A green and efficient Bi 13 S 18 Br2 preparation methods and applications

Abstract

This invention relates to a green and efficient Bi 13 S 18 The preparation method and application of Br2 belong to the field of piezoelectric catalysis technology. The method involves adding a bismuth salt solution to a mixed solution of a sulfur source and a bromine source, stirring at 80℃~130℃ for 4 h~7 h to carry out a co-precipitation reaction, and filtering, washing, drying, and grinding the resulting black precipitate to obtain Bi2. 13 S 18 Br2; the application is as an antibacterial functional material in marine antifouling coatings. The method is green and efficient, and is simple, low-cost, uses readily available raw materials, and is easy to produce. The application is based on the principle of piezoelectric effect, Bi... 13 S 18 Br2 possesses an intrinsic asymmetry that results in an internal dipole moment, which can effectively utilize external mechanical energy such as ocean wave energy to generate an internal piezoelectric potential. This leads to a piezoelectric catalytic reaction that produces reactive oxygen species. These reactive oxygen species kill marine bacteria and other fouling microorganisms, ultimately achieving the goal of marine antifouling.

Description

Technical Field

[0001] This invention relates to a green and efficient Bi 13 S 18 Br2 preparation method and its application, specifically, a green and efficient method for preparing Bi using a co-precipitation method. 13 S 18 The method of using Br2, and its application as a piezoelectric catalytic coating material for marine antifouling, belongs to the field of piezoelectric catalysis technology. Background Technology

[0002] Marine biofouling refers to the phenomenon of marine bacteria, algae, and shellfish adhering to the surface of marine engineering equipment. This not only accelerates the corrosion of underwater facilities, but for the shipping industry, severe biofouling can significantly increase hull surface roughness, increase navigation resistance, and lead to potential safety problems and substantial economic losses. Generally, the occurrence of marine biofouling follows these steps: 1) After the substrate is immersed in seawater, small molecules such as organic matter will adhere to the surface of the substrate to form a base film; 2) Marine microorganisms, represented by bacteria, attach to the basement membrane and carry out a series of physiological activities, forming a biofilm; 3) Large algae, shellfish, and other organisms attach to the biofilm, causing further biofouling.

[0003] In response to the characteristics of the aforementioned marine biofouling process, researchers have developed various antifouling methods to prevent and control marine biofouling. Traditional antifouling methods include mechanical methods, electrochemical methods, and antifouling coatings, but these methods have drawbacks such as being reactive, energy-intensive, and costly. Therefore, there is a need to develop a greener, more efficient, and preventative antifouling measure.

[0004] Piezoelectric catalytic materials are a class of materials based on the piezoelectric effect. In the marine environment, the widespread ocean wave energy can apply external stress to piezoelectric materials, causing them to deform and thus generating a piezoelectric field. Under the influence of the piezoelectric field, the internal charges of the material migrate directionally to the surface, reacting with the surrounding seawater to produce various reactive oxygen species (ROS) free radicals. These free radicals interact with bacteria, destroying bacterial cell structure and effectively killing bacteria. Therefore, piezoelectric catalysis technology mainly controls subsequent marine fouling processes by inhibiting biofilm formation, exhibiting green and efficient characteristics, and has thus attracted widespread attention. However, in the practical application of this technology, many traditional piezoelectric materials require extremely high external stress. Therefore, most research focuses on using ultrasound to excite the piezoelectric catalytic process of the materials. Given this, there is currently very little research on the application of this technology in the field of marine antifouling, and ultrasound is still the main implementation method.

[0005] In the prior art, bismuth-based sulfides Bi13 S 18 The main methods for preparing Br2 include high-temperature solid-state methods, solvothermal methods, and mechanical methods. However, these methods are complex to operate, energy-intensive, and have low safety, which limits the application of Bi. 13 S 18 Further industrial production and application of Br2. For bismuth-based compounds, coprecipitation is a commonly used preparation method, characterized by its ease of operation, large-scale production capability, and high safety. However, in practical applications, coprecipitation often requires precise control of reaction conditions, such as pH, reaction temperature, and reaction time, based on the specific target product and the properties of the raw materials, to succeed. Currently, there are no known methods for preparing Bi using coprecipitation. 13 S 18 Reports related to Br2. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, one of the objectives of this invention is to provide a green and efficient Bi 13 S 18 The method for preparing Br2 is a coprecipitation method, which is green and efficient, and the method is simple, low-cost, uses readily available raw materials, and is easy to produce.

[0007] The second objective of this invention is to provide a green and efficient Bi 13 S 18 Bi prepared by Br2 preparation method 13 S 18 The application of Br2 is as an antibacterial functional material in marine antifouling coatings, utilizing Bi... 13 S 18 Br2 possesses an intrinsic dipole moment due to its intrinsic asymmetry, which allows it to effectively utilize ocean wave energy rather than ultrasonic excitation for its piezoelectric catalysis. This enables it to achieve good piezoelectric catalysis in marine environments and shows promising application prospects in the field of marine antifouling.

[0008] To achieve the objectives of this invention, the following technical solutions are provided.

[0009] A green and efficient Bi 13 S 18 The method for preparing Br2, which is a coprecipitation method, includes the following steps: A bismuth (Bi) salt solution was added to a mixed solution of a sulfur (S) source and a bromine (Br) source, and a co-precipitation reaction was carried out by stirring at 80 ℃ to 130 ℃ for 4 h to 7 h. The resulting black precipitate was filtered, washed, dried, and ground to obtain Bi. 13 S 18 Br2; In this bismuth salt solution, the bismuth salt is bismuth nitrate, the solvent is ethylene glycol, and the Bi content in the bismuth salt solution is... 3+ The molar concentration is 40 mmol / L ~ 60 mmol / L. Furthermore, the Bi in the bismuth salt solution... 3+ The molar concentration is 40 mmol / L ~ 50 mmol / L; The sulfur source is thiourea, the bromine source is potassium bromide, and the solvent in the mixed solution of the sulfur and bromine sources is ethylene glycol. The concentration of the sulfur source is 8 g / L ~ 12 g / L, and the concentration of the bromine source is 40 mmol / L ~ 60 mmol / L; further, the concentration of the sulfur source is 8 g / L ~ 10.5 g / L, and the concentration of the bromine source is 40 mmol / L ~ 50 mmol / L. The volume ratio of the bismuth salt solution to the mixed solution of the sulfur and bromine sources is 1:1.

[0010] Furthermore, when preparing a mixed solution of bismuth salt, sulfur source, and bromine source, the solute is added to the solvent and then heated to 110 ℃ ~ 130 ℃ to dissolve it, thus obtaining the corresponding solution; Furthermore, at 80 ℃ ~ 120 ℃, the heated and dissolved bismuth salt solution was added dropwise to a mixed solution of sulfur source and bromine source, and the temperature was kept constant. The reaction solution was stirred for 4 h ~ 6 h to carry out a coprecipitation reaction.

[0011] Preferably, the stirring speed is set to 300 rpm ~ 500 rpm; Preferably, the drying is carried out at 60 ℃ ~ 80 ℃ for 6 h ~ 8 h.

[0012] A Bi according to the present invention 13 S 18 The application of Br2 is as an antibacterial functional material in marine antifouling coatings, utilizing Bi... 13 S 18 Br2 possesses an intrinsic dipole moment due to its intrinsic asymmetry, which allows it to effectively utilize ocean wave energy rather than ultrasonic excitation for its piezoelectric catalysis. This enables it to achieve good piezoelectric catalysis in marine environments and shows promising application prospects in the field of marine antifouling.

[0013] Furthermore, the application is as an antibacterial functional material in marine antifouling coatings to kill typical marine fouling microorganisms such as Pseudomonas aeruginosa and Staphylococcus aureus.

[0014] Beneficial effects (1) This invention provides a green and efficient Bi 13 S 18A method for preparing Br2, wherein the method is a coprecipitation method, which is green and efficient. At the same time, the method is simple, low-cost, and uses readily available raw materials and is easy to produce. (2) This invention provides a green and efficient Bi 13 S 18 Br2 preparation method, wherein the method is based on Bi 13 S 18 Based on the characteristics of Br2, the inventors creatively proposed a co-precipitation method with temperatures ranging from 80 ℃ to 130 ℃, using ethylene glycol as the solvent. During their research, the inventors discovered that Bi could not be prepared below 80 ℃. 13 S 18 Br2 products, but setting the temperature above 130 ℃ may cause excessive evaporation of the reaction solvent and produce harmful substances; (3) This invention provides a green and efficient Bi 13 S 18 A method for preparing Br2, wherein the method yields Bi with intrinsic asymmetric properties. 13 S 18 Br2, the asymmetry is Bi 13 S 18 Br2 introduces an internal dipole moment, which can more effectively promote the directional migration of internal charges; (4) This invention provides a green and efficient Bi 13 S 18 Br2 preparation method, wherein the Bi prepared by the method is... 13 S 18 Br2 consists of needle-like nanoparticles with an aspect ratio close to 1:10, enabling more efficient harvesting of ocean wave energy without ultrasonic excitation. When subjected to external stress perpendicular to the needle, the needle can effectively deform and generate a stronger internal piezoelectric field. Compared to more common uniform rod-shaped nanomaterials, Br2 exhibits superior performance due to its needle-like structure. 13 S 18 One end of the Br2 particle has a needle-like shape. When subjected to the same external stress, the needle-like part can generate a stronger stress concentration area, thereby generating a stronger potential. Furthermore, the Bi prepared by the method 13 S 18 Br2 consists of needle-like nanoparticles with a diameter of 175.5 ± 54.1 nm and a length of 1.70 ± 0.76 μm. (5) This invention provides a Bi 13 S 18 The application of Br2 is as an antibacterial functional material in marine antifouling coatings, based on the principle of piezoelectric effect. Bi 13 S18 Br2 has an internal dipole moment due to intrinsic asymmetry, which can effectively utilize external mechanical energy such as ocean wave energy to generate an internal piezoelectric potential, thereby undergoing a piezoelectric catalytic reaction to produce reactive oxygen species. These reactive oxygen species kill marine bacteria and other fouling microorganisms, ultimately achieving the purpose of marine antifouling. (6) The present invention provides a Bi 13 S 18 The application of Br2 is as an antibacterial functional material in marine antifouling coatings to kill typical marine fouling microorganisms such as Pseudomonas aeruginosa and Staphylococcus aureus, with good bactericidal effect and recyclability. Attached Figure Description

[0015] Figure 1 These are the X-ray diffraction (XRD) analysis patterns of the final products prepared in Examples 1, 2 and Comparative Example 1; Figure 2 The images show scanning electron microscope (SEM) images and elemental mapping analysis of the final products prepared in Examples 1, 2 and Comparative Example 1. Figure 3 This is the X-ray photoelectron spectrum of the final product prepared in Example 1; Figure 4 This is a piezoelectric microscopy test result of the final product prepared in Example 1; Figure 5 The graph shows the performance of the final product prepared in Example 1 in killing Pseudomonas aeruginosa and Staphylococcus aureus, respectively. Figure 6 The graph shows the recyclability of the final product prepared in Example 1 in killing Pseudomonas aeruginosa and Staphylococcus aureus, respectively. Detailed Implementation

[0016] The features and performance of the present invention will be further described in detail below with reference to embodiments: Example 1 A green and efficient Bi 13 S 18 The method for preparing Br2, which is a coprecipitation method, includes the following steps: 1 mmol of Bi(NO3)·H2O was added to 20 mL of ethylene glycol and stirred until dissolved. The solution was then heated to 120 °C to fully dissolve the Bi(NO3)·H2O, yielding a bismuth salt solution, in which Bi... 3+ The molar concentration of the source was 50 mmol / L; 0.205 g of thiourea and 1 mmol of potassium bromide were added to 20 mL of ethylene glycol and stirred to dissolve. The solution was then heated to 120 °C to obtain a mixed solution of sulfur source and bromine source, wherein the concentration of sulfur source was 10.25 g / L and the concentration of bromine source was 50 mmol / L. The bismuth salt solution was added dropwise to a mixed solution of sulfur and bromine sources, and stirred at 300 rpm for 6 hours at 120 °C. The resulting black precipitate was washed three times using a vacuum filter with a washing solution of deionized water and anhydrous ethanol in a volume ratio of 1:1. After washing, the product was filtered and dried in an oven at 70 °C for 8 hours. Finally, the product was ground in a mortar and pestle to obtain the final product.

[0017] Example 2 A green and efficient Bi 13 S 18 The method for preparing Br2, which is a coprecipitation method, includes the following steps: 0.8 mmol of Bi(NO3)·H2O was added to 20 mL of ethylene glycol solution and stirred until dissolved. The solution was then heated to 80 °C to obtain a bismuth salt solution, in which Bi... 3+ The molar concentration of the source was 40 mmol / L; 0.16 g of thiourea and 0.8 mmol of potassium bromide were added to 20 mL of ethylene glycol solution and stirred to dissolve. The solution was then heated to 80 °C to obtain a mixed solution of sulfur source and bromine source, wherein the concentration of sulfur source was 8 g / L and the concentration of bromine source was 40 mmol / L. The bismuth salt solution was added dropwise to a mixed solution of sulfur and bromine sources, and stirred at 500 rpm for 4 h at 80 °C. The resulting black precipitate was washed three times using a vacuum filter with a washing solution of deionized water and anhydrous ethanol in a volume ratio of 1:1. After washing, the product was filtered and dried in an oven at 60 °C for 6 h. Finally, it was ground in a mortar and pestle to obtain the final product.

[0018] Comparative Example 1 The method and steps are the same as described in Example 1, except that the reaction temperature is set to 50 °C.

[0019] Product and performance testing: The final products prepared in Examples 1, 2 and Comparative Example 1 were tested as follows: The final product was analyzed by scanning electron microscopy, elemental mapping, X-ray diffraction, and X-ray photoelectron spectroscopy. The results are as follows: Figure 1 As shown in ~4.

[0020] (1) Figure 1 It is the X-ray diffraction pattern of the final product. Figure 1 a and Figure 1 b are the X-ray diffraction patterns of the final products prepared in Examples 1 and 2, respectively, corresponding to Bi. 13 S 18Br2 (PDF: 73-1157), all diffraction peaks in the spectrum can be attributed to the hexagonal crystal system, and the sharp diffraction peaks indicate that the final product has good crystallinity. Figure 1 c is the X-ray diffraction pattern of the final product prepared in Comparative Example 1, corresponding to Bi2S3 (PDF: 75-1306). All the desired diffraction peaks in the pattern can be attributed to the orthorhombic crystal system, and the disordered peak shapes indicate that the crystallinity of the prepared final product is poor.

[0021] (2) Figure 2 This is a scanning electron microscope image of the morphology of the final product. Figure 2 a and Figure 2 b represents the final product Bi prepared in Examples 1 and 2, respectively. 13 S 18 The microstructure image of Br2 shows the material as black nanoparticles with a needle-like morphology and good crystallinity. Further, the Bi... 13 S 18 Br2 consists of needle-like nanoparticles with a diameter of 175.5 ± 54.1 nm and a length of 1.70 ± 0.76 μm. Figure 2 c is a microscopic morphology diagram of the final product Bi2S3 prepared in Comparative Example 1, in which the material is rod-shaped nanoparticles with uneven morphology and poor crystallinity.

[0022] (3) Figure 3 This is the X-ray photoelectron spectrum of the final product prepared in Example 1. Figure 3 a can clearly prove that the final product Bi 13 S 18 The presence of Bi, S, and Br elements in Br2. Figure 3 b shows the final product Bi 13 S 18 The overlapping energy spectra of Bi 4f and S 2p in Br2, where the values ​​at 158.2 eV and 163.5 eV represent Bi 4f and S 2p, respectively. 3+ Bi 4f 7 / 2 and Bi 4f 5 / 2 The spin orbitals, and 160.8 eV and 162.6 eV are respectively S 2- S 2p 3 / 2 and S 2p 1 / 2 . spin orbit. Figure 3 c shows the peaks at 67.6 eV and 68.4 eV in Br 3d, corresponding to Br , respectively. - Br 3d ions 3 / 2 ,Br 3d 5 / 2 .

[0023] (4) Figure 4 The results are obtained from piezoelectric microscopy of the final product prepared in Example 1. Figure 4 a and Figure 4 b respectively shows the final product Bi 13 S 18 The piezoelectric microscopy morphology and phase mapping of Br2 show excellent matching in regional color contrast, which is representative of Bi. 13 S 18 Polarization of Br2 in uniform presence. Figure 4 c shows the final product Bi 13 S 18 The piezoelectric coefficient d of Br2 33 (Approximately 0.17 nm / V), indicating that the final product Bi 13 S 18 Br2 has good piezoelectric properties; The piezoelectric microscopy results of the final product prepared in Example 2 are similar to those in Example 1, indicating that the final product Bi 13 S 18 Br2 has good piezoelectric properties.

[0024] (5) Figure 5 This is a graph showing the performance of the final product prepared in Example 1 in killing Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The final product Bi prepared in Example 1... 13 S 18 Pseudomonas aeruginosa was killed by piezoelectric catalysis in Br2 under stirring. The bacterial culture was serially diluted to 10. 6 cfu / mL, 5 mg of the final product Bi 13 S 18 Br2 was added to 5 mL of bacterial culture, and after approximately 30 min in the dark, adsorption / desorption equilibrium was reached. Stirring was used to simulate ocean waves at a speed of 700 rpm. Before stirring, 100 μL of bacterial culture was transferred from the reaction system and spread onto LB agar plates, incubated at 37 °C for 24 h, and plate counts were performed. After 45 min of reaction, 100 μL of bacterial culture was transferred from the reaction system and spread onto LB agar plates, incubated at 37 °C for 24 h, and plate counts were performed. A setup without the addition of the final product Bi was also included. 13 S 18 The Br2 system served as a blank control group. The sterilization rate was calculated using the following formula: Sterilization rate (%) = 100 - (N) t / N0) × 100, where N0 and N t The figures show the number of viable bacteria before and after the stirring reaction, respectively. Each experiment was performed in triplicate to obtain the average value. It can be seen that in the bacterial culture system of the blank control group, the inactivation rates of *Pseudomonas aeruginosa* and *Staphylococcus aureus* were extremely low, at 6.9% and 5.8%, respectively, indicating that the activity of these two bacteria under natural conditions was unaffected. After adding the final product Bi...13 S 18 In the Br2 bacterial culture system, Bi 13 S 18 Br2 exhibited high piezoelectric catalytic bactericidal performance; under stirring conditions, Bi... 13 S 18 The bactericidal rates of Br2 against Pseudomonas aeruginosa and Staphylococcus aureus reached 91.2% and 88.2%, respectively. The performance of the final product prepared in Example 2 in killing Pseudomonas aeruginosa and Staphylococcus aureus was also tested. The results were similar to those in Example 1, indicating that the final product Bi 13 S 18 Br2 has good bactericidal properties.

[0025] (6) Figure 6 Bi is the final product prepared in Example 1. 13 S 18 Circulating performance diagram of Br2 in killing Pseudomonas aeruginosa and Staphylococcus aureus, respectively. After 5 cycles, Bi... 13 S 18 Br2 maintained high bactericidal rates against Pseudomonas aeruginosa and Staphylococcus aureus, at 81.2% and 76.6%, respectively. The recyclability of the final product prepared in Example 2, which was used to kill Pseudomonas aeruginosa and Staphylococcus aureus, was also tested. The results were similar to those in Example 1, indicating that the final product Bi 13 S 18 Br2 has good cyclic bactericidal properties.

[0026] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A green and efficient Bi 13 S 18 The method for preparing Br2 is characterized by: The method is a coprecipitation method, and the steps are as follows: Bismuth salt solution was added to a mixed solution of sulfur and bromine sources, and a co-precipitation reaction was carried out by stirring at 80 ℃ to 130 ℃ for 4 h to 7 h. The resulting black precipitate was filtered, washed, dried, and ground to obtain Bi. 13 S 18 Br2.

2. A green and efficient Bi according to claim 1 13 S 18 The method for preparing Br2 is characterized by: At 80 ℃~120 ℃, the heated and dissolved bismuth salt solution was added dropwise to a mixed solution of sulfur source and bromine source, and the temperature was kept constant. The reaction solution was stirred for 4 h~6 h to carry out a coprecipitation reaction.

3. A green and efficient Bi according to claim 1 or 2 13 S 18 The method for preparing Br2 is characterized by: The bismuth salt in the bismuth salt solution is bismuth nitrate, the solvent is ethylene glycol, the sulfur source is thiourea, the bromine source is potassium bromide, and the solvent in the mixed solution of the sulfur source and the bromine source is ethylene glycol.

4. A green and efficient Bi according to claim 3 13 S 18 The method for preparing Br2 is characterized by: Bi in bismuth salt solution 3+ The molar concentration of the source was 40 mmol / L ~ 60 mmol / L; the concentration of the sulfur source was 8 g / L ~ 12 g / L; and the concentration of the bromine source was 40 mmol / L ~ 60 mmol / L.

5. A green and efficient Bi according to claim 4 13 S 18 The method for preparing Br2 is characterized by: Bi in bismuth salt solution 3+ The molar concentration of the source was 40 mmol / L ~ 50 mmol / L; the concentration of the sulfur source was 8 g / L ~ 10.5 g / L; and the concentration of the bromine source was 40 mmol / L ~ 50 mmol / L.

6. A green and efficient Bi according to claim 4 13 S 18 The method for preparing Br2 is characterized by: The volume ratio of the bismuth salt solution to the mixed solution of the sulfur and bromine sources is 1:

1.

7. A green and efficient Bi according to claim 1 or 2 13 S 18 The method for preparing Br2 is characterized by: When preparing a bismuth salt solution, a sulfur source, and a bromine source mixed solution, the solute is added to the solvent and heated to 110 ℃~130 ℃ to dissolve it, thus obtaining the corresponding solution.

8. A green and efficient Bi according to claim 1 or 2 13 S 18 The method for preparing Br2 is characterized by: The stirring speed is 300 rpm to 500 rpm; the drying is carried out at 60 ℃ to 80 ℃ for 6 h to 8 h.

9. A Bi as described in any one of claims 1 to 8 13 S 18 The application of Br2 is characterized by: As an antibacterial functional material in marine antifouling coating materials.

10. A Bi according to claim 9 13 S 18 The application of Br2 is characterized by: As an antibacterial functional material in marine antifouling coatings, it is used to kill marine fouling microorganisms such as Pseudomonas aeruginosa and Staphylococcus aureus.

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