Silver nanocube and preparation method and application thereof
Silver nanocubes were prepared by a simple mixing and centrifugation method of sorbitol and soluble silver salt, which solved the problems of complex equipment and high cost in the existing technology and obtained uniformly distributed antibacterial silver nanocubes, which are suitable for antibacterial materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-04-24
AI Technical Summary
Existing methods for preparing silver nanocubes suffer from problems such as complex equipment, high reaction temperatures, high costs, and cumbersome processes.
Silver nanocubes were prepared by mixing sorbitol and soluble silver salt at room temperature and then stirring and centrifuging. This method avoids complex hydrothermal reactions and additional additives, and controls the reaction conditions to obtain multiple fine silver particles that are evenly distributed.
A low-cost and simple preparation process was achieved, and the obtained silver nanocubes have antibacterial properties, making them suitable for antibacterial materials, and the particles are uniformly distributed.
Smart Images
Figure CN121911896A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of silver nanocube technology, and in particular to a silver nanocube, its preparation method, and its application. Background Technology
[0002] Metal nanoparticles (NPs) are a type of nanomaterial. Compared to all known nanoparticles to date, metal nanoparticles (especially silver nanoparticles (Ag-NPs)) exhibit significant characteristics such as surface plasmon resonance, high specific surface area, thermal and electrical conductivity, and optical properties. Previously, a series of silver nanostructures with different morphologies have been synthesized, including rod-shaped, sheet-like, fibrous, triangular, prism-like, and cubic structures. Among these, the cubic structure has received considerable attention. In terms of plasmon optics, silver nanocubes, due to their sharp vertices and angular structures, can generate an extremely strong local electromagnetic field enhancement effect under external field excitation, the so-called hotspot effect.
[0003] Compared to isotropic silver nanospheres and two-dimensional silver nanosheets, silver nanocubes exhibit field enhancement strengths that are 1-3 orders of magnitude higher, a characteristic demonstrated in their application in surface-enhanced Raman scattering (SERS). In catalysis and sensing applications, the atoms at the edges and corners of silver nanocubes possess higher unsaturation and surface energy, providing numerous highly active adsorption and reaction sites for reactive molecules. In contrast, the crystal faces of silver nanospheres are randomly exposed with dispersed active sites, while the main exposed surfaces of silver nanosheets are relatively inert basal planes, with active sites limited to their edges. Silver nanocubes, with their greater effective surface area, exhibit superior optical and catalytic properties.
[0004] Previously, there were relatively mature methods for preparing silver nanocubes. Some researchers used ethylene glycol to reduce silver nitrate and polyvinylpyrrolidone (PVP) as a surfactant to synthesize silver nanocube crystals. They also used pyridine and thiocyanate ions (SCN-) as probe molecules to preliminarily study the SERS activity of the silver nanocube crystal assembly system. (Ke Yan, Chen Bin, Zhou Ningning, et al. Cellulose acetate nanofibers loaded with silver nanocubes and their SERS activity[J]. Journal of the Chinese Ceramic Society, 2021, 49(2):220-228.). Their research showed that the morphology of the product was greatly affected by temperature, silver nitrate concentration, PVP and the molar ratio of silver nitrate. Other researchers used an appropriate amount of silver seed crystals and hexadecyl ammonium bromide (CTAB) surfactant to synthesize silver nanocubes in aqueous solution by ascorbic acid reduction of silver nitrate. Their research showed that the key to obtaining silver nanocubes is to control the concentration of CTAB, the reduction rate of silver nitrate, and the heat treatment temperature and time in the reaction system. Only by fully utilizing the selective adsorption of CTAB surfactant molecules on specific crystal faces of silver nanocrystals can the growth rate of different crystal faces be adjusted, thereby forming nanocubes with complete morphology. (Wang Yuehui, Zhang Qi, Zhou Ji. Preparation of silver nanocubes and its influencing factors [J]. Materials Reports, 2008, 22(3):144-147.). Another preparation method uses a solvothermal hydrothermal method with ethylene glycol and glycerol as co-solvents. By adjusting the viscosity, pressure, and hydrothermal temperature of the reaction system, monodisperse silver nanocubes with uniform morphology and sizes ranging from 40 to 120 nm were obtained. Their research showed that the high pressure conditions generated by solvothermal treatment are conducive to the formation of single-crystal silver seeds, and that the yield, morphology, and particle size of silver nanocubes are closely related to parameters such as surfactant PVP concentration, glycerol content, reaction temperature, and reaction time.
[0005] However, the above-mentioned methods for preparing silver nanocubes have some shortcomings, such as complex reaction equipment, high reaction temperature, complicated preparation process, and high cost. Summary of the Invention
[0006] The purpose of this invention is to provide a silver nanocube, its preparation method, and its application. It does not require complex hydrothermal reactions or the addition of crosslinking agents and surfactants. The reaction conditions are simple and the cost is low. The resulting silver nanocube consists of multiple fine particles that are evenly distributed.
[0007] To achieve the above objectives, the present invention provides a method for preparing silver nanocubes, comprising the following steps: S1. Dissolve sorbitol in water, heat and stir until uniformly dispersed to obtain a sorbitol solution; S2. Dissolve the soluble silver salt in water and stir at room temperature in the dark until it is evenly dispersed to obtain a soluble silver salt solution. Store it in the dark for later use. S3. Mix the sorbitol solution obtained in S1 with the soluble silver salt solution obtained in S2, and heat and stir until light yellow to obtain a mixed solution; S4. Centrifuge the mixture obtained in S3 and remove the supernatant. Add water and centrifuge again. Repeat the centrifugation operation and dry the obtained solid to obtain silver nanocubes.
[0008] Preferably, in S1, the mass fraction of the sorbitol solution is 1-20%.
[0009] Preferably, in S2, the soluble silver salt is one or more of silver nitrate and silver acetate.
[0010] Preferably, in S2, the mass fraction of the soluble silver salt solution is 0.1-2%.
[0011] Preferably, in S3, the volume ratio of sorbitol solution to soluble silver salt solution is 1:1.
[0012] Preferably, in step S3, the heating and stirring temperature is 50-90℃, the stirring speed is 300-600rpm, and the stirring time is 5-10h.
[0013] Preferably, in S4, the centrifugation speed is 4000-6000 rpm and the centrifugation time is 3-10 min.
[0014] Silver nanocubes were prepared using the method described above.
[0015] Preferably, the silver nanocubes are composed of multiple tiny silver particles.
[0016] The aforementioned silver nanocubes are used in the preparation of antibacterial materials.
[0017] Therefore, the present invention employs the above-mentioned silver nanocube, its preparation method, and its application, and its beneficial effects are as follows: 1. The preparation method provided by this invention does not require complex hydrothermal reactions or additional crosslinking agents and surfactants. The reaction conditions are simple and the cost is low. 2. The silver nanocubes prepared by this invention have certain antibacterial properties and can be used as antibacterial materials or to prepare other antibacterial materials; 3. The silver nanocubes prepared by this invention are composed of multiple fine silver particles, which are evenly distributed and have a side length of 200-1000 nm.
[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0019] Figure 1 This is a scanning electron microscope image of the silver nanocubes in Embodiment 1 of the present invention. Figure 1 In the image, 'a' is a scanning electron microscope image of the silver nanocubes from Example 1. Figure 1 b in the image is a magnified scanning electron microscope image of the silver nanocubes in Example 1; Figure 2 This is a scanning electron microscope image of the silver nanocubes in Example 2 of the present invention; Figure 3 This is a scanning electron microscope image of the silver nanocubes in Comparative Example 1 of this invention; Figure 4 This is the X-ray energy dispersive spectroscopy (EDS) analysis diagram of the silver nanocubes in Example 1 of this invention; Figure 5 This is a transmission electron microscope image of the silver nanocubes in Example 1 of the present invention; Figure 6 This is a diagram illustrating the combined antibacterial effect of silver nanocubes against Escherichia coli in Example 1 of this invention. Figure 6 In the diagram, 'a' represents a schematic representation of the blank control group, the experimental group, and the control group. Figure 6 In the figure, b represents the antibacterial effect of the blank control group, the experimental group, and the control group; Figure 7 This is a diagram illustrating the combined antibacterial effect of silver nanocubes against Staphylococcus aureus in Example 1 of this invention. Figure 7 In the diagram, 'a' represents a schematic representation of the blank control group, the experimental group, and the control group. Figure 7 In the diagram, b represents the antibacterial effect of the blank control group, the experimental group, and the control group. Detailed Implementation
[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.
[0021] This invention provides a method for preparing silver nanocubes, comprising the following steps: S1. Dissolve sorbitol in water, heat and stir until uniformly dispersed to obtain a sorbitol solution; S2. Dissolve the soluble silver salt in water and stir at room temperature in the dark until it is evenly dispersed to obtain a soluble silver salt solution. Store it in the dark for later use. S3. Mix the sorbitol solution obtained in S1 with the soluble silver salt solution obtained in S2, and heat and stir until a light yellow color is obtained to obtain a mixed solution. In this process, sorbitol has both reducing and surface-modifying effects, and its hydroxyl groups will react with Ag... + Restored to Ag 0 Meanwhile, its hydroxyl structure is adsorbed on specific crystal faces of silver nanocrystals, which promotes the development of silver nanocrystals along three-dimensional equiaxial directions to obtain silver nanocubes.
[0022] S4. Centrifuge the mixture obtained in S3 and remove the supernatant. Add water and centrifuge again. Repeat the centrifugation operation and then dry the resulting solid.
[0023] In some embodiments of the present invention, in S1, the mass fraction of the sorbitol solution is 1-20%.
[0024] In some embodiments of the present invention, in S2, the soluble silver salt is one or more of silver nitrate and silver acetate. The soluble silver salt ionizes in water to produce Ag. + Preparation and storage under light-protected conditions can prevent Ag from being contaminated. + The silver element is prematurely precipitated due to light reduction.
[0025] In some embodiments of the present invention, in S2, the mass fraction of the soluble silver salt solution is 0.1-2%. By controlling the raw material concentration, localized Ag... + Excessive amounts can cause particle aggregation.
[0026] In some embodiments of the present invention, in step S3, the volume ratio of sorbitol solution to soluble silver salt solution is 1:1. The hydroxyl group of sorbitol will... + Restored to Ag 0 Stirring ensures uniform temperature and concentration in the reaction system, promoting the reaction of Ag. 0 Directional growth results in a cubic morphology.
[0027] In some embodiments of the present invention, in step S3, the heating and stirring temperature is 50-90°C, the stirring speed is 300-600 rpm, and the stirring time is 5-10 hours. This synergistic control of the nucleation rate and crystal growth direction avoids irregular morphology.
[0028] In some embodiments of the present invention, in step S4, the centrifugation speed is 4000-6000 rpm and the centrifugation time is 3-10 min. The reacted silver nanocubes are collected by centrifugation and repeatedly washed with water to remove unreacted sorbitol and Ag. + The product is dried to remove moisture, thereby improving its purity and preventing impurities from affecting the dispersibility of the silver nanocubes.
[0029] The silver nanocubes prepared by the above-mentioned method are uniformly distributed and are composed of multiple tiny silver particles.
[0030] In some embodiments of the present invention, a silver nanocube is used in the preparation of an antibacterial material.
[0031] Example 1 S1. Dissolve 5g of sorbitol in 30-40mL of water, heat to 50℃, and magnetically stir at 500rpm until uniformly dispersed. Make up to 50mL with water and continue magnetically stirring until uniform to obtain a 10% sorbitol solution.
[0032] S2. Dissolve 0.1g of silver nitrate powder in 50mL of water, and stir magnetically at 500rpm at room temperature in the dark until uniformly dispersed to obtain a 0.2% silver nitrate solution. Store in the dark for later use.
[0033] S3. Pipette 2 mL of the sorbitol solution obtained in S1 and 2 mL of the silver nitrate solution obtained in S2 and mix them. Seal the mixture with aluminum foil and stir at 80°C and 500 rpm for 6 hours until it turns light yellow to obtain the mixture.
[0034] S4. Centrifuge the mixture obtained in S3 at 5000 rpm for 5 min, remove the supernatant, add water, and centrifuge again at 5000 rpm for 5 min. Repeat the centrifugation operation, and then put the obtained solid into an oven and dry it at 80℃ for 1 h to obtain silver nanocubes.
[0035] Example 2 S1. Dissolve 1g of sorbitol in 30-40mL of water, heat to 50℃, and magnetically stir at 500rpm until uniformly dispersed. Make up to 50mL with water and continue magnetically stirring until uniform to obtain a 2% sorbitol solution.
[0036] S2. Dissolve 0.1g of silver nitrate powder in 50mL of water, and stir magnetically at 500rpm at room temperature in the dark until uniformly dispersed to obtain a 0.2% silver nitrate solution. Store in the dark for later use.
[0037] S3. Pipette 2 mL of the sorbitol solution obtained in S1 and 2 mL of the silver nitrate solution obtained in S2 and mix them. Seal the mixture with aluminum foil and stir at 80°C and 500 rpm for 6 hours until it turns light yellow to obtain the mixture.
[0038] S4. Centrifuge the mixture obtained in S3 at 5000 rpm for 5 min, remove the supernatant, add water, and centrifuge again at 5000 rpm for 5 min. Repeat the centrifugation operation, and then put the obtained solid into an oven and dry it at 80℃ for 1 h to obtain silver nanocubes.
[0039] Comparative Example 1 S1. Dissolve 0.05g of sorbitol in 30-40mL of water, heat to 50℃, and magnetically stir at 500rpm until uniformly dispersed. Make up to 50mL with water and continue magnetically stirring until uniform to obtain a 1% sorbitol solution.
[0040] S2. Dissolve 0.5g of silver nitrate powder in 50mL of water, and stir magnetically at 500rpm at room temperature in the dark until uniformly dispersed to obtain a 1% silver nitrate solution. Store in the dark for later use.
[0041] S3. Mix 2 mL of the sorbitol solution obtained in S1 with 2 mL of the silver nitrate solution obtained in S2. Seal the mixture with aluminum foil and stir at 80°C and 500 rpm for 6 hours until the mixture changes color to obtain the final mixture.
[0042] S4. Centrifuge the mixture obtained in S3 at 5000 rpm for 5 min, remove the supernatant, add water, and centrifuge again at 5000 rpm for 5 min. Repeat the centrifugation operation, and then put the obtained solid into an oven and dry it at 80℃ for 1 h to obtain silver nanoparticles.
[0043] Test case a. Scanning electron microscope test Scanning electron microscopy was performed on the silver nanocubes in Examples 1-2 and Comparative Example 1, and the results are as follows: Figures 1-3 As shown, by Figure 1 It can be seen that the silver nanocubes obtained in Example 1 are uniformly distributed and have a nanocube structure, with a larger side length of 1000 nm and a smaller side length of 200 nm. Figure 2 It can be seen that most of the silver nanocubes obtained in Example 2 are cubic structures, with a larger side length of 300 nm and a smaller side length of 100 nm. A small portion are irregular particle structures with a particle size of approximately 50-100 nm. Figure 3 As can be seen, Comparative Example 1 yielded a silver nanoparticle structure, in which the particle size is approximately between 50-200 nm.
[0044] b. X-ray energy dispersive spectroscopy analysis X-ray energy dispersive spectroscopy (EDS) analysis was performed on the silver nanocubes in Example 1, and the results are as follows: Figure 4 As shown, the silver content is relatively high, and the silver nanocubes are composed of multiple tiny silver particles.
[0045] c. Transmission electron microscopy test The silver nanocubes in Example 1 were tested using transmission electron microscopy, and the results are as follows: Figure 5As shown, the silver nanocube is composed of multiple tiny silver particles with distinct boundaries, and the side length of the silver nanocube is 900 nm.
[0046] d. Antibacterial test Escherichia coli and Staphylococcus aureus were used as experimental bacteria to test the antibacterial properties of silver nanocubes and to perform qualitative and quantitative determination.
[0047] Taking Escherichia coli as an example, the original E. coli bacteria are diluted to a bacterial concentration of 1x10⁻⁶. 8 Prepare bacterial liquid and solid culture media using CFU / mL. Autoclave all silver nanocubes used at 121°C. Measure two 10mL aliquots of 1x10⁻⁶ CFU / mL. 8 One portion of the bacterial suspension containing CFU / mL was used as the experimental group, with 5 mg of silver nanocubes from Example 1 added, and the other portion served as the control group without silver nanocubes. A separate 10 mL portion of pure liquid culture medium, without silver nanocubes, was used as a blank control group to compare and demonstrate the antibacterial effect of the silver nanocubes.
[0048] The prepared bacterial suspension containing 5 mg of silver nanocubes, pure bacterial suspension, and pure liquid culture medium were placed in a shaker and shaken uniformly at 150 rpm and 37°C for 24 hours. After incubation, 20 μL of each of the blank control group, control group, and experimental group was pipetted and evenly spread onto solid culture medium. The solid culture medium was then incubated at 37°C for 24 hours, and the growth of colonies was observed. This was used to test the antibacterial properties of the silver nanocubes. The antibacterial results are as follows: Figure 6 As shown. The test method for Staphylococcus aureus is the same as that for Escherichia coli, and the antibacterial results are as follows. Figure 7 As shown.
[0049] according to Figure 6 As shown in Figure 'a', from left to right, they are the blank control group, the experimental group, and the control group; according to Figure 6 As shown in b, from left to right, the results after culturing the blank control group, the experimental group, and the control group are shown. The colony growth indicates that the silver nanocubes have a certain antibacterial effect on Escherichia coli.
[0050] according to Figure 7 As shown in 'a', from left to right, they are the blank control group, the experimental group, and the control group; according to Figure 7 As shown in b, from left to right, the results after culturing the blank control group, the experimental group, and the control group are shown. The colony growth indicates that silver nanocubes also have a certain antibacterial effect on Staphylococcus aureus.
[0051] Therefore, the present invention employs the above-mentioned silver nanocube, its preparation method, and its application, which does not require complex hydrothermal reactions or the addition of crosslinking agents and surfactants. The reaction conditions are simple, the cost is low, and the obtained silver nanocube consists of multiple fine particles that are uniformly distributed.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing silver nanocubes, characterized in that: Includes the following steps: S1. Dissolve sorbitol in water, heat and stir until uniformly dispersed to obtain a sorbitol solution; S2. Dissolve the soluble silver salt in water and stir at room temperature in the dark until it is evenly dispersed to obtain a soluble silver salt solution. Store it in the dark for later use. S3. Mix the sorbitol solution obtained in S1 with the soluble silver salt solution obtained in S2, and heat and stir until light yellow to obtain a mixed solution; S4. Centrifuge the mixture obtained in S3 and remove the supernatant. Add water and centrifuge again. Repeat the centrifugation operation and dry the obtained solid to obtain silver nanocubes.
2. The method for preparing silver nanocubes according to claim 1, characterized in that: In S1, the mass fraction of the sorbitol solution is 1-20%.
3. The method for preparing silver nanocubes according to claim 1, characterized in that: In S2, the soluble silver salt is one or more of silver nitrate and silver acetate.
4. The method for preparing silver nanocubes according to claim 1, characterized in that: In S2, the mass fraction of the soluble silver salt solution is 0.1-2%.
5. The method for preparing silver nanocubes according to claim 1, characterized in that: In S3, the volume ratio of sorbitol solution to soluble silver salt solution is 1:
1.
6. The method for preparing silver nanocubes according to claim 1, characterized in that: In S3, the heating and stirring temperature is 50-90℃, the stirring speed is 300-600rpm, and the stirring time is 5-10h.
7. The method for preparing silver nanocubes according to claim 1, characterized in that: In S4, the centrifugation speed is 4000-6000 rpm and the centrifugation time is 3-10 min.
8. A silver nanocube, characterized in that: The silver nanocubes were prepared according to any one of claims 1-7.
9. A silver nanocube according to claim 8, characterized in that: Silver nanocubes are composed of multiple tiny silver particles.
10. An application of silver nanocubes, characterized in that: The silver nanocube according to claim 9 is used in the preparation of antibacterial materials.