阅读说明：本技术 一种用碳氢有机化合物制备单层连续石墨烯薄膜的方法 (Method for preparing single-layer continuous graphene film by using hydrocarbon organic compound ) 是由 陈瑞 陈庚 韩军 李秀川 赵苡锋 吴浩南 高野 于 2021-09-30 设计创作，主要内容包括：本发明涉及一种单层连续石墨烯薄膜的制备方法。一种用碳氢有机化合物制备单层连续石墨烯薄膜的方法,它包括：预热,将保护气体通入放置在加热装置内的石英管里,向石英管加热区中央放置铜箔作为基底,升温到1000±20℃,保持2小时；反应,将碳氢有机化合物溶液经毛细管泵送入石英管内,反应5min,关闭泵停止进给所述碳氢有机化合物溶液；速冷,将铜箔推到石英管口,以10-20℃/s的速度用冷空气冷却石英管至低于300℃；转移,将铜基底剪成小块放入三氯化铁溶液中,待铜箔基底全部溶解后用布氏漏斗过滤掉溶液,用去离子水和丙酮清洗后去除分析滤纸,经真空烘干即可得到石墨烯薄膜。本发明的方法原料易得,不使用有害溶剂,有利于环保和可持续性发展。(The invention relates to a preparation method of a single-layer continuous graphene film. A method for preparing a single-layer continuous graphene thin film from a hydrocarbon organic compound, comprising: preheating, introducing protective gas into a quartz tube arranged in a heating device, placing a copper foil as a substrate in the center of a heating area of the quartz tube, heating to 1000 +/-20 ℃, and keeping for 2 hours; reacting, namely pumping the hydrocarbon organic compound solution into a quartz tube through a capillary tube, reacting for 5min, and stopping feeding the hydrocarbon organic compound solution by closing a pump; rapidly cooling, namely pushing the copper foil to a quartz pipe opening, and cooling the quartz pipe to be lower than 300 ℃ by using cold air at the speed of 10-20 ℃/s; and (2) transferring, namely cutting the copper substrate into small pieces, putting the small pieces into a ferric trichloride solution, filtering the solution by using a Buchner funnel after the copper foil substrate is completely dissolved, removing analysis filter paper after cleaning by using deionized water and acetone, and drying in vacuum to obtain the graphene film. The method has the advantages of easily obtained raw materials, no use of harmful solvents and contribution to environmental protection and sustainable development.)

1. A method for preparing a single-layer continuous graphene film by using a hydrocarbon organic compound is characterized by comprising the following steps: it includes:

a preheating step, introducing protective gas into a quartz tube arranged in a heating device, placing a copper foil with the thickness of 20 mu m at the center of a heating area of the quartz tube as a substrate, sealing the quartz tube, heating the heating device to 1000 +/-20 ℃, and keeping preheating for 2 hours;

a reaction step, namely delivering a chromatographically pure hydrocarbon organic compound solution into a quartz tube through a capillary tube by using a precision flow pump, reacting for 5min, and growing graphene on a copper foil; closing the flow pump to stop feeding the organic compound solution;

a quick cooling step, namely pushing the copper foil to a quartz pipe opening, and cooling the quartz pipe by using cold air at the speed of 10-20 ℃/s until the temperature is lower than 300 ℃;

and a transferring step, namely taking a Buchner funnel and sealing the lower part of the Buchner funnel, fully paving analysis filter paper in the Buchner funnel, pouring 0.5mol/L ferric chloride solution, cutting a copper substrate with graphene into small pieces, putting the small pieces into the ferric chloride solution, opening a lower liquid opening of the funnel after the copper substrate is completely dissolved, filtering out ferrous chloride and copper chloride solution, keeping the graphene above the filter paper, dropwise adding deionized water above the funnel for cleaning, repeatedly cleaning with acetone to remove the analysis filter paper, and drying in vacuum to obtain the graphene film.

2. The method of claim 1, wherein the hydrocarbon compound comprises a compound containing hydrogen and/or oxygen in a carbon chain of C1-C6.

3. The method for preparing a single-layer continuous graphene thin film from a hydrocarbon compound according to claim 2, wherein: the hydrocarbon compound includes but is not limited to methane, ethylene, ethanol or sucrose.

4. The method of claim 1, wherein the copper is laid flat against the pipe wall, and the copper foil is kept flat and smooth without dents and wrinkles.

5. The method for preparing a single-layer continuous graphene film from a hydrocarbon compound as claimed in claim 1, wherein the inert gas is preferably argon with a purity of more than 99.999%, and the flow rate is 200ml/min.

6. The method for preparing the single-layer continuous graphene film from the hydrocarbon compound as claimed in claim 3, wherein the purity of the chromatographically pure ethanol is more than 99.9%, the diameter of the capillary tube is 0.1-10 mm, and the gas flow rate is 1-20ml/min.

7. The method for preparing a single-layer continuous graphene film from hydrocarbon organic compounds as claimed in claim 1, wherein the diameter of the inlet pipe of the quartz tube is greater than 1/5.

8. The method for preparing a single-layer continuous graphene thin film according to claim 1, wherein the FeCl is₃The concentration of the solution is 0.5mol/L, the deionized water is filtered by a reverse osmosis membrane, the conductivity is less than 10 mu S/cm, and the acetone is used as an analytically pure reagent.

Technical Field

The invention relates to preparation of graphene, in particular to a preparation method of a single-layer continuous graphene film.

Background

Graphene (Graphene) is a single-layer carbon atom film peeled from a graphite material, and is a honeycomb two-dimensional crystal composed of a single layer of hexagonal primitive carbon atoms. Graphene has the advantages of ultrathin thickness, ultrahigh strength, super-strong electrical conductivity, room-temperature heat conduction and light transmission, stable structure and the like, is a key material for promoting the development of aviation high technology, and has a huge development prospect. The preparation method has wide application fields, and is applied to the fields of electronic devices, sensors, lithium batteries, medical health, composite materials, super capacitance, invisible coatings, 3D printing, solar batteries and the like. The graphene can be compared with the internet in the field of materials, and can be combined with different materials and technologies to form a novel material which has special performance and meets specific application. Like the development trend of the internet +, the graphene + is expected to become a great trend of the development of the future material field. Graphene is a novel material which has the most magical and most potential development in the twenty-first century.

The preparation method of graphene includes the following steps:

1) the solid phase method includes a mechanical peeling method and an epitaxial growth method, namely, graphene is obtained by sticking two side faces of a graphite sheet with an adhesive tape and repeatedly peeling, or the graphene is prepared by taking silicon carbide as a raw material and thermally decomposing and removing silicon on a specific crystal face.

2) The liquid phase method has an oxidation-reduction method, an ultrasonic dispersion method, an organic synthesis method, a solution heating method and the like, the method is suitable for mass production, but the used reagents pollute the environment, and the method can only prepare multilayer graphene, has small quantity of single-layer graphene, and is not suitable for application in special fields such as electronic screens, aviation, military industry, nuclear energy and the like.

In addition, the method for preparing the graphene in large quantity is low in cost and easy to operate, the natural crystalline flake graphite is prepared by taking the natural crystalline flake graphite as a raw material through an oxidation-reduction method, the natural graphite naturally grows in graphite ores and belongs to nonrenewable resources, and the nonrenewable resources in the world are rapidly reduced and surpassed along with rapid development of economy and science and technology, so that all countries in the world recognize the invaluity of the resources and adopt various measures to protect the resources, and the method is an important subject for how to supply the human needs by continuously producing high-tech new materials of the graphene in batches after the exhaustion of the graphite resources.

Disclosure of Invention

The present invention is directed to solving the above-mentioned drawbacks of the prior art and providing a method for preparing a single-layer continuous graphene thin film from a hydrocarbon organic compound. The method has the advantages of easily obtained raw materials, no use of harmful solvents, harmless products and contribution to environmental protection and sustainable development.

The invention is realized by the following steps: a method for preparing a single-layer continuous graphene thin film from a hydrocarbon organic compound, comprising:

a preheating step, introducing protective gas into a quartz tube arranged in a heating device, placing a copper foil with the thickness of 20 mu m at the center of a heating area of the quartz tube as a substrate, sealing the quartz tube, heating the heating device to 1000 +/-20 ℃, and keeping preheating for 2 hours;

a reaction step, namely delivering a chromatographically pure hydrocarbon organic compound solution into a quartz tube through a capillary tube by using a precision flow pump, reacting for 5min, and growing graphene on a copper foil; closing the flow pump to stop feeding the organic compound solution;

a quick cooling step, namely pushing the copper foil to a quartz pipe opening, and cooling the quartz pipe by using cold air at the speed of 10-20 ℃/s until the temperature is lower than 300 ℃;

and a transferring step, namely taking a Buchner funnel and sealing the lower part of the Buchner funnel, fully paving analysis filter paper in the Buchner funnel, pouring 0.5mol/L ferric chloride solution, cutting a copper substrate with graphene into small pieces, putting the small pieces into the ferric chloride solution, opening a lower liquid opening of the funnel after the copper substrate is completely dissolved, filtering out ferrous chloride and copper chloride solution, keeping the graphene above the filter paper, dropwise adding deionized water above the funnel for cleaning, repeatedly cleaning with acetone to remove the analysis filter paper, and drying in vacuum to obtain the graphene film.

The method for preparing the single-layer continuous graphene film by using the hydrocarbon compound comprises a compound containing hydrogen and/or oxygen of a carbon chain of C1-C6.

The method for preparing the single-layer continuous graphene film by using the hydrocarbon organic compound comprises but is not limited to methane, ethylene, ethanol or sucrose.

The method for preparing the single-layer continuous graphene film by using the hydrocarbon organic compound is characterized in that the thickness of the copper foil is 20 mu m, the copper foil is tightly attached to the wall of a pipe and is tiled, and the copper foil is kept flat and smooth and has no dent or crease.

According to the method for preparing the single-layer continuous graphene film by using the hydrocarbon compound, argon with the purity of more than 99.999 percent is preferably selected as the inert gas, and the flow rate is 200ml/min.

According to the method for preparing the single-layer continuous graphene film by using the hydrocarbon organic compound, the purity of chromatographically pure ethanol is more than 99.9%, the diameter of a capillary tube is 0.1-10 mm, and the gas flow is 1-20ml/min.

In the method for preparing the single-layer continuous graphene film by using the hydrocarbon organic compound, the diameter of the inlet pipe of the quartz tube is 1/5 larger than that of the outlet pipe of the quartz tube.

The method for preparing the single-layer continuous graphene film by using the hydrocarbon organic compound, the FeCl₃The concentration of the solution is 0.5mol/L, the deionized water is filtered by a reverse osmosis membrane, the conductivity is less than 10 mu S/cm, and the acetone is used as an analytically pure reagent.

The chemical vapor deposition method provided by the invention has strong operability and is suitable for preparing continuous single-layer graphene films in batches, and can meet the requirements of special, high, precise and sharp fields. Meanwhile, natural flake graphite is not used as a raw material, hydrocarbons such as methane, ethylene, ethanol, cane sugar and the like are used as the raw material and are prepared by pyrolysis in a resistance furnace, and the methanol, the ethanol and the like can be extracted by crops such as corn, straws and the like, so that the raw material sources are not influenced by less and less mineral resources such as graphite, a guarantee is provided for the continuous and wider application of the graphene to scientific and technological life in the future, and a new way is opened up.

Drawings

FIG. 1 is an SEM image of a product of the invention.

Figure 2 is a TEM image of the product of the invention.

Detailed Description

The invention discloses a method for preparing a single-layer continuous graphene film by using a hydrocarbon organic compound, which comprises the following steps:

a preheating step, introducing protective gas into a quartz tube arranged in a heating device, placing a copper foil with the thickness of 20 mu m at the center of a heating area of the quartz tube as a substrate, sealing the quartz tube, heating the heating device to 1000 +/-20 ℃, and keeping preheating for 2 hours;

a reaction step, namely delivering a chromatographically pure hydrocarbon organic compound solution into a quartz tube through a capillary tube by using a precision flow pump, reacting for 5min, and growing graphene on a copper foil; closing the flow pump to stop feeding the organic compound solution;

a quick cooling step, namely pushing the copper foil to a quartz pipe opening, and cooling the quartz pipe by using cold air at the speed of 10-20 ℃/s until the temperature is lower than 300 ℃;

and a transferring step, namely taking a Buchner funnel and sealing the lower part of the Buchner funnel, fully paving analysis filter paper in the Buchner funnel, pouring 0.5mol/L ferric chloride solution, cutting a copper substrate with graphene into small pieces, putting the small pieces into the ferric chloride solution, opening a lower liquid opening of the funnel after the copper substrate is completely dissolved, filtering out ferrous chloride and copper chloride solution, keeping the graphene above the filter paper, dropwise adding deionized water above the funnel for cleaning, repeatedly cleaning with acetone to remove the analysis filter paper, and drying in vacuum to obtain the graphene film.

The method for preparing the single-layer continuous graphene film by using the hydrocarbon compound comprises a compound containing hydrogen and/or oxygen of a carbon chain of C1-C6.

A method for preparing a single-layer continuous graphene film by using a hydrocarbon organic compound is characterized in that the purity of high-purity argon is more than 99.999%, and the flow rate of the high-purity argon is 200ml/min.

The thickness of the copper foil is 20 μm, the area of the copper foil can be enlarged according to the output and the process requirements, and the copper foil is flatly laid close to the pipe wall.

The chromatographic purity is ethanol with the purity of more than 99.9 percent, the diameter of the capillary tube is 0.1-10 mm, the gas flow is 1-20ml/min, and the capillary tube is made of high-temperature resistant iron, nickel and cobalt stainless steel alloy.

The concentration of FeCl3 solution used for transferring is 0.5mol/L, the conductivity of deionized water is less than 10 mu S/cm after reverse osmosis filtration, and acetone is used as an analytical reagent.

The diameter of the inlet pipe of the quartz tube is 1/5 larger than that of the outlet pipe, so that the argon in the quartz reaction chamber can be kept to have certain pressure, the air can be quickly exhausted, and the purity of the argon can be kept!

The surface of the copper foil must be kept flat and smooth, no dent or crease exists, the thickness of the single-layer graphene is less than 1nm, if carbon atoms are deposited on a rough surface, the growth of the single-layer graphene is not facilitated, the microstructure of the copper foil is flatter and smoother than that before the treatment only after the high-temperature pretreatment at 1000 ℃, the copper crystal grains are recrystallized at high temperature, and the crystal grains and the surface with larger sizes are obtained in the growth process of the crystal grains, so that the deposition and the crystallization growth of the carbon atoms are facilitated to form a large-area continuous graphene film.

The quartz tube is 1.5m long, the inner diameter is 35mm, and the inner volume is 0.15m³The argon flow is 180-250 ml/min, the argon flow is too large to cause waste, the pressure in the tube is also too large, single-layer graphene deposition is not facilitated, the flow is small, the internal pressure is reduced, and normal operation of air removal and internal reaction is not facilitated.

The feed amount of the hydrocarbon compound solution was related to the volume of the inside of the reaction chamber and the size of the copper foil, the quartz tube was 1.5m long, the inner diameter was 35mm, and the area of the copper foil was 0.5cm²The feeding flow rate of the ethanol is 20 mu L/min, the reaction time is 5min, and the feeding amount of the hydrocarbon organic compound solution is proportionally increased along with the increase of the volume of the reaction chamber and the area of the copper foil. The reaction time is related to the area of the copper foil and the flow rate of the ethanol solution, and generally, the reaction time is relative to the reaction time when the area of the copper foil is increased along with the increase of the feeding amount of the hydrocarbon compound solutionThe growth speed is 2:1, and the reaction time is independent of the flow of the protective gas.

The hydrocarbon organic compound in each of the following examples is ethanol.

Example 1

Taking ethanol with the purity of 99.9% as a carbon source, connecting the ethanol with a precise flow pump by using a conduit, connecting the precise flow pump to a quartz tube, sealing, placing copper foil with the thickness of 20 mu m in a central heating zone of the quartz tube, sealing the quartz tube, and only reserving a tail gas outlet on an outlet rubber plug. Argon is introduced according to the flow rate of 200ml/min, and simultaneously the temperature is raised,

when the temperature is raised to 1000 ℃, keeping the temperature unchanged for 2 hours, then sending an ethanol solution with the purity of 99.9 percent into a quartz tube through a precision flow pump, wherein the feeding speed of the solution is adjusted according to the size of the quartz tube and the area of a copper foil, the length of the quartz tube is 1.5m, the inner diameter of the quartz tube is 35mm, and the area of the copper foil is 0.5cm²When the reaction is finished, closing the flow pump and stopping feeding the ethanol solution, wherein the feeding speed of the ethanol is 20 mu L/min, the carbon atoms of the ethanol carbon source are decomposed in the high-temperature reaction zone and are deposited and grown on the metal substrate to form a continuous graphene film, and the reaction time is 5 min; pushing the copper foil to the outlet of the quartz tube cooling chamber, and cooling the quartz tube by using cold air at the speed of 10-20 ℃/s until the temperature is lower than 300 ℃; and taking out the copper foil, cooling for 5 minutes, and then carrying out graphene conversion operation. The method comprises the following specific steps: taking a Buchner funnel, sealing the lower part of the Buchner funnel, fully spreading analysis filter paper in the Buchner funnel, pouring 0.5mol/L ferric trichloride solution, cutting a copper substrate with graphene into small blocks, putting the small blocks into the ferric trichloride solution, opening a lower liquid opening of the funnel after copper foil is completely dissolved, dropwise adding deionized water above the funnel for cleaning, transferring the filter paper and the graphene onto a 325-mesh test sieve by using acetone, putting one block into a vacuum drying box for drying to obtain a graphene film, clamping by using tweezers, putting the film on an analysis balance with the precision of 0.1mg, and weighing the graphene film to be 0.0263g.

Taking a graphene sheet prepared in the embodiment, placing the graphene sheet on a glass slide, pushing away and covering the glass slide, adjusting the light intensity parameters, placing the graphene sheet into a Phenom ProX sample cell of a Scanning Electron Microscope (SEM) Feina desktop scanning electron microscope produced by the Netherlands Feina company, and adjustingAfter various parameters are well observed, a layer of transparent film-shaped structural substance (shown in figure 1) is observed, the appearance of an electron microscope is scanned, and a Hitachi Transmission Electron Microscope (TEM) HT7700 is adopted to observe the microstructure of graphene particles, so that the graphene particles are of a two-dimensional film-shaped structure (shown in figure 2), and are illustrated as graphene. The specific surface area of the single-layer graphene particle is measured to be 2297m by using an F-Sorb2400 type nitrogen adsorption specific surface area instrument produced by Beijing gold Escher science and technology company²(ii) in terms of/g. The conductivity of the single-layer graphene particles is measured to be 1.78 multiplied by 10 by adopting a Shanghai thunder magnetic DDSJ-318 conductivity meter⁶s/m。

Example 2

Preparation of a reaction apparatus: a quartz tube with the length of 3 meters and the diameter of 60mm is connected, and the diameter of the feeding capillary tube is correspondingly increased to 1 time. Preheating, introducing high-purity argon into a quartz tube arranged in a resistance furnace, wherein the diameter of an argon inlet hole is 8mm, and placing the quartz tube with the thickness of 20 mu m and the area of 10cm to the center of a heating area of the quartz tube²The copper foil is used as a substrate, a cover is used for covering the outlet of the quartz tube according to the figure, only a tail gas outlet with the diameter of 5mm is left, the temperature of the resistance furnace is raised to 1000 +/-20 ℃, and the temperature is kept for 2 hours; sending the chromatographic pure ethanol solution into a quartz tube through a capillary tube by a precision flow pump, and reacting for 10 min; closing the flow pump to stop feeding the ethanol solution; pushing the copper foil to a quartz tube outlet cooling area, and cooling the quartz tube by using cold air at the speed of 10-20 ℃/s until the temperature is lower than 300 ℃; and taking out the copper foil, cooling for 5 minutes, and then carrying out graphene transfer operation. The method comprises the following specific steps: taking a Buchner funnel, sealing the lower part of the Buchner funnel, fully paving analysis filter paper in the Buchner funnel, pouring 0.5mol/L ferric trichloride solution, cutting a copper substrate with graphene into small blocks, putting the small blocks into the ferric trichloride solution, opening a lower liquid outlet of the funnel after copper foil is completely dissolved, dropwise adding deionized water above the funnel for cleaning, transferring the filter paper and the graphene onto a 325-mesh test sieve together by using acetone, putting one block into a vacuum drying box for drying to obtain a graphene film, clamping by using tweezers, putting the piece into an analysis balance with the precision of 0.1mg, and weighing the graphene film to 0.5617g.

Placing a graphene sheet prepared by the invention on a glass slide, pushing open and covering the glass slide, adjusting light intensity parameters, and placing the graphene sheet on a platform type (SEM) storage platform produced by the Holland storage companyIn a Phenom ProX sample cell of a scanning electron microscope, after various parameters are adjusted, a layer of transparent film-shaped substance is observed as shown in figure 1, and the scanning electron microscope is used for observing the appearance, and a Hitachi Transmission Electron Microscope (TEM) HT7700 is adopted to observe the microstructure of graphene particles, namely a two-dimensional film-shaped structure is shown in figure 2, namely graphene. The specific surface area of the single-layer graphene particle is determined to be 2321m by using an F-Sorb2400 type nitrogen adsorption specific surface area instrument produced by Beijing Jineeangstrom science and technology company²(ii) in terms of/g. The conductivity of the single-layer graphene particles is measured to be 1.81 multiplied by 10 by adopting a Shanghai thunder magnetic DDSJ-318 conductivity meter⁶s/m。