Preparation method and application of single-layer graphene with nanopores

Abstract

The invention relates to a preparation method and application of single-layer graphene with nanopores, and belongs to the technical field of synthesis of nano materials. Comprising the following steps: S1, diluting a single-layer graphene dispersion liquid with deionized water, and adding a hydrogen peroxide solution to enable the final concentration of the mixed solution to be 0.1 M; s2, inserting a positive output electrode and a negative output electrode of a friction nano-generator into the mixed solution, starting the friction nano-generator, and continuously stirring the mixed solution to react so as to accelerate the generation of hydroxyl free radicals and quickly form nano-pores; and S3, collecting the solution after the reaction is completed, dialyzing for 3-5 times by using a dialysis bag with the size of 10kDa, and dialyzing for 3-5 hours each time, so as to finally obtain the single-layer graphene with the nanopores. The preparation cost is low, the preparation process is simple, other chemical substances are not easy to introduce in the preparation process, and large-scale batch production is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of nano material synthesis, and in particular to a preparation method of a single-layer graphene with nano holes and application thereof. Background Art

[0002] Graphene was first successfully isolated in 2004 by Andre Geim and Konstantin Novoselov of the University of Manchester in the UK through mechanical exfoliation. They used ordinary tape to peel off a single layer of graphene from a block of graphite, and this breakthrough discovery won them the 2010 Nobel Prize in Physics. Graphene is a two-dimensional material composed of carbon atoms, which are sp 2 The hybrid orbitals form hexagonal honeycomb lattices through covalent bonds. Each carbon atom is connected to three adjacent carbon atoms, and the remaining electron is in a delocalized state and can move freely, thus giving graphene excellent conductivity. This single-atom-thick structure makes graphene one of the thinnest materials known to date, with a thickness of only 0.34 nanometers.

[0003] Single-layer graphene is a two-dimensional material composed of a single carbon atom layer peeled from graphene. The main reason for preparing graphene into a single layer is that single-layer graphene has many unique physical, chemical and mechanical properties. Such as high electron mobility, high thermal conductivity, mechanical strength and flexibility, transparency, etc. These properties give single-layer graphene significant advantages in scientific research and practical applications. However, in practical applications, researchers have found that single-layer graphene with nanopores has a larger specific surface area, making it perform better in catalysis, sensing and energy storage applications. The nanopores on the surface of graphene can serve as active sites to enhance its catalytic performance. This is of great significance for electrocatalytic reactions (such as oxygen reduction reaction and hydrogen evolution reaction). At the same time, the holes help to accelerate the transmission of ions in the porous graphene structure, improving its ionic conductivity and electrochemical performance in batteries and supercapacitors. In addition, the hole structure can regulate the optical and electrical properties of porous graphene and improve its performance in optoelectronic devices, such as solar cells and photodetectors. By introducing nanopores into monolayer graphene, nanoporous monolayer graphene not only retains the excellent properties of graphene, but also overcomes its shortcomings in specific surface area, chemical activity and selective permeability, providing new possibilities for further expanding the application of graphene. In the future, with the continuous advancement of preparation technology and in-depth application research, nanoporous monolayer graphene is expected to play a more important role in energy storage, environmental protection, biomedicine and other fields.

[0004] Although single-layer graphene with nanopores has many excellent properties and broad application prospects, its research and development still faces some challenges: First of all, in terms of preparation, laser etching is currently mainly used, that is, high-energy lasers are used to perform micro-processing on the graphene surface to form a regular nanopore structure. Laser etching has high precision and controllability, and can achieve the preparation of complex patterns. However, the preparation cost is high and it is not suitable for large-scale preparation. In addition, the template method uses an organic or inorganic template to form a pore structure on the graphene surface, and then obtains porous graphene by removing the template. This aspect has a complex preparation process and is difficult to scale up. The chemical etching method is simple and easy to use. It is to form holes on the graphene surface by using a strong oxidant (such as hydrofluoric acid, nitric acid) or plasma treatment, but it is easy to introduce other chemical substances and the processing steps are cumbersome.

[0005] Therefore, developing a preparation method that can simply and efficiently etch single-layer graphene to form nanopores and can achieve large-scale production is of great significance for further large-scale development and application of single-layer graphene with nanopores in various fields of biomedicine. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a single-layer graphene with nanopores and its application. The technical solution of the present invention is as follows:

[0007] In a first aspect, a method for preparing a single-layer graphene with nanopores is provided, comprising:

[0008] S1, diluting the monolayer graphene dispersion with deionized water, and adding hydrogen peroxide solution to make the final concentration of the mixed solution 0.1M;

[0009] S2, inserting the positive and negative output electrodes of the friction nanogenerator into the mixed solution, starting the friction nanogenerator, and continuously stirring the mixed solution to react, so as to accelerate the generation of hydroxyl radicals and form nanopores quickly;

[0010] S3, collecting the solution after the reaction is completed, dialyzing it 3-5 times using a 10 kDa dialysis bag, each time for 3-5 hours, and finally obtaining a single-layer graphene with nanopores.

[0011] Optionally, the friction nanogenerator is a vertical contact-separation friction nanogenerator, a planar sliding friction nanogenerator, a single-electrode friction nanogenerator or an independent layer friction nanogenerator; preferably, it is a vertical contact-separation friction nanogenerator.

[0012] Optionally, the single-layer graphene dispersion is single-layer graphene prepared by a physical exfoliation method or a chemical method, and the solvent is deionized water with a concentration of 1 mg / ml.

[0013] Optionally, the concentration of the hydrogen peroxide solution is 0.1 mM-9.78 M, preferably 10 mM.

[0014] Optionally, in S1, the concentration of the monolayer graphene dispersion after dilution with deionized water is 10-500 μg / ml, preferably 100 μg / ml.

[0015] Optionally, the reaction temperature in S2 is room temperature, the stirring speed is 50-500 rpm, preferably 350 rpm, and the reaction time is 1-24 h, preferably 8 h.

[0016] Optionally, before S2, the step further includes: placing the mixed solution on a magnetic stirrer and stirring it at room temperature for 5 minutes to fully mix it.

[0017] In a second aspect, an application of a single-layer graphene with nanopores is provided. The single-layer graphene with nanopores is prepared by the preparation method of the single-layer graphene with nanopores described in the first aspect, and the single-layer graphene with nanopores is applied in the antibacterial field.

[0018] Optionally, the single-layer graphene with nanopores is used as an antibacterial material against Gram-positive bacteria, Gram-negative bacteria, Escherichia coli or Staphylococcus aureus.

[0019] All the above optional technical solutions can be combined arbitrarily, and the present invention does not provide detailed descriptions of the structures after the combinations.

[0020] By means of the above scheme, the beneficial effects of the present invention are as follows:

[0021] The monolayer graphene dispersion is diluted with deionized water, and a hydrogen peroxide solution is added to form a mixed solution, and then the positive and negative output electrodes of the friction nanogenerator are inserted into the mixed solution and the mixed solution is continuously stirred to react, so that the nanopores are quickly formed. A method for preparing a monolayer graphene with nanopores is provided, which has low preparation cost, simple preparation process, and is not easy to introduce other chemical substances in the preparation process. The method is simple and environmentally friendly, and the materials are easy to obtain, and the expanded production method is mature, which is conducive to the large-scale batch production of the monolayer graphene with nanopores. The monolayer graphene with nanopores prepared by the present invention has excellent photothermal properties, can effectively kill bacteria, and has obvious antibacterial effects.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a preparation method and sterilization flow chart of a single-layer graphene with nanopores provided by an embodiment of the present invention;

[0024] Figure 2 This is a sample image of a single-layer graphene with nanopores prepared in Example 1 of the present invention;

[0025] Figure 3 is an atomic force microscope image of a single-layer graphene with nanopores prepared in Example 1 of the present invention;

[0026] Figure 4 This is a photothermal image of a single-layer graphene with nanopores prepared in Example 1 of the present invention;

[0027] Figure 5 This is a schematic diagram of the survival of Escherichia coli after being treated with a single-layer graphene with nanopores prepared in Example 1 of the present invention;

[0028] Figure 6 It is a schematic diagram of the survival status of Staphylococcus aureus after being treated with the single-layer graphene with nanopores prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] like Figure 1 As shown, the method for preparing a single-layer graphene with nanopores provided by the present invention comprises the following steps:

[0031] S1, diluting the monolayer graphene dispersion with deionized water, and then adding hydrogen peroxide solution to make the final concentration of the mixed solution 0.1M.

[0032] The single-layer graphene dispersion provides a template, the single-layer graphene dispersion is single-layer graphene prepared by a physical exfoliation method or a chemical method, the solvent is deionized water, and the concentration is 1 mg / ml.

[0033] In a specific embodiment, the concentration of the hydrogen peroxide solution is 0.1 mM-9.78 M, preferably 10 mM.

[0034] In a specific embodiment, in S1, the concentration of the monolayer graphene dispersion after dilution with deionized water is 10-500 μg / ml, preferably 100 μg / ml.

[0035] S2, inserting the positive and negative output electrodes of the friction nanogenerator into the mixed solution, starting the friction nanogenerator, and continuously stirring the mixed solution for reaction to accelerate the generation of hydroxyl radicals and quickly form nanopores.

[0036] The triboelectric nanogenerator provides high voltage and low current to react with hydrogen peroxide to generate hydroxyl radicals (·OH). The triboelectric nanogenerator is a vertical contact-separation triboelectric nanogenerator, a planar sliding triboelectric nanogenerator, a single-electrode triboelectric nanogenerator or an independent layer triboelectric nanogenerator; preferably, a vertical contact-separation triboelectric nanogenerator.

[0037] In a specific embodiment, the reaction temperature in S2 is room temperature, the stirring speed is 50-500 rpm, preferably 350 rpm, and the reaction time is 1-24 h, preferably 8 h.

[0038] In a specific embodiment, before S2, the step further includes: placing the mixed solution on a magnetic stirrer and stirring it at room temperature for 5 minutes to fully mix it. Through this step, the mixed solution is stirred evenly before using the friction nanogenerator.

[0039] S3, collecting the solution after the reaction is completed, dialyzing it 3-5 times using a 10 kDa dialysis bag, each time for 3-5 hours, and finally obtaining a single-layer graphene with nanopores.

[0040] By dialysis using a 10 kDa dialysis bag, the small residual materials that have been stripped off can be removed.

[0041] To facilitate the description of the performance of the single-layer graphene with nanopores prepared by the embodiment of the present invention, a specific embodiment is provided below.

[0042] Embodiment 1:

[0043] The present embodiment provides a method for preparing a single-layer graphene with nanopores, which comprises: diluting a single-layer graphene dispersion with deionized water to a final concentration of 100 μg / ml, and then adding a hydrogen peroxide solution to a final concentration of 0.1 M of the mixed solution; placing the mixed solution on a magnetic stirrer and stirring it at room temperature for 5 minutes to fully mix it; inserting the positive and negative output electrodes of a vertical contact separation friction nanogenerator into the mixed solution, starting the friction nanogenerator, inputting the generated current into the reaction solution, and stirring the reaction solution to accelerate the generation of hydroxyl radicals, stirring continuously for 8 hours to allow nanopores to form quickly, collecting the solution after the reaction is completed, and dialyzing it 3-5 times using a 10 kDa dialysis bag, each time for 3-5 hours, to finally obtain a single-layer graphene with nanopores.

[0044] like Figure 2 As shown, it is a sample picture of the single-layer graphene with nanopores prepared in Example 1. The single-layer graphene with nanopores after dialyzing through a dialysis bag is a brown dispersion.

[0045] like Figure 3As shown, it is a schematic diagram of the result of scanning the single-layer graphene with nanopores prepared in Example 1 using an atomic force microscope. The results show that after the single-layer graphene is etched using hydroxyl radicals, holes of different sizes are formed in the middle of the sheet, indicating that the single-layer graphene with nanopores is successfully synthesized.

[0046] Furthermore, the present invention also tests the photothermal performance of the single-layer graphene with nanopores prepared in Example 1, specifically, using a thermometer to measure the temperature of the graphene after 808 laser irradiation (2W / cm 2 , 6min), the temperature changes of the control group (PBS buffer), 1mg / ml nanoporous monolayer graphene, and 2mg / ml nanoporous monolayer graphene. The measurement results are shown in Figure 4 As shown, compared with the control group, the photothermal effect of the nanoporous monolayer graphene increases with the increase of concentration. After irradiation for 200s, the temperature of 2mg / ml nanoporous monolayer graphene can reach 55°C.

[0047] Furthermore, the present invention also tests the antibacterial effect of the nanoporous monolayer graphene prepared in Example 1, and uses Staphylococcus aureus and Escherichia coli for antibacterial tests. The specific test method is as follows: First, different strains are inoculated into standard LB culture medium and cultured to about OD = 1.0. Then, the bacterial solution is dispersed in PBS buffer, nanoporous monolayer graphene, 0.5 mg / ml nanoporous monolayer graphene + 808 laser, and 1 mg / ml nanoporous monolayer graphene + 808 laser for co-incubation, and the antibacterial efficiency is calculated by coating the plate.

[0048] The test results are as follows Figure 5 As shown in the figure, compared with the control group, the survival of E. coli remained basically unchanged after being treated with nanoporous monolayer graphene; most of the E. coli were killed when 0.5 mg / ml nanoporous monolayer graphene was used + 808 laser; and almost all of the E. coli were killed when 1 mg / ml nanoporous monolayer graphene was used + 808 laser. Figure 6 As shown, the results of the antibacterial test using Staphylococcus aureus are similar to those of the Escherichia coli test. 1 mg / ml nanoporous monolayer graphene + 808 laser has a significant killing effect on bacteria and can effectively kill bacteria, thus being used as an antibacterial material.

[0049] In summary, the nanoporous single-layer graphene prepared by the present invention has good photothermal properties and has broad application prospects in the antibacterial field. In addition, the nanoporous single-layer graphene prepared by the embodiment of the present invention can also be used in the fields of anti-tumor, wastewater treatment, tissue repair or detection.

[0050] The single-layer graphene with nanopores prepared by the embodiment of the present invention can be applied in the antibacterial field, specifically as an antibacterial material against Gram-positive bacteria, Gram-negative bacteria, Escherichia coli or Staphylococcus aureus.

[0051] It should be noted that in the above content of the embodiment of the present invention, Graphpad10.1.1 software was used for statistical analysis of data, independent sample T test was used for comparison between two groups, and one-way analysis of variance was used for comparison between multiple groups. P<0.05 was considered statistically significant.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a single-layer graphene with nanopores, characterized in that: include: S1, diluting the monolayer graphene dispersion with deionized water, and adding hydrogen peroxide solution to make the final concentration of the mixed solution 0.1M; S2, inserting the positive and negative output electrodes of the friction nanogenerator into the mixed solution, starting the friction nanogenerator, and continuously stirring the mixed solution to react, so as to accelerate the generation of hydroxyl radicals and form nanopores quickly; S3, collecting the solution after the reaction is completed, dialyzing it 3-5 times using a 10 kDa dialysis bag, each time for 3-5 hours, and finally obtaining a single-layer graphene with nanopores.

2. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: The friction nanogenerator is a vertical contact-separation friction nanogenerator, a planar sliding friction nanogenerator, a single-electrode friction nanogenerator or an independent layer friction nanogenerator; preferably, the vertical contact-separation friction nanogenerator.

3. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: The single-layer graphene dispersion is a single-layer graphene prepared by a physical exfoliation method or a chemical method, and the solvent is deionized water with a concentration of 1 mg / ml.

4. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: The concentration of the hydrogen peroxide solution is 0.1 mM-9.78 M, preferably 10 mM.

5. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: In S1, the concentration of the monolayer graphene dispersion after dilution with deionized water is 10-500 μg / ml, preferably 100 μg / ml.

6. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: The reaction temperature in S2 is room temperature, the stirring speed is 50-500 rpm, preferably 350 rpm, and the reaction time is 1-24 h, preferably 8 h.

7. The method for preparing a single-layer graphene with nanopores according to claim 1, characterized in that: The S2 also includes: The mixed solution was placed on a magnetic stirrer and stirred at room temperature for 5 min to allow it to be fully mixed.

8. An application of a single-layer graphene with nanopores, wherein the single-layer graphene with nanopores is prepared by the preparation method of the single-layer graphene with nanopores according to any one of claims 1 to 7, characterized in that: The single-layer graphene with nanopores is applied in the antibacterial field.

9. The use of the single-layer graphene with nanopores according to claim 8, characterized in that: The single-layer graphene with nanopores is used as an antibacterial material in resisting Gram-positive bacteria, Gram-negative bacteria, Escherichia coli or Staphylococcus aureus.

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