Method for simultaneously preparing graphene and two-dimensional diamond
High-purity graphene and two-dimensional diamond were successfully prepared by combining ball milling and high temperature and high pressure, which solved the problems of preparation complexity and impurities in the existing technology and realized the efficient large-scale production of graphene and two-dimensional diamond.
Patent Information
- Application Number
- CN202610065833.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-19
- Publication Date
- 2026-03-17
AI Technical Summary
Existing technologies are difficult to use to simultaneously and efficiently prepare high-quality graphene and two-dimensional diamond, and there are problems such as high cost, complex process, poor repeatability, and unstable film quality, making it difficult to achieve large-scale production.
Single-crystal flake graphite powder and polymer powder were mixed using an all-around planetary ball mill. After being pressed into tablets, the temperature and pressure were controlled in a six-sided top press to obtain graphene and two-dimensional diamond. Subsequently, high-purity graphene and two-dimensional diamond were obtained by gradient centrifugation.
This method achieves the preparation of large quantities of high-purity graphene and two-dimensional diamond in a short period of time, solving the problems of complexity and impurities in the preparation process of existing technologies, and realizing the efficient preparation of graphene and two-dimensional diamond.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a method for simultaneously preparing graphene and two-dimensional diamond. BACKGROUND
[0002] Graphene is a two-dimensional honeycomb-like crystal formed by sp 2 hybridization of carbon atoms, with a unique complex hexagonal lattice structure. Since 2004, when British scientists Geim and Novoselov first obtained independent graphene by micro-mechanical exfoliation, this material has attracted widespread attention due to its excellent physical and chemical properties. Its thermal conductivity at room temperature can reach 5300 W·m -1 ·K -1 , the carrier mobility is as high as 15000 cm²·V -1 ·s -1 , and the Young's modulus is about 1.0 TPa, and the specific surface area is 2600 m 2 ·g -1 These characteristics make it show important application potential in the fields of electronic devices, transparent electrodes, supercapacitors, composite materials, and biomedical carriers. At present, the preparation methods of graphene mainly include bottom-up and top-down methods. The bottom-up method such as chemical vapor deposition (CVD) can obtain high-quality and large-area graphene films, but the cost is high, it depends on the substrate, and it is difficult to realize large-scale production. While the top-down method such as liquid phase exfoliation, electrochemical exfoliation and the like, although the process is relatively simple, often faces problems such as small product size, uneven layer number, easy introduction of impurities and low yield, which restricts its popularization in large-scale commercial applications.
[0003] At the same time, two-dimensional diamond, as another emerging carbon-based two-dimensional material, is formed by sp 3 hybridization of carbon atoms to form a single-layer diamond-like structure, with a theoretical Young's modulus close to 1 TPa, a thermal conductivity of about 2000 W / mK, and a direct wide band gap of about 4.3-5.2 eV, which has great application prospects in deep ultraviolet photoelectron devices, high-strength composite materials and high-efficiency thermal management systems. However, the preparation of two-dimensional diamond still faces many challenges. Although Sofo et al. theoretically predicted the hydrogenated graphene structure (graphane) in 2007, and Elias, Chernozatonskii and other teams subsequently promoted the research on the formation of "Diamane" by hydrogenating double-layer graphene in experiments and theories, but methods such as hydrogen plasma treatment of graphene, laser bombardment exfoliation, and chemical vapor deposition still have problems such as complex process control, poor repeatability, unstable film quality, or high equipment requirements, making it difficult to achieve controllable preparation of two-dimensional diamond with complete structure and stable performance. SUMMARY
[0004] This invention develops methods for preparing graphene and two-dimensional diamond.
[0005] This invention first uses an all-around planetary ball mill to mechanically mix single-crystal flake graphite powder and polymer powder evenly, then presses them into tablets and places them in a six-sided top press, controlling the temperature and pressure to press them to obtain graphene and two-dimensional diamond.
[0006] The technical solution of the present invention is as follows: A method for simultaneously preparing graphene and two-dimensional diamond, comprising: Single-crystal flake graphite powder and polymer are added to a ball mill jar and ball-milled until uniform. The resulting mixed powder is pressed into tablets and placed in a six-sided press. The tablets are pressed at 1100~1500 ℃ and 1.0~4.0 GPa (preferably 2.5 GPa) for 10~60 min (30 min) to obtain graphene and two-dimensional diamond. The polymers are selected from polypropylene (PP) and polyethylene (PE); The preferred mass ratio of single-crystal flake graphite powder to polypropylene is 1:0.1 to 1:1.5, and more preferably 1:1; The preferred mass ratio of single-crystal flake graphite powder to polyethylene is 1:1; The ball mill jar is preferably mixed at a rotation speed of 300~500 rpm (more preferably 350 rpm) and a revolution speed of 5 rpm for 30 min; The mixed powder is compressed into tablets using a tableting device with the following operating parameters: pressure 180~260 kN (preferably 210 kN) and holding time 5~30 s (preferably 10 s). The tablets are then demolded to obtain the tablet samples.
[0007] The material obtained by this invention contains both graphene and two-dimensional diamond, and the two can be separated. The specific operation is as follows: The pressed material was added to N-methyl-2-pyrrolidone (NMP), and graphene and two-dimensional diamond were obtained by gradient centrifugation, respectively. Gradient centrifugation conditions: centrifuge at 1000 rpm (low speed) for 10 min to remove large clumps; then centrifuge at 11000 rpm (high speed) for 30 min to separate the upper and lower phases. After washing with ethanol and drying, graphene and two-dimensional diamond were obtained, respectively.
[0008] The beneficial effects of this invention are reflected in: Compared with existing graphene and two-dimensional diamond preparation processes, this invention can obtain a large amount of graphene and a large amount of two-dimensional diamond in a shorter time, and the obtained graphene and two-dimensional diamond are free of impurities and have high purity. Attached Figure Description
[0009] Figure 1Raman spectrum of intrinsic single-crystal flake graphite powder.
[0010] Figure 2 Transmission electron microscope (TEM) image of intrinsic single-crystal flake graphite powder.
[0011] Figure 3 Raman spectrum of Example 1 (single crystal flake graphite powder: PP micro powder = 1:1, six-sided top press parameters 1100 ℃ - 1.0 GPa - 30 min).
[0012] Figure 4 TEM image of Example 1 (graphite powder: PP micro powder = 1:1 1100 ℃-1.0 GPa-30 min).
[0013] Figure 5 Raman spectrum of Example 2 (graphite powder: PP micro powder = 1:1 1100 ℃-2.5 GPa-30 min).
[0014] Figure 6 TEM image of Example 2 (graphite powder: PP micro powder = 1:1, 1100 ℃ - 2.5 GPa - 30 min).
[0015] Figure 7 Raman spectrum of Example 3 (graphite powder: PP micro powder = 1:1 1100 ℃-4.0 GPa-30 min).
[0016] Figure 8 TEM image of Example 3 (graphite powder: PP micro powder = 1:1, 1100 ℃ - 4.0 GPa - 30 min).
[0017] Figure 9 Raman spectrum of Example 4 (graphite powder: PP micro powder = 1:1, 1300 ℃ - 2.5 GPa - 30 min).
[0018] Figure 10 TEM image of Example 4 (graphite powder: PP micro powder = 1:1, 1300 ℃ - 2.5 GPa - 30 min).
[0019] Figure 11 Raman spectrum of Example 5 (graphite powder: PP micro powder = 1:1 1500 ℃-2.5 GPa-30 min).
[0020] Figure 12 TEM image of Example 5 (graphite powder: PP micro powder = 1:1, 1500 ℃ - 2.5 GPa - 30 min).
[0021] Figure 13 Raman spectrum of Example 6 (graphite powder: PP micro powder = 1:0.1, 1100 ℃-2.5 GPa-30 min).
[0022] Figure 14 TEM image of Example 6 (graphite powder: PP micro powder = 1:0.1, 1100 ℃ - 2.5 GPa - 30 min).
[0023] Figure 15 Raman spectrum of Example 7 (graphite powder: PP micro powder = 1:1.5, 1100 ℃-2.5 GPa-30 min).
[0024] Figure 16 TEM image of Example 7 (graphite powder: PP micro powder = 1:1.5, 1100 ℃ - 2.5 GPa - 30 min).
[0025] Figure 17 Raman spectrum of Example 8 (graphite powder: PP micro powder = 1:1 1100 ℃-2.5 GPa-10 min).
[0026] Figure 18 TEM image of Example 8 (graphite powder: PP micro powder = 1:1, 1100 ℃ - 2.5 GPa - 10 min).
[0027] Figure 19 Raman spectrum of Example 9 (graphite powder: PP micro powder = 1:1 1100 ℃-2.5 GPa-60 min).
[0028] Figure 20 TEM image of Example 9 (graphite powder: PP micro powder = 1:1, 1100 ℃ - 2.5 GPa - 60 min).
[0029] Figure 21 Raman spectrum of Example 10 (graphite powder: PE micro powder = 1:1 1100 ℃-2.5 GPa-30 min).
[0030] Figure 22 TEM image of Example 10 (graphite powder: PE micro powder = 1:1, 1100 ℃ - 2.5 GPa - 30 min).
[0031] Figure 23 Raman spectrum of Example 11 (graphite powder: PE micro powder = 1:1 1100 ℃-3.5 GPa-30 min).
[0032] Figure 24TEM image of Example 11 (graphite powder: PE micro powder = 1:1, 1100 ℃ - 3.5 GPa - 30 min). Detailed Implementation
[0033] The present invention is further described below through specific embodiments, but the scope of protection of the present invention is not limited thereto.
[0034] In the following embodiments, The single-crystal flake graphite powder was prepared by Qingdao Mingheda Graphite New Material Co., Ltd., with a purity of 99% and a particle size of 100 mesh. The PP was prepared by Dongguan Qianjing New Materials Co., Ltd., with a purity of 99% and a particle size of 50 μm; The PE was prepared by Dongguan Qianjing New Materials Co., Ltd., with a purity of 99% and a particle size of 50 μm; The all-around planetary ball mill equipment was purchased from Changsha Miqi Instrument Equipment Co., Ltd., model number MITR-QMQX-4L; The tablet pressing equipment was developed by Zhengzhou Abrasives & Grinding Research Institute Co., Ltd., and its model is MY-63. The six-sided top press equipment was manufactured by Tanghe Technology (Inner Mongolia) Co., Ltd., and its model number is 560. The centrifuge equipment was manufactured by Shanghai Lichen Instrument Technology Co., Ltd., and its model number is LC-LX-H165A.
[0035] Example 1
[0036] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0037] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0038] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0039] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press for 30 min at a temperature of 1100 ℃ and a pressure of 1.0 GPa. After pressing, take out the sample.
[0040] The sample obtained in Example 1 contained both graphene and two-dimensional diamond. It was added to N-methyl-2-pyrrolidone (NMP) solvent (>98%) and then subjected to gradient centrifugation. The large clumps were removed by low-speed centrifugation (1000 rpm) for 10 min, and the upper and lower phases were separated by high-speed centrifugation (11000 rpm) for 30 min. The resulting materials were repeatedly washed with ethanol and dried to separate graphene and two-dimensional diamond.
[0041] The composition of the sample obtained in Example 1 was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0042] Figure 1 The Raman spectrum of intrinsic single-crystal flake graphite powder mainly shows the distinct 1580 cm⁻¹ of graphite. -1 and 2700cm -1 The characteristic peaks correspond to the G peak and the 2D overtone Raman peaks of phonon complete dispersion associated with monolayer or few-layer graphene, respectively.
[0043] Figure 2 This is a TEM image of intrinsic flake graphite powder, which mainly shows the crystal plane information of graphite such as (002) and (100).
[0044] Figure 3 The Raman spectrum of Example 1 shows the position at 1350 cm⁻¹. -1 1583 cm -1 and 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1583 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peak is a 2D overtone Raman peak with complete phonon dispersion associated with monolayer or few-layer graphene. Compared to intrinsic graphite powder, the appearance of the D peak after applying temperature and pressure to the sample indicates that with increasing temperature and pressure, the disordered sp_p_state within the sample... 2 The carbon content gradually increases, and the crystallinity and order are relatively good. 2700 cm -1 Compared to intrinsic flake graphite powder, the 2D peak of graphene shows a significant increase in peak intensity, and the peak shape is complete with a narrower half-peak width, indicating a significant increase in the content, crystallinity, and order of graphene; moreover, the intensity of the 2D peak exceeds that of the G peak, indicating the presence of monolayer graphene in the system.
[0045] Figure 4 For example, the HRTEM of Example 1, such as Figure 4As shown, (a) is a low-magnification view of this position, showing a clear large-scale layered structure. The EDS carbon spectrum of region b embedded in (a) shows carbon enrichment. (b) is a magnification of region b in (a), and SAED (Selected Area Electron Diffraction)-b is the selected area electron diffraction of (b), mainly showing the (100) crystal plane information of graphene. (c) is a magnification of region c in (b), and FT (Fourier Transform)-c is the fast Fourier transform of (c). The diffraction information is consistent with SAED-b. c-1 is a magnification of region 1 in (c), and it can be found that there are stripes in three directions with a corresponding interplanar spacing of 0.213 nm, which is consistent with the (100) crystal plane of graphene. Combined with the Raman spectral information, it is therefore believed that the layered structure in region b in (a) is graphene.
[0046] (d) is a low-magnification view of another location on the sample, showing a clear large-scale layered structure. SAED-d is the selected area electron diffraction (SEED) of (d), mainly showing the diffraction information of the (111), (200), and (220) crystal planes of diamond. (e) is obtained by magnifying position e in (d). FT-e is the FT of (e), mainly showing the diffraction information of two pairs of diamond (111) crystal planes. (e-1) is a magnification of region 1 in (e), showing fringe information with a spacing of 0.206 nm in both directions and an angle of 70°, consistent with the spacing of the diamond (111) planes. (e-2) is a magnification of region 2 in (e), showing fringe information with a spacing of 0.206 nm in both directions and an angle of 70°, consistent with the spacing of the diamond (111) planes. Magnifying position f in (d) yields (f), where FT-f is the FT of (f), primarily displaying the diffraction information of two pairs of diamond (111) and one pair of diamond (200) crystal planes. f-1 is a magnification of region 1 in (f), showing fringe information with a spacing of 0.206 nm and an included angle of 70° in both directions, consistent with the spacing of the diamond (111) planes. Therefore, the sheet-like structure with a size of approximately 300 nm in regions e and f in (d) can be considered as two-dimensional diamond. In summary, we simultaneously obtained graphene and two-dimensional diamond in this sample.
[0047] Example 2
[0048] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0049] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0050] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0051] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0052] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0053] Figure 5 The Raman spectrum of Example 2 shows the position at 1352 cm⁻¹. -1 1582 cm -1 and 2700 cm -1 The three Raman peaks. 1352 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1582 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D peaks of overtone Raman spectroscopy, which are associated with monolayer or few-layer graphene and exhibit complete phonon dispersion. Compared with Example 1, the intensity of the D peak is significantly increased, indicating that increased pressure leads to an increase in the content of amorphous carbon in the system. The intensity of the 2D peak is comparable to that of Example 1, and both exceed the intensity of the G peak, indicating the presence of monolayer graphene at 2.5 GPa.
[0054] Figure 6 This is the HRTEM of Example 2. (As shown) Figure 6 As shown, (a) is a low-magnification view of this position, showing the near-circular sheet-like morphology and strip-like morphology. SAED-a is the selected area electron diffraction of (a), mainly showing the (100), (002), (110), and (101) crystal plane information of graphene. (b) is a magnification of region b in (a), showing the clearly dispersed sheet-like structure. (c) is a magnification of region c in (b), and FT-c is the fast Fourier transform of (c), showing the (100) and (101) crystal plane information of graphene. FT-c1 is the FT of region 1 in (c), which also shows the crystal plane information of graphene (100) and (101), consistent with FT-c. Furthermore, in c-1, two stripe information with corresponding interplanar spacings of 0.213 nm and 0.203 nm can be found, which are consistent with the crystal planes of graphene (100) and (101). Combined with the Raman spectral information, it is therefore believed that the sheet-like structure in region b in (a) is graphene.
[0055] (d) shows a low-magnification view of another location on the sample, and (d) is a low-magnification view of this location (200 nm). A large number of interwoven lamellar and strip structures can be seen. SAED-d is the selected area electron diffraction (SEED) of (d), mainly showing diffraction rings of graphite (002), (100), (101), and (110) crystal planes, as well as diffraction information from two pairs of diamond (111) crystal planes. Embedded C is the EDS carbon spectrum of a local region in (d), showing carbon enrichment. A partial magnified analysis of the lamellar structures in (a) yielded (e). FT-e is the FT of (e), showing mainly diffraction information from a pair of diamond (111) crystal planes. FT-e1 is the FT of region 1 in (e), mainly showing the diffraction information of a pair of diamond (111) planes, consistent with the diffraction information of FT-e and SAED-d. (e-1) is a magnification of region 1 in (e), showing fringe information with a crystal plane spacing of 0.206 nm in one direction, consistent with the spacing of the diamond (111) planes. (f) is a magnification of region f in (d), and FT-f is the FT of (f), showing the diffraction information of a pair of diamond (111) planes. FT-f1 is the FT of region 1 in (f), mainly showing the diffraction information of a pair of diamond (111) planes, consistent with the diffraction information of FT-f and SAED-d. (f-1) is a magnification of region 1 in (f), showing fringe information with a crystal plane spacing of 0.206 nm in one direction, consistent with the spacing of the diamond (111) planes. (h) is obtained by magnifying a local position g in (d). FT-h is the FT of (h), which mainly shows the diffraction information of two pairs of diamond (111) crystal planes, consistent with the diffraction information of FT-g and SAED-d. At the same time, (h) shows fringe information with a spacing of 0.206 nm and an angle of 70° in both directions, consistent with the spacing of diamond (111) crystal planes. (i) is a magnification of region i in (d), and FT-i is the FT of (i), which shows the diffraction information of two pairs of diamond (111) crystal planes. FT-i1 is the FT of region 1 in (i), which mainly shows the diffraction information of two pairs of diamond (111) planes, consistent with the diffraction information of FT-i and SAED-d. At the same time, (i) shows fringe information with a spacing of 0.206 nm and an angle of 70° in both directions, consistent with the spacing of diamond (111) crystal planes. Therefore, the sheet-like structures with a size of approximately 200 nm in regions e, f, g, and i in (d) can be considered as two-dimensional diamond. In summary, we obtained both graphene and two-dimensional diamond in this sample.
[0056] Example 3
[0057] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0058] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0059] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 KN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0060] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1100 ℃ and a pressure of 4.0 GPa. After pressing, take out the sample.
[0061] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0062] Figure 7 The Raman spectrum of Example 3 shows the position at 1352 cm⁻¹. -1 1583 cm -1 and 2708 cm -1 The three Raman peaks. 1352 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1583 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2708 cm⁻¹ -1 The peaks are phonon-dispersive 2D peaks associated with monolayer or few-layer graphene. Compared with the Raman spectrum of Example 1, the intensity of the 2D peak is reduced; compared with the Raman spectrum of Example 2, the intensities of both the D peak and the 2D peak are reduced.
[0063] Figure 8 This is the HRTEM of Example 3. For example... Figure 8As shown, (a) is a low-magnification view of this position. The EDS carbon spectrum of region b embedded in (a) shows carbon enrichment. (b) is a magnification of region b in (a), showing a near-circular sheet-like morphology and strip-like morphology. SAED-b is the selected area electron diffraction of (b), mainly showing the (100), (002), (110), and (101) crystal plane information of graphene. (c) is a magnification of region c in (b), and FT-c is the fast Fourier transform of (c), mainly showing the (100) and (102) crystal plane diffraction information of graphene. (c-1) is a magnification of region 1 in (c), showing stripe information in two directions with interplanar spacings of 0.213 nm and 0.181 nm, respectively, which are consistent with the (100) and (102) crystal planes of graphene. Based on the Raman spectral information, it is therefore believed that the sheet-like structure in region c of (b) is graphene.
[0064] (d) is a low-magnification view of another location of the sample. SAED-d is the selected area electron diffraction of (d), which mainly shows the diffraction information of the (111) (200) (220) crystal planes of diamond. (e) is obtained by magnifying position e in (d). FT-e is the FT of (e), which mainly shows the diffraction information of two pairs of diamond (111) crystal planes and one pair of diamond (200) crystal planes. (e-1) is a magnification of region 1 in (e). It can be seen that the interplanar spacing in both directions is 0.206 nm and the included angle is 70°, which is consistent with the interplanar spacing of the diamond (111) plane. (f) is obtained by magnifying position f in (d). FT-f is the FT of (f), which mainly shows the diffraction information of two pairs of diamond (111) and one pair of diamond (200) crystal planes. (f-1) is a magnification of region 1 in (f), showing fringe information with a spacing of 0.206 nm in both directions and an included angle of 70°, which matches the spacing of the diamond (111) plane. Analysis indicates that the lamellar structure with a size of approximately 100 nm in the red dashed area selected in (d) is two-dimensional diamond. Therefore, we obtained both graphene and two-dimensional diamond in this sample.
[0065] Example 4
[0066] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0067] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0068] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0069] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1300 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0070] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0071] Figure 9 The Raman spectrum of Example 4 shows the position at 1350 cm⁻¹. -1 1580 cm -1 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D overtone Raman peaks with complete phonon dispersion associated with monolayer or few-layer graphene. Compared with the Raman spectrum of intrinsic flake graphite powder, the intensities of both the D and 2D peaks are increased, indicating a relative increase in the content of amorphous carbon and graphene.
[0072] Figure 10 This is the HRTEM of Example 4. (As shown) Figure 10 As shown, (a) is a low-magnification view of this position, with the main morphology being a near-circular sheet-like structure. SAED-a is the selected area electron diffraction of (a), mainly showing the (100), (002), (110), and (101) crystal plane information of graphene. (b) is a magnification of region b in (a), FT-b is the fast Fourier transform of (b), mainly showing the crystal plane diffraction information of graphene (100), FT-b1 is the FT of region 1 in (b), mainly showing the crystal plane diffraction information of graphene (100), consistent with FT-b, and (b-1) is a magnification of region 1 in (b), where a stripe pattern with a corresponding interplanar spacing of 0.213 nm can be observed, consistent with the (100) crystal plane of graphene. (c) is a magnification of region c in (a), and FT-c is the Fast Fourier Transform of (c), mainly showing the diffraction information of the crystal planes of graphene (100). (c-1) is a magnification of region 1 in (c), and it can be found that there is a stripe information in one direction corresponding to a crystal plane spacing of 0.213 nm, which is consistent with the crystal planes of graphene (100). Combined with Raman spectroscopy, it is therefore believed that the layered structure in regions b and c of (a) is graphene.
[0073] (d) is a low-magnification (200 nm) view of another location in the sample, showing a structure with multiple stacked layers. The areas with deeper contrast are regions with more overlapping layers. A high-magnification view (e) is obtained by magnifying the thin region (e) in (d). FT-e is the FT of (e). FT-e shows the diffraction information of two pairs of diamond (111) crystal planes. Region 1 in (e) is magnified to obtain (e-1) and the corresponding FT (FT-e1). The information displayed in FT-e1 matches that of FT-e. (e-1) shows fringes in two directions with a spacing of 0.206 nm and an angle of 71°, consistent with the information displayed by the FT, which is consistent with the spacing and angle information of the diamond (111) crystal planes. (f) is a high-magnification view of another region in (d), showing similar diffraction and fringing information to (e). Analysis suggests that the layered structure with a size of approximately 600 nm in the red dashed line region selected in (d) is two-dimensional diamond. Therefore, we obtained graphene and two-dimensional diamond in this sample.
[0074] Example 5
[0075] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0076] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0077] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0078] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1500 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0079] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0080] Figure 11 The Raman spectrum of Example 5 shows the position at 1350 cm⁻¹. -1 1580 cm -1 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D phonon-dispersion octave Raman peaks associated with monolayer or few-layer graphene. Comparing the Raman spectra of Example 4, it can be observed that the intensity of the D peak further decreases, while the intensity of the 2D peak tends to stabilize.
[0081] Figure 12 This is the HRTEM of Example 5. For example... Figure 12 As shown, (a) is a low-magnification view of this location (2 μm), and (b) is a magnification of region b in (a) (1 μm), where the large-sized sheet-like morphology can still be seen. (c) is a magnification of region c in (b), showing a relatively complete large-sized sheet-like morphology. SAED-c is the selected area electron diffraction of (c), mainly showing the (100) and (110) crystal plane information of graphene. (d) is a magnification of region d in (c), and FFT-d is the fast Fourier transform of (d), mainly showing the crystal plane diffraction information of graphene (100). (d-1) is a magnification of region 1 in (d), where three fringe patterns with a corresponding interplanar spacing of 0.213 nm can be found, which is consistent with the (100) crystal plane of graphene. Based on the Raman spectral information, it is therefore believed that the sheet-like structure in region b in (a) is graphene.
[0082] (e) is a low-magnification (200 nm) view of another location on the sample. SAED-e is the selected area electron diffraction of (e), which mainly shows the diffraction information of the (111)(200)(220) crystal planes of diamond. (f) is obtained by magnifying position f in (e). FT-f is the FT of (f), which mainly shows the diffraction information of two pairs of diamond (111) and one pair of diamond (220) crystal planes. (f-1) is a magnification of region 1 in (f), which shows that the interplanar spacing in both directions is 0.206 nm and the included angle is 70°, which is consistent with the interplanar spacing of the diamond (111) plane. (g) is obtained by magnifying position g in (e). FT-g is the FT of (g), mainly showing the diffraction information of two pairs of diamond (111) crystal planes, one pair of diamond (200) crystal planes, and one pair of diamond (220) crystal planes. (g-1) is a magnification of region 1 in (g), showing fringe information with a spacing of 0.206 nm and an angle of 70° in both directions, which matches the spacing of the diamond (111) plane. (g-2) is a magnification of region 2 in (g), showing fringe information with a spacing of 0.206 nm and an angle of 70° in both directions, which matches the spacing of the diamond (111) plane. Analysis indicates that the sheet-like structure with a size of approximately 1 μm in the red dashed area selected in (e) is two-dimensional diamond. Therefore, we obtained both graphene and two-dimensional diamond in this sample.
[0083] Example 6
[0084] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:0.1 to obtain raw materials.
[0085] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0086] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0087] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0088] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0089] Figure 13 The Raman spectrum of Example 6 shows the position at 1350 cm⁻¹. -1 1580 cm -1 and 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D overtone Raman peaks with complete phonon dispersion associated with monolayer or few-layer graphene, indicating the presence of graphene in the sample.
[0090] Figure 14 This is the HRTEM of Example 6. For example... Figure 14As shown, (a) is a low-magnification (1 μm) view of this location, showing an interlaced structure. Magnification analysis of edge region b yields (b), revealing a clear lamellar structure. SAED-b is the selected area electron diffraction (SEED) of (b), primarily displaying the diffraction information of the graphite (002), (100), (101), and (110) crystal planes, as well as the diamond (111) crystal plane. Magnification of regions c and d yields high-magnification views (c) and (d), along with the corresponding Fourier transforms (FTs). FT-c primarily displays the diffraction information of two pairs of graphite (002) and graphite (100) crystal planes. Magnification of region 1 in c reveals fringe information with interplanar spacings of 0.336 nm and 0.203 nm in two directions, consistent with the diffraction information of FT-c1 and FT-c. FT-d primarily displays information related to the graphite (101) and (002) crystal planes. Fringe information related to the graphite (002) crystal plane can also be seen in (d). Magnifying local and regional areas in (d) yields (d-1) and (d-2), revealing fringe information with an interplanar spacing of 0.203 nm, consistent with the corresponding FT-d1 and FT-d2 diffraction information. Therefore, the lamellar structure in the selected analytical region in (b) can be considered to be graphene. (e) is a magnification of region e in (b), with FT-e representing the FT at that location, showing diffraction information of a pair of diamond (111) crystal planes and exhibiting arc-shaped diffraction information representing a lamellar structure. Magnifying local region 1 in (e) yields (e-1) and the corresponding FT (FT-e1). FT-e1 shows the same diffraction information as FT-e, while (e-1) shows fringe information with an interplanar spacing of 0.206 nm, consistent with the diamond information. Therefore, the lamellar structure in region e in (b) can be considered to be a two-dimensional diamond structure. Thus, in this sample, we simultaneously obtained graphene and two-dimensional diamond.
[0091] Example 7
[0092] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1.5 to obtain raw materials.
[0093] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0094] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 KN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0095] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0096] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0097] Figure 15 The Raman spectrum of Example 7 shows the position at 1350 cm⁻¹. -1 1580 cm -1 and 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D overtone Raman peaks with complete phonon dispersion associated with monolayer or few-layer graphene. It can be seen that the intensity of the 2D peak exceeds that of the G peak, indicating the presence of monolayer graphene in the sample.
[0098] Figure 16 This is the HRTEM of Example 7. For example... Figure 16 As shown, (a) is a low-magnification (200 nm) view of this location, revealing a large number of overlapping and interwoven near-circular lamellar and strip structures with high density and small lamellar size. SAED-a is a selected electron diffraction at this location, mainly showing the diffraction information of the graphite (002), (100), (101), and (110) crystal planes. High-magnification (b), (c), and (d) images and corresponding FTs (FT-b, FT-c, FT-d) are obtained by magnifying regions b, c, and d in (a). FT-b shows the diffraction information of a pair of graphite (100) crystal planes, consistent with the fringe information of region 1 in (b) with a spacing of 0.212 nm. FT-c shows the diffraction information of a pair of graphite (101) crystal planes. Magnification analysis of region 1 in (c) yields (c-1) and FT-c1, which also show fringes and diffraction information consistent with FT-c. FT-d also shows the diffraction information of the (101) crystal plane of graphite. (d-1) is a magnification of region 1 in d, and FT-d1 is the corresponding FT. It can be seen that it also shows the fringes and diffraction information consistent with FT-d. Therefore, it can be considered that the lamellar structure phase of the selected analytical region in (a) is graphene.
[0099] (e) shows a low-magnification (100 nm) view of another location on the sample, mainly exhibiting a small-sized, flat or vertically stacked lamellar morphology. SAED-e is the selected area electron diffraction (SED) of (e), primarily showing the diffraction information of the (111) crystal plane of diamond. High-magnification (f) and the corresponding Fourier transform (FT) are obtained by magnifying and analyzing region f in (e). FT-f shows that it mainly displays the diffraction information of two pairs of diamond (111) crystal planes. By magnifying and analyzing regions 1 and 2 in (f), we obtained (f-1), (f-2), and the corresponding FT. It can be seen that FT-f1 and FT-f2 show the same diffraction information for the (111), (200), and (220) crystal planes of diamond as FT-f. Furthermore, (j-1) and (j-2) both show the same fringe information with a spacing of 0.206 nm and an angle of 70° between the crystal planes in two directions, consistent with the information shown in the FT. Therefore, the lamellar structure with a size of approximately 50 nm in the red dashed area selected in (e) is considered to be two-dimensional diamond. Thus, we simultaneously obtained graphene and two-dimensional diamond in this sample.
[0100] Example 8
[0101] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0102] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0103] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0104] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 10 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0105] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0106] Figure 17 The Raman spectrum of Example 8 shows the position at 1350 cm⁻¹. -1 1580 cm -1 1620 cm -1 2700cm -1 and 2950 cm -1 The five Raman peaks. 1350 cm -1 peak is sp 2D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 1620 cm⁻¹ -1 The peak is the D' peak related to graphite edge defects; 2700 cm⁻¹ -1 The peak is a frequency-harmonic Raman 2D peak with complete phonon dispersion associated with monolayer or few-layer graphene; 2950 cm⁻¹ -1 The peaks are D+D' peaks related to the expression of auxiliary defects. The intensity of the 2D peak is slightly lower than that of the G peak, indicating that the sample contains bilayer or multilayer graphene.
[0107] Figure 18 This is the HRTEM of Example 8. For example... Figure 18 As shown, (a) is a 200 nm low-magnification view of the sample at this location, showing a small number of sheets and a large number of stacked strip-like morphologies. SAED-a is a selected electron diffraction at this location, mainly showing the diffraction information of the graphite (002), (100), (101), and (110) crystal planes. Selecting a local area in (a) and magnifying it to obtain (b) clearly shows the sheet-like and strip-like morphologies with uneven contrast. (c) is a high-magnification view of the thin sheet-like structure region c in b. FT-c is the FT of (c), showing the diffraction information of a pair of graphite (100) crystal planes. Selecting a local area in c and magnifying it to obtain (c-1) shows the stripe information with a crystal plane spacing of 0.213 nm in one direction, which is consistent with the diffraction information of FT-c1 and FT-c. Therefore, it can be considered that the sheet-like structure in region c in (b) is a graphene phase.
[0108] (d) is a low-magnification (200 nm) view of another location on the sample, showing a large number of strip-like structures and lamellar morphologies stacked together. The strip-like structures are vertically oriented lamellar structures. (e) is a magnification of region e in (d). FT-e is the FT of (e), showing diffraction information mainly from a pair of diamond (111) crystal planes and a pair of graphene (101) crystal planes. FT-f is the FT of (f), showing diffraction information mainly from a pair of diamond (111) crystal planes and a pair of graphene (101) crystal planes, consistent with the diffraction information in FT-e. (f) is a magnification of region f in (e), showing fringe information with a spacing of 0.206 nm in one direction and non-overlapping fringe information with a spacing of 0.203 nm in another direction, consistent with the spacing of the diamond (111) and graphene (101) crystal planes. Therefore, graphene and two-dimensional diamond structures coexist in (f). (g) is a low-magnification view (200 nm) of another location, where numerous strip-like structures and lamellar morphologies are stacked together. (h) is a magnification of region h in (g), and FT-h is the FT of (h), showing diffraction information mainly from a pair of diamond (111) crystal planes. FT-i is the FT of (i), also showing diffraction information mainly from a pair of diamond (111) planes, consistent with the diffraction information in FT-h. (i) is a magnification of region i in (h), showing stripes with a spacing of 0.206 nm in one direction, consistent with the spacing of the diamond (111) crystal planes. Therefore, the lamellar structure belonging to region i in (h) can be considered as two-dimensional diamond with a size of approximately 150 nm. In summary, we obtained both graphene and two-dimensional diamond in this sample.
[0109] Example 9
[0110] (1) Weigh and mix single-crystal flake graphite powder and PP micro powder at a mass ratio of 1:1 to obtain raw materials.
[0111] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PP.
[0112] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0113] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 60 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0114] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0115] Figure 19 The Raman spectrum of Example 9 shows the position at 1350 cm⁻¹. -1 1580 cm -1 and 2700 cm -1 The three Raman peaks. 1350 cm -1 peak is sp 2 D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 2700 cm⁻¹ -1 The peaks are 2D overtone Raman peaks with complete phonon dispersion associated with monolayer or few-layer graphene, indicating that the sample contains graphene.
[0116] Figure 20 The HRTEM of Example 9. For example... Figure 20 As shown, (a) is a 200 nm low-magnification view of the sample at this location, showing a large number of near-circular sheet structures stacked together. Compared to Example 10, the sheet size is larger, and there are fewer strip structures. SAED-a mainly shows the diffraction information of the graphite (002), (100), (101), and (110) crystal planes. Selecting regions b, c, and d in (a) for magnified analysis yields high-magnification views (b), (c), and (d), as well as the corresponding FT (FT-b, FT-c, FT-d). FT-b shows the diffraction information of three pairs of graphite (100) crystal planes. Selected area magnification (b-1) shows the stripe information of the graphite (100) crystal planes, which is consistent with the corresponding FT (FT-b1). FT-c shows the diffraction information of two pairs of graphite (100) crystal planes and one pair of graphite (101) crystal planes. (c-1) is a magnification of region 1 in c, showing fringes with interplanar spacings of 0.213 nm and 0.203 nm, which is consistent with the diffraction information shown in FT-c1 and FT-c. FT-d shows the diffraction information of two pairs of graphite (100) crystal planes. Selected area magnification (d-1) shows fringes with interplanar spacings of 0.213 nm in both directions, which is consistent with the corresponding FT(FT-d1) and FT-d. Therefore, the sheet structure of the selected analytical region in (a) can be considered to be a graphene phase.
[0117] (e) Low magnification (200 nm) of another location of the sample shows a large number of lamellar structures and some strip structures. SAED-e is the selected area electron diffraction of (e), which mainly shows diffraction rings of graphite (002), (100), (101), and (110) crystal planes as well as diffraction information of two pairs of diamond (111) crystal planes. (f) is obtained by magnifying the position f in (e). FT-f is the FT of (f), mainly showing the diffraction information of two pairs of diamond (111) crystal planes. (g) is a magnification of region g in (f), and FT-g is the FT of (g), mainly showing the diffraction information of two pairs of diamond (111) crystal planes and one pair of diamond (200) crystal planes, which is consistent with the diffraction information of FT-f and SAED-e. At the same time, (g) shows fringe information with a spacing of 0.206 nm in both directions and an included angle of 70°, which is consistent with the spacing of the diamond (111) crystal planes. Therefore, the sheet-like structure with a size of about 200 nm in region f in (e) can be considered as two-dimensional diamond. In summary, we obtained graphene and two-dimensional diamond in this sample.
[0118] Example 10
[0119] (1) Weigh and mix single-crystal flake graphite powder and PE micro powder at a mass ratio of 1:1 to obtain raw materials.
[0120] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PE.
[0121] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0122] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press it for 30 min at a temperature of 1100 ℃ and a pressure of 2.5 GPa. After pressing, take out the sample.
[0123] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0124] Figure 21 The Raman spectrum of Example 10 shows the position at 1350 cm⁻¹. -1 1580 cm -1 1620 cm -1 and 2700cm -1 The four Raman peaks. 1350 cm -1 peak is sp 2D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 1620 cm⁻¹ -1 The peak is the D' peak induced by defects; 2700 cm⁻¹ -1 The peaks are 2D phonon-dispersion octave Raman peaks associated with monolayer or few-layer graphene. It can be seen that the ratio of the 2D peak intensity to the G peak intensity is greater than 0.5, indicating the presence of bilayer graphene in the sample and a high overall graphene content.
[0125] Figure 22 The images are HRTEM images from Example 10. (a) and (d) show the corresponding low-magnification views, revealing that the morphology is still mainly composed of flat or vertically arranged sheets. SAED-a and SAED-d both show the diffraction information of the graphite (002), (100), and (101) crystal planes. Regions b and e in (a) and (d) were selected for magnification analysis to obtain high-magnification views (b) and (e) and the corresponding FT. FT-b shows the diffraction information of three pairs of graphite (101) crystal planes. Region c in (b) was further selected for magnification to obtain (c). FT-c shows the same diffraction information as FT-b, and (c) shows fringe information with a spacing of 0.202 nm between crystal planes in three directions and adjacent angles of 60°, which is consistent with the information shown by FFT. Therefore, it can be considered that the sheet structure in region b in (a) is graphene. FT-e shows the diffraction information of a pair of graphite (101) crystal planes. Continuing to select regions 1 and 2 in (e) and magnify them to obtain (e-1), (e-2) and the corresponding FT. FT-e1 and FT-e2 both show the same diffraction information as FT-e, and (e-1 and e-2) both show fringe information with a crystal plane spacing of 0.202 nm in one direction, which is consistent with the information shown by FT. Therefore, it can be considered that the sheet structure in region e in (d) is graphene.
[0126] (f) shows a low-magnification view of another location on the sample, mainly exhibiting a small-sized, flat, layered morphology. SAED-f is the selected area electron diffraction (SED) of (f), which mainly shows diffraction rings of graphite (101) and (110) crystal planes, as well as diffraction information of two pairs of diamond (111) crystal planes. High-magnification analysis of region g in (f) yields (g) and the corresponding Fourier transform (FT). FT-g shows that it mainly displays diffraction information of two pairs of diamond (111) crystal planes and one pair of diamond (200) crystal planes. Magnified analysis of regions 1 and 2 in (g) yielded (g-1) and (g-2), along with the corresponding Fourier Transform (FT) results. FT-g1 and FT-g2 exhibited the same diffraction information as FT-g. Furthermore, both (g-1) and (g-2) displayed the same fringe pattern with a spacing of 0.206 nm and an angle of 70° in two directions, consistent with the information shown in the FT. Therefore, the lamellar structure in region g of (f) can be considered to be two-dimensional diamond with a size of approximately 200 nm. Thus, we simultaneously obtained graphene and two-dimensional diamond in this sample.
[0127] Example 11
[0128] (1) Weigh and mix single-crystal flake graphite powder and PE micro powder at a mass ratio of 1:1 to obtain raw materials.
[0129] (2) The raw materials were put into a ball mill jar and mixed for 30 min to obtain a uniformly mixed powder of single crystal flake graphite and PE.
[0130] (3) The mixed powder processed in step (2) is compressed into tablets and held under a pressure of 210 kN for 10 s. Then, the tablets are demolded to obtain tablet samples with a diameter of 23.95 mm and a thickness of 10~15 mm.
[0131] (4) Assemble the tablet sample obtained in step (3) into the six-sided top press synthesis block, place it in the six-sided top press, and press for 30 min at a temperature of 1100 ℃ and a pressure of 3.5 GPa. After pressing, take out the sample.
[0132] The composition of the samples after the experiment was observed using laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM).
[0133] Figure 23 The Raman spectrum of Example 11 shows the position at 1350 cm⁻¹. -1 1580 cm -1 1620 cm -1 2700cm -1 and 2950 cm -1 The five Raman peaks. 1350 cm -1 peak is sp 2D peak of disordered or defective states related to bonded carbon; 1580 cm⁻¹ -1 peak is sp 2 G peak for bonded carbon; 1620 cm⁻¹ -1 The peak is the D' peak induced by defects; 2700 cm⁻¹ -1 The peak is a frequency-harmonic Raman 2D peak with complete phonon dispersion associated with monolayer or few-layer graphene; 2950 cm⁻¹ -1 The peaks are D+D' peaks related to auxiliary defect expression. It can be seen that the sample at this point is mainly composed of multilayer graphene phases.
[0134] Figure 24 The image shown is an HRTEM image of Example 11. Low magnification (a) shows a morphology similar to Example 10, but with smaller graphene sheet sizes and denser packing between sheets. SAED-a still shows the diffraction information of the graphite (002), (100), and (101) crystal planes. (b), (e), and (g) are magnified views of regions b, e, and g in a, respectively, all showing clear and complete sheet structures. FT-b and FT-e both show the diffraction information of two pairs of graphite (101) crystal planes, while FT-g shows the diffraction information of three pairs of graphite (100) crystal planes. Magnified analysis of regions c and d in b yielded (c) and (d) and their corresponding Fourier Transform (FT) results. FT-c and FT-d both showed the same diffraction information as FT-b. FT-d showed diffraction information for another pair of graphite (100) crystal planes, and the interplanar spacing information shown in (c) and (d) matched the information shown in the FT results. Therefore, the sheet structure in regions (c) and (d) can be considered to be graphene. Magnified analysis of region f in e yielded (f) and its corresponding FT results. The fringes and local diffraction information matched FT-e, indicating that the sheet structure in region (f) is graphene. Magnified analysis of region h in g yielded (h) and its corresponding FT results. The fringes and local diffraction information matched FT-g, indicating that the sheet structure in region (h) is graphene.
[0135] (i) is a low-magnification (200 nm) view of another location in the sample, mainly showing a small-sized, flat or vertically arranged lamellar morphology. SAED-i mainly shows the diffraction information of the graphite (002), (100), and (101) crystal planes. High-magnification (j) and the corresponding Fourier transform (FT) are obtained by magnifying and analyzing region j in (i). FT-j shows the diffraction information of two pairs of diamond (111) crystal planes. Regions 1 and 2 in (j) are magnified and analyzed to obtain (j-1), (j-2), and the corresponding FT. FT-j1 and FT-j2 show the same diffraction information as FT-j, and both j-1 and j-2 show the same two-direction interplanar spacing of 0.206 nm and an angle of 70°, consistent with the information shown in the FT. Therefore, the lamellar structure in region j in (i) can be considered as two-dimensional diamond with a size of approximately 50 nm. Thus, we obtained both graphene and two-dimensional diamond in this sample.
Claims
1. A method of simultaneously producing graphene and two-dimensional diamond, characterized by, Comprise: The single crystal flake graphite powder and the polymer are added into a ball mill tank, and are ball-mixed uniformly, the obtained mixed powder is pressed into a tablet, and the tablet is placed in a cubic press machine, and is pressed at 1100-1500 ℃ and 1.0-4.0 GPa for 10-60 min, to obtain graphene and two-dimensional diamond; The polymer is selected from polypropylene and polyethylene.
2. The method of claim 1, wherein the graphene and two-dimensional diamond are simultaneously produced. When the polymer is polypropylene, the mass ratio of the single crystal flake graphite powder to the polypropylene is 1:0.1-1:1.
5.
3. The method of claim 1, wherein the graphene and two-dimensional diamond are simultaneously produced by the method. When the polymer is polyethylene, the mass ratio of the single crystal flake graphite powder to the polyethylene is 1:
1.
4. The method of claim 1, wherein the graphene and two-dimensional diamond are simultaneously produced. The single crystal flake graphite powder and the polymer are added into a ball mill tank, and are mixed at a self-rotation speed of 300-500 rpm and a revolution speed of 5 rpm for 30 min.
5. The method of claim 1, wherein the graphene and two-dimensional diamond are simultaneously produced. The mixed powder is pressed into a tablet by using a tablet pressing device, and the working parameters are as follows: pressure 180-260 kN, pressure maintaining time 5-30 s, and then demolding to obtain a tablet sample.
6. The method of claim 1, wherein the graphene and two-dimensional diamond are simultaneously produced. The obtained mixed powder is pressed into a tablet, and the tablet is placed in a cubic press machine, and is pressed at 1100-1500 ℃ and 2.5 GPa for 30 min.