A method for preparing a single-layer graphene film

Abstract

The application provides a preparation method of a single-layer graphene film, and belongs to the technical field of material preparation. The application forms graphene by chemical vapor deposition on a substrate, marks the graphene with ink, etches away the substrate by using etching liquid, and obtains ink-marked graphene; the ink-marked graphene is lifted to water by using etching liquid, then the edges of the ink are supported from bottom to top by using double-layer metal wires, and then the graphene is vertically lifted and dried, so that the single-layer graphene film is obtained. The application provides a method for preparing a suspended single-layer graphene film by clean transfer, and the thin liquid surface formed between the double-layer metal wires reduces the influence of liquid tension on the graphene layer when the graphene is pulled from the liquid, so that a relatively complete large-size single-layer graphene film can be obtained, and the method has high efficiency and good stability, effectively realizes the introduction of pollutants, and realizes clean, glue-free, efficient and complete graphene transfer.

Description

Technical Field

[0001] This invention relates to the field of materials preparation technology, and in particular to a method for preparing a single-layer graphene film. Background Technology

[0002] Graphene is a two-dimensional monolayer sp. 2 Graphene is a sheet of hybrid carbon atoms, tightly packed into a hexagonal lattice structure. As a novel form of carbon, it has been extensively studied in various fields due to its unique physical and chemical properties. Existing methods for graphene preparation include micromechanical exfoliation, chemical vapor deposition (CVD), epitaxial growth, and graphene oxide reduction. Among these, CVD on Ni and Cu substrates has become the preferred method for producing high-quality, large-area continuous graphene due to its economic efficiency, low cost, and relatively high efficiency. In practical applications, the process of transferring graphene from the substrate to the surface to which it is applied is crucial. Introducing contaminants or damage during the transfer process can affect the performance of the graphene. Therefore, it is essential to invent a method for clean and damage-free transfer of suspended graphene. Furthermore, suspended graphene can be applied to various sensors to detect sound waves, strain, and biological parameters. The preparation of suspended graphene typically involves manually peeling samples directly onto pre-drilled substrates, but this method is inefficient, unstable, and produces poor-quality graphene. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a method for preparing a single-layer graphene film. This invention utilizes a thin liquid surface formed between two layers of metal wires to reduce the influence of liquid tension on the graphene layer when graphene is pulled from the liquid, thereby obtaining a relatively complete, large-sized single-layer graphene film with high efficiency and good stability.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing a single-layer graphene film, comprising the following steps:

[0006] Graphene is formed by chemical vapor deposition on a substrate, the graphene is marked with ink, and the substrate is etched away with an etching solution to obtain ink-marked graphene.

[0007] The graphene marked with ink and the etching solution were scooped up into water, and then the edges of the ink were supported from bottom to top with a double-layer metal wire and lifted vertically. After drying, the single-layer graphene film was obtained.

[0008] Preferably, the double-layer metal wire is made of copper, gold, silver, iron, or chromium.

[0009] Preferably, the double-layer metal wire is square, circular, star-shaped, or trapezoidal.

[0010] Preferably, the diameter of the double-layer metal wire is 0.5 to 1.5 mm.

[0011] Preferably, the diameter of the double-layer metal wire is 1 mm.

[0012] Preferably, the ink is marker ink or paint pen ink.

[0013] Preferably, the etching solution is an FeCl3 solution.

[0014] Preferably, the FeCl3 solution has a mass fraction of 10% to 15%.

[0015] Preferably, the lifting time is 8 to 15 seconds.

[0016] Preferably, the lifting time is 10 seconds.

[0017] This invention provides a method for preparing a single-layer graphene film, comprising the following steps: performing chemical vapor deposition on a substrate to form graphene; marking the graphene with ink; etching away the substrate with an etching solution to obtain ink-marked graphene; scooping the ink-marked graphene and the etching solution into water; then supporting the edge of the ink with a double-layer metal wire from bottom to top, lifting it vertically, and then drying it to obtain the single-layer graphene film.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] This invention provides a clean transfer method for preparing suspended monolayer graphene films. By using a thin liquid surface (liquid film) formed between two layers of metal wires, the two metal wires are perpendicular to the liquid surface when the graphene is pulled from the liquid, minimizing the influence of tension. This reduces the impact of liquid tension on the graphene layer, resulting in a relatively complete large-size monolayer graphene film with high efficiency and good stability. It effectively achieves the clean, glue-free, and efficient transfer of complete graphene without introducing contaminants (including polymer media during exfoliation). This provides an efficient and simple method for applications such as the fabrication of suspended graphene sensors and the study of graphene properties. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a double-layer metal wire structure;

[0021] Figure 2 This is a side view of a double-layered metal wire.

[0022] Figure 3 A schematic diagram illustrating the process of retrieving graphene. Figure 31 is a copper ring, 2 is an ink mark, 3 is graphene, and 4 is a liquid film formed between copper wires;

[0023] Figure 4 This is a side view of the graphene being retrieved. Detailed Implementation

[0024] This invention provides a method for preparing a single-layer graphene film, comprising the following steps:

[0025] Graphene is formed by chemical vapor deposition on a substrate, the graphene is marked with ink, and the substrate is etched away with an etching solution to obtain ink-marked graphene.

[0026] The graphene marked with ink and the etching solution were scooped up into water, and then the edges of the ink were supported from bottom to top with a double-layer metal wire and lifted vertically. After drying, the single-layer graphene film was obtained.

[0027] Unless otherwise specified, all raw materials used in this invention are commercially available products in the field.

[0028] The present invention involves performing chemical vapor deposition (CVD) on a substrate to form graphene, marking the graphene with ink, and etching away the substrate with an etching solution to obtain ink-marked graphene.

[0029] In this invention, the substrate is preferably copper, nickel, quartz, Si or SiO2.

[0030] The present invention does not impose any special limitations on the specific parameters of the chemical vapor deposition; parameters well known to those skilled in the art can be used.

[0031] In this invention, the ink is preferably marker ink or paint pen ink.

[0032] In this invention, the etching solution is preferably an FeCl3 solution.

[0033] In this invention, the mass fraction of the FeCl3 solution is preferably 10% to 15%.

[0034] In this invention, the graphene grown on the substrate is preferably immersed in acetone to remove impurities, then taken out and dried, and marked with ink to the required size of graphene. After the ink dries, the substrate is etched away with the FeCl3 solution. After the etching is completed, the ink-marked graphene is obtained.

[0035] After obtaining the ink-marked graphene, the present invention retrieves the ink-marked graphene and etching solution into water, then uses a double-layer metal wire to support the edge of the ink from bottom to top, lifts it vertically, and then dries it to obtain the single-layer graphene film.

[0036] In this invention, the material of the double-layer metal wire is preferably copper, gold, silver, iron or chromium.

[0037] In this invention, the shape of the double-layer metal wire is preferably square, circular, star-shaped or trapezoidal. The two layers of the double-layer metal wire can have the same shape or different shapes, as long as they can form a stable liquid surface when lifted.

[0038] In this invention, the double-layer metal wire refers to a parallel relationship, with one layer nested inside the other.

[0039] In this invention, the double-layer metal wire is preferably provided with a handle, the function of which is to facilitate lifting.

[0040] Figure 1 This is a schematic diagram of a double-layer metal wire structure. Figure 2 This is a side view of a double-layered metal wire. Figure 2 The diagonal line represents the handle.

[0041] In this invention, the diameter of the double-layer metal wire is preferably 0.5 to 1.5 mm, and more preferably 1 mm.

[0042] In this invention, the water is preferably deionized water.

[0043] In this invention, after the graphene marked with ink and the etching solution are retrieved into water, it is preferable to allow it to stand for 20 to 30 minutes. The purpose of standing is to fully immerse the single-layer graphene.

[0044] In this invention, the settling process preferably includes a repeated scooping-setting process, that is, the ink-marked graphene and liquid are scooped up into water again and settling again. The repeated scooping-setting is preferably repeated 2 to 3 times. The purpose of repeated scooping-setting is to clean the monolayer graphene and remove impurities from the monolayer graphene.

[0045] In this invention, the lifting time is preferably 8 to 15 seconds, more preferably 10 seconds.

[0046] In this invention, the vertical lifting refers to lifting the double-layer metal wire perpendicular to the water surface to minimize the effect of tension.

[0047] Taking the double-layered metal wire as a copper ring as an example, the process of retrieving graphene is as follows: Figure 3 As shown, Figure 3 In the diagram, 1 represents a copper ring, 2 represents ink markings, 3 represents graphene, and 4 represents a liquid film formed between copper wires. The ink markings and the graphene in the middle will be lifted together. Figure 4 This is a side view of the graphene being retrieved.

[0048] After obtaining the retrieved graphene, the present invention preferably transfers the retrieved graphene to a substrate for drying to obtain the single-layer graphene film.

[0049] The present invention does not impose any special limitation on the type of substrate; it can be selected according to actual needs.

[0050] The present invention does not impose any particular limitation on the specific drying method; any method known to those skilled in the art can be used.

[0051] The single-layer graphene film obtained by the present invention is a large-size suspended graphene, which refers to graphene with a side length of 1 mm or more.

[0052] This invention utilizes a thin liquid surface formed between two layers of metal wires to reduce the impact of liquid tension on the graphene layer when graphene is lifted from the liquid. This allows for the relatively complete transfer of large-sized graphene onto the substrate. This method effectively achieves efficient transfer of complete graphene without introducing contaminants, providing an efficient and simple approach for applications such as the fabrication of suspended graphene sensors and the study of graphene properties.

[0053] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0054] Example 1

[0055] CVD graphene grown on a copper substrate is immersed in acetone to remove impurities. After being taken out and dried, graphene of the required size is marked with ink. After the ink dries, the copper substrate is etched away with a 10% FeCl3 solution. After etching, the graphene marked with ink, along with a large amount of FeCl3 solution, is lifted with a large spatula and immersed in deionized water for 30 minutes for cleaning. The cleaning process is repeated twice. Then, a double-layer copper wire is used to support the edge of the ink from bottom to top, and the graphene is lifted vertically for 10 seconds. The lifted graphene is then transferred to the desired substrate and dried, thus obtaining a large-sized suspended graphene. This process achieves the relatively complete extraction of large-sized graphene from water using a ring made of double-layer copper wire, resulting in a relatively complete and clean large-area graphene with high surface quality, intact shape, and few defects.

[0056] The double-layer copper wire ring used is a double-layer circle with a diameter of 4cm and a copper wire diameter of 0.5mm. At the end, there is a handle with a length of 5cm for operating the copper wire.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a single-layer graphene film, characterized in that, Includes the following steps: Graphene is formed by chemical vapor deposition on a substrate, the graphene is marked with ink, and the substrate is etched away with an etching solution to obtain ink-marked graphene. The graphene marked with ink and the etching solution are scooped up into water, and then the edge of the ink is supported from bottom to top with a double-layer metal wire, lifted vertically, and then dried to obtain the single-layer graphene film; the double-layer metal wire refers to the parallel relationship, one layer nested inside the other; the diameter of the double-layer metal wire is 0.5~1.5mm.

2. The preparation method according to claim 1, characterized in that, The double-layer metal wire is made of copper, gold, silver, iron, or chromium.

3. The preparation method according to claim 1 or 2, characterized in that, The double-layer metal wire can be square, round, star-shaped, or trapezoidal.

4. The preparation method according to claim 1, characterized in that, The diameter of the double-layer metal wire is 1 mm.

5. The preparation method according to claim 1, characterized in that, The ink is marker ink or paint pen ink.

6. The preparation method according to claim 1, characterized in that, The etching solution is a FeCl3 solution.

7. The preparation method according to claim 6, characterized in that, The FeCl3 solution has a mass fraction of 10-15%.

8. The preparation method according to claim 1, characterized in that, The lifting time is 8-15 seconds.

9. The preparation method according to claim 1 or 8, characterized in that, The lifting time is 10 seconds.

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