A 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and its preparation method and application

Abstract

The present invention discloses a 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and a preparation method and application thereof, belonging to the technical field of water micropollutant treatment. Black phosphorus and carbon nitride are uniformly dispersed in an organic solvent A according to a preset addition amount, and centrifuged to obtain the 2D / 2D black phosphorus / carbon nitride; PVDF-HFP powder is uniformly dispersed in an organic solvent B to obtain a first mixed solution; the 2D / 2D black phosphorus / carbon nitride is uniformly dispersed in the first mixed solution to obtain a second mixed solution; the second mixed solution is applied to a flat substrate and heat treated to obtain the 2D / 2D black phosphorus / carbon nitride@PVDF-HFP. The present invention utilizes black phosphorus, carbon nitride and PVDF-HFP to provide a pollutant treatment agent with good effect, environmental friendliness and high efficiency.

Description

Technical Field

[0001] The present invention relates to 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and a preparation method and application thereof, belonging to the technical field of water micropollutant treatment. Background Art

[0002] Amidst increasingly severe global environmental challenges, water pollution has become a major obstacle to sustainable social development. Due to their diverse nature, high toxicity, and resistance to degradation, persistent organic pollutants (POPs) pose a serious threat to ecosystem safety and human health. With the acceleration of industrialization and population growth, the discharge of various industrial and domestic wastewaters has increased dramatically, leading to a significant increase in the concentration of POPs in natural water bodies such as rivers. Consequently, there is an urgent need to develop more efficient and environmentally friendly water management technologies.

[0003] Traditional methods for treating micropollutants in water primarily include physical, chemical, and biological treatment. Physical treatments such as filtration and sedimentation primarily remove suspended matter and impurities from water bodies, but are limited in their effectiveness against dissolved micropollutants. Chemical treatments can remove some organic micropollutants through oxidation reactions, but they can produce new pollutants, leading to secondary pollution and requiring the continuous addition of chemical agents. Biological treatments rely on the green metabolic degradation of microorganisms, but take longer to treat persistent organic pollutants that are difficult to degrade, resulting in less than ideal results. Summary of the Invention

[0004] The purpose of the present invention is to provide a 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and its preparation method and application, so as to solve the problems of secondary pollution, low efficiency and poor effect existing in the prior art.

[0005] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, comprising:

[0007] Black phosphorus and carbon nitride are uniformly dispersed in an organic solvent A according to a preset addition amount, and subjected to centrifugal treatment to obtain 2D / 2D black phosphorus / carbon nitride;

[0008] Evenly dispersing PVDF-HFP powder in organic solvent B to obtain a first mixed solution;

[0009] uniformly dispersing 2D / 2D black phosphorus / carbon nitride in the first mixed solution to obtain a second mixed solution;

[0010] The second mixed solution is coated on a flat substrate and heat-treated to obtain 2D / 2D black phosphorus / carbon nitride@PVDF-HFP.

[0011] Furthermore, the mass ratio of the added amount of the black phosphorus and the carbon nitride is (0.05~0.5):1.

[0012] Furthermore, the step of uniformly dispersing black phosphorus and carbon nitride in a predetermined amount in an organic solvent A comprises:

[0013] Black phosphorus and carbon nitride were added into organic solvent A according to a preset amount and uniformly dispersed by ultrasonic treatment using a liquid phase exfoliation method.

[0014] Furthermore, the organic solvent A is N-methyl-2-pyrrolidone, and the purity of the organic solvent A is 98-99.5%;

[0015] The organic solvent B is a mixed solvent of N,N-dimethylformamide and acetone, wherein the molar ratio of N,N-dimethylformamide to acetone to acetone is (7-5):4, and the purity of the organic solvent B is 98-99.5%.

[0016] Furthermore, the rotation speed of the centrifugal treatment is 3000-4000 r / min, and the time is 10-20 minutes.

[0017] Furthermore, the PVDF-HFP powder is uniformly dispersed in the organic solvent B by ultrasonic treatment, and the 2D / 2D black phosphorus / carbon nitride is uniformly dispersed in the first mixed solution by ultrasonic treatment;

[0018] The temperature of the ultrasonic treatment process is 60-80° C. and the time is 20-40 minutes.

[0019] Furthermore, the flat substrate is a 1-2 m×1-2 m nickel fiber foam pad;

[0020] The coating is accomplished by casting / spin coating.

[0021] Furthermore, the heat treatment includes:

[0022] In an inert gas or reducing gas atmosphere, treat at 150~180 ℃ for 1~2 h.

[0023] In a second aspect, the present invention provides a 2D / 2D black phosphorus / carbon nitride@PVDF-HFP prepared by any of the methods described in the first aspect.

[0024] In a third aspect, the present invention provides an application of 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, in which the 2D / 2D black phosphorus / carbon nitride@PVDF-HFP prepared by any of the methods described in the first aspect is used to degrade persistent organic pollutants in water under the dual effects of solar energy and water flow energy.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and its preparation method and application. Black phosphorus, carbon nitride and PVDF-HFP are used as main raw materials to prepare a new non-metallic composite material. The unique two-dimensional structure and excellent electrical and optical properties of black phosphorus are utilized. The advantages of carbon nitride, such as simple synthesis, low cost, high stability, non-toxicity, narrow band gap and high photoresponse under visible light, are utilized. The advantages of PVDF-HFP, such as good mechanical strength, chemical stability, electrochemical stability and piezoelectric properties, which can generate a piezoelectric field under the action of water flow (further enhancing the photocatalytic efficiency of the system and extending its service life), are utilized. By combining black phosphorus, carbon nitride and PVDF-HFP, the 2D / 2D heterostructure not only expands the light absorption range, but also provides abundant charge transfer channels, while enhancing the interfacial contact between the materials to promote charge transfer, thereby significantly improving the degradation efficiency of persistent organic pollutants. The materials used do not have the risk of secondary pollution.

[0027] In addition, on the basis of photocatalytic technology, piezoelectric catalytic technology is combined to utilize solar energy and water flow energy to further promote the separation and transmission of photogenerated carriers, improve the efficiency of photocatalytic reaction, extend the service life of the system, and facilitate its laying in river environment to degrade persistent organic pollutants.

[0028] This photocatalytic-piezoelectric system (using solar energy and water flow energy) is simple in material preparation, cost-effective and environmentally friendly. It is suitable for the efficient, green and sustainable removal of difficult-to-degrade persistent organic pollutants in natural water bodies such as rivers. There is no risk of metal ion leakage in the water environment, and it makes full use of renewable energy to reduce the pollution of nanoparticles in the water environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of a method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a 2D / 2D black phosphorus / carbon nitride@PVDF-HFP applied to river management according to an embodiment of the present invention;

[0031] Figure 3 Schematic diagram of the concentration monitoring of the degradation of persistent organic pollutants (PCBs) before and after 24 hours using black phosphorus / carbon nitride, 2D / 2D black phosphorus / carbon nitride, and 2D / 2D black phosphorus / carbon nitride@PVDF-HFP in a simulated river environment, provided by an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of concentration monitoring after the degradation of persistent organic pollutants (DDT) using 2D / 2D black phosphorus / carbon nitride@PVDF-HFP provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0034] In recent years, photocatalytic technology has garnered widespread attention as a green and sustainable means of water remediation. However, its practical application still faces challenges, such as the need to improve the efficiency of photocatalysts against recalcitrant organic pollutants in water and the difficulty of recovering powdered photocatalysts from water bodies. Therefore, the development of new, efficient, and recyclable photocatalysts is needed to address the increasingly complex pollution situation in natural water bodies, such as rivers.

[0035] Photocatalytic technology uses light energy to excite catalysts to generate free radicals, thereby degrading organic pollutants. The piezoelectric effect, on the other hand, generates electrical signals by applying mechanical stress, promoting reactions at the catalyst's active sites. Combining these two technologies not only enhances the catalyst's light absorption capacity but also potentially improves its photocatalytic performance, potentially enabling the sustainable and efficient removal of persistent organic pollutants from natural water bodies such as rivers.

[0036] Therefore, the present invention specifically solves the problems of the prior art described in the summary of the invention through the following Examples 1 and 2, and verifies the effects of the present invention through specific experiments.

[0037] Example 1.

[0038] like Figure 1 As shown, the present invention provides a preparation method of 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, comprising the following steps:

[0039] Black phosphorus and carbon nitride were uniformly dispersed in N-methyl-2-pyrrolidone (purity 99%) by liquid phase exfoliation and ultrasonic treatment (temperature 70 ℃, time 30 minutes) in a certain ratio (mass ratio of 0.05:1). The mixture was then centrifuged (speed 3500 r / min, time 15 minutes) to obtain 2D / 2D black phosphorus / carbon nitride. PVDF-HFP (vinylidene fluoride-hexafluoropropylene copolymer) powder was uniformly dispersed in N,N-dimethylformamide and acetone (N,N-dimethylformamide and acetone molar ratio 6:4, the purity of the mixed solvent was 99%) by ultrasonic treatment (temperature 70 ℃, time 35 minutes). 2D / 2D black phosphorus / carbon nitride was then added and ultrasonic treatment was performed again (temperature 70 ℃, time 30 minutes). The resulting uniform mixture was coated on a 1.5 m×1.5 m nickel foam fiber mat by a casting method and heat treated (inert gas, temperature 160 ℃, time 1.5 h), and 2D / 2D black phosphorus / carbon nitride@PVDF-HFP was obtained.

[0040] Example 2.

[0041] like Figure 1 As shown, the present invention provides a preparation method of 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, comprising the following steps:

[0042] Black phosphorus and carbon nitride were uniformly dispersed in N-methyl-2-pyrrolidone (purity 99%) by liquid phase exfoliation and ultrasonic treatment (temperature 70 ℃, time 30 min) in a certain ratio (mass ratio of 0.1:1). The mixture was then centrifuged (speed 3500 r / min, time 15 min) to obtain 2D / 2D black phosphorus / carbon nitride. PVDF-HFP powder was uniformly dispersed in N,N-dimethylformamide and acetone (N,N-dimethylformamide and acetone molar ratio 6:4, the purity of the mixed solvent was 99%) by ultrasonic treatment (temperature 70 ℃, time 35 min). 2D / 2D black phosphorus / carbon nitride was then added and ultrasonic treatment was performed again (temperature 70 ℃, time 30 min). The resulting uniform mixture was coated on a 2 m×2 m nickel foam fiber mat by a casting method and heat treated (inert gas, temperature 160 ℃, time 1.5 h), obtaining 2D / 2D black phosphorus / carbon nitride@PVDF-HFP.

[0043] like Figure 2 As shown, the prepared 2D / 2D black phosphorus / carbon nitride@PVDF-HFP was applied to river management and the following simulation tests were carried out:

[0044] The 2D / 2D black phosphorus / carbon nitride@PVDF-HFP and black phosphorus / carbon nitride and 2D / 2D black phosphorus / carbon nitride prepared in Example 1 were used to treat the persistent organic pollutant polychlorinated biphenyls in a simulated river environment. Figure 3 As shown in the figure, the concentration changes of polychlorinated biphenyls under the action of different materials were monitored within 24 hours. The results showed that the degradation rate of 2D / 2D black phosphorus / carbon nitride@PVDF-HFP was increased by 47% compared with black phosphorus / carbon nitride material, and increased by 26% compared with 2D / 2D black phosphorus / carbon nitride, indicating that the 2D / 2D black phosphorus / carbon nitride@PVDF-HFP composite material has a significant degradation effect on persistent organic pollutants polychlorinated biphenyls in rivers.

[0045] The 2D / 2D black phosphorus / carbon nitride@PVDF-HFP prepared in Example 2 was used to treat the persistent organic pollutant DDT in a simulated river environment. Figure 4 As shown in the figure, the concentration changes of DDT under the action of different materials were monitored within 24 hours. The results showed that the degradation rate of DDT by 2D / 2D black phosphorus / carbon nitride@PVDF-HFP reached 77% within 16 hours, and the degradation rate could be as high as 85% within 24 hours.

[0046] In summary, 2D / 2D black phosphorus / carbon nitride@PVDF-HFP exhibited high degradation efficiency and good stability in the degradation of persistent organic pollutants.

[0047] In the chemical formula: @ means load, the content after @ is the carrier, and / means compound.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, characterized in that: include: Black phosphorus and carbon nitride are uniformly dispersed in an organic solvent A according to a preset addition amount, and subjected to centrifugal treatment to obtain 2D / 2D black phosphorus / carbon nitride; Evenly dispersing PVDF-HFP powder in organic solvent B to obtain a first mixed solution; uniformly dispersing 2D / 2D black phosphorus / carbon nitride in the first mixed solution to obtain a second mixed solution; The second mixed solution is coated on a flat substrate and heat-treated to obtain 2D / 2D black phosphorus / carbon nitride@PVDF-HFP; Wherein, the heat treatment includes: In an inert gas or reducing gas atmosphere, treat at 150~180 ℃ for 1~2 h.

2. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, characterized in that: The mass ratio of the added amounts of the black phosphorus and the carbon nitride is (0.05-0.5):

1.

3. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, wherein: The method of uniformly dispersing black phosphorus and carbon nitride in an organic solvent A according to a preset addition amount comprises: Black phosphorus and carbon nitride were added into organic solvent A according to a preset amount and uniformly dispersed by ultrasonic treatment using a liquid phase exfoliation method.

4. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, wherein: The organic solvent A is N-methyl-2-pyrrolidone, and the purity of the organic solvent A is 98-99.5%; The organic solvent B is a mixed solvent of N,N-dimethylformamide and acetone, wherein the molar ratio of N,N-dimethylformamide to acetone is (7-5):4, and the purity of the organic solvent B is 98-99.5%.

5. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, wherein: The rotation speed of the centrifugal treatment is 3000-4000 r / min, and the time is 10-20 minutes.

6. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, wherein: The PVDF-HFP powder is uniformly dispersed in the organic solvent B by ultrasonic treatment, and the 2D / 2D black phosphorus / carbon nitride is uniformly dispersed in the first mixed solution by ultrasonic treatment; The temperature of the ultrasonic treatment process is 60-80° C. and the time is 20-40 minutes.

7. The method for preparing 2D / 2D black phosphorus / carbon nitride@PVDF-HFP according to claim 1, wherein: The flat base is a 1~2 m×1~2 m nickel fiber foam pad; The coating is accomplished by casting / spin coating.

8. A 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, characterized in that: Prepared by the method according to any one of claims 1 to 7.

9. An application of 2D / 2D black phosphorus / carbon nitride@PVDF-HFP, characterized in that: The 2D / 2D black phosphorus / carbon nitride@PVDF-HFP prepared by the method according to any one of claims 1 to 7 is used to degrade persistent organic pollutants in water under the dual effects of solar energy and water flow energy.

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