Surface wave-shaped gold nanocrystalline material and preparation method and application thereof

Abstract

The invention relates to the field of materials, and discloses a surface wave-shaped gold nanocrystalline material and a preparation method and application thereof.The preparation method comprises the steps that a chloroauric acid solution A1, a sodium hydroxide solution B1 and a solution C1 containing a first ligand react to obtain a first solution; the first ligand is selected from more than one of nitrite, citrate, sulfite and hypophosphite; a solution 1 containing a second ligand, a solution 2 containing a nanocrystalline template and a reducing agent solution 3 are mixed to obtain a mixed solution 4, the solution I is added into the mixed solution 4 to obtain a solution II, and the second ligand is selected from one or more of polyvinylpyrrolidone and poly (diallyldimethylammonium chloride) heat exchange sodium dodecyl benzene sulfonate; and mediating a mediating agent into the solution II to obtain the gold nanocrystalline material with the wavy surface. According to the method, the gold nanocrystals are synthesized in a water phase at normal temperature and normal pressure by adopting a wet chemical method, the surfaces of the prepared gold nanocrystals are wavy, and the roughness is continuously adjustable.

Description

Technical Field

[0001] This invention relates to the field of materials, specifically to a surface-wave-shaped gold nanocrystal, its preparation method, and its application. Background Technology

[0002] Rough-surfaced gold nanocrystals exhibit significant differences in optics, catalysis, surface chemistry, and stability compared to ordinary gold nanocrystals. Among them, wavy-surfaced gold nanocrystals are surface-roughened nanomaterials with periodic or aperiodic undulations, and their unique morphology endows them with enhanced plasmon resonance, catalytic activity, and surface-enhanced spectral properties. For example, due to the presence of more nanoscale protrusions, pores, and defects, wavy-surfaced gold nanocrystals can enhance the localized surface plasmon resonance (LSPR) effect, thus exhibiting stronger surface-enhanced Raman scattering (SERS) activity and light absorption. Furthermore, the exposed high-activity crystal faces and step sites of wavy-surfaced gold nanocrystals may significantly improve catalytic performance.

[0003] Currently available methods for preparing this type of gold nanocrystal are mostly electrochemical deposition and displacement reaction etching, which are easily affected by parameters such as electrode potential and electrolyte composition, resulting in uneven product morphology. At the same time, due to the fast reaction kinetics, it is difficult to precisely control the surface roughness. Summary of the Invention

[0004] The purpose of this application is to overcome the problems of uneven morphology and uncontrollable surface roughness of existing gold nanocrystal products, and to provide a gold nanocrystal with a wavy surface, its preparation method, and its application. The gold nanocrystals prepared by the method of this invention have a wavy surface, the reaction conditions are mild and can be carried out at room temperature and pressure, and the surface roughness of the prepared gold nanocrystals is continuously adjustable, making them suitable for industrial application.

[0005] To achieve the above objectives, the first aspect of this application provides a method for preparing surface-wave-like gold nanocrystals, wherein the preparation method includes: A first reaction is carried out with chloroauric acid solution A1, sodium hydroxide solution B1 and solution C1 containing a first ligand to obtain solution I, wherein the first ligand is selected from one or more of nitrite, citrate, sulfite and hypophosphite; Solution 1 containing a second ligand, solution 2 containing a nanocrystalline template, and reducing agent solution 3 are mixed to obtain mixed solution 4. Solution I is added to mixed solution 4 to obtain solution II. The second ligand is selected from one or more of polyvinylpyrrolidone, polydiallyldimethylammonium chloride, or sodium dodecylbenzenesulfonate. The solution II was added to solution 5 containing a mediator and mixed to carry out a second reaction to obtain a gold nanocrystal material with a wavy surface.

[0006] This invention uses nanocrystalline templates, a first ligand, a second ligand, sodium hydroxide, chloroauric acid, a reducing agent, and a mediator as raw materials to synthesize gold nanocrystals in an aqueous phase using a wet chemical method under ambient temperature and pressure. The resulting gold nanocrystals have a wavy surface with continuously tunable roughness. Compared with existing technologies, the reaction conditions of this invention are milder, and the wavy surface of the gold nanocrystals is continuous, resulting in a stronger reaction signal in plasma-enhanced photocatalysis.

[0007] Preferably, the mediator is selected from one or more of chloroplatinic acid, potassium chloroplatinate, palladium nitrate, and sodium chloropalladium.

[0008] Preferably, the reducing agent is selected from one or more of sodium borohydride, glucose, ascorbic acid, and hydrazine hydrate.

[0009] Preferably, the molar ratio of chloroauric acid in solution A1 to reducing agent in reducing agent solution 3 is 1:1-10. For example, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:7, 1:10, or any value between any two of these numbers.

[0010] Preferably, the molar ratio of the mediator in solution 5 to chloroauric acid in solution A1 is 2400-2600:1. For example, it can be 2400:1, 2450:1, 2470:1, 2500:1, 2520:1, 2550:1, 2600:1, or any value between any two of these numbers.

[0011] Preferably, the temperature of the second reaction is 30-60℃, and the time is 6-36h. The temperature of the second reaction can be any value between any two of 30℃, 40℃, 50℃, 60℃, and the time can be any value between any two of 6h, 8h, 10h, 12h, 15h, 20h, 25h, 30h, 36h, and the time can be any value between any two of 6h, 8h, 10h, 12h, 15h, 20h, 25h, 30h, 36h.

[0012] Preferably, based on the total amount of solution A1, the concentration of solution A1 is 0.05-0.5 mol / L, such as 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, and any value between any two of them; Based on the total amount of solution B1, the concentration of solution B1 is 0.05-1 mol / L, such as 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 1 mol / L, and any value between any two of them; Based on the total amount of solution C1, the concentration of solution C1 is 0.05-0.5 mol / L, such as 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, and any value between any two of them.

[0013] Preferably, the molar ratio of chloroauric acid in solution A1, sodium hydroxide in solution B1, and the first ligand in solution C1 is 1:5-8:3-5. The solute in solution A1 is chloroauric acid, the solute in solution B1 is sodium hydroxide, and the solute in solution C1 is sodium sulfite. Specifically, their molar ratios can be 1:5:3, 1:5:4, 1:5:5, 1:6:3, 1:7:3, 1:8:3, or any value between any two of these numbers.

[0014] The first reaction can take 10-15 hours. Specifically, it can be 10 hours, 12 hours, 15 hours, or any value between any two of them, and it is carried out at room temperature.

[0015] Preferably, based on the total amount of solution 1, the concentration of solution 1 is 5-15 wt.%, such as 5 wt.%, 10 wt.%, 15 wt.%, and any value between any two of them.

[0016] Preferably, based on the total amount of solution 3, the concentration of solution 3 is 0.1-1 mol / L, such as 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.75 mol / L, 1 mol / L, and any value between any two of them.

[0017] Preferably, the preparation step of the solution 2 including the nanocrystalline template includes: Silver nitrate solution F, sodium citrate solution G, and hydrogen peroxide solution H are added to ultrapure water in a solute molar ratio of 1:30-100:190-250 to obtain mixed solution a. Sodium borohydride solution I is then added to mixed solution a to obtain solution III. The molar ratio of the solute in silver nitrate solution F to sodium borohydride solution I is 1:5-8. Solution IV was obtained by mixing chloroauric acid solution A2, sodium hydroxide solution B2 and solution C2 containing the first ligand in a solute molar ratio of 1:3-6:1-6. The solutions III and IV are mixed with sodium hydroxide solution B3, solution D containing the second ligand, and reducing agent solution E to obtain a nanocrystalline template. The molar ratio of solute in sodium hydroxide solution B2 and sodium hydroxide solution B3 is 5-8:5, and the molar ratio of solute in sodium hydroxide solution B3, solution D containing the second ligand, and reducing agent solution E is 1:0.02-0.03:1.

[0018] When preparing solution 2 of the nanocrystalline template, the molar ratio of silver nitrate in silver nitrate solution F to chloroauric acid in chloroauric acid solution A2 is 5:2-4, which can be 5:2, 5:3, 5:4, or any value between any two of them.

[0019] When preparing solution III, the molar ratio of silver nitrate, sodium citrate, and hydrogen peroxide can be 1:30:190, 1:30:200, 1:30:250, 1:40:190, 1:50:190, 1:70:190, 1:100:190, or any value between any two of these numbers. The molar ratio of silver nitrate in silver nitrate solution F to sodium borohydride in sodium borohydride solution I can be 1:5, 1:6, 1:7, 1:8, or any value between any two of these numbers.

[0020] When preparing solution IV, the molar ratio of chloroauric acid in solution A2, sodium hydroxide in solution B2, and the first ligand in solution C2 can be 1:3:1, 1:3:2, 1:3:3, 1:3:4, 1:3:5, 1:3:6, 1:4:1, 1:5:1, 1:6:1, or any value between any two of these ratios.

[0021] When preparing the nanocrystalline template, the concentrations of sodium hydroxide solution B3 and sodium hydroxide solution B2 are the same, and the molar ratio of solute (sodium hydroxide) contained in them can be 5:5, 6:5, 7:5, 8:5 and any value between any two of them. The molar ratio of solute in sodium hydroxide solution B3, solution D of the second ligand and reducing agent solution E can be 1:0.02:1, 1:0.025:1, 1:0.03:1 and any value between any two of them.

[0022] Preferably, based on the total amount of solution F, the concentration of solution F is 0.05-0.15 mol / L, such as 0.05 mol / L, 0.8 mol / L, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, and any value between any two of them.

[0023] Preferably, based on the total amount of solution G, the concentration of solution G is 0.05-0.15 mol / L, such as 0.05 mol / L, 0.8 mol / L, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, and any value between any two of them; Preferably, based on the total amount of solution H, the volume concentration of solution H is 25-35 wt.%, such as 25 wt.%, 27 wt.%, 30 wt.%, 32 wt.%, 35 wt.%, and any value between any two of them.

[0024] Preferably, based on the total amount of solution I, the concentration of solution I is 0.05-0.15 mol / L, such as 0.05 mol / L, 0.8 mol / L, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, and any value between any two of them.

[0025] Preferably, based on the total amount of solution A2, the concentration of solution A2 is 0.2-0.3 mol / L, such as 0.2 mol / L, 0.22 mol / L, 0.24 mol / L, 0.26 mol / L, 0.28 mol / L, 0.3 mol / L, and any value between any two of them.

[0026] Preferably, based on the total amount of the corresponding solutions, the concentrations of solutions B2 and B3 are independently 0.1-0.3 mol / L, such as 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, and any value between any two of them.

[0027] Preferably, based on the total amount of solution C2, the concentration of solution C2 is 0.3-0.6 mol / L, such as 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, and any value between any two of them.

[0028] Preferably, based on the total amount of solution D, the concentration of solution D is 5-15 wt.%, such as 5 wt.%, 10 wt.%, 15 wt.%, and any value between any two of them.

[0029] Preferably, based on the total amount of solution E, the concentration of solution E is 0.3-0.6 mol / L, such as 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, and any value between any two of them.

[0030] A second aspect of this invention provides a gold nanocrystalline material prepared by the preparation method described in the first aspect of this invention. The gold nanocrystalline material prepared by the method provided by this invention exhibits a characteristic peak around 640 nm under 300-800 nm ultraviolet light irradiation.

[0031] The third aspect of the present invention provides an application of a gold nanocrystalline material prepared by the preparation method described in the first aspect of the present invention or the gold nanocrystalline material described in the second aspect of the present invention in surface-enhanced Raman spectroscopy.

[0032] Compared with the prior art, the present invention has the following advantages: (I) The present invention first uses sodium hydroxide to adjust the pH and uses chloroauric acid and ligand 1 as raw materials to obtain a gold precursor solution; then uses nanocrystalline template, gold precursor, second ligand, reducing agent and mediator as raw materials to deposit the gold precursor onto the surface of nanocrystalline template to obtain gold nanocrystals with a wavy surface.

[0033] (II) The present invention achieves a low-consumption and green chemical reaction in an aqueous phase system at room temperature and normal pressure.

[0034] (III) The present invention can achieve continuous and precise control of surface roughness by controlling the kinetics of precursor reduction reaction, and obtain a series of surface wavy gold nanocrystals with continuously adjustable surface roughness.

[0035] (V) The entire reaction process of this invention uses non-toxic and harmless reagents, achieving green and environmentally friendly results.

[0036] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings: Figure 1 TEM image of the nanocrystalline template prepared in Example 1; Figure 2 UV-vis image of the nanocrystalline template prepared in Example 1; Figure 3 A digital photograph of the nanocrystalline template prepared in Example 1; Figure 4 TEM image of the surface-wave-like gold nanocrystals prepared in Example 1; Figure 5This is a TEM image of the surface-wave-like gold nanocrystals prepared in Example 2; Figure 6 This is a TEM image of the surface-wave-like gold nanocrystals prepared in Example 3; Figure 7 The UV-vis image shows the surface wavy gold nanocrystals prepared in Example 3. Figure 8 A digital photograph of the surface-wave-like gold nanocrystals obtained in Example 3; Figure 9 This is a TEM image of the surface-wave-like gold nanocrystals prepared in Example 4; Figure 10 This is a partial HRTEM image of the surface-wave-like gold nanocrystals prepared in Example 4; Figure 11 The image shows a TEM image of the gold nanocrystals prepared in Comparative Example 1. Figure 12 The images show the Raman spectra of gold nanocrystals prepared in Example 4 and Comparative Example 1 for detecting low concentrations of crystal violet. Detailed Implementation

[0038] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0039] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0040] Furthermore, the term "and / or" in the specification and claims is used to describe the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0043] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0044] The present invention will be further illustrated below with reference to embodiments and comparative examples. Unless otherwise specified, all reagents or instruments used in the following embodiments and comparative examples are commercially available conventional products. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply.

[0045] The room temperature in this invention refers to 30-60°C.

[0046] Preparation Example 1 Preparation of nanocrystalline templates Step 1: Prepare seed crystal colloidal solution at 30℃: Step 1.1 Prepare the following solutions according to the required concentration: Solution I: 3 mL of 0.1 mol / L sodium borohydride solution; Solution F: 0.5 mL of 0.1 mol / L silver nitrate solution; Solution G: 20 mL of 0.1 mol / L sodium citrate solution; Solution H: 1 mL of 30 wt.% (9.79 mol / L) hydrogen peroxide solution; The solvent for all the above solutions is water.

[0047] Step 1.2 Add solutions F, G and H to 500 mL of ultrapure water under stirring to obtain mixed solution a.

[0048] Step 1.3 Use a pipette to quickly add solution I to mixed solution a and stir for 0.5 h and let stand for 6 h to obtain solution III, i.e., seed crystal colloidal solution.

[0049] Step 2: Preparation of nanocrystalline templates at room temperature (30℃): Step 2.1 Prepare the following solutions according to the concentration requirements: Solution A2: 0.12 mL of 0.25 mol / L chloroauric acid solution; Solution B2: 0.7 mL of 0.2 mol / L sodium hydroxide solution; Solution B3: 0.5 mL of 0.2 mol / L sodium hydroxide solution; Solution C2: 0.2 mL of 0.5 mol / L sodium sulfite solution; Solution D: 1 mL of 10 wt% polyvinylpyrrolidone solution; Solution E: 0.2 mL of 0.5 mol / L ascorbic acid solution; The solvent for all the above solutions is water.

[0050] Step 2.2 Mix solutions A2, B2, and C2 to obtain solution IV; Step 2.3 Mix the solution obtained in Step 1 (III) with solutions B3, D, E and IV, stir for 12 h, then centrifuge and wash with water to obtain the nanocrystalline template. Redisperse the obtained nanocrystalline template in ultrapure water to obtain 1 mL of nanocrystalline template solution (solution 2) for later use.

[0051] The nanocrystalline template prepared in Example 1 was characterized. Figure 1 The image shows a TEM image of the nanocrystalline template obtained in Example 1. It can be seen that the nanocrystalline template has a smooth surface and uniform morphology, is sheet-like, and has good dispersibility. Figure 2 The image shows the UV-Vis spectrum (test wavelength range 300-800 nm) of the nanocrystalline template obtained in Example 1. It can be seen from the image that the peak position of the nanocrystalline template is around 625 nm. Figure 3 This is a digital photograph of the nanocrystalline template obtained in Example 1. The image shows that the colloidal solution is uniformly dispersed in a deep blue color. Example 1

[0052] Preparation of surface-wave-like gold nanocrystals Step 1: Prepare the gold precursor solution at room temperature (30℃): Step 1.1 Prepare the following solutions according to the required concentration: Solution A1: 0.1 mL of 0.25 mol / L chloroauric acid solution; Solution B1: 0.3 mL of 0.5 mol / L sodium hydroxide solution; Solution C1: 1 mL of 0.1 mol / L sodium sulfite solution; The solvent for all the above solutions is water.

[0053] Step 1.2 After mixing solutions A1 and B1 thoroughly with stirring, add solution C1 and let stand for 12 h to obtain the gold growth solution (solution I), which is ready for use.

[0054] Step 2: Preparation of surface-wave-like gold nanocrystals at room temperature (30℃): Step 2.1 Prepare the following solutions according to the concentration requirements: Solution 1: 1 ml of 10 wt% polyvinylpyrrolidone solution; Solution 2: Nanocrystalline template solution from Preparation Example 1 (all solutions); Solution 3: 0.2 mL of 0.5 mol / L ascorbic acid solution; The solvent for all the above solutions is water.

[0055] Mix solutions 1, 2, and 3 thoroughly to obtain solution 4.

[0056] Step 2.2 Add the solution I obtained in Step 1 to Solution 4 to obtain Solution II.

[0057] Step 2.3 Dissolve the mediator sodium chloropalladium in water to obtain solution 5 (0.001 M 10 μL). Quickly add solution II to solution 5 using a pipette. Stir at 30°C for 10 h to finally obtain a surface wavy gold nanocrystal colloidal solution. After centrifugation and washing, the surface wavy gold nanocrystal colloidal solution is redispersed in water and stored in colloidal solution form or vacuum dried and stored in powder form.

[0058] Figure 4 This is a TEM image of the surface-wave-like gold nanocrystals prepared in Example 1. The image shows that the gold nanocrystals have good dispersibility. Figure 4 As can be seen from the magnified image (the small image in the upper left corner), the prepared gold nanocrystals have a wavy structure on their surface. Example 2

[0059] The procedure is the same as in Example 1, with the only difference being: Step 1: The concentration of solution C1 is 0.2 mol / L.

[0060] Figure 5 This is a TEM image of the gold nanocrystals with wavy surfaces prepared in Example 2. The image shows that the gold nanocrystals have good dispersibility and the wavy surface is more pronounced than in Example 3. Example 3

[0061] The procedure is the same as in Example 1, with the only difference being: Step 1: The concentration of solution C1 is 0.5 mol / L.

[0062] Figure 6This is a TEM image of the gold nanocrystals with wavy surfaces obtained in Example 3. The image shows that the gold nanocrystals have good dispersibility and the surface is obviously wavy. Figure 7 This is the UV-vis image of the gold nanocrystals obtained in Example 3. It can be seen from the image that the peak position of the gold nanocrystals is around 640 nm. Figure 8 This is a digital photograph of the nanocrystalline template obtained in Example 3. The image shows that the colloidal solution is uniformly dispersed in blue.

[0063] As can be seen from Examples 1-3, the number of wavy patterns shows a significant increasing trend as the concentration of the first ligand solution C1 increases. Example 4

[0064] The procedure was carried out in accordance with Example 3, except that the gold growth solution was obtained by standing for 24 hours in step 1.2.

[0065] Figure 9 This is a TEM image of the gold nanocrystals prepared in Example 4. As can be seen from the magnified view in the upper left corner of the image, the surface of the gold nanocrystals has obvious wavy shape. Figure 10 This is a partial HRTEM image of the gold nanocrystals with wavy surfaces obtained in Example 4. The image shows that the surface of the gold nanocrystals is obviously wavy.

[0066] Furthermore, it can be seen from Examples 3 and 4 that, with the increase of the standing time, the gold nanocrystals prepared in Example 4 have a more uniform wave distribution and larger wave peaks / troughs.

[0067] Comparative Example 1 The procedure is carried out in accordance with Example 4, except that there is no mediator solution (i.e., solution 5) in step 2.3 of step two.

[0068] The product obtained in Comparative Example 1 was characterized. Figure 11 The TEM image of the product obtained in Comparative Example 1 shows that the edges of the obtained gold nanocrystals are smooth and without wavy texture.

[0069] Using the gold nanocrystals prepared in Example 4 and Comparative Example 1 as examples, Raman spectroscopy was performed. The specific method was as follows: the materials were cleaned, vacuum dried, and then subjected to SERS analysis at room temperature using a 633 nm He-Ne laser line. The objective lens was 50 × long working distance (LWD), the laser power was 0.3 mW, and the signal acquisition time was 10 seconds. The detection results are as follows: Figure 12 As shown in the figure, the rough, wavy gold nanocrystals prepared in Example 4 exhibit a stronger signal response than the smooth gold nanocrystals in Comparative Example 1. The signal intensity of Example 4 is approximately 1.1 × 10⁻⁶. 6 about.

[0070] The contents not described in detail in this specification are existing technologies known to those skilled in the art, and will not be elaborated upon here.

[0071] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a surface-wave-like gold nanocrystalline material, characterized in that, The preparation method includes: A first reaction is carried out with chloroauric acid solution A1, sodium hydroxide solution B1 and solution C1 containing a first ligand to obtain solution I, wherein the first ligand is selected from one or more of nitrite, citrate, sulfite and hypophosphite; Solution 1 containing a second ligand, solution 2 containing a nanocrystalline template, and reducing agent solution 3 are mixed to obtain mixed solution 4. Solution I is added to mixed solution 4 to obtain solution II. The second ligand is selected from one or more of polyvinylpyrrolidone, polydiallyldimethylammonium chloride, or sodium dodecylbenzenesulfonate. The solution II was added to solution 5 containing a mediator and mixed to carry out a second reaction to obtain a gold nanocrystal material with a wavy surface.

2. The preparation method according to claim 1, wherein, The mediator is selected from one or more of chloroplatinic acid, potassium chloroplatinate, palladium nitrate, and sodium chloropalladium. And / or, the reducing agent is selected from one or more of sodium borohydride, glucose, ascorbic acid and hydrazine hydrate.

3. The preparation method according to claim 1 or 2, wherein, The molar ratio of chloroauric acid in solution A1 to reducing agent in reducing agent solution 3 is 1:1-10; And / or, the molar ratio of the mediator in solution 5 to chloroauric acid in solution A1 is 2400-2600:1; And / or, the temperature of the second reaction is 30-60°C, and the time is 6-36 h.

4. The preparation method according to claim 3, wherein, The molar ratio of chloroauric acid in solution A1, sodium hydroxide in solution B1, and the first ligand in solution C1 is 1:5-8:3-5; And / or, the time for the first reaction is 10-15 hours.

5. The preparation method according to claim 4, wherein, Based on the total amount of solution A1, the concentration of solution A1 is 0.05-0.5 mol / L; And / or, based on the total amount of solution B1, the concentration of solution B1 is 0.05-1 mol / L; And / or, based on the total amount of solution C1, the concentration of solution C1 is 0.05-0.5 mol / L.

6. The preparation method according to claim 3, wherein, Based on the total amount of solution 1, the concentration of solution 1 is 5-15 wt.%; And / or, based on the total amount of solution 3, the concentration of solution 3 is 0.1-1 mol / L.

7. The preparation method according to any one of claims 1, 2, 4-6, wherein, The preparation steps of the solution 2 containing the nanocrystalline template include: Silver nitrate solution F, sodium citrate solution G, and hydrogen peroxide solution H are added to ultrapure water in a solute molar ratio of 1:30-100:190-250 to obtain mixed solution a. Sodium borohydride solution I is then added to mixed solution a to obtain solution III. The molar ratio of the solute in silver nitrate solution F to sodium borohydride solution I is 1:5-8. Solution IV was obtained by mixing chloroauric acid solution A2, sodium hydroxide solution B2 and solution C2 containing the first ligand in a solute molar ratio of 1:3-6:1-6. The solutions III and IV are mixed with sodium hydroxide solution B3, solution D containing the second ligand, and reducing agent solution E to obtain a nanocrystalline template. The molar ratio of solute in sodium hydroxide solution B2 and sodium hydroxide solution B3 is 5-8:5, and the molar ratio of solute in sodium hydroxide solution B3, solution D containing the second ligand, and reducing agent solution E is 1:0.02-0.03:

1.

8. The preparation method according to claim 7, wherein, Based on the total amount of solution F, the concentration of solution F is 0.05-0.15 mol / L; And / or, based on the total amount of solution G, the concentration of solution G is 0.05-0.15 mol / L; And / or, based on the total amount of solution H, the volume concentration of solution H is 25-35 wt.%; And / or, based on the total amount of solution I, the concentration of solution I is 0.05-0.15 mol / L; And / or, based on the total amount of solution A2, the concentration of solution A2 is 0.2-0.3 mol / L; And / or, based on the total volume of the corresponding solutions, the concentrations of solutions B2 and B3 are independently 0.1-0.3 mol / L; And / or, based on the total amount of solution C2, the concentration of solution C2 is 0.3-0.6 mol / L; And / or, based on the total amount of solution D, the concentration of solution D is 5-15 wt.%; And / or, based on the total amount of solution E, the concentration of solution E is 0.3-0.6 mol / L.

9. Gold nanocrystalline materials prepared by the preparation method according to any one of claims 1-8.

10. The application of a gold nanocrystalline material prepared by the preparation method according to any one of claims 1-8 or the gold nanocrystalline material according to claim 9 in surface-enhanced Raman spectroscopy.

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