TW202229166A - Graphene formation device - Google Patents

Abstract

The present invention discloses a graphene formation device, which comprises a reaction tank, a graphite electrode and a counter electrode, a fixed member and a power supply unit. The reaction tank contains an electrolyte. The graphite electrode and the counter electrode are disposed in the reaction tank at intervals. The fixed member is disposed in the reaction tank. The graphite electrode is disposed in the reaction tank through the fixed member, and the fixed member exposes partial of the graphite electrode to the electrolyte. The power supply unit is electrically connected with the graphite electrode and the counter electrode.

Description

Graphene generation device

The present invention relates to a generating device, in particular to a graphene generating device that utilizes an electrochemical exfoliation method to generate graphene.

Graphene is a single-layer atom-thick carbon material. Each carbon atom forms bonds with three adjacent atoms by sp ² mixing and extends into a honeycomb-like two-dimensional structure. Graphene is known for its good carrier mobility. Because of its excellent electrical properties, chemical stability, good thermal conductivity and high permeability, it has been widely used in semiconductors, mobile phones, tablets, etc. Popular materials in fields such as touch panels or solar cells.

Generally, graphene is produced by methods such as mechanical exfoliation, epitaxial growth, chemical vapor deposition (CVD), and chemical exfoliation. Among them, although the mechanical exfoliation method and the epitaxial growth method can generate graphene with better quality, neither of these two methods can synthesize graphene in large quantities. However, the operating temperature of chemical vapor deposition is a high temperature of nearly 1,000 degrees and an expensive metal substrate, and the preparation process takes several hours to complete. The shortcomings of the above methods all limit the production and subsequent application of graphene. The chemical exfoliation method is to generate graphene through the oxidation and reduction of graphite under the conditions of strong acid and strong oxidation. Although this method is suitable for mass production, the surface structure and size of the graphene produced by it are not ideal.

In addition to the above-mentioned generation methods, graphene can also be generated by electrochemical exfoliation. The main principle is that the surface layer of the graphite material is oxidized and exfoliated through the interaction between the electrolyte and the graphite surface. Compared with the other generation methods mentioned above, the electrochemical exfoliation method can rapidly and economically fabricate graphene at room temperature. In other words, if the generation efficiency of the chemical exfoliation method can be improved, the electrochemical exfoliation method will become an economical and large-scale graphene generation method.

The purpose of the present invention is to provide a graphene generating device that utilizes an electrochemical exfoliation method to generate graphene, which can quickly and economically manufacture graphene at room temperature.

The invention provides a graphene generating device, which includes a reaction tank, a graphite electrode and a pair of opposite electrodes, a fixing member and a power supply unit. The reaction tank accommodates an electrolyte; the graphite electrode and the opposite electrode are arranged in the reaction tank at intervals; the fixing part is arranged in the reaction tank, the graphite electrode is arranged in the reaction tank through the fixing part, and the fixing part exposes part of the graphite electrode to the electrolyte ; The power supply unit is electrically connected with the graphite electrode and the opposite electrode.

In one embodiment, viewed from the side of the reaction tank, the width of the upper side of the reaction tank is greater than the width of the lower side.

In one embodiment, two opposite side walls of the reaction tank have a plurality of guide rails, and the counter electrode and the fixing member are disposed in the reaction tank through the guide rails.

In one embodiment, the area of the counter electrode is larger than that of the graphite electrode.

In one embodiment, the area ratio of the counter electrode to the graphite electrode is greater than or equal to 2 and less than or equal to 8.

In one embodiment, the material of the counter electrode or the fixing member is inert metal or graphite material, or a combination thereof.

In one embodiment, the fixing member includes at least one opening, and the opening of the fixing member exposes a part of the graphite electrode to the electrolyte.

In one embodiment, the number of openings of the fixing member is plural.

In one embodiment, the fixing member includes two sub-fixing members, and the graphite electrode is located between the two sub-fixing members.

In one embodiment, the power supply unit makes the graphite electrode and the opposite electrode form a voltage difference, and the voltage difference is less than or equal to 15 volts.

In one embodiment, the graphene generating device further includes a handle, which is connected with the fixing member or the opposite electrode.

In one embodiment, the numbers of the graphite electrodes and the counter electrodes are respectively plural, and the graphite electrodes and the counter electrodes are alternately arranged in the reaction tank.

In one embodiment, the graphene generating device further includes a stirring unit, which stirs the electrolyte.

In one embodiment, the graphene generating device further includes at least one collecting tank connected to the bottom of the reaction tank.

Continuing from the above, in the graphene generating device of the present invention, the electrolyte is accommodated by the reaction tank; the graphite electrode and the opposite electrode are arranged in the reaction tank at intervals; the fixing member is arranged in the reaction tank, and the graphite electrode is arranged on the The reaction tank, and the fixture exposes part of the graphite electrode in the electrolyte; and the design of the electrical connection between the power supply unit and the graphite electrode and the counter electrode, so that the present invention utilizes the electrochemical stripping method to generate the graphene generating device of the graphene. To achieve the purpose of rapidly and economically producing graphene at room temperature.

The graphene generating apparatus according to the preferred embodiment of the present invention will be described below with reference to the related drawings, wherein the same elements will be described with the same reference symbols. Dimensions and proportions of elements or units appearing in the drawings of the following embodiments are only to illustrate the interrelationships between units and elements, and have nothing to do with the dimensions and proportions of actual units or elements.

The graphene generating device of the following embodiments utilizes the electrochemical exfoliation method to generate graphene, and the main principle is that the surface layer of the graphite material is oxidized and exfoliated into graphene flakes through the interaction between the electrolyte and the surface of the graphite material at room temperature or powder, and finally the graphene flakes or powders that are peeled off and left in the electrolyte are vacuum-dried to obtain a product.

1A and FIG. 1B are a schematic diagram of a combination and a schematic diagram of a decomposition of a graphene generating apparatus according to an embodiment of the present invention, respectively, and FIG. 1C is a schematic cross-sectional view of the graphene generating apparatus shown in FIG. 1A , respectively. Here, the power supply unit 15 is only shown in FIG. 1A , and the electrolyte S is only shown in FIG. 1C .

As shown in FIGS. 1A to 1C , the graphene generating apparatus 1 includes a reaction tank 11 , a graphite electrode 12 , a pair of opposite electrodes 13 , a fixing member 14 and a power supply unit 15 . In addition, the graphene generating device 1 of this embodiment may further include at least one collecting tank 17 .

The reaction tank 11 is an accommodating tank body for accommodating the electrolyte S ( FIG. 1C ). As shown in FIG. 1C , in this embodiment, there is an electrolyte S in the reaction tank 11 , and the graphite electrode 12 , the counter electrode 13 and the fixing member 14 are immersed in the electrolyte S. When viewed from the side of the reaction tank 11 , the width of the upper side of the reaction tank 11 is larger than that of the lower side (the upper width is narrower and the lower side resembles an inverted cone), so that the electrolyte S can be easily collected at the bottom of the reaction tank 11 . The electrolyte S in this embodiment may include water, sulfuric acid, sulfates (such as ammonium sulfate, sodium sulfate), nitrates (such as potassium nitrate), potassium hydroxide, sodium chloride, lithium chloride, lithium perchlorate , perchloric acid, phosphoric acid, oxalic acid, or dimethylsulfoxide, or a combination thereof.

The graphite electrode 12 is disposed opposite to the opposite electrode 13 , and the graphite electrode 12 and the opposite electrode 13 are disposed in the reaction tank 11 at intervals. Here, the graphite electrode 12 and the counter electrode 13 are spaced apart and connected to the side wall 112 of the reaction tank 11 , respectively. In addition, the fixing member 14 is provided in the reaction tank 11 . The fixing member 14 can fix the graphite electrode 12 so that the graphite electrode 12 can be disposed in the reaction tank 11 through the fixing member 14 , and the fixing member 14 can expose part of the graphite electrode 12 to the electrolyte S.

Specifically, the two opposite side walls 112 of the reaction tank 11 of the present embodiment have a plurality of guide rails 111 (four guide rails 111 are shown in FIG. 1B ), and the opposite electrodes 13 and the two sides of the fixing member 14 are respectively connected with the guide rails 111 . The guide rails 111 are correspondingly arranged so that the counter electrode 13 and the fixing member 14 can be installed on the side wall 112 of the reaction tank 11 through the guide rails 111 , so that the graphite electrode 12 and the counter electrode 13 are arranged in the reaction tank 11 at intervals, thereby Electrochemical reaction is carried out using electrolyte S.

In addition, in order to allow the electrolyte S in the reaction tank 11 to contact the graphite electrode 12, and thereby generate an electrochemical reaction with the graphite electrode 12, the fixing member 14 in this embodiment may include at least one opening O1, and the opening O1 of the fixing member 14 will Part of the graphite electrode 12 is exposed to the electrolyte S, so that the electrolyte S in the reaction tank 11 can contact the graphite electrode 12 through the opening O1. In detail, as shown in FIG. 1B , the fixing member 14 of this embodiment includes two sub-fixing members 14a and 14b, and the graphite electrode 12 is located between the sub-fixing members 14a and 14b, so that the graphite electrode 12 can be surrounded by the sub-fixing member 14a. , 14b are clamped and fixed, and then the graphite electrode 12 is set in the reaction tank 11 through the sub-fixtures 14a, 14b and the guide rail 111 . In different embodiments, the fixing member 14 can also be of other types (for example, there is only a single plate body), or the graphite electrode 12 can also be connected to the fixing member 14 in other ways (eg, locking, fitting), as long as the use of The fixing member 14 fixes the graphite electrode 12 and is disposed in the reaction tank 11, so that at least part of the graphite electrode 12 can be exposed to the electrolyte S, which is not limited in the present invention.

The number of the openings O1 of the fixing member 14 in this embodiment is plural. Here, each of the sub-fixtures 14a, 14b has corresponding openings O1 of the same size (the size may also be different), so as to expose a part of the graphite electrode 12 to the electrolyte S. As shown in FIG. In order to allow a larger area of the graphite electrode 12 to be exposed and contact the electrolyte S to accelerate the reaction speed, the opening O1 for exposing the graphite electrode 12 can be as large as possible. In addition, the electrolyte S in the reaction tank 11 can be uniform and in contact with the graphite electrode 12. In some embodiments, the graphene generating device may further include a stirring unit (not shown), such as but not limited to: A pump or agitator is used to agitate the electrolyte S in the reaction tank 11 . In addition, in order to make the electrolyte S in the reaction tank 11 mix more uniformly during stirring, the fixing member 14 (the sub-fixing members 14a, 14b) in this embodiment also has openings O2 and O3 of the same size. Therefore, stirring the reaction When the electrolyte S in the tank 11 is used, the electrolyte S can pass through the openings O2 and O3 of the fixing member 14 to be more uniform.

Referring to FIG. 1C again, the area of the counter electrode 13 in this embodiment is larger than that of the graphite electrode 12 , and the area of the counter electrode 13 is also larger than that of the fixing member 14 . Here, the area ratio of the counter electrode 13 to the graphite electrode 12 may be greater than or equal to 2 and less than or equal to 8. In some embodiments, the area ratio of the counter electrode 13 to the graphite electrode 12 is, for example, greater than or equal to 4 and less than or equal to 6. Among them, the size of the area ratio of the counter electrode 13 and the graphite electrode 12 is to control a fixed current density. When the area ratio of the counter electrode 13 to the graphite electrode 12 changes, the current value needs to be adjusted to maintain a certain current density to optimize the electrolysis efficiency, thereby controlling the optimization of the product yield.

As the name implies, the graphite electrode 12 is an electrode made of graphite material (eg, a graphite plate), and the graphite material can be artificial graphite or natural graphite, which is not limited. In addition, the material of the counter electrode 13 or the fixing member 14 can be an inert metal or a graphite material, or a combination thereof, the inert metal is for example but not limited to titanium, gold, silver, or platinum, or a combination thereof, and the graphite material can be artificial Graphite or natural graphite can be used as long as it does not chemically interact with the electrolyte S and has good electrical conductivity. In this embodiment, the materials of the counter electrode 13 and the fixing member 14 are respectively titanium metal as an example.

The power supply unit 15 is electrically connected to the graphite electrode 12 and the counter electrode 13 . The power supply unit 15 can form a voltage difference between the graphite electrode 12 and the opposite electrode 13, and the voltage difference can be less than or equal to 15 volts, and can be direct current or alternating current, which is not limited in the present invention. As shown in FIG. 1A , the graphite electrode 12 in this embodiment is connected to the positive electrode of the power supply unit 15 through the fixing member 14 , and the opposite electrode 13 is connected to the negative electrode of the power supply unit 15 , but it is not limited to this. In the embodiment, the connection relationship between the two can be reversed.

In addition, in order to easily install the fixing member 14 (graphite electrode 12 ) and the counter electrode 13 in the reaction tank 11 , or take out the fixing member 14 (graphite electrode 12 ) and the counter electrode 13 from the reaction tank 11 , the graphite electrode of this embodiment is The olefin generating device 1 may further include at least one handle 16 , and the handle 16 is connected to the fixing member 14 or the counter electrode 13 . A fixed handle 16 is installed on the top of the fixing member 14 and the opposite electrode 13 in this embodiment to facilitate extraction or placement. Of course, in different embodiments, the handle 16 can also be a movable type, and the fixing member 14 or the opposite electrode 13 can be removed and then installed.

In addition, the graphene generating device 1 of this embodiment may further include at least one collecting tank 17 , and the collecting tank 17 is connected to the bottom of the reaction tank 11 . In this embodiment, a collection tank 17 is connected to the bottom of the reaction tank 11 through a connecting pipeline 18 . The connecting pipeline 18 is provided with a valve 181 , and the electrolyte S can be supplemented by the connecting pipeline 18 through the control of the valve 181 , or the electrolyte S can be discharged to the collecting tank 17 . Here, with the reaction tank 11 having a wide upper part and a narrow lower part, it is easy to discharge the electrolyte S from the bottom of the reaction tank 11 to the collecting tank 17 .

In actual operation, the electrolyte S in the reaction tank 11 of this embodiment can contact the graphite electrode 12 through the opening O1 of the fixing member 14 , and the power supply unit 15 can provide electromotive force to the graphite electrode 12 and the counter electrode 13 to make the graphite electrode 12 A voltage difference is formed between the electrode 12 and the counter electrode 13 , and the electrolytic solution S is used to generate an electrochemical reaction. During the electrochemical reaction, the voltage difference will cause the electrolyte S to electrolyze and generate gases (such as hydrogen and oxygen) and ions (such as ammonium ions or sulfate ions). The graphite monolayer or multi-layer on the surface of the graphite electrode 12 in contact with the liquid S expands, and is exfoliated into graphene flakes or powders that are mixed in the electrolyte S.

After the electrochemical reaction is carried out for a period of time (the operating temperature can be between room temperature and 40°C), the electrolyte S with graphene sheets or powder is discharged to the collection tank 17 through the connecting pipeline 18, and after filtration and vacuum drying Graphene products can be obtained. In an application example of actually generating graphene, under the condition that the voltage difference is 5 volts and the current is 2 amperes, the graphene generating device 1 of the present embodiment is used to react for one hour, and after filtration and vacuum drying, about 1 gram of graphene powder.

It is supplemented that the exfoliation speed, properties, and yield of graphene can be changed by adjusting the concentration of electrolyte S, the type of electrolyte, the type of solvent, and the voltage difference. Furthermore, in other implementations, the graphene generating apparatus of this embodiment may also include a module for filtering and separating products. In order to achieve the purpose of a continuous process, the product exfoliated by the graphene generating device of the present embodiment can filter the unexfoliated coarse-grained graphite particles through the microporous screen of the module for filtering and separating the product, and obtain suitable graphite particles through screening. After the size of the product (usually thin-layer graphene below 10 nm), a large amount of deionized water is used to remove the residual electrolyte, or other ionic solutions that can dissolve and replace residual ions are used.

In addition, please refer to FIG. 2 and FIG. 3 , which are schematic diagrams of graphene generating apparatuses according to different embodiments of the present invention, respectively.

As shown in FIG. 2 , the graphene generation device 1 a of the present embodiment is substantially the same as the graphene generation device 1 of the previous embodiment in the component composition and the connection relationship between the components. The difference lies in that, in the graphene generating device 1a of this embodiment, the number of graphite electrodes 12 (fixing parts 14 ) and the counter electrodes 13 is 3 respectively, and the graphite electrodes 12 (and the fixing parts 14 ) and the The counter electrodes 13 are arranged in the reaction tank 11 in a staggered manner. Wherein, the graphite electrodes 12 (and the fixing member 14 ) and the counter electrodes 13 may be staggered on the side wall 112 of the reaction tank 11 at equal or unequal distances, which is not limited. In addition, the graphite electrodes 12 in this embodiment can be connected to the positive electrode of the power supply unit (not shown), and the opposite electrodes 13 are connected to the negative electrode of the power supply unit; of course, the connection relationship can also be reversed.

In addition, as shown in FIG. 3 , the graphene generation device 1b of the present embodiment is substantially the same as the graphene generation device 1 or 1a of the previous embodiment in the component composition and the connection relationship of each element. The difference is that the graphene generating device 1b of this embodiment includes two collecting tanks 17a, 17b, and the collecting tanks 17a, 17b can be connected to the bottom of the reaction tank 11 through a connecting pipeline 18, respectively. Electrolyte S with different concentrations in the reaction tank 11 can be collected by the two collection tanks 17a and 17b. For example, the electrolyte S with graphene flakes or powder is first discharged to the collection tank 17a through the connecting pipe 18, and then the electrolyte S is discharged to the collection tank 17b through another connecting pipe 18, then the collection tanks 17a, 17b The concentration of the graphene flakes or powder of the electrolyte S is different, the concentration of the collection tank 17a will be greater than the concentration of the collection tank 17b, and the weight of the graphene obtained after filtration and vacuum drying is not the same.

Compared with the conventional electrochemical stripping process, the graphene generating device of the present invention has at least the following advantages: the voltage used in the present invention is relatively low, the operating temperature is normal temperature, and the thickness of the product will be concentrated in the standard required by the industry, and the device The structure is simple and the operation is easy, therefore, the graphene generating device of the present invention can be applied to generate graphene and meet the needs of mass production.

To sum up, in the graphene generating device of the present invention, the electrolyte is accommodated by the reaction tank; the graphite electrode and the opposite electrode are arranged in the reaction tank at intervals; the fixing member is arranged in the reaction tank, and the graphite electrode is arranged through the fixing member at The reaction tank, and the fixture exposes part of the graphite electrode to the electrolyte; the design of the electrical connection between the power supply unit and the graphite electrode and the counter electrode enables the graphene generation device of the present invention to utilize the electrochemical stripping method to generate graphene to achieve The purpose of producing graphene at room temperature quickly and economically.

The above description is exemplary only, not limiting. Any equivalent modifications or changes that do not depart from the spirit and scope of the present invention shall be included in the appended patent application scope.

1,1a,1b: Graphene generation device 11: Reaction tank 111: Rails 112: Sidewall 12: Graphite electrode 13: Counter electrode 14: Fixing parts 14a, 14b: Sub-fixtures 15: Power supply unit 16: Handle 17, 17a, 17b: Collection tank 18: Connect the pipeline 181: Valve O1, O2, O3: opening S: Electrolyte

1A and FIG. 1B are a combined schematic diagram and an exploded schematic diagram of a graphene generating apparatus according to an embodiment of the present invention, respectively. FIG. 1C is a schematic cross-sectional view of the graphene generating apparatus shown in FIG. 1A , respectively. FIG. 2 and FIG. 3 are schematic diagrams of graphene generating apparatuses according to different embodiments of the present invention, respectively.

1: Graphene generation device

11: Reaction tank

111: Rails

112: Sidewall

12: Graphite electrode

13: Counter electrode

14: Fixing parts

16: Handle

17: Collection tank

18: Connect the pipeline

181: Valve

O1, O2, O3: opening

S: Electrolyte

Claims (14)

A graphene generating device, comprising: a reaction tank, containing an electrolyte; A graphite electrode and a pair of facing electrodes are arranged in the reaction tank at intervals; a fixing member disposed in the reaction tank, the graphite electrode is disposed in the reaction tank through the fixing member, and the fixing member exposes a part of the graphite electrode to the electrolyte; and A power supply unit is electrically connected with the graphite electrode and the opposite electrode. The graphene generating device according to claim 1, wherein, viewed from the side of the reaction tank, the width of the upper side of the reaction tank is greater than the width of the lower side. The graphene generating device according to claim 1, wherein two opposite side walls of the reaction tank have a plurality of guide rails, and the counter electrode and the fixing member are disposed in the reaction tank through the guide rails. The graphene generating device according to claim 1, wherein the area of the counter electrode is larger than that of the graphite electrode. The graphene generating device according to claim 1, wherein the area ratio of the counter electrode and the graphite electrode is greater than or equal to 2 and less than or equal to 8. The graphene generating device according to claim 1, wherein the material of the counter electrode or the fixing member is an inert metal or a graphite material, or a combination thereof. The graphene generating device according to claim 1, wherein the fixing member includes at least one opening, and the opening of the fixing member exposes a part of the graphite electrode to the electrolyte. The graphene generating device according to claim 7, wherein the number of the openings of the fixing member is plural. The graphene generating device according to claim 7, wherein the fixing member includes two sub-fixing members, and the graphite electrode is located between the two sub-fixing members. The graphene generating device according to claim 1, wherein the power supply unit causes the graphite electrode and the counter electrode to form a voltage difference, and the voltage difference is less than or equal to 15 volts. The graphene generating device as claimed in claim 1, further comprising: A handle is connected with the fixing member or the opposite electrode. The graphene generating device according to claim 1, wherein the number of the graphite electrodes and the counter electrodes is plural respectively, and the graphite electrodes and the counter electrodes are alternately arranged in the reaction tank. The graphene generating device as claimed in claim 1, further comprising: An agitating unit agitates the electrolyte. The graphene generating device as claimed in claim 1, further comprising: At least one collection tank is connected with the bottom of the reaction tank.

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