Preparation method of three-dimensional graphene

Abstract

The invention relates to a graphene preparation method, in particular to a preparation method of three-dimensional graphene, which comprises the following steps: cutting foamed nickel into a rectangular specification, putting into a glass plate filled with acetone for ultrasonic cleaning, and then putting into a drying oven at 50 DEG C for heating; graphene growth parameters are set through a control panel of the tubular furnace, and after the tubular furnace is heated to 1000 DEG C, the foamed nickel is annealed for 30 min at the constant temperature. And introducing CH4 gas for 35 minutes continuously. And after the growth is finished, opening the furnace cover to cool the quartz tube, and taking out the quartz tube after the quartz tube is cooled to room temperature. And placing the cooled graphene nickel hybrid three-dimensional foam material in a FeCl3 mixed solution with the concentration of 15%, and etching at normal temperature for 48 hours. And repeatedly replacing the etching solution until the nickel is completely etched and the solution does not become green any more. And washing the graphene with distilled water to remove residual impurities, fishing out the graphene, and drying the graphene in a drying oven at 80 DEG C for 3 hours to finally prepare the graphene foam with a three-dimensional structure.

Description

Technical Field

[0001] The invention relates to a method for preparing graphene, and in particular to a method for preparing three-dimensional graphene. Background Art

[0002] Graphene is a planar structure with a single atomic layer thickness composed of sp2 hybridized carbon atoms. It has a perfect two-dimensional crystal structure and excellent chemical and physical properties. It has broad application prospects in nanoelectronics, energy storage and conversion, chemical and biological sensors, composite materials and biotechnology. Three-dimensional graphene is a three-dimensional macroscopic structure constructed by two-dimensional graphene sheets. It not only inherits the excellent properties of graphene, but also has the characteristics of low density, good mechanical properties, compressibility, high porosity, large specific surface area, etc. It has broad development prospects in many fields such as sensors, energy, environmental protection, biomedicine, etc. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing three-dimensional graphene, which prepares large-area, high-quality three-dimensional graphene by chemical vapor deposition. The method cuts nickel foam into rectangular specifications, puts it into a glass dish filled with acetone, ultrasonically cleans it, and heats it. The graphene growth parameters are set by the control panel of the tube furnace, and after the growth is completed, the furnace cover is opened to cool the quartz tube, and the etching solution is repeatedly replaced until the nickel is completely etched and the solution no longer turns green. Then, the graphene is washed with distilled water to remove residual impurities, and the graphene is fished out and dried to prepare a graphene foam with a three-dimensional structure.

[0004] The objective of the present invention is achieved through the following technical solutions: A method for preparing three-dimensional graphene, the method comprising the following steps: Step S1, cutting the nickel foam with a thickness of 2 mm into a rectangular size of 60 x 160 mm; Step S2, placing the cut nickel foam into a glass dish filled with acetone and ultrasonically cleaning it for 30 minutes; Step S3, ultrasonically cleaning the cleaned nickel foam with distilled water for 30 minutes; Step S4, placing the cleaned nickel foam in an oven at 50° C. and heating for 5 hours; Step S5, using tweezers to place the cleaned nickel foam on the quartz boat; Step S6, placing the quartz boat in the middle of the quartz tube of the tube furnace and tightening the flange on one side of the quartz tube; Step S7, starting the vacuum pump to evacuate the inside of the quartz tube; Step S8, setting graphene growth parameters through the control panel of the tube furnace; Step S9, introducing 400 sccm of Ar and 200 sccm of H2 and starting the tubular furnace heating system; Step S10, after the temperature of the tubular furnace is raised to 1000° C., the nickel foam is annealed for 30 minutes while maintaining the constant temperature; Step S11, introducing CH4 gas for 35 min; Step S12, stop the introduction of CH4 and turn off the heating system. At this time, continue to maintain the continuous introduction of 400 sccm of Ar and 200 sccm of H2.

[0005] Step S13, after the graphene growth is completed, the furnace cover is opened to cool the quartz tube; Step S14, taking out the graphene-nickel hybrid three-dimensional foam material after the quartz tube is cooled to room temperature; Step S15, placing the cooled graphene-nickel hybrid three-dimensional foam material in a FeCl3 mixed solution for etching; Step S16, repeatedly changing the etching solution until the nickel is completely etched and the solution no longer turns green; Step S17, washing the graphene foam with distilled water for multiple times to remove residual impurities; Step S18, taking out the graphene and drying it in an oven at 80° C. for three hours to obtain three-dimensional graphene; The advantages and effects of the present invention are: Based on the chemical vapor deposition method of the present invention, large-area, high-quality three-dimensional graphene can be prepared. Through Raman testing, it can be seen that the D peak (Raman shift at 1580 cm -1 The G peak caused by the sp2 carbon atom plane vibration (Raman shift at 2400 cm -1 ), and the 2D peak of the interlayer stacking mode of the reactive carbon atoms (Raman shift at 2700 cm -1 These typical characteristic peaks indicate the presence of graphene. The three-dimensional graphene grid structure can be observed through a scanning electron microscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0007] Figure 1 It is a schematic diagram of the flow chart of the present invention; Figure 2 This is a physical picture of a three-dimensional graphene growth tube furnace in Example 1 of the present invention; Figure 3This is a graph showing the changes in gas flow rate and growth temperature over time during the three-dimensional graphene growth process in Example 1 of the present invention; Figure 4 Provided is a photograph of nickel foam being ultrasonically dispersed in acetone for 30 minutes for Example 1 of the present invention; Figure 5 Provide a photograph of the actual object of nickel foam graphene for Example 1 of the present invention; Figure 6 Provide a photograph of nickel foam graphene etched in FeCl3 solution for Example 1 of the present invention; Figure 7 Provide a photo of three-dimensional graphene for Example 1 of the present invention; Figure 8 Provide a three-dimensional graphene Raman spectrum curve diagram for Example 1 of the present invention; Fig. 9 Provide a three-dimensional graphene scanning electron microscope image for Example 1 of the present invention; Fig.10 A scanning electron microscope image of three-dimensional graphene is provided for Example 1 of the present invention. DETAILED DESCRIPTION

[0008] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention. Example 1

[0009] The preparation flow chart of the three-dimensional graphene of the present invention is as follows Figure 1 As shown, the method comprises the following steps: The 2mm thick nickel foam was cut into a 60x160mm rectangular size, placed in a glass dish containing acetone and ultrasonically cleaned for 30 minutes, then ultrasonically cleaned with distilled water for 30 minutes, and then heated in an oven at 50°C for 5 hours. Use tweezers to place the cleaned nickel foam on the quartz boat, then put the nickel foam and the quartz boat into the middle of the quartz tube (length 410mm, outer diameter 120mm, inner diameter 100mm) of the tube furnace, and then tighten the flange on one side of the quartz tube. Start the vacuum pump to evacuate the inside of the quartz tube. When the vacuum inside the quartz tube is less than 2Pa, turn off the vacuum pump and observe the pressure change inside the quartz tube. Set the graphene growth parameters through the control panel of the tube furnace, then introduce 400sccm of Ar and 200sccm of H2 and start the tube furnace heating system. After the tube furnace is heated to 1000°C, keep the constant temperature to anneal the nickel foam for 30 minutes. The CH4 gas was introduced for 35 minutes, and then the introduction of CH4 was stopped and the heating system was turned off. At this time, 400 sccm of Ar and 200 sccm of H2 were continuously introduced. After the growth was completed, the furnace cover was opened to cool the quartz tube, and the quartz tube was taken out when it cooled to room temperature. The cooled graphene nickel mixed three-dimensional foam material was placed in a 15% FeCl3 mixed solution and etched at room temperature for 48 hours. The etching solution was repeatedly replaced until the nickel foam was completely etched and the solution no longer turned green. The graphene foam was then washed with distilled water to remove residual impurities, and the graphene foam was fished out and placed in an 80°C oven for three hours to finally obtain a graphene foam with a three-dimensional structure.

[0010] Three-dimensional graphene foam was grown on nickel foam template by chemical vapor deposition. In order to verify the growth of graphene on nickel foam, the three-dimensional graphene was characterized. Through Raman testing, it can be seen that the D peak caused by structural defects (Raman shift at 1580 cm -1 The G peak caused by the sp2 carbon atom plane vibration (Raman shift at 2400 cm -1 ), and the 2D peak of the interlayer stacking mode of the reactive carbon atoms (Raman shift at 2700 cm -1 These typical characteristic peaks indicate the presence of graphene. The three-dimensional graphene grid structure can be observed through a scanning electron microscope.

[0011] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

Claims

1. A method for preparing three-dimensional graphene, characterized in that: The method comprises the following steps: Step S1, cutting the nickel foam with a thickness of 2 mm into a rectangular size of 60 x 160 mm; Step S2, placing the cut nickel foam into a glass dish filled with acetone and ultrasonically cleaning it for 30 minutes; Step S3, ultrasonically cleaning the cleaned nickel foam with distilled water for 30 minutes; Step S4, placing the cleaned nickel foam in an oven at 50° C. and heating for 5 hours; Step S5, using tweezers to place the cleaned nickel foam on the quartz boat; Step S6, placing the quartz boat in the middle of the quartz tube of the tube furnace and tightening the flange on one side of the quartz tube; Step S7, starting the vacuum pump to evacuate the inside of the quartz tube; Step S8, setting graphene growth parameters through the control panel of the tube furnace; Step S9, introducing 200 sccm of Ar and 100 sccm of H2 and starting the tubular furnace heating system; Step S10, after the temperature of the tubular furnace is raised to 1000° C., the nickel foam is annealed for 30 minutes while maintaining the constant temperature; Step S11, introducing CH4 gas for 35 min; Step S12, stop the introduction of CH4 and turn off the heating system. At this time, continue to maintain the continuous introduction of 200 sccm of Ar and 100 sccm of H2; Step S13, after the graphene growth is completed, the furnace cover is opened to cool the quartz tube; Step S14, taking out the graphene-nickel hybrid three-dimensional foam material after the quartz tube is cooled to room temperature; Step S15, placing the cooled graphene-nickel hybrid three-dimensional foam material in a FeCl3 mixed solution for etching; Step S16, repeatedly changing the etching solution until the nickel is completely etched and the solution no longer turns green; Step S17, washing the graphene foam with distilled water for multiple times to remove residual impurities; Step S18, taking out the graphene and putting it into an oven at 80° C. to dry for three hours to obtain three-dimensional graphene.

2. The method for preparing three-dimensional graphene according to claim 1, characterized in that: The nickel foam is placed in an ultrasonic bath for 30 minutes.

3. The method for preparing three-dimensional graphene according to claim 1, characterized in that: The method introduced 200 sccm of Ar and 100 sccm of H2 and started the tube furnace heating system.

4. The method for preparing three-dimensional graphene according to claim 1, characterized in that: After the temperature of the tube furnace is raised to 1000° C., the constant temperature is maintained to anneal the nickel foam for 30 minutes.

5. The method for preparing three-dimensional graphene according to claim 1, characterized in that: The cooled graphene-nickel hybrid three-dimensional foam material is placed in a FeCl3 solution for etching.

6. The method for preparing three-dimensional graphene according to claim 1, characterized in that: The graphene was placed in an oven at 80° C. and dried for three hours.

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