Synthetic method for constructing Ag nanowire / ZnO nano array superstructure particles and application of Ag nanowire / ZnO nano array superstructure particles

Abstract

The invention provides a synthesis method and application for growing a ZnO nano array on an Ag nanowire, and the method comprises the following steps: adding a predetermined amount of polyvinylpyrrolidone powder into a predetermined amount of 1, 2-propylene glycol solution, heating to a first predetermined temperature in an oil bath, and continuously reacting for a first predetermined time to obtain a ZnO nano array; then adding a sodium chloride solution with a first predetermined concentration and continuously reacting for a second predetermined time, then adding a silver nitrate solution with a second predetermined concentration and continuously reacting for a third predetermined time, and centrifugally drying the product to obtain the Ag nanowire; and dispersing the Ag nanowires in a zinc acetate solution with a third predetermined concentration, continuously stirring for a fourth predetermined time at a second predetermined temperature, then adding a sodium hydroxide solution with a fourth predetermined concentration to adjust the pH value of the solution to 7, continuously reacting for a fifth predetermined time, carrying out centrifugal separation, and drying the obtained solid to obtain the Ag nanowires. The Ag-ZnO superstructure composite particles with the ZnO nano array characteristic distribution on the Ag nanowires are obtained.

Description

Technical Field

[0001] The present invention relates to a synthesis method for constructing superstructure particles by growing a ZnO nanoarray on an Ag nanowire, and is mainly used for photo-antibacterial applications. Background Art

[0002] Nanoarrays, a typical superstructure, possess a finely designed and controlled nanoscale structure and can be constructed through methods such as self-assembly, chemical synthesis, or physical synthesis. By precisely controlling the particle size, shape, and surface properties, various functions of the particles can be optimized. In the field of photoantibacterial applications, superstructured particles can provide a larger specific surface area and more active sites, optimizing light absorption and charge separation, thereby improving antibacterial efficacy.

[0003] Silver nanomaterials possess excellent antimicrobial properties and are widely used in the medical and health fields, effectively inhibiting a wide range of bacteria and microorganisms. Silver nanowire structures can achieve a sustained release effect, extending the duration of antimicrobial activity. Furthermore, Ag nanowires can bind to semiconductor photosensitizers to generate active free radicals under light. Therefore, constructing composite particles based on Ag nanowires offers significant technical advantages for further enhancing antimicrobial efficacy. However, most reported preparation methods simply involve depositing semiconductor particles or coating Ag nanowires with semiconductor shells. For example, one invention describes a catalyst material with high electrocatalytic methanol oxidation activity by depositing a PtAg alloy onto Ag nanowires (CN117305886A); another describes a CO2 conversion electrocatalyst material by in situ coating an Ag nanowire skeleton with a discontinuous Ag2S shell (CN118497780A). However, these simple particle structures expose limited heterogeneous interface active sites, which compromises their antimicrobial efficacy.

[0004] ZnO has the advantages of being non-toxic, non-irritating to the skin, highly stable, and low-cost, making it a promising semiconductor photosensitizer. Therefore, developing a synthetic method for growing ZnO nanoarrays on Ag nanowires to construct superstructured particles is a key step. Summary of the Invention

[0005] To address the problems in the above-mentioned background technology, the present invention provides a synthesis method and application of constructing Ag nanowire / ZnO nanoarray superstructure particles. By adjusting the concentration of zinc acetate solution, the present invention grows ZnO nanoarrays of different lengths on Ag wires. The superstructure particles have a stronger photoantibacterial effect and achieve efficient inactivation of Staphylococcus aureus and Escherichia coli.

[0006] One aspect of the present invention provides a method for synthesizing Ag nanowire / ZnO nanoarray superstructure particles, comprising the following steps: (1) adding a predetermined amount of polyvinyl pyrrolidone powder to a predetermined amount of 1,2-propylene glycol solution, heating the oil bath to a first predetermined temperature, and continuing the reaction for a first predetermined time, then adding a sodium chloride solution of a first predetermined concentration and continuing the reaction for a second predetermined time, then adding a silver nitrate solution of a second predetermined concentration and continuing the reaction for a third predetermined time, and centrifuging and drying the product to obtain Ag nanowires; (2) The Ag nanowires are dispersed in a zinc acetate solution of a third predetermined concentration, stirred continuously for a fourth predetermined time at a second predetermined temperature, and then a sodium hydroxide solution of a fourth predetermined concentration is added to adjust the pH of the solution to 7, and the reaction is continued for a fifth predetermined time, and then centrifuged and dried to obtain Ag-ZnO superstructure particles.

[0007] Another aspect of the present invention further provides the application of the Ag nanowire / ZnO nanoarray superstructure particles in the field of photoantibacterial.

[0008] Compared with the existing technology, the present invention has the following advantages: the method is simple, the oil bath heating and stirring are highly operable and reproducible; ZnO nanoarrays are grown on Ag nanowires through a two-step method to construct unique superstructured particles; the growth length of the ZnO nanoarrays on the Ag nanowires is effectively controlled by adjusting the concentration of the zinc acetate solution; the prepared superstructured particles have a stronger light antibacterial effect, achieving efficient inactivation of Staphylococcus aureus and Escherichia coli. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are intended only to illustrate preferred embodiments and are not to be construed as limiting the present invention. It should be understood that the drawings described below are merely examples of the present invention, and that those skilled in the art will be able to derive other drawings from these drawings without inventive effort. Throughout the drawings, identical reference numerals are used to denote identical components.

[0010] In the attached figure: Figure 1 This is a scanning electron microscope image of the Ag nanowires prepared by the present invention; Figure 2 This is a scanning electron microscope image of the Ag-ZnO superstructure particles with a ZnO nanoarray length of 200 nm prepared by the present invention; Figure 3This is a scanning electron microscope image of Ag-ZnO superstructure particles with a ZnO nanoarray length of 120 nm prepared by the present invention; Figure 4 is a correlation diagram of Ag-ZnO superstructure particles with a ZnO nanoarray length of 50 nm prepared by the present invention, wherein, Figure 4 (a) is a scanning electron microscope image; Figure 4 Middle (b) to Figure 4 Middle (c) is a transmission electron microscope image; Figure 4 Middle (d) is the scanning-transmission electron microscope image and element distribution map; Figure 5 This is the X-ray diffraction pattern of the Ag-ZnO superstructure particles with a ZnO nanoarray length of 50 nm prepared by the present invention; Figure 6 is a correlation diagram of Ag-ZnO superstructure particles with a ZnO nanoarray length of 25 nm prepared by the present invention, wherein, Figure 6 Middle (a) to Figure 6 Middle (b) is a scanning electron microscope image; Figure 6 Medium (c) to Figure 6 Middle (d) is a transmission electron microscope image; Figure 7 This is a photoantibacterial test graph of the Ag-ZnO superstructure particles with a ZnO nanoarray length of 50 nm prepared by the present invention against Staphylococcus aureus and Escherichia coli. DETAILED DESCRIPTION

[0011] Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0012] To facilitate understanding of the embodiments of the present invention, further explanation will be given below using specific embodiments as examples in conjunction with the accompanying drawings, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0013] like Figures 1 to 7 As shown, the synthesis method of ZnO nanoarrays on Ag nanowires includes the following steps: (1) adding a predetermined amount of polyvinyl pyrrolidone powder to a predetermined amount of 1,2-propylene glycol solution, heating the oil bath to a first predetermined temperature, and continuing the reaction for a first predetermined time, then adding a sodium chloride solution of a first predetermined concentration and continuing the reaction for a second predetermined time, then adding a silver nitrate solution of a second predetermined concentration and continuing the reaction for a third predetermined time, and centrifuging and drying the product to obtain Ag nanowires; (2) The Ag nanowires are dispersed in a zinc acetate solution of a third predetermined concentration, stirred continuously for a fourth predetermined time at a second predetermined temperature, and then a sodium hydroxide solution of a fourth predetermined concentration is added to adjust the pH of the solution to 7, and the reaction is continued for a fifth predetermined time, and then centrifuged and dried to obtain Ag-ZnO superstructure particles.

[0014] Preferably, in step (1), the amount of 1,2-propylene glycol solution used is 10 ml, and the amount of polyvinyl pyrrolidone powder used is 0.4 g.

[0015] Preferably, in step (1), the first predetermined concentration is 1 mmol / L, and the second predetermined concentration is 0.15 mol / L.

[0016] Preferably, in step (1), the first predetermined time is 60 minutes, the second predetermined time is 5 minutes, and the third predetermined time is 40 minutes.

[0017] Preferably, in step (2), the third predetermined concentration is 0.6 mol / L, and the fourth predetermined concentration is 0.00625-0.05 mol / L.

[0018] Preferably, in step (2), the fourth predetermined time is 30 minutes, and the fifth predetermined time is 120 minutes.

[0019] Example 1: This embodiment provides a method for preparing Ag nanowires, comprising the following steps: Dissolve 0.4 g of polyvinylpyrrolidone (PVP) powder in 10 mL of 1,2-propylene glycol and stir continuously at 500 rpm in a 160°C oil bath. After 60 minutes, slowly drop 1 ml of 1 mmol / L sodium chloride solution into the above solution. After 5 minutes, pour in 4 ml of 0.15 mol / L silver nitrate solution. After reacting for 40 minutes, centrifuge and dry the obtained silver powder to obtain the following: Figure 1 The Ag nanowires shown.

[0020] Example 2: This embodiment is a method for growing a ZnO nanoarray with a length of 200 nm on an Ag nanowire, and finally a method for preparing an Ag nanowire / ZnO nanoarray superstructure particle, comprising the following steps: 40 mg of Ag nanowires were ultrasonically dispersed in 20 mL of deionized water. 219 mg of zinc acetate powder was weighed and added to the aqueous solution. The mixture was placed in a water bath and stirred at room temperature for 30 minutes to dissolve. Then, 0.6 mol / L sodium hydroxide solution was added and the pH value of the zinc acetate solution was adjusted to 7. The mixture was stirred for 120 minutes to obtain a mixed solution. Deionized water and anhydrous ethanol were used for centrifugation at 8000 rpm. After the solution became completely transparent, it was collected and dried to obtain the product. Figure 2 The ZnO nanoarrays shown are Ag-ZnO superstructure particles with a length of 200 nm.

[0021] Example 3: This embodiment is a method for growing a ZnO nanoarray with a length of 120 nm on an Ag nanowire, and finally a method for preparing an Ag nanowire / ZnO nanoarray superstructure particle, comprising the following steps: 40 mg of Ag nanowires were ultrasonically dispersed in 20 mL of deionized water. 109.5 mg of zinc acetate powder was weighed and added to the aqueous solution. The mixture was placed in a water bath and stirred at room temperature for 30 minutes to dissolve. Then, 0.6 mol / L sodium hydroxide solution was added and the pH value of the zinc acetate solution was adjusted to 7. The mixture was stirred for 120 minutes to obtain a mixed solution. Deionized water and anhydrous ethanol were used for centrifugation at 8000 rpm. After the solution became completely transparent, it was collected and dried to obtain the product. Figure 3 The ZnO nanoarrays shown are Ag-ZnO superstructure particles with a length of 120 nm.

[0022] Example 4: This embodiment is a method for growing a ZnO nanoarray with a length of 50 nm on an Ag nanowire, and finally a method for preparing an Ag nanowire / ZnO nanoarray superstructure particle, comprising the following steps: 40 mg of Ag nanowires were ultrasonically dispersed in 20 mL of deionized water. 54.75 mg of zinc acetate powder was weighed and added to the aqueous solution. The mixture was placed in a water bath and stirred at room temperature for 30 minutes to dissolve. Then, 0.6 mol / L sodium hydroxide solution was added and the pH value of the zinc acetate solution was adjusted to 7. The mixture was stirred for 120 minutes to obtain a mixed solution. Deionized water and anhydrous ethanol were used for centrifugation at 8000 rpm. After the solution became completely transparent, it was collected and dried to obtain the product. Figure 4 The ZnO nanoarrays shown are Ag-ZnO superstructure particles with a length of 50 nm.

[0023] The X-ray diffraction images of the Ag-ZnO composite particles prepared in this example are as follows: Figure 5As shown, the Ag-ZnO composite particles have typical diffraction peaks consistent with Ag at 38.114°, 44.298°, 64.441° and 77.395°, and typical diffraction peaks consistent with ZnO at 31.731°, 34.363° and 36.206°, proving that the composite particles contain only Ag and ZnO without other impurities.

[0024] Example 5: This embodiment is a method for growing a ZnO nanoarray with a length of 25 nm on an Ag nanowire, and finally a method for preparing an Ag nanowire / ZnO nanoarray superstructure particle, comprising the following steps: 40 mg of Ag nanowires were ultrasonically dispersed in 20 mL of deionized water. 27.375 mg of zinc acetate powder was weighed and added to the aqueous solution. The mixture was placed in a water bath and stirred at room temperature for 30 minutes to dissolve. Then, 0.6 mol / L sodium hydroxide solution was added and the pH value of the zinc acetate solution was adjusted to 7. The mixture was stirred for 120 minutes to obtain a mixed solution. Deionized water and anhydrous ethanol were used for centrifugation at 8000 rpm. After the solution became completely transparent, it was collected and dried to obtain the product. Figure 6 The ZnO nanoarrays shown are Ag-ZnO superstructure particles with a length of 25 nm.

[0025] Experimental example: This experiment used blank control and the Ag-ZnO superstructure particles prepared in Example 4 as experimental samples to verify their antibacterial effects on Staphylococcus aureus and Escherichia coli. The specific process was as follows: the bacterial solution was diluted to 10 7 For each sample, 5 ml of the sample was added (final concentration: 0.5 mg / ml) and incubated in a 37°C incubator with shaking for 24 h. After incubation, the bacterial solution was serially diluted 10-fold with sterile PBS solution, and 100 μL of the dilution was evenly spread on LB solid medium. The culture was incubated in a 37°C incubator for 18 h. The sample was then removed, photographed, and the number of colonies recorded.

[0026] Calculation method for bacterial solution concentration (CFU / mL): number of colonies × dilution factor × 10 (0.1 mL coating) Antibacterial rate = (1-concentration of bacterial solution in experimental group / concentration of bacterial solution in control group) × 100% Its antibacterial effect on Staphylococcus aureus and Escherichia coli is shown in Table 1, Table 2 and Figure 7 shown.

[0027] Table 1 Antibacterial effect of Ag-ZnO superstructured particles against Staphylococcus aureus Table 2 Antibacterial effect of Ag-ZnO superstructured particles on Escherichia coli Because of the heterogeneous Schottky barrier at the junction of ZnO and Ag nanowires, the ZnO nanoarray generates reactive oxygen species upon photoexcitation. Furthermore, the unique LSPR effect of the Ag nanowires themselves can generate unique hot electrons, further enhancing the rate of reactive oxygen species generation, thereby destroying bacterial cell membranes and DNA, achieving a favorable photoantibacterial effect. However, if the ZnO nanoarray length is too short, it will limit the effective separation of ZnO photogenerated carriers, while if it is too long, it will affect the injection of hot electrons into the Ag nanowires, ultimately limiting the effective photoantibacterial effect. Therefore, the optimal ZnO nanoarray length for the material demonstrated in this experimental example is 50 nm.

[0028] The synthesis of Ag nanowires in this invention involves using polyvinyl pyrrolidone (PVP) as a stabilizer in 1,2-propylene glycol, reacting at a specific temperature, and sequentially adding sodium chloride solution and silver nitrate solution. The morphology and size of the Ag nanowires can be controlled, resulting in high-quality nanowire structures with excellent electrical conductivity and optical properties, particularly the localized surface plasmon resonance (LSPR) effect, which provides a foundation for enhancing the separation efficiency of photogenerated ZnO carriers. ZnO nanoarrays are grown on the Ag nanowires: Ag nanowires are dispersed in a zinc acetate solution, the pH is adjusted, and a hydrothermal reaction is performed to generate ZnO nanoarrays of varying lengths. The length of the ZnO nanoarrays can be controlled by varying the amount of zinc acetate. An appropriate ZnO nanoarray length (e.g., 50 nm) effectively promotes the separation of photogenerated electron-hole pairs while maintaining sufficient surface area to facilitate the generation of reactive oxygen species, thereby enhancing antibacterial performance.

[0029] A bacterial solution was diluted in LB medium, then the Ag-ZnO superstructured particles were added and incubated in an incubator. The colony counts were then used to assess the antibacterial efficacy. The experimental results showed that the Ag-ZnO superstructured particles exhibited extremely high antibacterial efficacy against both Staphylococcus aureus and Escherichia coli (99.29% and 99.84%, respectively). This is attributed to the combined effects of reactive oxygen species generated by the ZnO nanoarrays under illumination and the LSPR effect of the Ag nanowires, which enhanced the material's antibacterial ability.

[0030] The Ag nanowire / ZnO nanoarray composite structure developed in this method fully utilizes the synergistic effect between the two, not only improving the antibacterial properties of the material, but also providing a new strategy for the development of efficient and environmentally friendly antibacterial materials. In particular, finding the optimal ZnO nanoarray length is crucial for maximizing its photocatalytic and antibacterial properties.

[0031] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by this specification and without departing from the scope of protection of the claims of the present invention, may also devise various forms, all of which fall within the scope of protection of the present invention.

Claims

1. A method for synthesizing Ag nanowire / ZnO nanoarray superstructure particles, comprising the following steps: (1) adding a predetermined amount of polyvinyl pyrrolidone powder to a predetermined amount of 1,2-propylene glycol solution, heating the oil bath to a first predetermined temperature, and continuing the reaction for a first predetermined time, then adding a sodium chloride solution of a first predetermined concentration and continuing the reaction for a second predetermined time, then adding a silver nitrate solution of a second predetermined concentration and continuing the reaction for a third predetermined time, and centrifuging and drying the product to obtain Ag nanowires; (2) The Ag nanowires are dispersed in a zinc acetate solution of a third predetermined concentration, stirred continuously for a fourth predetermined time at a second predetermined temperature, and then a sodium hydroxide solution of a fourth predetermined concentration is added to adjust the pH of the solution to 7, and the reaction is continued for a fifth predetermined time, and then centrifuged and dried to obtain Ag-ZnO superstructure particles.

2. The synthesis method according to claim 1, wherein Preferably, the amount of 1,2-propylene glycol solution used is 10 ml, and the amount of polyvinyl pyrrolidone powder used is 0.4 g.

3. The synthesis method according to claim 1, wherein The first predetermined concentration is 1 mmol / L, the second predetermined concentration is 0.15 mol / L, the third predetermined concentration is 0.6 mol / L, and the fourth predetermined concentration is 0.00625-0.05 mol / L.

4. The synthesis method according to claim 1, characterized in that The first predetermined temperature is 160°C, and the second predetermined temperature is room temperature 18-23°C.

5. The synthesis method according to claim 1, characterized in that The first scheduled time is 60 minutes, the second scheduled time is 5 minutes, the third scheduled time is 40 minutes, the fourth scheduled time is 30 minutes, and the fifth scheduled time is 120 minutes.

6. The Ag-ZnO superstructure particle according to claim 1, characterized in that: Uniform growth of ZnO nanoarrays on a single Ag nanowire.

7. Application of the Ag-ZnO superstructure particles prepared according to the method of claim 1 in the field of photo-antibacterial.

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