A method for preparing a single-layer amorphous fullerene film
Through the assembly of amphiphilic fullerene at the water-air interface and the preparation technology of Langomeu films, combined with the pyrolysis method, the contradiction between the amount of carbon source and the number of growth cores in the growth of a single-layer amorphous 2D fullerene film is solved, and the number of growth cores is achieved. The stable preparation and thickness control of the monolayer fullerene film were demonstrated, and high order and large-area applicability were demonstrated.
Patent Information
- Application Number
- CN202310556103.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-17
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2043-05-17
AI Technical Summary
It is difficult to prepare a monolayer amorphous 2D fullerene film in the prior art, mainly due to the contradiction between the amount of carbon source and the number of growth cores, making it difficult to achieve stable growth of the monolayer structure.
The amphiphilic fullerene monomer was assembled at the water-air interface and combined with pyrolysis method through Langomeu film preparation technology, a monolayer amorphous fullerene film was prepared. By regulating the interface pressure and pyrolysis conditions, the Growth and thickness control of single-layer film.
An ultrathin single-layer amorphous fullerene film with a thickness of 3nm to 6nm was successfully prepared. The fullerenes in the film are arranged in a highly orderly manner and have controllable thickness. They are suitable for large-area preparation and maintain the unique properties of the material.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of functional materials, and relates to a method for preparing a single-layer fullerene film, and in particular to a method for preparing a single-layer amorphous fullerene film. Background Art
[0002] Carbon is one of the most versatile elements in the periodic table. It can react with almost all elements in the form of sp, sp 2 and sp 3 Hybridization is combined. Two-dimensional (2D) carbon materials composed of conjugated network structures have unique π-electron systems and special carrier transport properties. We can adjust the physical and chemical properties of 2D carbon materials, especially the band gap, by changing the periodicity of the hybridized carbon atom network. These 2D carbon materials have a wide range of applications in transistors, energy storage devices, and superconductors.
[0003] So far, the development of 2D carbon materials has been limited to structures with periodic networks of interwoven atomic building blocks, such as graphene. The use of advanced building blocks (e.g., clusters) to construct 2D carbon materials has rarely been studied. 2D carbon materials constructed from nanocluster building blocks are expected to have superior topological structures and unique properties. Fullerene (C 60 ) is a typical carbon cluster. Under extremely high pressure, C 60 The C 60 Such a layered polymer has a C 60 It is a crystallized regular topological structure of repeating units and has unique electronic and magnetic properties. Recently, the Institute of Chemistry of the Chinese Academy of Sciences reported the controllable preparation of a single-layer fullerene film in a crystalline state. The material has high crystallinity, good thermal stability and semiconductor properties. So far, amorphous fullerene films have not been reported.
[0004] Amorphous carbon film is a carbon film that lacks long-range order. Unlike crystalline carbon film, amorphous carbon film has many excellent physical properties and can be widely used in materials such as optical windows, solar cells, and magnetic storage devices. At present, there are only a few reports on crystalline 2D fullerene films. The crystalline 2D fullerene film prepared by the research group of Zheng Jian, a researcher at the Institute of Chemistry, Chinese Academy of Sciences, was prepared by chemical vapor deposition. Amorphous 2D fullerene film has not been reported yet, mainly because of the lack of effective preparation methods. There is a contradiction between the amount of carbon source and the number of growth cores in the growth of a single layer of amorphous fullerene. According to the Arrhenius equation, the growth of a single layer of fullerene requires as many growth nucleation cores as possible, which can usually be met in chemical vapor deposition by providing a large amount of fullerene gas. But at the same time, a large amount of carbon source will accelerate the growth of fullerene into a multilayer structure instead of staying in a single layer. Amorphous 2D fullerene film will exhibit different properties from crystalline 2D fullerene film. 2D fullerene film has potential application value in optoelectronic devices such as transistors and salt difference power generation.
[0005] At present, the crystalline 2D fullerene film prepared by the research group of Researcher Zheng Jian from the Institute of Chemistry, Chinese Academy of Sciences adopts the "chemical vapor deposition + exfoliation dispersion" method, and uses the organic cation intercalation strategy to exfoliate the obtained multilayer material to obtain a single-layer fullerene film. This method is difficult to obtain a large-area single-layer fullerene film. Summary of the invention
[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for preparing a single-layer amorphous fullerene film, so as to achieve controllable preparation of amorphous fullerene film with a single-atom thickness.
[0007] In order to achieve the above object, the present invention adopts the following technical solutions:
[0008] A method for preparing a single-layer amorphous fullerene film comprises the following steps:
[0009] Step 1, preparing amphiphilic fullerene;
[0010] Step 2: Dissolve the amphiphilic fullerene synthesized in step 1 in chloroform to prepare a 1 mg / L solution, and drop 20 uL of the solution onto a 50 cm 2 water-air interface;
[0011] Step 3: After the chloroform is completely volatilized, the baffle of the Langmuir film preparation instrument is slowly pushed to maintain the fullerene molecular interface assembly film at an interface pressure of 5 to 20 mN / m, and the assembled film is transferred to the substrate by vertical deposition transfer at the interface;
[0012] Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 300-600° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
[0013] Preferably, the method for preparing amphiphilic fullerene described in step 1 comprises the following steps:
[0014] S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60 Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene.
[0015] S2. The monosubstituted fullerene prepared in S1 is dissolved again in 50 mL of toluene, diethyl malonate and NaH are added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, the mixture is stirred and reacted at 60°C for 3 h, and the mixture is separated by a chromatographic column again to obtain pure disubstituted fullerene, i.e., amphiphilic fullerene.
[0016] Preferably, the waiting time for the chloroform described in step 3 to completely volatilize is 15 to 30 minutes.
[0017] Preferably, the substrate described in step three comprises a copper sheet or a silicon sheet.
[0018] Compared with the prior art, the present invention has the following technical effects:
[0019] The present invention discloses a method for preparing an amorphous fullerene film by assembling an amphiphilic fullerene monomer into a film at a water-air interface and then transferring and pyrolyzing the film. A large-area single-layer fullerene film is prepared from organic small molecules "from bottom to top" by a two-step method of Langmuir film formation and pyrolysis. This preparation method solves the contradiction between the amount of carbon source and the number of growth cores in the growth of a single-layer fullerene. Each amphiphilic fullerene molecule is a nucleation core. The low volatility of the amphiphilic fullerene molecule also ensures that there are sufficient fullerene molecules in the film growth process. Furthermore, the Langmuir film preparation technology is used to reasonably control the interface pressure and adjust the distance between the amphiphilic fullerene molecules, thereby further reducing the amount of carbon source and realizing the film thickness control. The single-layer fullerene film prepared by the method of the present invention has a thickness of 3nm to 6nm.
[0020] The single-layer amorphous fullerene film prepared by the present invention is ultra-thin and has a precisely controlled thickness, and the film thickness is nanometers; the fullerenes in the film are highly ordered and anisotropic, and can be controlled at the molecular level;
[0021] The film-making conditions of the invention are mild and the operation is simple, and the invention is suitable for preparing a large-area single-layer amorphous fullerene film. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 The structure diagram of amphiphilic fullerene;
[0023] Figure 2 Schematic diagram of preparing fullerene film from amphiphilic fullerene;
[0024] Figure 3 The Langmuir interface isotherm diagram of the amphiphilic fullerene molecule prepared in Example 1 is the fullerene Langmuir isotherm;
[0025] Figure 4 An optical microscope image of a single-layer amorphous fullerene film transferred to a silicon wafer prepared in Example 1 (dark color);
[0026] Figure 5 An atomic force microscope (AFM) image of a single-layer amorphous fullerene film prepared in Example 1;
[0027] Figure 6 The Raman spectrum (Raman) of the single-layer amorphous fullerene film prepared in Example 1;
[0028] Figure 7 X-ray photoelectron spectroscopy (XPS) graph of the single-layer amorphous fullerene film prepared in Example 1. DETAILED DESCRIPTION
[0029] The specific contents of the present invention are further explained in detail below in conjunction with embodiments.
[0030] Example 1
[0031] A method for preparing a single-layer amorphous fullerene film comprises the following steps:
[0032] Step 1: Preparation of amphiphilic fullerene:
[0033] S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60 Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene.
[0034] S2. The monosubstituted fullerene prepared in S1 is dissolved again in 50 mL of toluene, diethyl malonate and NaH are added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, the mixture is stirred and reacted at 60°C for 3 h, and the mixture is separated by a chromatographic column again to obtain pure disubstituted fullerene, i.e., amphiphilic fullerene.
[0035] Step 2: Dissolve 10 mg of the amphiphilic fullerene synthesized in step 1 in 10 mL of chloroform to prepare a 1 mg / L solution. Add an appropriate amount of deionized water to the water tank of the Langmuir membrane instrument. Insert the cleaned silicon wafer treated with 60 W power for 30 seconds in a plasma cleaner into the water tank. Add 20 uL of the solution to a 50 cm 2 On the water-air interface in the Langmuir membrane instrument;
[0036] Step 3: After standing for 30 minutes and the chloroform is completely evaporated, the slide barrier of the Gemu thin film preparation instrument is controlled to slowly compress the molecules. After the surface pressure reaches 15mN / m, the slide barrier is fixed, and the silicon wafer is pulled at a speed of 1mm / min to transfer the assembled film to the substrate through interface vertical deposition transfer;
[0037] Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 400° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
[0038] Figure 3 This is a Langmuir interface isotherm diagram of the amphiphilic fullerene molecule prepared in Example 1. As an example, the average molecular area under the transfer surface pressure of 10 mN / m is marked on the diagram.
[0039] Figure 4 This is an optical microscope image of the single-layer amorphous fullerene film on the silicon wafer substrate after heat treatment prepared in Example 1. It can be seen from the image that the film is still intact after heat treatment.
[0040] Figure 5 This is an atomic force microscope image of the single-layer amorphous fullerene film on the silicon wafer substrate after heat treatment prepared in Example 1. It can be seen from the image that the film after heat treatment is relatively flat and has an overall thickness of 3 nm.
[0041] Figure 6 The Raman spectrum of the single-layer amorphous fullerene film on the silicon wafer substrate after heat treatment prepared in Example 1. The Raman spectrum of the film after heat treatment has an obvious D peak (1250cm -1 ) and G peak (1600cm -1 ), proving the characteristics of its amorphous structure.
[0042] Figure 7 This is the X-ray photoelectron spectrum of the single-layer amorphous fullerene film on the silicon wafer substrate after heat treatment prepared in Example 1. Figure 7 a It can be seen that the fine spectrum of carbon before heat treatment includes a main peak and a shoulder. The main peak comes from fullerene and the shoulder comes from dimethyl malonate group. The fine spectrum of carbon after heat treatment has only one peak, which can be attributed to carbon in fullerene ( Figure 7 b) The relevant results prove that the dimethyl malonate group is decomposed and removed during the thermal treatment.
[0043] Example 2
[0044] A method for preparing a single-layer amorphous fullerene film comprises the following steps:
[0045] Step 1: Preparation of amphiphilic fullerene:
[0046] S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60 Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene.
[0047] S2. The monosubstituted fullerene prepared in S1 is dissolved again in 50 mL of toluene solution, diethyl malonate and NaH are added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, the mixture is stirred and reacted at 60°C for 3 h, and the mixture is separated by a chromatographic column again to obtain pure disubstituted fullerene, i.e., amphiphilic fullerene.
[0048] Step 2: Dissolve 10 mg of the amphiphilic fullerene synthesized in step 1 in 10 mL of chloroform to prepare a 1 mg / L solution. Add an appropriate amount of deionized water to the water tank of the Langmuir membrane instrument. Insert the cleaned silicon wafer treated with 60 W power for 30 seconds in a plasma cleaner into the water tank. Add 20 uL of the solution to a 50 cm 2 On the water-air interface in the Langmuir membrane instrument;
[0049] Step 3: After standing for 20 minutes to allow the chloroform to completely evaporate, control the slide barrier of the Gemu thin film preparation instrument to slowly compress the molecules. After the surface pressure reaches 5 mN / m, fix the slide barrier and pull the silicon wafer at a speed of 1 mm / min to transfer the assembled film to the substrate through interface vertical deposition transfer;
[0050] Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 300° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
[0051] Example 3
[0052] A method for preparing a single-layer amorphous fullerene film comprises the following steps:
[0053] Step 1: Preparation of amphiphilic fullerene:
[0054] S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene.
[0055] S2. The monosubstituted fullerene prepared in S1 is dissolved again in 50 mL of toluene solution, diethyl malonate and NaH are added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, the mixture is stirred and reacted at 60°C for 3 h, and the mixture is separated by a chromatographic column again to obtain pure disubstituted fullerene, i.e., amphiphilic fullerene.
[0056] Step 2: Dissolve 10 mg of the amphiphilic fullerene synthesized in step 1 in 10 mL of chloroform to prepare a 1 mg / L solution. Add an appropriate amount of deionized water to the water tank of the Langmuir membrane instrument. Insert the copper sheet cleaned by a plasma cleaner at 60 W for 30 seconds into the water tank. Add 20 uL of the solution to a 50 cm 2 On the water-air interface in the Langmuir membrane instrument;
[0057] Step 3: After standing for 15 minutes and the chloroform is completely evaporated, the slide barrier of the Gemu thin film preparation instrument is controlled to slowly compress the molecules. After the surface pressure reaches 10mN / m, the slide barrier is fixed, and the silicon wafer is pulled at a speed of 1mm / min to transfer the assembled film to the substrate through interface vertical deposition transfer;
[0058] Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 600° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
[0059] Example 4
[0060] A method for preparing a single-layer amorphous fullerene film comprises the following steps:
[0061] Step 1: Preparation of amphiphilic fullerene:
[0062] S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60 Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene.
[0063] S2. The monosubstituted fullerene prepared in S1 is dissolved again in 50 mL of toluene solution, diethyl malonate and NaH are added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, the mixture is stirred and reacted at 60°C for 3 h, and the mixture is separated by a chromatographic column again to obtain pure disubstituted fullerene, i.e., amphiphilic fullerene.
[0064] Step 2: Dissolve 10 mg of the amphiphilic fullerene synthesized in step 1 in 10 mL of chloroform to prepare a 1 mg / L solution. Add an appropriate amount of deionized water to the water tank of the Langmuir membrane instrument. Insert the copper sheet cleaned by a plasma cleaner at 60 W for 30 seconds into the water tank. Add 20 uL of the solution to a 50 cm 2 On the water-air interface in the Langmuir membrane instrument;
[0065] Step 3: After standing for 25 minutes and the chloroform is completely evaporated, the slide barrier of the Gemu thin film preparation instrument is controlled to slowly compress the molecules. After the surface pressure reaches 20mN / m, the slide barrier is fixed, and the silicon wafer is pulled at a speed of 1mm / min to transfer the assembled film to the substrate through interface vertical deposition transfer;
[0066] Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 500° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the present invention.
Claims
1. A method for preparing a single-layer amorphous fullerene film, characterized in that: The following steps are involved: Step 1, preparing amphiphilic fullerene; Step 2: Dissolve the amphiphilic fullerene synthesized in step 1 in chloroform to prepare a 1 mg / L solution, and drop 20 uL of the solution onto a 50 cm 2 water-air interface; Step 3: After the chloroform is completely volatilized, the baffle of the Langmuir film preparation instrument is slowly pushed to maintain the fullerene molecular interface assembly film at an interface pressure of 5 to 20 mN / m, and the assembled film is transferred to the substrate by vertical deposition transfer at the interface; Step 4: Transfer the substrate with the assembled film to a rapid thermal processing tube furnace, and pyrolyze it at 300-600° C. for 1 min at normal pressure in an argon atmosphere to obtain a single-layer amorphous fullerene film.
2. The method for preparing a single-layer amorphous fullerene film according to claim 1, characterized in that: The method for preparing amphiphilic fullerene described in step 1 comprises the following steps: S1. Under nitrogen atmosphere, 0.5 mmol of fullerene C 60 Dissolved in 50 mL of toluene, according to the fullerene C 60 Dimethyl malonate and NaH were added in a molar ratio of 1:3:20, and the mixture was stirred at 60°C for 3 hours. The reaction product was separated by a chromatographic column to obtain a substituted fullerene. S2. The monosubstituted fullerene prepared in S1 was dissolved in 50 mL of toluene, diethyl malonate and NaH were added at a molar ratio of monosubstituted fullerene: diethyl malonate: NaH of 1:3:20, and the mixture was stirred at 60°C for 3 h. The mixture was separated by a chromatographic column again to obtain a pure disubstituted fullerene, i.e., an amphiphilic fullerene.
3. The method for preparing a single-layer amorphous fullerene film according to claim 1, characterized in that: The waiting time for the chloroform described in step 3 to completely evaporate is 15 to 30 minutes.
4. The method for preparing a single-layer amorphous fullerene film according to claim 1, characterized in that: The substrate described in step three includes a copper sheet or a silicon sheet.