Graphene preparation method

Abstract

The invention provides a graphene preparation method, and relates to the technical field of graphene. The method comprises the following steps: putting crystalline flake graphite powder into a preset solvent, and uniformly stirring to obtain a solution to be treated; pouring the solution to be treated into a first-stage stirring furnace, and stirring for a first time to obtain a first-stage solution; adding iron powder into the first-stage solution, uniformly mixing to obtain a mixed solution, pouring the mixed solution into a second-stage stirring furnace, stirring for a second duration to obtain a second-stage solution, electrifying and de-electrifying each electromagnet according to a preset strategy so as to adsorb iron powder particles in the mixed solution by electrifying, and forming a cluster-shaped collision target on the inner wall of the second-stage stirring furnace, the iron powder particles in the cluster-shaped collision target and the graphite particles embedded in the cluster-shaped collision target are released in a power-off mode; and pouring the secondary solution into an oscillation furnace, preparing into colloid, applying a high-frequency transformation magnetic field to the colloid, and separating the graphene from the colloid after a third time period. The method for preparing the graphene is relatively low in cost and relatively high in efficiency of preparing the graphene.

Description

Technical Field

[0001] The present application relates to the field of graphene technology, and in particular to a method for preparing graphene. Background Art

[0002] Graphene is a new two-dimensional carbon material with unique physical properties in the fields of thermal, mechanical, optics, and electronic applications. It is a new material that deserves high attention.

[0003] In the industrial preparation of graphene, the traditional mechanical exfoliation and chemical exfoliation methods have low exfoliation efficiency and long time consumption, and chemical exfoliation also has the problem of high cost. Therefore, how to improve the efficiency of graphene preparation at a lower cost is an urgent problem to be solved.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The present application provides a method for preparing graphene, which at least provides a solution with low cost and high efficiency for preparing graphene.

[0006] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0007] According to one aspect of the present application, a graphene preparation method is provided, wherein graphene is prepared using a three-stage preparation furnace, wherein the three-stage preparation furnace comprises a primary stirring furnace, a secondary stirring furnace and an oscillating furnace, wherein the inner wall of the primary stirring furnace is provided with a plurality of metal corrosion sheets, and the outer wall of the secondary stirring furnace is provided with a plurality of electromagnets, wherein the method comprises: placing flake graphite powder into a preset solvent and stirring evenly to obtain a solution to be treated; pouring the solution to be treated into the primary stirring furnace and stirring for a first time to obtain a primary solution; adding iron powder to the primary solution and mixing evenly to obtain A mixed solution is prepared, and the mixed solution is poured into the secondary stirring furnace and stirred for a second period of time to obtain a secondary solution, wherein each electromagnet is powered on and off according to a preset strategy, so as to adsorb iron powder particles in the mixed solution and form a clustered collision target on the inner wall of the secondary stirring furnace, and to release the iron powder particles in the clustered collision target and the graphite particles embedded in the clustered collision target when powered on; the secondary solution is poured into the oscillation furnace and modulated into a colloid, and a high-frequency conversion magnetic field is applied to the colloid for a third period of time to separate graphene from the colloid.

[0008] In the primary stirring furnace, the rough edges of multiple metal corrosion sheets are used to collide with graphite particles. Since the metal corrosion sheets are a whole, they can be more stable when colliding with graphite particles, so the single-layer or multi-layer graphite in the graphite particles can be quickly separated to form a primary solution mainly including single-layer graphene and multi-layer graphene and finer graphite particles. After that, the cluster collision target composed of iron powder is adsorbed from the inner wall of the secondary stirring furnace by an electromagnet. Since the cluster collision target has a larger area for colliding with fine graphite particles and multi-layer graphene, the multi-layer graphene and fine graphite particles in the primary solution can be quickly collided into a single layer or graphene with a smaller number of layers. Finally, in the oscillating furnace, the high-frequency magnetic field is used to oscillate the iron powder particles to collide with the multi-layer graphene and the stretching effect of the colloid, so that the multi-layer graphene can be quickly and better collided to separate the single-layer graphene, and finally the graphene with uniform thickness and thinner graphene is obtained. By utilizing the different contents of graphite particles and multilayer graphene during the preparation process and preparing graphene through a three-stage preparation furnace, high-quality graphene with uniform thickness and thinner thickness can be prepared more quickly, and it is beneficial to the preparation of graphene for industrial applications.

[0009] In one embodiment of the present application, each of the multiple metal corrosion sheets has a frame to maintain the structure of the metal corrosion sheet; the structure of at least one of the multiple metal corrosion sheets is a semi-spiral surface, and the setting direction is spirally toward the bottom of the first-level stirring furnace.

[0010] The metal corrosion sheet has a frame to keep the structure of the metal corrosion sheet stable, prevent the metal corrosion sheet from being deformed by impact in high-speed liquid, ensure that the metal corrosion sheet can fully collide with the graphite particles, and extend the life of the metal corrosion sheet.

[0011] By setting the structure of the metal corrosion sheet to a semi-helical surface, the solution flow can be guided to prevent graphite particles and single-layer or multi-layer graphene from being stuck on the metal corrosion sheet.

[0012] In one embodiment of the present application, the ratio of the diameter of the primary stirring furnace to the height of each metal corrosion sheet in the diameter direction is 15:1~8.5:1.

[0013] By setting the ratio of the diameter of the first-stage stirring furnace to the height of each metal corrosion sheet in the diameter direction to 15:1-8.5:1, the collision area between the metal corrosion sheet and the graphite particles can be guaranteed while ensuring that the solution in the first-stage stirring furnace can be stirred at a high speed.

[0014] In one embodiment of the present application, the plurality of metal corrosion sheets are of the same size and shape and are evenly arranged in the circumferential direction of the inner wall of the first-stage stirring furnace at the same height.

[0015] By arranging multiple metal corrosion sheets of the same size and shape and evenly arranging them in the circumferential direction at the same height of the inner wall of the first-stage stirring furnace, the solution in the first-stage stirring furnace can rotate more stably during stirring, which is beneficial to the separation of graphene.

[0016] In one embodiment of the present application, the multiple electromagnets are evenly arranged in the height direction of the secondary stirring furnace, and are evenly arranged in the circumference direction of the secondary stirring furnace in sequence; the preset strategy includes: in the height direction of the secondary stirring furnace, each electromagnet is powered off in sequence from high to low at every fourth time interval, and when the next electromagnet is powered off, the electromagnet that is currently in the power-off state is powered on again, and only one electromagnet is in the power-off state at the same time.

[0017] By evenly arranging multiple electromagnets in the height direction of the secondary stirring furnace and in turn evenly arranging them in the circumference direction of the secondary stirring furnace, it is beneficial to the rotation of the solution in the secondary stirring furnace, and it is beneficial for graphite particles and multilayer graphene at different heights in the solution to fully collide with the clustered collision target, so as to better peel off the single-layer graphene.

[0018] By using a preset strategy of powering off the electromagnets one by one and only having one electromagnet in the power-off state at the same time, it is possible to avoid graphite particles and multilayer graphene from being embedded in the clustered collision target, so that the secondary solution obtained after treatment with the secondary stirring furnace has a higher content of single-layer graphene, thereby preparing high-quality graphene with uniform thickness and thinner thickness more quickly.

[0019] In one embodiment of the present application, the preset solvent is deionized water, and the weight ratio of the flake graphite powder to the deionized water is 1:2000~1:500.

[0020] In one embodiment of the present application, the rotation speed when stirring the solution to be treated in the first-level stirring furnace is 1800~2300r / min, and the first time length is 40~60min; the rotation speed when stirring the solution to be treated in the second-level stirring furnace is 2000~5000r / min, and the second time length is 15~30min; the third time length is 10~30min.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A flow chart of a method for preparing graphene in one embodiment of the present application is shown.

[0024] Figure 2 A schematic diagram of a primary stirring furnace in one embodiment of the present application is shown.

[0025] Figure 3 A schematic diagram of a two-stage stirring furnace in one embodiment of the present application is shown.

[0026] Figure 4 A schematic diagram showing a metal corrosion sheet in one embodiment of the present application. DETAILED DESCRIPTION

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0028] In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus their repeated description will be omitted.

[0029] like Figure 1 As shown, the graphene preparation method in one embodiment of the present application may include S101 to S104.

[0030] Among them, Figure 2 and Figure 3 As shown, graphene is prepared using a three-stage preparation furnace, which includes a first-stage stirring furnace 1, a second-stage stirring furnace 2 and an oscillation furnace, wherein the inner wall of the first-stage stirring furnace 1 is provided with a plurality of metal corrosion sheets 11, and the outer wall of the second-stage stirring furnace 2 is provided with a plurality of electromagnets 21.

[0031] S101, placing flake graphite powder into a preset solvent and stirring it evenly to obtain a solution to be treated.

[0032] The embodiments of the present application do not limit the specific solvent of the preset solvent, for example, the preset solvent is deionized water. The embodiments of the present application do not limit the weight ratio of the flake graphite powder to the preset solvent, for example, the weight ratio of the flake graphite powder to the preset solvent is 1:2000~1:500.

[0033] In one embodiment, the preset solvent is deionized water, and the weight ratio of flake graphite powder to deionized water is 1:2000-1:500.

[0034] In another embodiment, the preset solvent includes: one or more of water, alkanes, alcohols, ketones, aromatic compounds, organic amines, heterocyclic compounds or ionic liquids. The embodiments of the present application do not limit the weight ratio of each type of solvent in the preset solvent.

[0035] In some embodiments, an active substance may be added to the solution to be treated to facilitate subsequent mechanical exfoliation of graphene from the graphite particles. The embodiments of the present application do not limit the specific substance of the active substance. For example, the active substance is a natural polymer (e.g., a protein molecule chain), a surfactant, etc.

[0036] S102, pouring the solution to be treated into a first-level stirring furnace and stirring for a first time to obtain a first-level solution.

[0037] The specific number of the multiple metal corrosion sheets in the primary stirring furnace is not limited in the embodiments of the present application. For example, the multiple metal corrosion sheets are three metal corrosion sheets.

[0038] In one embodiment, each of the plurality of metal corrosion sheets has a frame to maintain the structure of the metal corrosion sheet.

[0039] The metal corrosion sheet has a frame to keep the structure of the metal corrosion sheet stable, prevent the metal corrosion sheet from being deformed by impact in high-speed liquid, ensure that the metal corrosion sheet can fully collide with the graphite particles, and extend the life of the metal corrosion sheet.

[0040] In one embodiment, at least one of the plurality of metal corrosion sheets has a structure of a semi-spiral surface, and is arranged in a spiral direction toward the bottom of the primary stirring furnace.

[0041] By setting the structure of the metal corrosion sheet to a semi-helical surface, the solution flow can be guided to prevent graphite particles and single-layer or multi-layer graphene from being stuck on the metal corrosion sheet.

[0042] In one embodiment, Figure 4As shown, at least one of the multiple metal etching sheets 11 is curved in shape. When arranged in the primary stirring furnace, the bending direction of the metal etching sheet is opposite to the flow direction of the solution in the primary stirring furnace.

[0043] The embodiments of the present application do not limit the rotation speed used to stir the solution to be treated. For example, the rotation speed when stirring the solution to be treated in the first-stage stirring furnace is 1800~2300r / min.

[0044] The embodiment of the present application does not limit the value of the first duration. In one embodiment, when the rotation speed is 1800-2300 r / min, the first duration is 40-60 min. In the primary stirring furnace, when the rotation speed is 1800-2300 r / min and the first duration is 40-60 min, the graphite particles can be collided into tiny particles and multilayer graphene, completing the processing requirements of the primary stirring furnace.

[0045] The embodiments of the present application do not impose any limitation on the height of the metal corrosion sheet on the inner wall of the primary stirring furnace.

[0046] In one embodiment, the ratio of the diameter of the primary stirring furnace to the height of each metal corrosion sheet in the diameter direction thereof is 15:1 to 8.5:1.

[0047] By setting the ratio of the diameter of the first-stage stirring furnace to the height of each metal corrosion sheet in the diameter direction to 15:1-8.5:1, the collision area between the metal corrosion sheet and the graphite particles can be guaranteed while ensuring that the solution in the first-stage stirring furnace can be stirred at a high speed.

[0048] In one embodiment, the plurality of metal corrosion sheets are of the same size and shape and are evenly arranged in the circumferential direction of the inner wall of the primary stirring furnace at the same height.

[0049] By arranging multiple metal corrosion sheets of the same size and shape and evenly arranging them in the circumferential direction at the same height of the inner wall of the first-stage stirring furnace, the solution in the first-stage stirring furnace can rotate more stably during stirring, which is beneficial to the separation of graphene.

[0050] S103, adding iron powder to the primary solution and mixing evenly to obtain a mixed solution, pouring the mixed solution into a secondary stirring furnace, stirring for a second period of time to obtain a secondary solution, wherein each electromagnet is powered on and off according to a preset strategy, so as to facilitate power-on to adsorb iron powder particles in the mixed solution to form a clustered collision target on the inner wall of the secondary stirring furnace, and power-off to release the iron powder particles in the clustered collision target and the graphite particles embedded in the clustered collision target.

[0051] In one embodiment, the plurality of electromagnets are evenly arranged in the height direction of the secondary stirring furnace, and are sequentially evenly arranged in the circumference direction of the secondary stirring furnace.

[0052] In one embodiment, the preset strategy includes: in the height direction of the secondary stirring furnace, each electromagnet is powered off in turn from high to low every fourth time period, and when the next electromagnet is powered off, the electromagnet that is currently in the power-off state is powered on again, and only one electromagnet is in the power-off state at the same time.

[0053] The embodiment of the present application does not limit the specific value of the fourth time length. For example, if the number of electromagnets is n, then the fourth time length = the second time length / n.

[0054] By evenly arranging multiple electromagnets in the height direction of the secondary stirring furnace and in turn evenly arranging them in the circumference direction of the secondary stirring furnace, it is beneficial to the rotation of the solution in the secondary stirring furnace, and it is beneficial for graphite particles and multilayer graphene at different heights in the solution to fully collide with the clustered collision target, so as to better peel off the single-layer graphene.

[0055] By using a preset strategy of powering off the electromagnets one by one and only having one electromagnet in the power-off state at the same time, it is possible to avoid graphite particles and multilayer graphene from being embedded in the clustered collision target, so that the secondary solution obtained after treatment with the secondary stirring furnace has a higher content of single-layer graphene, thereby preparing high-quality graphene with uniform thickness and thinner thickness more quickly.

[0056] The embodiments of the present application do not limit the rotation speed used to stir the primary solution. For example, the rotation speed when stirring the solution to be treated in the secondary stirring furnace is 2000~5000r / min.

[0057] The embodiment of the present application does not limit the value of the second time length. In one embodiment, when the rotation speed in the secondary stirring furnace is 2000~5000r / min, the second time length is 15~30min. In the secondary stirring furnace, when the rotation speed is 2000~5000r / min, when the second time length is 15~30min, the content of single-layer graphene in the obtained secondary solution meets the preset requirements, so that the processing requirements of the secondary stirring furnace can be completed.

[0058] S104, pouring the secondary solution into an oscillating furnace and modulating it into a colloid, applying a high-frequency conversion magnetic field to the colloid, and separating graphene from the colloid after a third period of time.

[0059] The embodiments of the present application do not limit how to prepare the secondary solution into a colloid. For example, rubber powder is added to the secondary solution. For another example, rubber powder and glycerol are added to the secondary solution, heated and stirred until completely dissolved, and then methyl silicone oil is added to obtain the colloid.

[0060] The embodiment of the present application does not limit the specific value of the third duration. For example, the third duration is 10 to 30 minutes.

[0061] In the primary stirring furnace, the rough edges of multiple metal corrosion sheets are used to collide with graphite particles. Since the metal corrosion sheets are a whole, they can be more stable when colliding with graphite particles, so the single-layer or multi-layer graphite in the graphite particles can be quickly separated to form a primary solution mainly including single-layer graphene and multi-layer graphene and finer graphite particles. After that, the cluster collision target composed of iron powder is adsorbed from the inner wall of the secondary stirring furnace by an electromagnet. Since the cluster collision target has a larger area for colliding with fine graphite particles and multi-layer graphene, the multi-layer graphene and fine graphite particles in the primary solution can be quickly collided into a single layer or graphene with a smaller number of layers. Finally, in the oscillating furnace, the high-frequency magnetic field is used to oscillate the iron powder particles to collide with the multi-layer graphene and the stretching effect of the colloid, so that the multi-layer graphene can be quickly and better collided to separate the single-layer graphene, and finally the graphene with uniform thickness and thinner graphene is obtained. By utilizing the different contents of graphite particles and multilayer graphene during the preparation process and preparing graphene through a three-stage preparation furnace, high-quality graphene with uniform thickness and thinner thickness can be prepared more quickly, and it is beneficial to the preparation of graphene for industrial applications.

[0062] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope of the present application is indicated by the appended claims.

Claims

1. A method for preparing graphene, characterized in that: Graphene is prepared using a three-stage preparation furnace, the three-stage preparation furnace comprising a primary stirring furnace, a secondary stirring furnace and an oscillating furnace, the inner wall of the primary stirring furnace is provided with a plurality of metal corrosion sheets, the outer wall of the secondary stirring furnace is provided with a plurality of electromagnets, and the method comprises: Putting flake graphite powder into a preset solvent and stirring evenly to obtain a solution to be treated; Pour the solution to be treated into the first-level stirring furnace and stir for a first period of time to obtain a first-level solution; Add iron powder to the primary solution and mix them evenly to obtain a mixed solution, pour the mixed solution into the secondary stirring furnace, stir for a second period of time, and obtain a secondary solution, wherein each electromagnet is powered on and off according to a preset strategy, so as to power on to adsorb iron powder particles in the mixed solution to form a clustered collision target on the inner wall of the secondary stirring furnace, and power off to release the iron powder particles in the clustered collision target and the graphite particles embedded in the clustered collision target; The secondary solution is poured into the oscillating furnace and modulated into a colloid, a high-frequency conversion magnetic field is applied to the colloid, and graphene is separated from the colloid after a third period of time.

2. The method for preparing graphene according to claim 1, characterized in that: Each of the plurality of metal corrosion sheets has a frame to maintain the structure of the metal corrosion sheet; At least one of the plurality of metal corrosion sheets has a structure of a semi-spiral surface, and is arranged in a spiral direction toward the bottom of the primary stirring furnace.

3. The method for preparing graphene according to claim 1, characterized in that: The ratio of the diameter of the first-stage stirring furnace to the height of each metal corrosion sheet in the diameter direction is 15:1-8.5:

1.

4. The method for preparing graphene according to any one of claims 1 to 3, characterized in that: The multiple metal corrosion sheets are of the same size and shape and are evenly arranged in the circumferential direction of the inner wall of the first-stage stirring furnace at the same height.

5. The method for preparing graphene according to claim 1, characterized in that: The plurality of electromagnets are evenly arranged in the height direction of the secondary stirring furnace, and are evenly arranged in sequence in the circumference direction of the secondary stirring furnace; The preset strategy includes: in the height direction of the secondary stirring furnace, each electromagnet is powered off in turn from high to low every fourth time period, and when the next electromagnet is powered off, the electromagnet that is currently in the power-off state is powered on again, and only one electromagnet is in the power-off state at the same time.

6. The method for preparing graphene according to claim 1, characterized in that: The preset solvent is deionized water, and the weight ratio of the flake graphite powder to the deionized water is 1:2000-1:

500.

7. The method for preparing graphene according to claim 1, characterized in that: The rotation speed of the solution to be treated when stirred in the primary stirring furnace is 1800-2300 r / min, and the first time length is 40-60 min; The rotation speed of the solution to be treated when stirred in the secondary stirring furnace is 2000-5000 r / min, and the second time length is 15-30 min; The third duration is 10 to 30 minutes.

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