A method for preparing zero-dimensional structured black phosphorus nano-functional materials using plasma technology

Abstract

The present invention relates to a method for preparing a zero-dimensional structured black phosphorus nano-functional material using plasma technology, which comprises the following steps: S1) preparing a two-dimensional black phosphorus nanosheet solution; S2) using atmospheric pressure plasma to treat an organic solution of two-dimensional black phosphorus nanosheets at room temperature to obtain a solution having black phosphorus zero-dimensional nanomaterials; S3) separating black phosphorus zero-dimensional nanomaterials from the solution having black phosphorus zero-dimensional nanomaterials obtained in step S2); in step S2), the atmospheric pressure plasma treatment time is 10 to 40 minutes; in step S1), the concentration of two-dimensional black phosphorus nanosheets in the two-dimensional black phosphorus nanosheet solution is 10 μg / mL to 1 mg / mL, and the organic solution is a mixture of an organic solvent and water. The method of the present invention can prepare black phosphorus zero-dimensional nanomaterials in a short time at room temperature and for the first time proposes the concept of preparing zero-dimensional structured nanomaterials by plasma oxidation shearing.

Description

Technical Field

[0001] The invention belongs to the field of low-dimensional nano material preparation, and specifically relates to a method for preparing zero-dimensional structured black phosphorus nano functional materials using plasma technology. Background Art

[0002] Black phosphorus quantum dots are a type of black phosphorus nanomaterial with a zero-dimensional structure. Due to the quantum confinement effect and edge effect, black phosphorus quantum dots are expected to have better photoelectric properties than black phosphorus bulk materials. Currently, the methods for preparing black phosphorus quantum dots include liquid exfoliation, solvent thermal synthesis, electrochemical exfoliation, pulsed laser irradiation, etc. Black phosphorus crystals or blocks are usually used as starting materials, such as China's invention patent CN107442144B, a bandgap adjustable black phosphorus quantum dot photocatalyst and its preparation method and application, that is, using black phosphorus crystal powder as a precursor and a mixed solution of N-methylpyrrolidone and oleic acid as a reaction solvent, and preparing it under heating conditions of 150-200°C and a holding time of 6-24 hours. Another example is China's invention patent CN110229667B, a composite material of black phosphorus quantum dots, titanium dioxide and black phosphorus quantum dots, and its preparation method and application, which is to add black phosphorus blocks to a nitrogen-saturated aqueous solution, ultrasonically treat for 2-6 hours in an ice-water bath to obtain a black phosphate nanosheet dispersion, add it to a reactor at 180-200°C, and hydrothermally react for 6-12 hours to obtain an aqueous solution containing black phosphorus quantum dots. Existing methods can well prepare zero-dimensional black phosphorus quantum dot materials, but require higher reaction heat and longer reaction time. Therefore, how to further simplify the preparation process, improve preparation efficiency, reduce energy consumption, and shorten reaction time has become a technical breakthrough direction for the preparation of zero-dimensional black phosphorus nanomaterials.

[0003] Atmospheric pressure plasma technology is an important means of material preparation and functionalization. Black phosphorus nanomaterials can be prepared using atmospheric pressure plasma. In terms of quantum dot preparation, atmospheric pressure plasma can also achieve the preparation of carbon quantum dots, such as CN2012104055867 Carbon quantum dot preparation method based on atmospheric pressure microplasma technology, CN201510423597.5 Normal pressure microplasma assisted preparation method and application of acid-resistant carbon quantum dots, CN202110750654.6 A method for preparing fluorescent carbon quantum dots using gas-liquid two-phase plasma technology, etc. These known technologies show the advantages of atmospheric pressure plasma in preparing quantum dots, but the above methods all use organic matter containing carbon elements to undergo chemical reactions under the action of plasma to generate carbon quantum dots, which is different from the preparation of zero-dimensional black phosphorus materials using two-dimensional black phosphorus materials. Those skilled in the art still face problems such as low efficiency, high energy consumption, and long reaction time in preparing zero-dimensional black phosphorus materials. Summary of the invention

[0004] The prior art generally adopts a higher reaction temperature and a longer reaction time to prepare black phosphorus quantum dots. In view of the problems existing in the prior art, the purpose of the present invention is to propose a method for quickly and efficiently preparing black phosphorus quantum dot materials using plasma technology.

[0005] One aspect of the present invention provides a method for preparing a black phosphorus zero-dimensional nanomaterial, the preparation method comprising the following steps:

[0006] S1) preparing a two-dimensional black phosphorus nanosheet solution;

[0007] S2) treating an organic solution of two-dimensional black phosphorus nanosheets at room temperature with atmospheric pressure plasma to obtain a solution having black phosphorus zero-dimensional nanomaterials;

[0008] S3) separating the black phosphorus zero-dimensional nanomaterial from the solution containing the black phosphorus zero-dimensional nanomaterial obtained in step S2);

[0009] In step S2), the atmospheric pressure plasma treatment time is 10 minutes to 40 minutes;

[0010] In step S1), the concentration of the two-dimensional black phosphorus nanosheets in the two-dimensional black phosphorus nanosheet solution is 10 μg / mL to 1 mg / mL, and the organic solution is a mixture of an organic solvent and water.

[0011] Further, the atmospheric pressure plasma is selected from the plasma generated inside the solution or the plasma generated above the solution.

[0012] Further, the gas used in the atmospheric pressure plasma is selected from argon, nitrogen, air, and helium;

[0013] Further, the atmospheric pressure plasma is selected from gas-liquid plasma, liquid phase plasma, plasma jet, etc.;

[0014] Furthermore, the organic solution is a mixture of an organic solvent and water, wherein the volume ratio of the organic solvent to water is 1:0.01 to 1:0.1.

[0015] Furthermore, the organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0016] Furthermore, the normal temperature is 20-35°C.

[0017] Further, in step S2), the atmospheric pressure plasma jet is a plasma generated above the solution, and the length from the solution is 1-20 mm, preferably 5-15 mm.

[0018] Furthermore, the concentration of two-dimensional black phosphorus nanosheets in the two-dimensional black phosphorus nanosheet solution is 20 μg / mL, 30 μg / mL, 40 μg / mL, 50 μg / mL, 60 μg / mL, 70 μg / mL, 80 μg / mL, 90 μg / mL, 100 μg / mL, 200 μg / mL, 300 μg / mL, 400 μg / mL, 500 μg / mL, 600 μg / mL, 700 μg / mL, 800 μg / mL, 900 μg / mL, and 1 mg / mL.

[0019] Furthermore, the black phosphorus zero-dimensional nanomaterial is black phosphorus quantum dots or black phosphorus clusters.

[0020] Furthermore, the size of the black phosphorus zero-dimensional nanomaterial is 0.1-5 nm.

[0021] Furthermore, the size of the black phosphorus quantum dots is 1-5 nm, and the size of the black phosphorus clusters is 0.1-1 nm.

[0022] Furthermore, in step S2), the plasma treatment time for generating the black phosphorus quantum dots is no more than 30 minutes, for example, 10-25 minutes; the plasma treatment time for generating the black phosphorus clusters is more than 30 minutes, for example, 30-40 minutes.

[0023] Furthermore, in step S3), the separation method is centrifugation or filtration.

[0024] Furthermore, the rotation speed used for centrifugation is 5000-25000 rpm, and the supernatant is taken after centrifugation.

[0025] Another aspect of the present invention provides a black phosphorus zero-dimensional nanomaterial, which is prepared by the above-mentioned preparation method.

[0026] Furthermore, the black phosphorus zero-dimensional nanomaterial is black phosphorus quantum dots or black phosphorus clusters.

[0027] Furthermore, the size of the black phosphorus zero-dimensional nanomaterial is 0.1-5 nm.

[0028] Beneficial Effects

[0029] Compared with the prior art, the present invention can prepare black phosphorus zero-dimensional nanomaterials in a short time at room temperature and proposes for the first time the concept of preparing zero-dimensional structured nanomaterials by plasma oxidation shearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a scanning electron microscope photo of the prepared black phosphorus quantum dots. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation modes of the present invention are described in detail below, but it should not be understood as limiting the applicable scope of the present invention.

[0032] Example 1

[0033] 0.5 mg of two-dimensional black phosphorus nanosheets were placed in 10 mL of N,N-dimethylformamide solution containing 1% water by volume, and then a plasma jet was constructed using helium as the discharge gas. The organic solution containing black phosphorus nanosheets was treated with an atmospheric pressure plasma jet at room temperature, with a jet distance of 5 mm from the solution and a treatment time of 20 minutes. The treated solution was centrifuged at 8000 rpm, and the supernatant was taken to obtain black phosphorus quantum dots with a zero-dimensional structure of 3-5 nm in size.

[0034] Figure 1 The figure shows a scanning electron microscope photo of black phosphorus quantum dots in a solution. As shown in the figure, the quantum dots prepared by the method of the present invention have regular shapes, uniform sizes, and are dispersed.

[0035] Different from the prior art that uses atmospheric pressure plasma to reduce the initial raw materials through chemical reactions to prepare carbon quantum dots, the present invention uses two-dimensional black phosphorus nanosheets with the same composition as the prepared black phosphorus zero-dimensional nanomaterial as raw materials, and uses the oxidative shearing of atmospheric pressure plasma to further disperse the two-dimensional black phosphorus nanosheets in the solution into black phosphorus zero-dimensional nanomaterials. The preparation method is environmentally friendly, rapid and efficient.

[0036] Example 2

[0037] 0.3mg of two-dimensional black phosphorus nanosheets were placed in 30mL of N,N-dimethylformamide solution containing 5% volume ratio of water, and then air was used as the discharge gas to construct a gas-liquid plasma, that is, the solution and the metal placed on the solution were used as the two electrodes of plasma discharge, and the organic solution containing black phosphorus nanosheets was treated at room temperature using atmospheric pressure plasma, the plasma distance from the solution was 5mm, and the treatment time was 15min. The treated solution was centrifuged at 7500 rpm, and the supernatant was taken to obtain black phosphorus quantum dots with a zero-dimensional structure of 3-5nm in size.

[0038] Example 3

[0039] 0.1 mg of two-dimensional black phosphorus nanosheets were placed in 5 mL of N-methylpyrrolidone solution containing 2% volume ratio of water, and then a plasma jet was constructed with argon as the discharge gas. The organic solution containing black phosphorus nanosheets was treated with atmospheric pressure plasma jet at room temperature, with the jet distance of 2 mm from the solution and the treatment time of 40 min. The treated solution was centrifuged at 20,000 rpm, and the supernatant was taken to obtain zero-dimensional black phosphorus clusters with a size of 0.1-0.5 nm.

[0040] Example 4

[0041] 1 mg of two-dimensional black phosphorus nanosheets was placed in 10 mL of dimethyl sulfoxide solution containing 10% water by volume, and then liquid plasma was constructed using argon as the discharge gas, that is, two metal electrodes were placed in the solution and gas was introduced to form plasma discharge, and the organic solution containing black phosphorus nanosheets was treated at room temperature using atmospheric pressure plasma for 30 minutes. The treated solution was centrifuged at 20,000 rpm, and the supernatant was taken to obtain zero-dimensional black phosphorus clusters with a size of 0.1-0.5 nm.

[0042] Example 5

[0043] 20mg of two-dimensional black phosphorus nanosheets were placed in 50mL of N,N-dimethylformamide solution containing 8% volume ratio of water, and then a plasma jet was constructed with nitrogen as the discharge gas. The organic solution containing black phosphorus nanosheets was treated with atmospheric pressure plasma jet at room temperature, with the jet distance of 15mm from the solution and the treatment time of 20min. The treated solution was centrifuged at 8000 rpm, and the supernatant was taken to obtain black phosphorus quantum dots, a zero-dimensional structure of black phosphorus nanomaterials with a size of 3-5nm.

Claims

1. A method for preparing black phosphorus zero-dimensional nanomaterial, characterized in that: The preparation method comprises the following steps: S1) preparing an organic solution of two-dimensional black phosphorus nanosheets; S2) treating an organic solution of two-dimensional black phosphorus nanosheets at room temperature with atmospheric pressure plasma to obtain a solution having black phosphorus zero-dimensional nanomaterials; S3) separating the black phosphorus zero-dimensional nanomaterial from the solution containing the black phosphorus zero-dimensional nanomaterial obtained in step S2); In step S2), the atmospheric pressure plasma treatment time is 10 minutes to 40 minutes; In step S1), the concentration of the two-dimensional black phosphorus nanosheets in the two-dimensional black phosphorus nanosheet solution is 10 μg / mL~1 mg / mL, and the organic solution is a mixture of an organic solvent and water.

2. The preparation method according to claim 1, characterized in that: The atmospheric pressure plasma is selected from a plasma generated inside a solution or a plasma generated above a solution.

3. The preparation method according to claim 2, characterized in that: In step S2), the plasma generated above the solution is an atmospheric pressure plasma jet, and the length from the solution is 1-20 mm.

4. The preparation method according to claim 1, characterized in that: The gas used in the atmospheric pressure plasma is selected from argon, nitrogen, air and helium.

5. The preparation method according to claim 1, characterized in that: The atmospheric pressure plasma is selected from gas-liquid plasma, liquid phase plasma, and plasma jet.

6. The preparation method according to claim 1, characterized in that: The volume ratio of the organic solvent to water in the organic solution is 1:0.01 to 1:0.

1.

7. The preparation method according to claim 6, characterized in that: The organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone.

8. The preparation method according to claim 1, characterized in that: The normal temperature is 20-35°C.

9. The preparation method according to claim 1, characterized in that: The black phosphorus zero-dimensional nanomaterial is black phosphorus quantum dots or black phosphorus clusters.

10. The preparation method according to claim 9, characterized in that: In step S2), the plasma treatment time for generating the black phosphorus quantum dots is no more than 30 minutes; the plasma treatment time for generating the black phosphorus clusters is more than 30 minutes.

11. The preparation method according to claim 1, characterized in that: The size of the black phosphorus zero-dimensional nanomaterial is 0.1-5 nm.

Images