Two-dimensional boron alkene, friction nano-generator and preparation method and application of friction nano-generator

Abstract

The invention relates to a two-dimensional boron alkene, a friction nano-generator and a preparation method and application thereof. The preparation method of the two-dimensional boron alkene comprises the following steps: performing ultrasonic stripping on beta-rhombic boron powder dispersion liquid to obtain the two-dimensional boron alkene, the mass of the beta-rhombic boron powder in the beta-rhombic boron powder dispersion liquid is 1-8 g; the power of the ultrasonic stripping is 2-4kW. According to the method, the beta-rhombic boron powder is used as the raw material and is matched with the specific ultrasonic stripping power, the gram-level raw material can be processed at a time to obtain the two-dimensional boron alkene, correspondingly, the two-dimensional boron alkene with the level of at least 100 milligrams can be obtained at a time, and the production efficiency of the two-dimensional boron alkene is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and more specifically, to a two-dimensional borophene, a friction nanogenerator, and a preparation method and application thereof. Background Art

[0002] With the development of 5G, the significant increase in data transmission rates has driven the rapid development of the Internet of Things (IoT). Flexible wearable sensors and electronic devices such as processors can achieve intelligent interconnection, transmitting massive amounts of data collected by human sensors to the digital world in real time via high-speed wireless networks. Triboelectric nanogenerators (TENGs) convert mechanical energy into electrical energy through electrostatic friction. Compared with other flexible sensors, TENGs are simple to prepare, low-cost, and durable. They have been proven to be stable and reliable energy harvesters and self-powered sensors, and therefore have great potential for development in the energy and biosensing fields.

[0003] The performance of a friction nanogenerator is largely determined by the performance of the friction layer material. Currently, the output voltage of a friction nanogenerator prepared with a single friction layer material (such as a polymer material) is limited, and its output voltage easily decays after long-term operation, resulting in its inability to work stably for a long time. Therefore, various methods are needed to improve its working performance.

[0004] Due to their excellent properties, two-dimensional materials are often used as charge capture materials and compounded with polymer materials to form nanocomposites. Their use can significantly increase the output voltage of friction nanogenerators.

[0005] Two-dimensional (2D) borophene has been a hot topic of research in recent years. The use of 2D borophene composites as friction layers in triboelectric nanogenerators has been reported (DOI: 10.1002 / advs.202201507). However, existing preparation processes can only produce small amounts of 2D borophene per batch, resulting in low production efficiency and difficulty meeting the demand for large-scale borophene in TENG device fabrication. Summary of the Invention

[0006] The primary purpose of the present invention is to overcome the problem of low production efficiency of two-dimensional borophene produced by the above-mentioned existing preparation process and to provide a preparation method of two-dimensional borophene.

[0007] A further object of the present invention is to provide a two-dimensional borophene.

[0008] A further object of the present invention is to provide an application of the above-mentioned two-dimensional borophene in the preparation of a triboelectric nanogenerator.

[0009] A further object of the present invention is to provide a triboelectric nanogenerator.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] A method for preparing two-dimensional borophene comprises the following steps:

[0012] Ultrasonic exfoliation is performed on a dispersion of β-rhombus boron powder to obtain the two-dimensional borophene;

[0013] The mass of the β-rhombus boron powder in the β-rhombus boron powder dispersion is 1 to 8 g;

[0014] The power of the ultrasonic peeling is 2-4 kW.

[0015] In the prior art, χ3 boron powder can only be used to produce two-dimensional borophene via CVD, and the resulting two-dimensional borophene cannot be separated from the substrate. Alternatively, two-dimensional borophene can be obtained by ultrasonic exfoliation of α-rhombic boron powder. However, this process can only process milligrams of raw material at a time, yielding only ten milligrams of two-dimensional borophene at a time, resulting in low production efficiency. If the amount of raw material processed at a time is too large, the ultrasonic exfoliation power must be increased accordingly. However, if the ultrasonic exfoliation power is too high, the stability of the borophene is significantly reduced. Even at low temperatures (<10°C), two-dimensional borophene cannot be obtained, and instead, borophene oxide is primarily obtained.

[0016] Through research, the inventors discovered that using β-rhombic boron powder as the raw material and combining it with a specific ultrasonic exfoliation power, it is possible to process grams of raw material in a single pass to produce two-dimensional borophene, yielding at least 100 milligrams of 2D borophene. This significantly improves the production efficiency of 2D borophene. This is because 2D borophene maintains excellent stability even under high-power ultrasonic exfoliation.

[0017] If the ultrasonic exfoliation power is too low, the peel strength per unit of β-rhombic boron powder is insufficient, and the boron powder cannot be exfoliated into two-dimensional borophene. If the ultrasonic exfoliation power is too high, the two-dimensional borophene will be oxidized and the dispersant in the dispersion may volatilize, making ultrasonic exfoliation impossible.

[0018] The inventors of the present invention also discovered that two-dimensional borophene prepared from other types of boron powder (such as α-rhombus) is an intrinsic semiconductor. The two-dimensional borophene obtained by the preparation method of the present invention is a P-type semiconductor. In addition to having a high specific capacitance, it is also easier to obtain electrons. Moreover, due to its ridge structure and large specific surface area, it has a stronger ability to capture electrons. At the same time, the rich electron state density in the pz orbit near the Fermi level enables it to have the ability to accommodate a large number of electrons. These two effects make the output voltage of the friction nanogenerator higher.

[0019] Surprisingly, the two-dimensional borophene obtained by the preparation method of the present invention has a Dirac cone, which can make the two-dimensional borophene have very high differential quantum capacitance, surface storage charge and integral capacitance, thus showing a very high specific capacitance, which can greatly weaken the charge decay behavior of the friction nanogenerator during operation and effectively improve its working stability.

[0020] In the present invention, the mass of the β-rhombus boron powder can be 1, 2, 3, 4, 5, 6, 7 or 8 g; and the power of the ultrasonic stripping can be 2, 3 or 4 kW.

[0021] Preferably, the dispersant of the β-rhombus boron powder dispersion is at least one of ethanol, acetone, acetonitrile, N,N-dimethylformamide (DMF) or N-methylpyrrolidone (NMP).

[0022] Preferably, the β-rhombus boron powder in the β-rhombus boron powder dispersion is amorphous β-rhombus boron powder.

[0023] Preferably, the dosage ratio of the β-rhombus boron powder and the dispersant in the β-rhombus boron powder dispersion is (0.5-2) g:1 L.

[0024] Preferably, the preparation process of the β-rhombus boron powder dispersion is as follows: adding the β-rhombus boron powder into a dispersant to obtain the dispersion.

[0025] Preferably, before the ultrasonic peeling, a step of preheating the ultrasonic equipment is also included.

[0026] Preferably, the ultrasonic peeling time is 8 to 12 hours.

[0027] Preferably, the temperature of the ultrasonic stripping is ≤20°C; more preferably 5-20°C.

[0028] Preferably, the ultrasonic stripping further includes the steps of separation and drying.

[0029] More preferably, the separation process is:

[0030] Let it stand, take the supernatant, centrifuge at 10000-12000 rpm for 8-15 minutes, and take the precipitate;

[0031] Or let it stand, take the supernatant, centrifuge it at 1200-1700 rpm for 8-15 minutes, take supernatant A, centrifuge supernatant A at 1200-1700 rpm for 1 minute to obtain supernatant B, centrifuge supernatant B at 1200-1700 rpm for 8-15 minutes to obtain supernatant C, centrifuge supernatant C at 10000-12000 rpm for 8-15 minutes, and take the precipitate;

[0032] Or let it stand, take the supernatant, centrifuge it at 2300-2700 rpm for 8-15 min to obtain supernatant D, then centrifuge the supernatant D at 2300-2700 rpm for 1 min to obtain supernatant E, then centrifuge the supernatant E at 2300-2700 rpm for 8-15 min to obtain supernatant F, then centrifuge the supernatant F at 10000-12000 rpm for 8-15 min to take the precipitate.

[0033] A two-dimensional borophene is prepared by the above preparation method.

[0034] Preferably, the thickness of the two-dimensional borophene is 3 to 5 nm.

[0035] The application of the above-mentioned two-dimensional borophene in the preparation of a friction nanogenerator is also within the scope of the present invention.

[0036] A triboelectric nanogenerator comprises a first triboelectric electrode layer, wherein the first triboelectric electrode layer comprises a two-dimensional borene composite material layer, and the two-dimensional borene composite material layer comprises a polymer material and the above-mentioned two-dimensional borene.

[0037] The friction nanogenerator of the present invention can have either a single-electrode structure or a double-electrode structure.

[0038] Preferably, the thickness of the first friction electrode layer is 600-1000 μm.

[0039] Preferably, the preparation process of the two-dimensional borophene composite material layer is: mixing a two-dimensional borophene dispersion with a polymer material, and solidifying the mixture to obtain the composite material.

[0040] More preferably, the mass of the two-dimensional borophene dispersion is 10-50% of the mass of the polymer material; and the content of two-dimensional borophene in the two-dimensional borophene dispersion is 0.5-2 mg / mL.

[0041] Preferably, the first friction electrode layer further includes a conductive layer stacked with the two-dimensional borene composite material layer.

[0042] More preferably, the material of the conductive layer includes but is not limited to at least one of Cu, Al, ITO or Ag.

[0043] More preferably, the thickness of the conductive layer is 50-100 μm.

[0044] Preferably, the polymer material is at least one of polydimethylsiloxane, EcoFlex silicone, polyvinylidene fluoride or polytetrafluoroethylene.

[0045] Preferably, the triboelectric nanogenerator further includes a second triboelectric electrode layer; the first triboelectric electrode layer is a negative friction layer, and the second triboelectric electrode layer is a positive friction layer.

[0046] When the triboelectric nanogenerator of the present invention further includes a second triboelectric electrode layer, it has a dual-electrode structure.

[0047] More preferably, the second friction electrode layer includes a stacked polymer material layer and a conductive layer; the material of the polymer material layer includes but is not limited to at least one of nylon, polylactic acid or polytetrafluoroethylene; the material of the conductive layer includes but is not limited to at least one of Cu, Al, ITO or Ag.

[0048] More preferably, the thickness of the polymer material layer is 100-200 μm.

[0049] More preferably, the thickness of the conductive layer is 50-100 μm.

[0050] Preferably, the triboelectric generator further includes a sealing layer.

[0051] More preferably, the thickness of the sealing layer is 50-100 μm.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] (1) The present invention uses β-rhombus boron powder as raw material and cooperates with a specific ultrasonic stripping power to process gram-level raw materials in a single process to obtain two-dimensional borophene, and obtains at least hundreds of milligrams of two-dimensional borophene, which greatly improves the production efficiency of two-dimensional borophene.

[0054] (2) Compared to two-dimensional borophene prepared from other boron powders, the two-dimensional borophene prepared by the preparation method of the present invention has a stronger ability to capture electrons due to its ridge structure and large specific surface area. Furthermore, the rich density of electron states in the pz orbital near the Fermi level enables it to accommodate a large number of electrons. These two factors contribute to a higher output voltage of the triboelectric nanogenerator. Due to the structural asymmetry of the two-dimensional borophene itself, the piezoelectric charge generated by the external force can also serve as an additional charge source to further enhance the electrical performance of the triboelectric nanogenerator.

[0055] (3) The two-dimensional borophene obtained by the preparation method of the present invention has a Dirac cone, which can make the two-dimensional borophene have very high differential quantum capacitance, surface storage charge and integral capacitance, and thus exhibit a very high specific capacitance, which can greatly weaken the charge decay behavior during the operation of the friction nanogenerator and effectively improve its working stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is an AFM image of the product obtained in step 4.1) of Example 1.

[0057] Figure 2This is an AFM image of the product obtained in step 4.2) of Example 1.

[0058] Figure 3 This is an AFM image of the product obtained in step 4.3) of Example 1.

[0059] Figure 4 This is the XPS chart of the product obtained in step 4.3) of Example 1.

[0060] Figure 5 This is the SEM image of the product obtained in step 4.3) of Example 1.

[0061] Figure 6 TEM image of the product obtained in step 4.3) of Example 1.

[0062] Figure 7 Schematic diagram of the structure of the friction nanogenerator of Example 4.

[0063] Figure 8 Schematic diagram of the structure of the friction nanogenerator of Example 5.

[0064] Figure 9 Graph (A) and its broken line graph (B) showing the output voltage test results of the friction nanogenerator of Example 4.

[0065] Figure 10 This is a graph showing the output voltage test results of the friction nanogenerator of Example 5.

[0066] Figure 11 This is a graph showing the output voltage test results of the friction nanogenerator of Example 5 after being pressed continuously for 15,000 times. DETAILED DESCRIPTION

[0067] In order to more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0068] Example 1

[0069] This embodiment provides a method for preparing two-dimensional borophene, comprising the following steps:

[0070] 1) Weigh 2 g of amorphous β-rhombic boron powder (brand: RHAWN) and introduce it into 2 L of anhydrous ethanol to obtain a β-rhombic boron powder dispersion.

[0071] 2) Preheat the ultrasonic equipment (Ningbo Xianchang XC-4000) to 15°C, and then place the β-rhombus boron powder dispersion into the ultrasonic equipment;

[0072] 3) ultrasonically exfoliating the β-rhombus boron powder dispersion (ultrasonic exfoliation conditions are: power 3 kW, temperature 15° C., time 12 h) to obtain a boron olefin dispersion;

[0073] 4) Separation:

[0074] The boron olefin dispersion was allowed to stand for 24 h, and 100 mL of the supernatant (F) was taken and subjected to the following treatments 4.1), 4.2), and 4.3) respectively:

[0075] 4.1) Centrifuge the supernatant at 11,000 rpm for 10 min, collect the precipitate, and dry it to obtain the product;

[0076] 4.2) The supernatant was centrifuged at 1500 rpm for 10 min to obtain supernatant A, which was then centrifuged at 1500 rpm for 10 min to obtain supernatant B. Supernatant B was then centrifuged at 1500 rpm for 10 min to obtain supernatant C. Supernatant C was then centrifuged at 11000 rpm for 10 min. The precipitate was collected and dried to obtain the product.

[0077] 4.3) The supernatant was centrifuged at 2500 rpm for 10 min to obtain supernatant D, which was then centrifuged at 2500 rpm for 10 min to obtain supernatant E. Supernatant E was then centrifuged at 2500 rpm for 10 min to obtain supernatant F. Supernatant F was then centrifuged at 11000 rpm for 10 min. The precipitate was collected and dried to obtain the product.

[0078] The AFM image of the product obtained by 4.1) is as follows Figure 1 As shown, from Figure 1 The boron layers are stacked layer by layer on a 5nm thick two-dimensional borophene, forming three thickness steps: 54nm, 82nm, and 106nm, with the thickness gradually decreasing from the center to the edge. This process yields approximately 1200mg of product, a 60% yield.

[0079] The AFM image of the product obtained by 4.2) is as follows Figure 2 As shown, from Figure 2 The boron layers are stacked layer by layer on the two-dimensional borophene, with a maximum thickness of 40nm. This process yields a product mass of approximately 500mg, or a 40% yield.

[0080] The AFM image of the product obtained by 4.3) is as follows Figure 3 As shown, from Figure 3 The maximum thickness of the two-dimensional borophene is 3.7 nm. This process yields a product mass of approximately 200 mg, or a 10% yield.

[0081] As can be seen above, two-dimensional borophene can be obtained through the treatments in 4.1), 4.2), and 4.3). The products of 4.1) and 4.2) also contain a certain amount of multilayer boron, while the product of 4.3) is high-purity two-dimensional borophene. Therefore, the yield of two-dimensional borophene obtained by the preparation method of this example is 10%.

[0082] Figure 4 The XPS diagram of the product obtained by 4.3) is shown in FIG. Figure 4 It can be seen that the proportion of BO bonds is much smaller than that of BB bonds, which is the normal edge oxidation of two-dimensional borophene, proving that what is obtained is two-dimensional borophene, rather than boron oxide or borophene oxide.

[0083] Figure 5 is the SEM picture of the product obtained by 4.3), Figure 5 It can be seen that the products are all translucent flake materials, which eliminates the possibility of bulk boron and further proves that what is obtained is high-purity two-dimensional borophene.

[0084] Figure 6 The TEM image of the product obtained by 4.3) further proves that what is obtained is two-dimensional borophene.

[0085] Example 2

[0086] This embodiment provides a method for preparing two-dimensional borophene, which is different from that of Example 1 in that the amount of amorphous β-rhombus boron powder used in step 1) is 6 g.

[0087] Example 3

[0088] This embodiment provides a method for preparing two-dimensional borophene, which is different from that of Example 1 in that the power of ultrasonic exfoliation in step 3) is 2 kW.

[0089] The experimental results of Example 2 and Example 3 are similar to those of Example 1, and both obtain high-purity two-dimensional borophene with a yield of more than 10%.

[0090] Example 4

[0091] This embodiment provides a triboelectric nanogenerator, which includes a first triboelectric electrode layer, such as Figure 7 As shown, the first triboelectrode layer comprises, from top to bottom, a two-dimensional borophene composite material layer 1 and a conductive layer 2. The conductive layer 2 is 50 μm thick and made of copper; the two-dimensional borophene composite material layer 1 is 1000 μm thick and made of PDMS and the two-dimensional borophene obtained in 4.3) of Example 1.

[0092] The method for preparing the triboelectric nanogenerator of this embodiment includes the following steps:

[0093] 1) Preparation of a two-dimensional borophene dispersion: Disperse the two-dimensional borophene obtained in 4.3) of Example 1 in anhydrous ethanol at room temperature and perform water bath sonication for 30 min to obtain a two-dimensional borophene dispersion with a concentration of 1 mg / mL;

[0094] 2) Preparation of two-dimensional borophene nanocomposites: First, a two-dimensional borophene dispersion was mixed with PDMS glue A in a certain ratio (the two-dimensional borophene dispersion accounted for 10 wt.%, 20 wt.%, 30 wt.%, 40 wt.% or 50 wt.% of the glue A), and stirred for 2 h to fully mix to form a two-dimensional borophene-PDMS mixture; secondly, the two-dimensional borophene-PDMS mixture was mixed with PDMS glue B (curing agent) (the mass ratio of glue A to glue B was 10:1), and stirred for 45 min to uniformly mix to form a two-dimensional borophene-PDMS colloid; finally, the two-dimensional borophene-PDMS colloid was introduced into a mold and placed in an oven at 80°C for 2 h to obtain a two-dimensional borophene composite material layer;

[0095] 3) Electrode preparation: Use conductive glue to bond the two-dimensional boron olefin composite material layer to the copper foil to form the first friction electrode layer, thereby obtaining a friction nanogenerator with a single electrode structure.

[0096] Example 5

[0097] This embodiment provides a triboelectric nanogenerator, which includes a first triboelectric electrode layer and a second triboelectric electrode layer. Figure 8 As shown, it includes, from top to bottom, a first sealing layer 3, a first copper foil 4, a two-dimensional borene composite material layer 5 with a protruding structure, a nylon membrane 6, a second copper foil 7 and a second sealing layer 8; the thickness of the first copper foil 4 and the second copper foil 7 are both 50 μm; the thickness of the nylon membrane 6 is 100 μm, the thickness of the two-dimensional borene composite material layer 5 with a protruding structure is 600 μm, wherein the height of the protruding structure is 500 μm, and the material is PDMS and the two-dimensional borene obtained in 4.3) of Example 1; the material of the sealing layer is polyimide, and the thickness is 100 μm.

[0098] The method for preparing the triboelectric nanogenerator of this embodiment includes the following steps:

[0099] 1) Preparation of a two-dimensional borophene dispersion: The two-dimensional borophene obtained in 4.3) of Example 1 was dispersed in anhydrous ethanol at room temperature and subjected to water bath sonication for 30 min to prepare a two-dimensional borophene dispersion with a concentration of 1 mg / mL.

[0100] 2) Preparation of two-dimensional borophene nanocomposites: First, a two-dimensional borophene dispersion was mixed with PDMS glue A in a certain ratio (the two-dimensional borophene dispersion accounted for 10wt.%, 20wt.%, 30wt.%, 40wt.% or 50wt.% of the glue A), and stirred for 2 hours to fully mix to form a two-dimensional borophene-PDMS mixture; secondly, the two-dimensional borophene-PDMS mixture was mixed with PDMS glue B (curing agent) (the mass ratio of glue A to glue B was 10:1), and stirred for 45 minutes to uniformly mix to form a two-dimensional borophene-PDMS colloid; finally, the two-dimensional borophene-PDMS colloid was introduced into a mold with a spacer layer structure and placed in an oven at 80°C for 2 hours to obtain a two-dimensional borophene composite material layer with a protruding structure;

[0101] 3) bonding the copper foil and the non-protrusion surface of the two-dimensional boron olefin composite material layer with the protrusion structure using a conductive adhesive to form a first triboelectrode layer;

[0102] 4) A layer of Cu was deposited on the nylon film by magnetron sputtering to form a second triboelectrode layer;

[0103] 5) Packaging: The first sealing layer and the second sealing layer are used to stack and seal the second triboelectrode layer, wherein the surface with the protrusions in the first triboelectrode layer contacts the nylon of the second triboelectrode layer, thereby obtaining a triboelectric nanogenerator with a dual-electrode structure.

[0104] Comparative Example 1

[0105] This comparative example provides a friction generator, which is different from Example 4 in that the two-dimensional borophene composite material layer is replaced by a pure PDMS layer, that is, the friction layer does not contain two-dimensional borophene.

[0106] Comparative Example 2

[0107] This comparative example provides a friction generator, which is different from Example 5 in that the two-dimensional borophene composite material layer with a protruding structure is replaced by a pure PDMS layer with a protruding structure, that is, the friction layer does not contain two-dimensional borophene.

[0108] Performance Testing

[0109] Figure 9The output voltages of the two-dimensional boron olefin nanocomposite triboelectric nanogenerators at different weight ratios for the triboelectric generators of Example 4 (10 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.%) and Comparative Example 1 (0 wt.%), under conditions of a contact-separation cycle of 4 Hz and a contact pressure of 5 N. At a weight ratio of 0 wt.%, the output voltage of the PDMS-based TENG device was 75 V. As the amount of two-dimensional boron olefin increased, the output voltage of the triboelectric nanogenerator first increased and then decreased. When the weight ratio of two-dimensional boron olefin increased to 40 wt.%, the triboelectric nanogenerator achieved optimal output performance, with its output voltage increasing to 205 V, approximately three times the output voltage of the triboelectric nanogenerator device without the addition of two-dimensional boron olefin. The above research clearly demonstrates that the use of two-dimensional boron olefin nanocomposite materials significantly improves the output voltage of the triboelectric nanogenerator, which may provide new ideas for achieving high-performance triboelectric nanogenerators.

[0110] Figure 10 The output voltages of the two-dimensional boron olefin nanocomposite triboelectric nanogenerators at different weight ratios are shown for the triboelectric generators of Example 5 (10 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.%) and Comparative Example 2 (0 wt.%), when the contact-separation cycle is 4 Hz and the contact pressure is 5 N. At a weight ratio of 0 wt.%, the output voltage of the PDMS-based TENG device is 80 V. As the amount of two-dimensional boron olefin increases, the output voltage of the triboelectric nanogenerator first increases and then decreases. When the weight ratio of two-dimensional boron olefin increases to 40 wt.%, the triboelectric nanogenerator achieves optimal output performance, with its output voltage increasing to 310 V, which is approximately 3.8 times the output voltage of the triboelectric nanogenerator device without the addition of two-dimensional boron olefin.

[0111] Figure 11 This is the output voltage graph of the triboelectric nanogenerator of Example 5 (the ratio of two-dimensional boron olefin to A-gel is 40 wt.%) under the above test conditions after 15,000 consecutive presses. Figure 9 It can be seen that the performance degradation of the triboelectric nanogenerator is only about 3%, indicating that it has good working stability.

[0112] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing two-dimensional borophene, characterized in that: The steps include: Ultrasonic exfoliation is performed on a dispersion of β-rhombus boron powder to obtain the two-dimensional borophene; The mass of the β-rhombus boron powder in the β-rhombus boron powder dispersion is 1 to 8 g; The power of the ultrasonic peeling is 2-4 kW.

2. The preparation method according to claim 1, characterized in that The dispersion liquid of the β-rhombus boron powder dispersion liquid is at least one of ethanol, acetone, acetonitrile, N,N-dimethylformamide or N-methylpyrrolidone.

3. The preparation method according to claim 1, characterized in that: The dosage ratio of the β-rhombus boron powder and the dispersant in the β-rhombus boron powder dispersion is (0.5-2) g:1 L.

4. The preparation method according to claim 1, characterized in that The ultrasonic peeling time is 8 to 12 hours.

5. The preparation method according to claim 1, characterized in that: The temperature of the ultrasonic stripping is ≤20°C.

6. A two-dimensional borophene, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the two-dimensional borophene according to claim 6 in the preparation of a triboelectric nanogenerator.

8. A triboelectric nanogenerator, characterized in that: The invention comprises a first friction electrode layer, wherein the first friction electrode layer comprises a two-dimensional borene composite material layer, and the two-dimensional borene composite material layer comprises a polymer material and the two-dimensional borene according to claim 6.

9. The triboelectric nanogenerator according to claim 8, characterized in that: The polymer material is at least one of polydimethylsiloxane, ecoflex silicone, polyvinylidene fluoride or polytetrafluoroethylene.

10. The triboelectric nanogenerator according to claim 8, characterized in that: The friction nanogenerator also includes a second friction electrode layer; the first friction electrode layer is a negative friction layer, and the second friction electrode layer is a positive friction layer.

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