A device and method for process-controlled large-area double-layer two-dimensional material transfer

Abstract

The present invention provides a process-controlled large-area double-layer two-dimensional material transfer device and method thereof, the device comprising a metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, an electrode clip, a counter electrode, a reference electrode, an electrochemical workstation, two electrode sheets, a constant potential instrument, an electrolyte, and an electrolytic cell; wherein the two electrode sheets are placed horizontally or vertically in the electrolytic cell. The device of the present invention has strong practicality, simple structure, and low cost, and can obtain a large-area double-layer two-dimensional material sample, which has a cleaner surface than the double-layer two-dimensional material sample obtained by the transfer method, and has a more controllable size and angle than the double-layer two-dimensional material sample obtained by the chemical vapor deposition method.

Description

Technical Field

[0001] The present invention belongs to the technical field of two-dimensional material transfer, and specifically relates to a device and method for transferring a double-layer two-dimensional material. Background Art

[0002] Since people successfully stripped a single layer of graphene from natural graphite for the first time in 2004, its unique physical and chemical properties have attracted widespread attention. At the same time, the van der Waals interaction between graphene layers is also an effective means to regulate its physical properties. In 2018, it was found that if double-layer graphene is stacked at a specific twist angle (such as the "magic angle"), it can exhibit rich physical properties such as unconventional superconductivity, Mott insulator state, moiré excitons and ferromagnetism, and has broad application prospects in the fields of semiconductors, integrated circuits, and corrosion protection. However, at present, the preparation of graphene-like double-layer two-dimensional material samples still has problems such as high technical difficulty, complex process, small size, and uncontrollable angle. For example, the size of double-layer graphene flakes prepared by electrochemical exfoliation (method for preparing high-quality graphene by electrochemical efficient exfoliation, CN103991862A) is small, and the method of multiple transfer (method for preparing multilayer graphene structure with controllable twist angle, CN104029431A) is technically difficult, complex process, and the quality of graphene is not high due to polymer attachment. The double-layer graphene prepared by chemical vapor deposition (a large single-crystal double-layer graphene and its preparation method, CN106335897A) has problems such as difficulty in controlling the angle. Therefore, it is necessary to develop a method that is simple, highly controllable, and can prepare double-layer two-dimensional materials over a large area. Summary of the invention

[0003] The present invention provides a device and method for transferring a large-area double-layer two-dimensional material with process control, wherein the metal foil on the surface of the double-layer two-dimensional material is uniformly etched by a constant electric field to obtain a large-area double-layer two-dimensional material sample. During the etching process, the etching process can be precisely controlled by monitoring by an electrochemical method. The technical solution of the present invention is as follows:

[0004] A device for process-controlled large-area double-layer single-crystal two-dimensional material transfer, comprising a metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, an electrode clamp, a counter electrode, a reference electrode, an electrochemical workstation, two electrode sheets, a constant potential instrument, an electrolyte, and an electrolytic cell; wherein one side of the metal foil-double-layer two-dimensional material-metal foil sample is glued to the glue or tape, the edge is sealed with glue or tape, and is fixed with an electrode clamp; the electrode clamp, the counter electrode, and the reference electrode are connected to the electrochemical workstation; the two electrode sheets are connected to the constant potential instrument; the metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, the electrode clamp, the counter electrode, the reference electrode, and the two electrode sheets are placed in an electrolytic cell filled with an electrolyte; wherein the metal foil-double-layer two-dimensional material-metal foil sample comprises a plurality of electrodes stacked in sequence. A first metal foil, a first layer of two-dimensional material, a second layer of two-dimensional material and a second metal foil are arranged in a stacked manner. The metal foil-double-layer two-dimensional material-metal foil sample includes a first surface and a second surface arranged opposite to each other, and the first surface and the second surface extend along a plane perpendicular to the stacking direction; wherein the first surface is the surface of the first metal foil away from the first layer of two-dimensional material, and the second surface is the surface of the second metal foil away from the second layer of two-dimensional material; all sides of the metal foil-double-layer two-dimensional material-metal foil sample are sealed with glue or tape, and the first surface of the metal foil-double-layer two-dimensional material-metal foil sample is sealed with glue or tape. The two-dimensional materials include graphene, borene, silicene, germanene, stanene, black phosphorus, boron nitride, and transition metal dichalcogenides. The materials of the metal foil include copper, nickel, and iron.

[0005] Among them, the metal foil-double-layer two-dimensional material-metal foil sample is made by hot pressing or hot melting two pieces of metal foils covered with single crystal two-dimensional materials to obtain a large-area double-layer two-dimensional material with controllable angle in the sandwich of the two layers of metal foils. The two-dimensional material on the outside of the metal foil is removed by acid pickling, plasma etching or tape tearing.

[0006] Among all the surfaces of the sample, only the second surface is in contact with the electrolyte, that is, only the second metal foil in the sample is in contact with the electrolyte.

[0007] The material of the glue or tape includes one or more of polyurethane, polydimethylsiloxane, polymethyl methacrylate, polypropylene, polyethylene, and polyvinyl chloride.

[0008] Among them, the electrode clip and the counter electrode are made of one of inert metals such as platinum, gold, and silver, the reference electrode is one of silver / silver chloride, mercury / mercurous chloride, mercury / mercurous oxide, and mercury-mercurous sulfate electrodes, and the distance between the electrode clip, the counter electrode, and the reference electrode and the liquid surface is 0 to 1 m.

[0009] The material of the electrode sheet is one of the inert metals such as gold, silver, platinum, palladium, rhodium, iridium, osmium and their alloys or one of the non-metallic carbon felt, graphite sheet, conductive glass and their composite materials, with a thickness of 1 to 200 μm. The two electrode sheets are placed horizontally or vertically opposite to each other in the electrolytic cell filled with electrolyte, and the electrode area is 1 cm 2 ~10m 2 , the electrode spacing is 1cm~1m.

[0010] The electrolyte is an aqueous electrolyte, and the electrolyte includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, and ammonium persulfate, with a concentration of 10 μM to 1M.

[0011] The length of the electrolytic cell is 4 cm to 1 m, the width is 4 cm to 4 m, the height is 5 cm to 4 m, and the main components are one or more of fiber, rubber, and plastic;

[0012] The operating method of the device for large-area double-layer two-dimensional material transfer controlled by the above process comprises the following steps:

[0013] (1) placing two electrode sheets horizontally or vertically in an electrolytic cell, adding electrolyte into the electrolytic cell to immerse the two electrode sheets, applying power to the two electrode sheets through a potentiostat, and forming an electric field in the electrolyte between the electrode sheets;

[0014] (2) gluing the first surface of the metal foil-double-layer two-dimensional material-metal foil sample to glue or tape, sealing all sides with glue or tape, exposing the second surface, fixing it with an electrode clamp, placing it in the electrolyte forming the electric field in parallel with the electrode sheet, and etching the second surface of the metal foil exposed to the electrolyte;

[0015] (3) placing the counter electrode and the reference electrode in an electrolyte, connecting the three electrodes through an electrochemical workstation and applying a small voltage to monitor the current change on the metal foil-double-layer two-dimensional material-metal foil sample;

[0016] (4) When it is determined based on the current monitoring results that the second metal foil has been completely etched to expose the position of the double-layer two-dimensional material, the potentiostat and the electrochemical workstation are turned off, the etched sample is taken out, and it is washed with deionized water to obtain a clean double-layer two-dimensional material sample.

[0017] The electric field strength applied by the potentiostat is 0.1 V / cm to 10 V / cm.

[0018] The voltage applied by the electrochemical workstation is 0.001V to 0.1V, which is the voltage relative to the reference electrode.

[0019] Beneficial effects of the present invention:

[0020] 1. The process-controlled large-area double-layer two-dimensional material transfer device of the present invention includes metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, electrode clamp, counter electrode, reference electrode, electrochemical workstation, two electrode sheets, constant potentiostat, electrolyte, and electrolytic cell; the composition and structure of the device are simple, the cost is low, the use is convenient, and the size controllability is strong.

[0021] 2. The process-controlled large-area double-layer two-dimensional material transfer method of the present invention utilizes the principle of stable migration of ions in a constant electric field to achieve the purpose of uniformly etching the metal foil on the surface of the double-layer two-dimensional material, thereby obtaining a large-area double-layer two-dimensional material sample; during the etching process, electrochemical technology is used to monitor the current on the sample surface, so as to accurately control the etching process and achieve the purpose of accurately and controllably etching the metal foil to obtain a large-area double-layer two-dimensional material. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0023] Figure 1 A schematic diagram of the angle control of stacked metal foils according to the present invention;

[0024] Figure 2 It is a schematic diagram of the high temperature bonding process and the removal of a layer of substrate on the surface of the present invention;

[0025] Figure 3 , 8 It is a structural schematic diagram of the device of the present invention;

[0026] In the figure: 1-electrode sheet, 2-potentiostat, 3-metal foil-double-layer two-dimensional material-metal foil sample, 4-glue or tape, 5-electrode clip, 6-counter electrode, 7-reference electrode, 8-electrochemical workstation, 9-electrolyte, 10-electrolytic cell;

[0027] Figure 4 Take photos of the optical microscope of the large area of ​​double-layer graphene obtained;

[0028] Figure 5 To monitor the current change curve on the copper foil-double-layer graphene-copper foil sample;

[0029] Figure 6 for Figure 5 The result curve of taking the current derivative of the curve;

[0030] Figure 7 The current change curve for monitoring the single-layer copper foil without graphene growth. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1:

[0033] like Figure 3 As shown, the device for large-area double-layer two-dimensional material transfer controlled by the process of the present invention comprises an electrode sheet 1, a potentiostat 2, a metal foil-double-layer two-dimensional material-metal foil sample 3, glue or tape 4, an electrode clip 5, a counter electrode 6, a reference electrode 7, an electrochemical workstation 8, an electrolyte 9, and an electrolytic cell 10; the electrode sheet 1 comprises a first electrode sheet and a second electrode sheet. Among them, the metal foil-double-layer two-dimensional material-metal foil sample 3 comprises a first metal foil, a first layer of two-dimensional material, a second layer of two-dimensional material, and a second metal foil stacked in sequence, and the metal foil-double-layer two-dimensional material-metal foil sample 3 comprises a first surface and a second surface arranged oppositely, and the first surface and the second surface extend along a plane perpendicular to the stacking direction. Among them, the first surface is the surface of the first metal foil away from the first layer of two-dimensional material, and the second surface is the surface of the second metal foil away from the second layer of two-dimensional material. The metal foil-double-layer two-dimensional material-metal foil sample 3 also includes a side extending along the stacking direction of the metal foil-double-layer two-dimensional material-metal foil sample 3, and the side connects the first surface and the second surface. Typically, the side surfaces include four side surfaces arranged along the circumference of the metal foil-double-layer two-dimensional material-metal foil sample 3 .

[0034] The method is as follows: an electrode sheet 1 is placed horizontally in an electrolytic cell 10, an electrolyte 9 is added to the electrolytic cell 10, and two electrode sheets are energized through a potentiostat 2 to form an electric field; a metal foil-double-layer two-dimensional material-metal foil sample 3 is then glued to glue or tape 4, the edge of the sample 3 is sealed with glue or tape 4, and fixed with an electrode clamp 5, and placed in an electrolyte 9 that forms an electric field; a counter electrode 6 and a reference electrode 7 are then placed in the electrolyte 9, the three electrodes are connected through an electrochemical workstation 8, and a voltage of 0.1 V relative to the reference electrode is applied, and the current change on the metal foil-double-layer two-dimensional material-metal foil sample 3 is monitored; the position of etching to the double-layer two-dimensional material is determined according to the current change. The potentiostat and the electrochemical workstation are turned off, the metal foil-double-layer two-dimensional material-metal foil sample is taken out, and it is washed with ultrapure water to obtain a clean double-layer two-dimensional material sample. The edge of the sample 3 is sealed with glue or tape 4, including using glue or tape 4 to seal all sides of the sample 3. Sticking the metal foil-double-layer two-dimensional material-metal foil sample 3 on glue or tape 4 includes sealing the first surface of the sample 3 with glue or tape 4, leaving only the second surface not sealed by glue or tape 4, or only the second surface of all the surfaces of the sample 3 is in contact with the electrolyte 9, that is, only the second metal foil in the sample 3 is in contact with the electrolyte 9.

[0035] Among them, the metal foil-double-layer two-dimensional material-metal foil laminated sample can be prepared by the following steps:

[0036] S1. providing a single crystal substrate stack having a certain interlayer angle;

[0037] In this step, if Figure 1 As shown, the plurality of single crystal substrates include a stacked first single crystal substrate 11 and a second single crystal substrate 21, wherein the first single crystal substrate 11 is located below the second single crystal substrate 21. A single crystal substrate can be cut into two single crystal substrates of the same or similar size. The first single crystal substrate 11 and the second single crystal substrate 21 are stacked and the second single crystal substrate 21 is rotated relative to the first single crystal substrate by a certain angle α, as shown in FIG. Figure 1 α2 in (a), Figure 1 α1 in (b) means that there is a certain interlayer rotation angle α between the first single crystal substrate 11 and the second single crystal substrate 21. In a specific embodiment, the overlapping area between the first single crystal substrate 11 and the second single crystal substrate 21 may be 30%-90% of the area of ​​the first single crystal substrate 11 or the area of ​​the second single crystal substrate 21. The first crystal orientation of the first single crystal substrate 11 and the second crystal orientation of the second single crystal substrate 21 have a certain interlayer rotation angle α, wherein the first crystal orientation and the second crystal orientation are the same crystal orientation. The single crystal substrate includes Cu, Au, Ag, Fe, Ni, Co, Ge, Pt, etc., with a thickness between 1μm and 1cm and an area of ​​1mm 2 ~1m 2In a specific embodiment, the Cu(111) direction of the first single crystal metal foil 11 and the Cu(111) direction of the second single crystal metal foil 21 have a certain interlayer rotation angle α.

[0038] The interlayer turning angle α can be designed according to needs, for example, the interlayer turning angle α can be 0°<α<90°.

[0039] In this step, the first single crystal substrate 11 and the second single crystal substrate 21 only need to be stacked in an upper and lower order without any special treatment, even if there is a certain gap between the first single crystal substrate 11 and the second single crystal substrate 21 .

[0040] S2, growing two-dimensional single crystal materials on opposite surfaces of two single crystal substrates in the single crystal substrate stack;

[0041] In this step, the single crystal substrate stack is placed in a chemical vapor deposition device, inert gas and reducing gas are introduced, and when the temperature is raised to 700-1100°C, the gas source required for growth or the solid source required for heating growth is introduced, and the growth time is 1s-48h.

[0042] In a specific embodiment, a single crystal substrate stack is placed in a chemical vapor deposition apparatus, Ar and H2 are introduced, the Ar flow rate is more than 300 sccm, the H2 flow rate is 0.1 to 200 sccm, and the working pressure is normal pressure (i.e., one atmosphere or about 1×10 5 Pa), and then start heating, the heating process lasts for 15 to 90 minutes; when the temperature rises to 700 to 1100 ° C, CH4 is introduced, the CH4 flow rate is 0.1 to 50 sccm, and the growth time is 1 second to 48 hours. Figure 2 As shown in (a), two-dimensional single crystal materials are grown on two opposite surfaces of the first single crystal substrate 11 and the second single crystal substrate 21, that is, the first two-dimensional single crystal material 31 is grown on the upper surface of the first single crystal substrate 11, and the second two-dimensional single crystal material 41 is grown on the lower surface of the second single crystal substrate 21. In a specific embodiment, the first two-dimensional single crystal material 31 and the second two-dimensional single crystal material 41 are both monolayer graphene.

[0043] Since the growth of two-dimensional single crystal materials has a certain selectivity, and there is a certain interlayer rotation angle α between the first single crystal substrate 11 and the second single crystal substrate 21, the first two-dimensional single crystal material 31 and the second two-dimensional single crystal material 41 also have a certain interlayer rotation angle α, and the obtained two-dimensional material single crystal has a thickness between 0.1nm and 100μm and an area of ​​1mm 2 ~1m 2 between.

[0044] S3, bonding the two-dimensional single crystal material;

[0045] In this step, if Figure 2 As shown in (b), the first two-dimensional single crystal material 31 and the second two-dimensional single crystal material 41 are bonded together by high-temperature hot melting or hot pressing. In a specific embodiment, after the growth of step S2 is completed, the supply of CH4 gas source is stopped, and Ar and H2 are used as protective gases at a temperature of 1050-1084°C to perform high-temperature bonding or hot pressing to bond the upper and lower single crystal materials.

[0046] In this embodiment:

[0047] The electrode sheet 1 is made of inert metal gold, with a thickness of 50 μm and an area of ​​25 cm 2 The electrode spacing between the two electrode sheets 1 is 5 cm.

[0048] Metal foil - double-layer two-dimensional material - Metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene. The material of the metal foil is single crystal copper, and there is a large area of ​​double-layer graphene in the interlayer of the two layers of metal foil.

[0049] The material of the glue or tape 4 is polyurethane.

[0050] The counter electrode 6 is platinum, the reference electrode 7 is mercury / mercurous chloride, and the distance between the electrode clamp 5, the counter electrode 6, and the reference electrode 7 and the liquid surface is 3 cm.

[0051] The electrolyte 9 is an aqueous solution of ammonium persulfate with a concentration of 100 μM.

[0052] The electrolytic cell 10 has a length of 10 cm, a width of 5 cm, a height of 10 cm, and is mainly composed of plastic;

[0053] The electric field strength of the electric field applied by the potentiostat 2 was 0.2 V / cm.

[0054] The voltage applied by the electrochemical workstation 8 was 0.05 V compared to the reference electrode 7 .

[0055] Attached Figure 4 To etch the metal foil-double-layer graphene-metal foil sample; Figure 5 The electrochemical curve of the process. In the gray area (corresponding to the etching time of about 90-96min, Figure 6 For Figure 5 The derivative results show that the slope rises rapidly between 90 and 96 minutes, and after 96 minutes the slope is greater than 1, which can be used as one of the characteristic points of polishing cutoff. The metal foil-double-layer graphene-metal foil sample is taken out and washed with ultrapure water to obtain a large area of ​​double-layer graphene.

[0056] Embodiment 2:

[0057] like Figure 3 As shown, the device for large-area double-layer two-dimensional material transfer controlled by the process of the present invention includes an electrode sheet 1, a potentiostat 2, a single metal foil 3 on which no two-dimensional material is grown, glue or tape 4, an electrode clamp 5, a counter electrode 6, a reference electrode 7, an electrochemical workstation 8, an electrolyte 9, and an electrolytic cell 10; the method is: the electrode sheet 1 is horizontally placed in the electrolytic cell 10, the electrolyte 9 is added into the electrolytic cell 10, and the two electrode sheets are energized through the potentiostat 2 to form an electric field; then the single metal foil 3 on which no two-dimensional material is grown is glued to the glue or tape 4, the edge is sealed with glue or tape 4, and it is fixed with the electrode clamp 5, and placed in the electrolyte 9 that forms the electric field; then the counter electrode 6 and the reference electrode 7 are placed in the electrolyte 9, the three electrodes are connected through the electrochemical workstation 8, and a voltage of 0.1V relative to the reference electrode is applied to monitor the current change on the single metal foil 3 on which no two-dimensional material is grown. The glue or tape 4 seals the upper surface and four sides of the metal foil 3 , but the glue or tape 4 does not seal the lower surface of the metal foil 3 , that is, the lower surface of the metal foil 3 is in contact with the electrolyte 9 .

[0058] In this embodiment:

[0059] Metal foil - double-layer two-dimensional material - Metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene. The material of the metal foil is single crystal copper, and there is a large area of ​​double-layer graphene in the interlayer of the two layers of metal foil.

[0060] The electrode sheet 1 is made of inert metal gold, with a thickness of 25 μm and an area of ​​25 cm 2 The electrode spacing between the two electrode sheets 1 is 5 cm.

[0061] The material of the glue or tape 4 is polyurethane.

[0062] The counter electrode 6 is platinum, the reference electrode 7 is mercury / mercurous chloride, and the distance between the electrode clamp 5, the counter electrode 6, and the reference electrode 7 and the liquid surface is 3 cm.

[0063] The electrolyte 9 is an aqueous solution of ammonium persulfate with a concentration of 100 μM.

[0064] The electrolytic cell 10 has a length of 10 cm, a width of 5 cm, a height of 10 cm, and is mainly composed of plastic;

[0065] The electric field strength of the electric field applied by the potentiostat 2 was 0.2 V / cm.

[0066] The voltage applied by the electrochemical workstation 8 was 0.05 V compared to mercury / mercurous chloride.

[0067] Attached Figure 7The electrochemical curve of the process of etching a single copper foil 3 without graphene growth is shown in FIG. Compared with the first embodiment, the current is relatively stable during the etching process, and the current drops rapidly after the single copper foil is completely etched.

[0068] Embodiment three:

[0069] like Figure 8 As shown, the device for large-area double-layer two-dimensional material transfer controlled by the process of the present invention comprises an electrode sheet 1, a potentiostat 2, a metal foil-double-layer two-dimensional material-metal foil sample 3, glue or tape 4, an electrode clamp 5, a counter electrode 6, a reference electrode 7, an electrochemical workstation 8, an electrolyte 9, and an electrolytic cell 10; the method is as follows: the electrode sheet 1 is vertically placed in the electrolytic cell 10, the electrolyte 9 is added into the electrolytic cell 10, and the two electrode sheets are energized by the potentiostat 2 to form an electric field; the metal foil-double-layer two-dimensional material-metal foil sample 3 is then glued to the glue or tape 4, the edge is sealed with glue or tape 4, and it is fixed with the electrode clamp 5, and placed in the electrolyte 9 forming the electric field; the counter electrode 6 and the reference electrode 7 are then placed in the electrolyte 9, the three electrodes are connected by the electrochemical workstation 8 and a voltage of 0.1 V relative to the reference electrode is applied, and the current change on the metal foil-double-layer two-dimensional material-metal foil sample 3 is monitored; and the position of etching to the double-layer two-dimensional material is determined according to the current change. Turn off the potentiostat and electrochemical workstation, take out the metal foil-double-layer two-dimensional material-metal foil sample, wash it with ultrapure water, and obtain a clean double-layer two-dimensional material sample.

[0070] Sealing the edge of the sample 3 with glue or tape 4 includes sealing all sides of the sample 3 with glue or tape 4. Sticking the metal foil-double-layer two-dimensional material-metal foil sample 3 to the glue or tape 4 includes sealing the first surface of the sample 3 with glue or tape 4, leaving only the second surface unsealed by the glue or tape 4, or only the second surface of all surfaces of the sample 3 is in contact with the electrolyte 9, that is, only the second metal foil in the sample 3 is in contact with the electrolyte 9. The metal foil-double-layer two-dimensional material-metal foil laminated sample is prepared by the same method as in Example 1.

[0071] In this embodiment:

[0072] Metal foil - double-layer two-dimensional material - Metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene. The material of the metal foil is single crystal copper, and there is a large area of ​​double-layer graphene in the interlayer of the two layers of metal foil.

[0073] The electrode sheet 1 is made of inert metal gold, with a thickness of 50 μm and an area of ​​25 cm 2 The electrode spacing between the two electrode sheets 1 is 5 cm.

[0074] The metal foil-double-layer graphene-metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene, and a large area of ​​double-layer graphene is sandwiched between the two layers of metal foil.

[0075] The material of the glue or tape 4 is polyurethane.

[0076] The counter electrode 6 is platinum, the reference electrode 7 is mercury / mercurous chloride, and the distance between the electrode clamp 5, the counter electrode 6, and the reference electrode 7 and the liquid surface is 3 cm.

[0077] The electrolyte 9 is an aqueous solution of ammonium persulfate with a concentration of 100 μM.

[0078] The electrolytic cell 10 has a length of 10 cm, a width of 5 cm, a height of 10 cm, and is mainly composed of plastic;

[0079] The electric field strength of the electric field applied by the potentiostat 2 was 0.2 V / cm.

[0080] The voltage applied by the electrochemical workstation 8 was 0.05 V compared to mercury / mercurous chloride.

[0081] A large-area double-layer two-dimensional material can also be obtained by this method, but the area is slightly smaller than that of Example 1.

[0082] Embodiment 4:

[0083] The device for large-area double-layer two-dimensional material transfer controlled by the process of the present invention comprises an electrode sheet 1, a potentiostat 2, a metal foil-double-layer two-dimensional material-metal foil sample 3, glue or tape 4, an electrode clamp 5, an electrolyte 9, and an electrolytic cell 10; the method is as follows: the electrode sheet 1 is horizontally placed in the electrolytic cell 10, the electrolyte 9 is added to the electrolytic cell 10, and the two electrode sheets are energized by the potentiostat 2 to form an electric field; then the metal foil-double-layer two-dimensional material-metal foil sample 3 is glued to the glue or tape 4, the edge is sealed with glue or tape 4, and fixed with an electrode clamp 5, and placed in the electrolyte 9 that forms the electric field. The polishing condition of the metal foil is judged by observing the color change of the metal foil on the electrode surface. When the color changes, the metal foil-double-layer two-dimensional material-metal foil sample is taken out and washed with ultrapure water to obtain a clean double-layer two-dimensional material sample.

[0084] Sealing the edge of the sample 3 with glue or tape 4 includes sealing all sides of the sample 3 with glue or tape 4. Sticking the metal foil-double-layer two-dimensional material-metal foil sample 3 to the glue or tape 4 includes sealing the first surface of the sample 3 with glue or tape 4, leaving only the second surface unsealed by the glue or tape 4, or only the second surface of all surfaces of the sample 3 is in contact with the electrolyte 9, that is, only the second metal foil in the sample 3 is in contact with the electrolyte 9. The metal foil-double-layer two-dimensional material-metal foil laminated sample is prepared by the same method as in Example 1.

[0085] In this embodiment:

[0086] Metal foil - double-layer two-dimensional material - Metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene. The material of the metal foil is single crystal copper, and there is a large area of ​​double-layer graphene in the interlayer of the two layers of metal foil.

[0087] The electrode sheet 1 is made of inert metal gold, with a thickness of 50 μm and an area of ​​25 cm 2 The electrode spacing between the two electrode sheets 1 is 5 cm.

[0088] The metal foil-double-layer two-dimensional material-metal foil sample 3 is obtained by hot pressing two pieces of metal foil covered with graphene. There is a large area of ​​double-layer graphene in the sandwich between the two layers of metal foil. The electrode clamp 5 clamps the metal foil-double-layer two-dimensional material-metal foil sample 3 at a distance of 0 cm from the liquid surface, that is, it is placed close to the electrode sheet 1.

[0089] The material of the glue or tape 4 is polyurethane.

[0090] The electrolyte 9 is an aqueous solution of ammonium persulfate with a concentration of 100 μM.

[0091] The electrolytic cell 10 has a length of 10 cm, a width of 5 cm, a height of 10 cm, and is mainly composed of plastic;

[0092] The electric field strength of the electric field applied by the potentiostat 2 was 0.2 V / cm.

[0093] Since the etching process of the double-layer two-dimensional material sample obtained by this embodiment is not monitored, the obtained double-layer sample has the problem that the surface of the double-layer two-dimensional material is not accurately etched and the double-layer two-dimensional material sample has defects.

[0094] Embodiment five:

[0095] The device for large-area double-layer two-dimensional material transfer controlled by the process of the present invention comprises an electrode sheet 1, a constant potential instrument 2, a metal foil-double-layer two-dimensional material-metal foil sample 3, glue or tape 4, an electrode clamp 5, a counter electrode 6, a reference electrode 7, an electrochemical workstation 8, an electrolyte 9, and an electrolytic cell 10; the method is as follows: the electrode sheet 1 is horizontally placed in the electrolytic cell 10, the electrolyte 9 is added into the electrolytic cell 10, and two electrode sheets are energized through the constant potential instrument 2 to form an electric field; the metal foil-double-layer two-dimensional material-metal foil sample 3 is then glued to the glue or tape 4, the edge is sealed with the glue or tape 4, and it is fixed with the electrode clamp 5, and placed in the electrolyte 9 that forms the electric field; the counter electrode 6 and the reference electrode 7 are then placed in the electrolyte 9, the three electrodes are connected through the electrochemical workstation 8 and a voltage of 0.05V relative to the reference electrode is applied, and the current change on the metal foil-double-layer two-dimensional material-metal foil sample 3 is monitored; and the position of etching to the double-layer two-dimensional material is judged according to the current change. Turn off the potentiostat and electrochemical workstation, take out the metal foil-double-layer two-dimensional material-metal foil sample, wash it with ultrapure water, and obtain a clean double-layer two-dimensional material sample.

[0096] Sealing the edge of the sample 3 with glue or tape 4 includes sealing all sides of the sample 3 with glue or tape 4. Sticking the metal foil-double-layer two-dimensional material-metal foil sample 3 to the glue or tape 4 includes sealing the first surface of the sample 3 with glue or tape 4, leaving only the second surface unsealed by the glue or tape 4, or only the second surface of all surfaces of the sample 3 is in contact with the electrolyte 9, that is, only the second metal foil in the sample 3 is in contact with the electrolyte 9. The metal foil-double-layer two-dimensional material-metal foil laminated sample is prepared by the same method as in Example 1.

[0097] In this embodiment:

[0098] Metal foil - double-layer two-dimensional material - Metal foil sample 3 is obtained by hot pressing two metal foils covered with graphene. The material of the metal foil is single crystal copper, and there is a large area of ​​double-layer graphene in the interlayer of the two layers of metal foil.

[0099] The electrode sheet 1 is made of inert metal platinum, with a thickness of 25 μm and an area of ​​1 m 2 The electrode distance between the two electrode sheets 1 is 0.5 m.

[0100] Metal foil-double-layer two-dimensional material-metal foil sample 3 is obtained by hot pressing two metal foils covered with two-dimensional materials, and a large area of ​​double-layer graphene is in the interlayer between the two layers of metal foil.

[0101] The material of the glue or tape 4 is polydimethylsiloxane.

[0102] The counter electrode 6 is platinum, the reference electrode 7 is silver / silver chloride, and the distance between the electrode clip 5, the counter electrode 6, and the reference electrode 7 and the liquid surface is 3 cm.

[0103] The electrolyte 9 is a sulfuric acid aqueous solution with a concentration of 1 mM.

[0104] The electrolytic cell 10 has a length of 0.5 m, a width of 1 m, a height of 1.5 m, and is mainly composed of plastic;

[0105] The electric field strength of the electric field applied by the potentiostat 2 was 0.5 V / cm.

[0106] The voltage applied by the electrochemical workstation 8 was 0.1 V vs. silver / silver chloride.

[0107] Through this embodiment, a large-area double-layer two-dimensional material of meter level can be obtained.

[0108] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations shall all fall within the scope defined by the appended claims.

Claims

1. A process-controlled large-area double-layer two-dimensional material transfer device, characterized in that: It includes a metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, an electrode clamp, a counter electrode, a reference electrode, an electrochemical workstation, two electrode sheets, a constant potential instrument, an electrolyte, and an electrolytic cell; wherein one surface and all sides of the metal foil-double-layer two-dimensional material-metal foil sample are sealed with glue or tape and fixed with an electrode clamp; the electrode clamp, the counter electrode, and the reference electrode are connected to the electrochemical workstation; the two electrode sheets are connected to the constant potential instrument; the metal foil-double-layer two-dimensional material-metal foil sample, glue or tape, the electrode clamp, the counter electrode, the reference electrode, and the two electrode sheets are placed in an electrolytic cell filled with electrolyte, and the electrode clamp, the counter electrode, and the reference electrode are placed between the two electrode sheets.

2. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The metal foil-double-layer two-dimensional material-metal foil sample includes a first metal foil, a first layer of two-dimensional material, a second layer of two-dimensional material and a second metal foil stacked in sequence, and the metal foil-double-layer two-dimensional material-metal foil sample includes a first surface and a second surface arranged opposite to each other, and the first surface and the second surface extend along a plane perpendicular to the stacking direction; wherein the first surface is the surface of the first metal foil away from the first layer of two-dimensional material, and the second surface is the surface of the second metal foil away from the second layer of two-dimensional material; the metal foil-double-layer two-dimensional material-metal foil sample also includes edges and sides extending along the stacking direction of the metal foil-double-layer two-dimensional material-metal foil sample; the two-dimensional material includes graphene, borene, silicene, germanene, stanene, black phosphorus, boron nitride, or transition metal dichalcogenides, and the material of the metal foil includes copper, nickel, or iron.

3. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 2, characterized in that: The metal foil-double-layer two-dimensional material-metal foil sample is made by hot pressing or hot melting two pieces of metal foil covered with single crystal two-dimensional material to obtain a large-area double-layer two-dimensional material with controllable angle in the sandwich of the two layers of metal foil. The two-dimensional material on the outside of the metal foil is removed by acid washing, plasma etching or tape tearing.

4. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 3, characterized in that: Among all the surfaces of the sample, only the second surface is in contact with the electrolyte, that is, only the second metal foil in the sample is in contact with the electrolyte.

5. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The material of the glue or tape includes one or more of polyurethane, polydimethylsiloxane, polymethyl methacrylate, polypropylene, polyethylene, and polyvinyl chloride.

6. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The electrode clip and the counter electrode are made of one of the inert metals platinum, gold, and silver; the reference electrode is one of the electrodes selected from silver / silver chloride, mercury / mercurous chloride, mercury / mercurous oxide, and mercury-mercurous sulfate; the distance between the electrode clip, the counter electrode, and the reference electrode and the liquid surface is 0 to 1 m.

7. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 6, characterized in that: The distance is 0~10 cm.

8. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The material of the electrode sheet is one of the inert metals gold, silver, platinum, palladium, rhodium, iridium, osmium or their alloys, or one of the non-metallic carbon felt, graphite sheet, conductive glass or their composite materials, with a thickness of 1~200 µm. The two electrode sheets are placed horizontally or vertically opposite to each other in the electrolytic cell filled with electrolyte, and the electrode area is 1 cm 2 ~10 m 2 , the electrode spacing is 1 cm~1 m.

9. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The electrolyte is an aqueous electrolyte, and the electrolyte includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, and ammonium persulfate, with a concentration of 10µM~1M.

10. The process-controlled large-area double-layer two-dimensional material transfer device according to claim 1, characterized in that: The length of the electrolytic cell is 4 cm~1 m, the width is 4 cm~4 m, and the height is 5 cm~4 m. The main components are one or more of fiber, rubber, and plastic.

11. A method for large-area double-layer two-dimensional material transfer using the device according to any one of claims 1 to 8, comprising the following steps: (1) Place two electrode sheets horizontally or vertically in an electrolytic cell, add electrolyte into the electrolytic cell to immerse the two electrode sheets, and apply power to the two electrode sheets through a potentiostat to form an electric field in the electrolyte between the electrode sheets; (2) gluing the first surface of the metal foil-double-layer two-dimensional material-metal foil sample to glue or tape, sealing all sides with glue or tape, exposing the second surface, fixing it with an electrode clamp, placing it in the electrolyte forming the electric field in parallel with the electrode sheet, and etching the second surface of the metal foil exposed to the electrolyte; (3) Place the counter electrode and the reference electrode in the electrolyte, connect the three electrodes through an electrochemical workstation and apply a small voltage to monitor the current change on the metal foil-double-layer two-dimensional material-metal foil sample; (4) When it is determined based on the current monitoring results that the second metal foil has been completely etched and the position of the double-layer two-dimensional material is exposed, the potentiostat and the electrochemical workstation are turned off, the etched sample is taken out, and it is washed with deionized water to obtain a clean double-layer two-dimensional material sample.

12. The process-controlled large-area double-layer two-dimensional material transfer method according to claim 11, characterized in that: The electric field strength applied by the potentiostat ranged from 0.1 V / cm to 10 V / cm.

13. The process-controlled large-area double-layer two-dimensional material transfer method according to claim 12, characterized in that: The voltage applied by the electrochemical workstation was 0.001 V~0.1 V, which was the voltage relative to the reference electrode.

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