 of the reactor 100, if the first separation kettle 410 is disconnected from the first feed port 102 of the reactor 100 and connected to the first discharge port 103 of the reactor 100, and the second separation kettle 420 is connected to the first feed port 102 of the reactor 100 and disconnected from the first discharge port 103 of the reactor 100, the second separation kettle 420 is switched to be used for delivering the material to the first feed port 102 of the reactor 100, and the first separation kettle 410 is used for receiving the material output from the first discharge port 103 of the reactor 100.

[0070] In some embodiments, the first separation kettle 410 is provided with a second feed port 412, a second discharge port 411 and a first powder discharge port 413, and the second separation kettle 420 is provided with a third feed port 422, a third discharge port 421 and a second powder discharge port 423; the second feed port 412 and the third feed port 422 are respectively connected to the first discharge port 103 through a switchable pipeline, and the second discharge port 411 and the third discharge port 421 are respectively connected to the first feed port 102 through a switchable pipeline; the first powder discharge port 413 and the second powder discharge port 423 are respectively connected to the feed port of the powder collector 500 through a switchable pipeline.

[0071] Specifically, when the first separation kettle 410 is used to transport the catalyst material and the second separation kettle 420 is used to recover the catalyst material, the second discharge port 411 is connected to the first feed port 102, the second feed port 412 is disconnected from the first discharge port 103, and the first powder discharge port 413 is disconnected from the feed port of the powder collector 500; the third discharge port 421 is disconnected from the first feed port 102, the third feed port 422 is connected to the first discharge port 103, and the second powder discharge port 423 is connected to the feed port of the powder collector 500; On the contrary, when the second separation kettle 420 is used to transport catalyst materials and the first separation kettle 410 is used to recover catalyst materials, the second discharge port 411 is disconnected from the first feed port 102, the second feed port 412 is connected to the first discharge port 103, and the first powder discharge port 413 is connected to the feed port of the powder collector 500; the third discharge port 421 is connected to the first feed port 102, the third feed port 422 is disconnected from the first discharge port 103, and the second powder discharge port 423 is disconnected from the feed port of the powder collector 500.

[0072] By providing the first separation kettle 410 and the second separation kettle 420 as backup for each other, the recycled materials can be recycled, thereby achieving continuous growth of graphene.

[0073] In some embodiments, a material level meter is provided in the first separation kettle 410 and the second separation kettle 420 respectively, for detecting the remaining material in the first separation kettle 410 and the second separation kettle 420, so as to trigger the function switching between the first separation kettle 410 and the second separation kettle 420 when the remaining material in either one is lower than a preset amount.

[0074] In some embodiments, the diameter of the pipeline for conveying the catalyst material is 2-2.3 times the diameter of the catalyst material itself to allow the catalyst material to pass through without obstruction and maintain the required blowing speed. In some embodiments, the diameter of the pipeline for conveying the catalyst material is 6-15 cm.

[0075] In some embodiments, the pipe elbows used to transport the catalyst material are all rounded elbows, which can ensure smooth transmission by controlling the pipe diameter and prevent the catalyst material from accumulating in the pipe due to slow air flow velocity and clogging the pipe.

[0076] In some embodiments, the diameter of the pipe used to transport graphene is 30-50 mm to improve the graphene transportation efficiency.

[0077] The following describes the high-quality graphene powder growth method based on solid-phase catalysis provided in the embodiments of the present application in combination with the above-mentioned growth equipment. This specification provides method operation steps such as the embodiments or flow charts, but more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual growth method is executed, it can be executed in the order of the methods shown in the embodiments or the accompanying drawings or in parallel. The growth method includes S1-S4:

[0078] S1, providing a prefabricated three-dimensional metal foil in a three-dimensional form, wherein the material of the prefabricated three-dimensional metal foil includes a catalyst metal.

[0079] Specifically, the prefabricated three-dimensional metal foil is a ball-shaped object with wrinkles formed by metal foil. For example, a metal foil is provided and the metal foil is kneaded into a loose ball to obtain a prefabricated three-dimensional metal foil with a three-dimensional structure. Figure 2 As shown, the ball-shaped metal foil has wrinkles and presents an uneven structure, and there are gaps between adjacent bent sheet structures to facilitate the entry of carbon source gas and the growth of graphene, and to facilitate the separation of graphene from the metal foil after separation.

[0080] Specifically, the prefabricated three-dimensional metal foil may be made of copper foil or copper alloy foil.

[0081] By prefabricating the metal foil into a three-dimensional form, the metal foil changes from a planar structure to a loose three-dimensional structure. The cross-section in any direction has a larger contact area with the gas than the vertical direction of the original planar structure, making it easier to be carried to the target position by the high-speed airflow; and the contact area between the three-dimensional metal foil monomers is very small. At a relatively low growth temperature, the three-dimensional metal foil is not easy to adhere to each other. It also has a certain rigidity and can better maintain its initial shape, so as to facilitate the stable growth of graphene and be able to be recycled.

[0082] In some embodiments, the thickness of the metal foil used in the prefabricated three-dimensional metal foil is 35-50um; in this way, the prefabricated three-dimensional metal foil is ensured to have sufficient rigidity and light weight, avoiding the rigidity being too weak due to being too thin, and thus preventing the monomer from softening, collapsing and bonding at the growth temperature, so that it can maintain its shape during a long process; and avoiding the excessive density of the monomer caused by the metal foil being too thick, thereby avoiding affecting the fluidity during the airflow transportation process, so that the three-dimensional metal foil can flow smoothly in the pipeline and the reactor 100.

[0083] Graphene grown on metal foil has low interfacial bonding with the metal foil, which facilitates subsequent graphene separation, reduces the metal content in the graphene product, eliminates the need for chemical corrosion purification, avoids the discharge of wastewater containing strong acids and heavy metal ions, and produces high-quality graphene with few defects.

[0084] In some embodiments, the diameter of the monomers of the prefabricated three-dimensional metal foil is 3-6.5 cm; thus, the monomer mass and particle size are ensured to be within an appropriate range to facilitate air flow transmission and smooth flow in the pipeline.

[0085] In some embodiments, the bulk density of the prefabricated three-dimensional metal foil is 1.62-2.54 g / cm 3 In this way, while ensuring the smooth transmission and flow of airflow, the gaseous carbon source can quickly flow to various places inside the metal foil, fully contacting its surface, and achieving efficient graphene growth.

[0086] S2, blowing the prefabricated three-dimensional metal foil from the feed port of the reactor 100 into the reactor 100 through the airflow. As the prefabricated three-dimensional metal foil rises in the reactor 100 with the airflow, the prefabricated three-dimensional metal foil is heated and contacts the carbon source gas introduced into the reactor 100, so as to grow graphene on the prefabricated three-dimensional metal foil.

[0087] Specifically, the interior of the reactor 100 includes a heating zone 101. As the prefabricated three-dimensional metal foil rises within the reactor 100 with the airflow, it is heated within the heating zone 101 using induction heating. The heating temperature is below the melting point of the prefabricated three-dimensional metal foil. Preferably, the heating temperature is below the softening point of the prefabricated three-dimensional metal foil, meaning that the prefabricated three-dimensional metal foil maintains rigidity at this heating temperature and remains substantially unchanged macroscopically.

[0088] After the prefabricated three-dimensional metal foil falls from the first separation kettle 410 or the second separation kettle 420 into the pipeline, it is blown to the first feed port 102 by the airflow in the pipeline, and rises from bottom to top in the reactor 100. After passing through the heating zone 101, it is heated to the growth temperature and comes into contact with the carbon source gas. The carbon source is cracked to form graphene under the catalytic action and heating action of the prefabricated three-dimensional metal foil.

[0089] In some embodiments, the heating temperature is less than or equal to 850°C; preferably, the heating temperature is 800-850°C. At the above growth temperature, the introduced carbon source gas will not spontaneously undergo a cracking reaction before contacting the rising metal foil, thereby avoiding affecting the product quality of the graphene powder; in addition, the lower growth temperature is conducive to the three-dimensional metal foil still having a certain rigidity at high temperatures, maintaining the initial shape of the prefabricated three-dimensional metal foil, and keeping the catalyst monomer stable. At the same time, it also avoids the three-dimensional metal foil from sticking when the temperature is too high, thereby avoiding affecting the stable continuous growth of graphene. In addition, the three-dimensional structured metal foil can be recycled again after being separated from the graphene in the solid-solid separation kettle to ensure the continuous growth of graphene powder.

[0090] Specifically, the gas flow for transporting the prefabricated three-dimensional metal foil is an inert gas flow, such as a nitrogen gas flow or a helium gas flow.

[0091] In some embodiments, the carbon source gas includes at least one of ethylene, propane, propylene, butane, butene, and acetylene; so that the carbon source can be efficiently cracked under the above-mentioned growth temperature and metal catalysis to form high-quality graphene.

[0092] In addition, the carbon source gas also includes inert gases such as nitrogen or helium.

[0093] In some embodiments, the intake flow rate of the conveying gas is 750-1100 L / min.

[0094] In some embodiments, the flow rate of the gaseous carbon source input into the carbon source gas is 200-250 L / min, and the flow rate of the inert gas is 50-80 L / min.

[0095] In this way, the carbon source gas and the inert gas intake are divided into two paths, one path is used to transport the metal foil, and the other path is filled into the heating zone 101 at different positions of the reactor 100, so that the inert gas flow carries the three-dimensional metal foil through the reactor 100 to reach the solid-solid separation reactor. When the three-dimensional metal foil rises from the bottom of the reactor 100 under the push of the inert gas flow, it is instantly heated to a high temperature by electromagnetic induction eddy current, and then the three-dimensional metal foil heated to the growth temperature rises to meet the carbon source gas molecules. As the three-dimensional metal foil continues to rise, graphene continues to grow in the heating zone 101 of the reactor 100, thereby obtaining high-quality grown graphene.

[0096] In some embodiments, along the blowing direction of the prefabricated three-dimensional metal foil, the length of the heating zone 101 in the inner cavity of the reactor 100 for heating the prefabricated three-dimensional metal foil is 6-8m; to ensure sufficient metal foil heating time and graphene growth time, thereby ensuring the quality of graphene.

[0097] In some embodiments, a gaseous carbon source inlet 201 for introducing a gaseous carbon source is located within the heating zone 101. Along the blowing direction of the prefabricated three-dimensional metal foil, the distance between the gaseous carbon source inlet 201 and the interface of the heating zone 101 near the feed port is 4-5 meters. If the blowing direction is from bottom to top, the 4-5 meter vertical spacing is used. In this way, the heating zone 101 is divided into two sections. The lower section is used to heat the rising metal foil to ensure that it reaches the heating temperature before contacting the carbon source. The upper section is used for graphene growth on the metal foil surface, ensuring sufficient growth time.

[0098] In some embodiments, the blowing speed of the prefabricated three-dimensional metal foil in the reactor 100 is 1.5-2.5 m / s. Combined with the above-mentioned setting of the lengths of the heating zone 101, the growth of graphene can be ensured and the prefabricated three-dimensional metal foil can be stably raised.

[0099] In some embodiments, the gaseous carbon source inlet 201 for introducing the gaseous carbon source is in the shape of a nozzle, including multiple nozzles, and the porosity of the gaseous carbon source inlet 201 is 55%-65%; in this way, the premixing effect of the carbon source gas is ensured and it enters the reaction chamber at a certain speed, so that the carbon source gas and the rising inert gas flow in the reaction chamber can be evenly distributed in the cross-sectional direction.

[0100] In some embodiments, the diameter of the nozzle is 3.5-5.5 cm; this allows the speed of the carbon source gas entering the reaction chamber to be within a controllable range and to cover a certain area.

[0101] In some embodiments, the instantaneous velocity of the carbon source gas entering the chamber of the reactor 100 is 6.5-8 m / s; this ensures uniform distribution of the carbon source gas on the cross section and prevents excessive velocity from affecting graphene growth.

[0102] In some embodiments, the diameter of the cavity of the reactor 100 is 18-25 cm.

[0103] In some embodiments, the growth apparatus includes a separation device for placing the prefabricated three-dimensional metal foil. The discharge port of the separation device is connected to the feed pipe of the reactor 100. The prefabricated three-dimensional metal foil enters the pipe under the action of gravity through the discharge port of the separation device at a drop rate of 100-250 pieces / min. By setting this drop rate, in conjunction with the reactor 100 and the inner diameter of the pipe, the prefabricated three-dimensional metal foil can flow smoothly through the pipe while maintaining a sufficient distribution density, thereby increasing graphene production.

[0104] In some embodiments, the diameter of the pipe used to transport the prefabricated three-dimensional metal foil is 2-2.3 times the diameter of the individual prefabricated three-dimensional metal foil; in some embodiments, the diameter of the pipe used to transport the prefabricated three-dimensional metal foil is 6-15 cm; in this way, the metal foil is ensured to be transported smoothly, while preventing the metal copper foil from accumulating in the pipe due to the slow air flow speed and clogging the pipe.

[0105] In some embodiments, graphene separated from the prefabricated three-dimensional metal foil is blown into the powder collector 500 of the growth apparatus through a pipe. The diameter of the pipe used to transport the graphene is 30-50 mm. This pipe diameter is larger than the diameter of the pipe used to transport the prefabricated three-dimensional metal foil, thereby appropriately reducing the airflow rate to ensure stable delivery of the graphene to the powder collector 500.

[0106] S3, cooling the prefabricated three-dimensional metal foil with graphene grown thereon output from the discharge port of the reactor 100 to separate the graphene from the prefabricated three-dimensional metal foil to obtain graphene powder.

[0107] In some embodiments, the cooling treatment method for the prefabricated three-dimensional metal foil on which graphene is grown is sudden cooling, such as heat exchange and cooling through a pipeline heat exchanger. In this way, the temperature is rapidly reduced through heat exchange. Due to the huge difference in the thermal expansion coefficients of graphene and metal, the interfacial bonding force between graphene and the three-dimensional metal foil is rapidly reduced. Then, under the scouring of the high-speed airflow, the graphene is quickly peeled off from the three-dimensional clumping metal foil to form powdered graphene. Then, in the solid-solid separation kettle, because the bulk density and monomer mass of the three-dimensional metal foil are much greater than those of the graphene powder, the graphene powder and the three-dimensional metal foil can be completely separated in the solid-solid separation kettle. The graphene enters the powder collector 500 with the airflow, and the metal foil falls into the separation device. As the airflow continues to flow, the growth process continues, and graphene powder is continuously collected in the powder collector 500. The collected graphene powder does not need to undergo chemical corrosion purification or high-temperature purification, which not only saves costs, but also does not contain wastewater discharge from heavy metal ions, strong acids and other chemical reagents during the entire preparation process, making it environmentally friendly and safe.

[0108] The catalyst metal content in the graphene powder obtained by this application is less than 10ppm, the conversion rate of the gaseous carbon source reaches more than 92%, and the proportion of graphene within 5 layers is as high as more than 91%, with a specific surface area of ​​550m 2 / g or more. In addition, the I D / I G The value is below 0.135, there are fewer defects, and the conductivity can reach above 11550S / m.

[0109] In some embodiments, the growth equipment includes a separation device for placing the prefabricated three-dimensional metal foil, the separation device includes a first separation kettle 410 and a second separation kettle 420, and one of the first separation kettle 410 and the second separation kettle 420 is used to transport the prefabricated three-dimensional metal foil into the reactor 100, and the other is used to recover the prefabricated three-dimensional metal foil; the growth method also includes S4: if it is detected that the remaining amount of the prefabricated three-dimensional metal foil in the target separation kettle currently used for transporting the prefabricated three-dimensional metal foil in the first separation kettle 410 and the second separation kettle 420 is low to a preset amount, the target separation kettle is switched to a separation kettle for recovering the prefabricated three-dimensional metal foil through pipeline control, and the separation kettle currently used for recovering the prefabricated three-dimensional metal foil in the first separation kettle 410 and the second separation kettle 420 is switched to a separation kettle for transporting the prefabricated three-dimensional metal foil.

[0110] That is, when there is too little metal foil in the separation kettle that outputs the three-dimensional metal foil, it is switched to a separation kettle that receives the metal foil, and another separation kettle originally used to receive the three-dimensional metal foil is switched to output the metal foil. In this way, through the redundant settings of the equipment and real-time material level detection, the recycling of the three-dimensional metal foil is achieved. During the continuous growth of graphene, there is no need to open the separation kettle to replenish the metal foil, thereby avoiding the risk of oxygen exposure and reducing the complexity of the growth process.

[0111] The following describes preferred embodiments of the high-quality graphene powder growth apparatus and growth method based on solid-phase catalysis of the present application in combination with the above embodiments.

[0112] Example 1

[0113] This embodiment provides a high-quality graphene powder 20 growth device based on solid phase catalysis, referring to Figure 1 The growth equipment includes a reaction kettle 100, a carbon source gas inlet device, a cooling device 300, a first separation kettle 410, a second separation kettle 420 and a powder collector 500.

[0114] The reactor 100 is provided with a first feed port 102 at the bottom, a first discharge port 103 at the top, and a heating zone 101 located within the cavity of the reactor 100. The top and bottom of the reactor 100 are both conical.

[0115] The carbon source gas intake device includes a first intake pipe 202, a second intake pipe 203, a mixing device 204, a third intake pipe 205 and a gaseous carbon source inlet 201. The first intake pipe 202 is used to introduce inert gas, such as nitrogen, and the second intake pipe 203 is used to introduce carbon-containing gas, such as propane. The outlet ends of the first intake pipe 202 and the second intake pipe 203 are respectively connected to the inlet end of the mixing device 204, and the outlet end of the mixing device 204 and the inlet end of the third intake pipe 205 can be connected and disconnected. The outlet end of the third intake pipe 205 is connected to the gaseous carbon source inlet 201, and the gaseous carbon source inlet 201 is a porous nozzle.

[0116] At least part of the third air inlet pipe 205 and the porous nozzle extends into the heating zone 101 to facilitate preheating. The air inlet nozzles of the porous nozzle are arranged downward, or air inlet nozzles are arranged on the lower surface and circumference of the porous nozzle.

[0117] Specifically, the diameter of the cavity of the reactor 100 is 18-25 cm, the length of the heating zone 101 in the longitudinal direction is 6-8 m, and the longitudinal distance between the gaseous carbon source inlet 201 and the bottom interface of the heating zone 101 is 4-5 m.

[0118] Specifically, the porosity of the porous nozzle is 55%-65%; the diameter of the nozzle is 3.5-5.5 cm; and the instantaneous speed of the carbon source gas entering the cavity of the reactor 100 is 6.5-8 m / s.

[0119] The first separation kettle 410 is provided with a second feed port 412, a second discharge port 411, and a first powder discharge port 413. The second separation kettle 420 is provided with a third feed port 422, a third discharge port 421, and a second powder discharge port 423. The second feed port 412 is located at the top of the first separation kettle 410, the second discharge port 411 is located at the bottom of the first separation kettle 410, and the first powder discharge port 413 is located at the upper side of the first separation kettle 410, opposite the second feed port 412. The lower portion of the first separation kettle 410 is conical. The third feed port 422 is located at the upper side of the second separation kettle 420, the third discharge port 421 is located at the bottom of the second separation kettle 420, and the second powder discharge port 423 is located at the upper side of the second separation kettle 420, opposite the third feed port 422. The lower portion of the second separation kettle 420 is conical.

[0120] The second discharge port 411 and the third discharge port 421 are respectively connected to the first feed port 102 through the control valve 800, and the pipeline connecting the second discharge port 411 and the third discharge port 421 is provided with a connected vertical pipe section 701 and a horizontal pipe section 702. The vertical pipe section 701 is connected to the second discharge port 411 or the third discharge port 421 through the control valve 800, and one end of the horizontal pipe section 702 is connected to the air inlet pipeline for transporting gas, and the other end is connected to the first feed port 102. The materials in the first separation kettle 410 and the second separation kettle 420 can enter the horizontal pipe section 702 through their discharge ports through the vertical pipe section 701 under the action of gravity, and then be blown to the first feed port 102 under the airflow of the transport gas. The pipeline between the first separation kettle 410 and the first feed port 102 is connected to the first gas pipeline 601 , and the pipeline between the second separation kettle 420 and the first feed port 102 is connected to the second gas pipeline 602 .

[0121] A cooling device 300 is provided on the material transmission pipeline connected to the first discharge port 103. The cooling device 300 is a water-cooled heat exchanger. The material transmission pipeline branches and is connected to the second feed port 412 and the third feed port 422 through a control valve 800.

[0122] The first powder discharge port 413 and the second powder discharge port 423 are respectively connected to the feed port of the powder collector 500 via the control valve 800 in a switchable manner.

[0123] The first separation kettle 410 and the second separation kettle 420 are respectively provided with material level meters for detecting the remaining amount of materials in the first separation kettle 410 and the second separation kettle 420 .

[0124] The diameters of the connecting pipes between the first separator 410 and the reactor 100, and between the second separator 420 and the reactor 100, are 2-2.3 times the diameter of the catalyst material alone; these pipes can be 6-15 cm in diameter. The diameters of the connecting pipes between the first separator 410 and the powder collector 500, and between the second separator 420 and the powder collector 500, are 30-50 mm in diameter.

[0125] The diameters of the first separation kettle 410 and the second separation kettle 420 are larger than the diameter of the pipeline. For example, the size of the first separation kettle 410 and the second separation kettle 420 can be (φ50cm~φ80cm)*160cm. After the airflow enters, the speed slows down, the catalyst material falls to the lower part of the separation kettle, and the graphene powder 20 enters the powder collector 500 with the airflow.

[0126] The powder collector 500 has an isolation member 501 therein, and a feed port of the powder collector 500 is disposed between the isolation member 501 and its bottom wall to prevent the graphene powder 20 from overflowing.

[0127] The control valve 800 of the pipeline between the second discharge port 411 and the first feed port 102 is opened, the control valve 800 of the pipeline between the second feed port 412 and the first discharge port 103 is closed, the control valve 800 between the first powder discharge port 413 and the powder collector 500 is closed, the control valve 800 between the third discharge port 421 and the first feed port 102 is closed, the control valve 800 between the third feed port 422 and the first discharge port 103 is opened, and the control valve 800 between the second powder discharge port 423 and the powder collector 500 is opened. In this state, the catalyst material in the first separation kettle 410 is blown into the reactor 100 through the first feed port 102 and enters the second separation kettle 420 through the first discharge port 103, thereby realizing the collection of graphene powder 20; The control valve 800 of the pipeline between the second discharge port 411 and the first feed port 102 is closed, the control valve 800 of the pipeline between the second feed port 412 and the first discharge port 103 is opened, the control valve 800 between the first powder discharge port 413 and the powder collector 500 is opened, the control valve 800 between the third discharge port 421 and the first feed port 102 is opened, the control valve 800 between the third feed port 422 and the first discharge port 103 is closed, and when the control valve 800 between the second powder discharge port 423 and the powder collector 500 is closed, the catalyst material in the second separation kettle 420 is blown into the reactor 100 through the first feed port 102 and enters the first separation kettle 410 through the first discharge port 103, thereby realizing the collection of graphene powder 20.

[0128] Specifically, the maximum valve diameter of the control valve 800 is the same as the diameter of the pipeline in which it is located.

[0129] Example 2

[0130] This embodiment provides a method for growing high-quality graphene powder 20 based on solid-phase catalysis, comprising:

[0131] 1. A catalyst metal copper foil with a thickness of 35-50 μm is prefabricated into a three-dimensional structure to obtain a prefabricated three-dimensional metal foil 10. The single body diameter is 3-6.5 cm and the bulk density is 1.62-2.54 g / cm 3 , put it into the first separation kettle 410, the control valve 800 between the second discharge port 411 and the first feed port 102 is in a closed state, and the control valve 800 on the pipeline between the first separation kettle 410, the second separation kettle 420 and the powder collector 500, as well as the control valve 800 on each air inlet pipeline are closed, the internal system of the equipment is evacuated, and then filled with inert gas to restore to normal pressure.

[0132] For example, the internal system is vacuumed. When the internal pressure of the system reaches 10~20Pa, the air inlet valve of the second air inlet pipe is opened, and nitrogen is introduced to restore the pressure to normal. The above operation is repeated 5 times. The control valve 800 between the powder collector 500 and the first separation kettle 410 and the second separation kettle 420 is opened, and nitrogen is introduced from the second air pipe 602 at 15~30L / min to maintain the system at normal pressure.

[0133] 2. Use an induction heating device to heat the heating zone 101 in the reactor 100. The induction heating temperature required to be reached in the cavity of the heating zone 101 is 800°C~850°C. Close the control valve 800 of the second gas pipe 602, the control valve 800 between the third discharge port 421 and the first feed port 102, the control valve 800 between the first discharge port 103 and the second feed port 412, and the control valve 800 between the first powder discharge port 413 and the feed port of the powder collector 500. Open the air inlet control valve 800 of the first gas pipe 601, the control valve 800 between the first discharge port 103 and the third feed port 422, and the control valve 800 between the second powder discharge port 423 and the feed port of the powder collector 500, and introduce 750~1100L / min of nitrogen from the first gas pipe 601. The second discharge port 411 is opened, and the prefabricated three-dimensional metal foil 10 falls from the first separation kettle 410 into the pipeline under the action of gravity. The falling speed is controlled by the valve, 100~250 pieces / min, and is carried to the first feed port 102 by the high-speed nitrogen flow introduced from the first gas pipeline 601 and enters the reactor 100. After rising into the heating zone 101, it is heated to 800℃~850℃ under the action of induction heating.

[0134] 3. When the prefabricated three-dimensional metal foil 10 is carried to the reactor 100 by a nitrogen flow, propane and nitrogen are introduced through the first and second inlet pipes 202 and 203 at flow rates of 200-250 L / min and 50-80 L / min, respectively. Only the propane and nitrogen gases are mixed in the mixing device 204, then enter the multi-hole nozzle through the third inlet pipe 205 extending into the heating zone 101. After preheating, they are sprayed into the heating zone 101. At the preset growth temperature of 800-850°C, the introduced carbon source gas does not spontaneously undergo a cracking reaction until it contacts the rising prefabricated three-dimensional metal foil 10. Upon contact with the rising copper foil, it cracks and grows into a graphene film on the copper foil heated to the growth temperature.

[0135] 4. The prefabricated three-dimensional metal foil 10 with graphene growth continues to rise with the airflow and is discharged from the first discharge port 103. It is cooled by heat exchange in a heat exchanger provided on the pipeline to separate the graphene and the prefabricated three-dimensional metal foil 10. The graphene and the prefabricated three-dimensional metal foil 10 are then blown into the third feed port 422 of the second separation vessel 420 under the airflow. The metal foil falls into the second separation vessel 420 under the action of gravity. The graphene powder 20, which is relatively light in weight, enters the powder collector 500 under the action of the airflow.

[0136] 5. When the material level meter of the first separation kettle 410 detects that the remaining amount of the prefabricated three-dimensional metal foil 10 in the first separation kettle 410 is low to a preset amount, the control valve 800 of the second gas pipe 602, the control valve 800 between the third discharge port 421 and the first feed port 102, the control valve 800 between the first discharge port 103 and the second feed port 412, and the control valve 800 between the first powder discharge port 413 and the feed port of the powder collector 500 are opened, and the first gas pipe 602 is closed. Nitrogen is introduced from the second gas pipeline 602 at a rate of 750-1100 L / min through the air inlet control valve 800 of pipe 601, the control valve 800 between the first discharge port 103 and the third feed port 422, and the control valve 800 between the second powder discharge port 423 and the feed port of the powder collector 500. This allows the prefabricated three-dimensional metal foil 10 in the second separation vessel 420 to fall under gravity and enter the reaction vessel 100, achieving cyclic and continuous growth of the graphene powder 20. Valve operation is automatically switched by the circuit control system.

[0137] During the growth process, if the pipeline is blocked, the flow rate of the transport air flow can be further increased to flush the pipeline.

[0138] Fifteen groups of samples of the graphene powder 20 collected from the powder collector 500 were subjected to AAS (atomic absorption spectroscopy), and the metal content obtained was ≤10 ppm, indicating that the graphene powder 20 prepared by the method of the present application was of high purity and did not require additional chemical corrosion purification or physical purification.

[0139] The mass of the graphene powder 20 grown during time t1 is denoted as m1, and the mass of C in the propane molecules introduced during this time period t1 is denoted as m2. The conversion rate is obtained by m1 / m2*100%, which is 92%~95%, indicating that the cracking efficiency of the introduced carbon source gas is relatively high in this reaction system.

[0140] Through TEM testing, the number of graphene layers observed in no less than 40 pictures taken in different areas was statistically analyzed, and the proportion of graphene layers within 5 layers was 91% to 93%.

[0141] The prepared graphene was tested by Raman spectroscopy. The Raman data of different regions were collected and the average value was calculated to obtain I D / I G =0.081~0.135, indicating that the number of defect layers of graphene powder 20 prepared by this method is controllable and has fewer defects.

[0142] The prepared graphene was subjected to BET test. Samples were taken from different positions of the powder in the powder collection tower. No less than 25 groups of samples were prepared for BET test. The average value was taken to obtain a specific surface area of ​​550~650m 2 / g, indicating that the number of prepared powder layers is small.

[0143] For the prepared graphene powder 20, 15 groups of samples were randomly selected and pressed into pellets at a pressure of 100 MPa. The powder resistivity was then tested using a four-probe tester. The average value after conversion yielded a conductivity of 11550~12600 S / m.

[0144] The above description has fully disclosed the specific embodiments of this application. It should be noted that any changes made by those skilled in the art to the specific embodiments of this application do not depart from the scope of the claims of this application. Accordingly, the scope of the claims of this application is not limited to the above specific embodiments.

Claims

1. A method for growing high-quality graphene powder based on solid-phase catalysis, using a high-quality graphene growth device based on solid-phase catalysis, wherein the growth device comprises a reactor (100), characterized in that: The method comprises: Providing a prefabricated three-dimensional metal foil in a three-dimensional form, wherein the material of the prefabricated three-dimensional metal foil includes a catalyst metal; The prefabricated three-dimensional metal foil is blown into the reactor (100) from a feed port of the reactor (100) by an airflow; while the prefabricated three-dimensional metal foil rises in the reactor (100) along with the airflow, the prefabricated three-dimensional metal foil is heated and brought into contact with a carbon source gas introduced into the reactor (100), thereby growing graphene on the prefabricated three-dimensional metal foil; The prefabricated three-dimensional metal foil on which graphene is grown and output from the discharge port of the reactor (100) is cooled to separate the graphene from the prefabricated three-dimensional metal foil, thereby obtaining graphene powder.

2. The growth method according to claim 1, characterized in that The prefabricated three-dimensional metal foil meets at least one of the following characteristics: The prefabricated three-dimensional metal foil is a ball-shaped object with wrinkles formed by metal foil; The thickness of the metal foil used in the prefabricated three-dimensional metal foil is 35-50 μm; The single body diameter of the prefabricated three-dimensional metal foil is 3-6.5 cm; The bulk density of the prefabricated three-dimensional metal foil is 1.62-2.54 g / cm 3 .

3. The growth method according to claim 1, characterized in that The growth method satisfies at least one of the following characteristics: The inner cavity of the reactor (100) has a heating zone (101), and when the prefabricated three-dimensional metal foil rises with the airflow in the reactor (100), the prefabricated three-dimensional metal foil is heated in the heating zone (101) by induction heating, and the heating temperature is lower than the melting point of the prefabricated three-dimensional metal foil; The heating temperature is less than or equal to 850°C; The cooling method of the prefabricated three-dimensional metal foil with grown graphene is rapid cooling.

4. The growth method according to claim 1, wherein The growth method satisfies at least one of the following characteristics: The carbon source gas includes at least one of ethylene, propane, propylene, butane, butene, and acetylene; Along the blowing direction of the prefabricated three-dimensional metal foil, the length of the heating zone (101) in the inner cavity of the reaction kettle (100) for heating the prefabricated three-dimensional metal foil is 6-8 m; A gaseous carbon source inlet (201) for introducing a gaseous carbon source is located in the heating zone (101), and along the blowing direction of the prefabricated three-dimensional metal foil, the distance between the gaseous carbon source inlet (201) and the interface of the heating zone (101) close to the feed port is 4-5 m; The blowing speed of the prefabricated three-dimensional metal foil in the reaction kettle (100) is 1.5-2.5 m / s.

5. The growth method according to claim 1, characterized in that The growth method satisfies at least one of the following characteristics: The gaseous carbon source inlet (201) for introducing the gaseous carbon source is in the shape of a nozzle and includes a plurality of nozzle holes. The porosity of the gaseous carbon source inlet (201) is 55%-65%. The diameter of the nozzle is 3.5-5.5 cm; The instantaneous speed of the carbon source gas entering the cavity of the reactor (100) is 6.5-8 m / s; The growth device comprises a separation device for placing the prefabricated three-dimensional metal foil, the discharge port of the separation device is connected to the feed port pipeline of the reactor (100), and the prefabricated three-dimensional metal foil enters the pipeline through the discharge port of the separation device under the action of gravity, with a falling speed of 100-250 pieces / min.

6. The growth method according to claim 1, characterized in that The growth method satisfies at least one of the following characteristics: The cavity diameter of the reactor (100) is 18-25 cm; The diameter of the pipeline used to transport the prefabricated three-dimensional metal foil is 2-2.3 times the diameter of the single body of the prefabricated three-dimensional metal foil; The diameter of the pipe used to transport the prefabricated three-dimensional metal foil is 6-15 cm; The graphene separated from the prefabricated three-dimensional metal foil is blown into the powder collector (500) of the growth device through a pipe, and the diameter of the pipe used for conveying the graphene is 30-50 mm.

7. The growth method according to any one of claims 1 to 6, characterized in that The growth device comprises a separation device for placing the prefabricated three-dimensional metal foil, the separation device comprising a first separation kettle (410) and a second separation kettle (420), one of the first separation kettle (410) and the second separation kettle (420) being used to transport the prefabricated three-dimensional metal foil into the reaction kettle (100), while the other is used to recover the prefabricated three-dimensional metal foil; the growth method further comprises: If it is detected that the remaining amount of the prefabricated three-dimensional metal foil in the target separation kettle currently used for conveying the prefabricated three-dimensional metal foil among the first separation kettle (410) and the second separation kettle (420) is lower than a preset amount, the target separation kettle is switched to a separation kettle for recycling the prefabricated three-dimensional metal foil through pipeline control, and the separation kettle currently used for recycling the prefabricated three-dimensional metal foil among the first separation kettle (410) and the second separation kettle (420) is switched to a separation kettle for conveying the prefabricated three-dimensional metal foil.

8. A high-quality graphene powder growth device based on solid-phase catalysis, applied to the growth method according to any one of claims 1 to 7, characterized in that: The growth device comprises a reactor (100), a cooling device (300), a separation device and a powder collector (500); the reactor (100) is connected to a carbon source air inlet pipe; The reactor (100) is provided with a first feed port (102), a first discharge port (103), and a heating zone (101) located between the first feed port (102) and the first discharge port (103); a gaseous carbon source gas inlet (201) is used to introduce carbon source gas into the heating zone (101); The discharge port of the separation device is connected to the first feed port (102) via a breakable pipeline, and the feed port of the separation device is connected to the second feed port (412) of the separation device via a breakable pipeline; The cooling device (300) is provided on the pipeline between the reactor (100) and the separation device, and is used to cool the conveyed material. The powder collector (500) is in communication with the powder discharge port of the separation device.

9. The growth device according to claim 8, characterized in that The separation device comprises a first separation kettle (410) and a second separation kettle (420), wherein the first separation kettle (410) and the second separation kettle (420) are respectively connected to the reaction kettle (100) in a disconnectable manner and are also connected to the powder collector (500) in a disconnectable manner; One of the first separation kettle (410) and the second separation kettle (420) is used to transport materials into the first feed port (102) of the reactor (100), while the other is used to recover materials output from the first discharge port (103) of the reactor (100); the first separation kettle (410) and the second separation kettle (420) can switch functions by controlling the on-off of the pipeline.

10. The growth device according to claim 9, characterized in that The first separation kettle (410) is provided with a second feed port (412), a second discharge port (411) and a first powder discharge port (413); the second separation kettle (420) is provided with a third feed port (422), a third discharge port (421) and a second powder discharge port (423); The second feed port (412) and the third feed port (422) are respectively connected to the first discharge port (103) through a disconnectable pipeline, and the second discharge port (411) and the third discharge port (421) are respectively connected to the first feed port (102) through a disconnectable pipeline; The first powder discharge port (413) and the second powder discharge port (423) are respectively connected to the feed port of the powder collector (500) via on-off pipelines.

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