An AuM nanoflower and its green, highly efficient and low-cost preparation method and application

Abstract

This application belongs to the technical field of functional nanomaterials, and particularly relates to an AuM nanoflower, a green, efficient and low-cost preparation method thereof, and an application thereof. The green, efficient and low-cost preparation method of the AuM nanoflower provided by this application incubates chloroauric acid trihydrate and a water-soluble compound of at least one noble metal in a green tea aqueous solution to obtain the AuM nanoflower. The raw materials used in the preparation method are easy to obtain, the process is simple, the operation is convenient, the universality is strong, and the repeatability is high. It has a high yield, low cost and environmental friendliness, and the product AuM nanoflower has adjustable size and composition, high purity and good dispersibility, thus solving the technical problem of the lack of a green synthesis method for noble metal alloy nanoflower structures in the prior art.

Description

Technical Field

[0001] This application belongs to the technical field of functional nanomaterials, and in particular relates to an AuM nanoflower and a green, efficient and low-cost preparation method and application thereof. Background Art

[0002] Precious metal alloys have unique physical, chemical and optical properties, making them play an extremely important role in fields such as industrial catalysis, and have received a great deal of attention and extensive research.

[0003] Precious metal alloys with structures such as nanospheres, nanoflowers, nanostars, nanowires, nanorods, nanosheets, icosahedrons, octahedrons, and decahedrons can reduce the actual usage of precious metals while effectively improving their catalytic activity, selectivity and stability; compared with precious metal alloys with nanosphere structures, nanoflowers have a higher specific surface area, excellent electron transfer ability and higher surface reaction activity, so various properties are more superior. Research shows that the 1-phenylethanol oxidation activity of Au 99 Ag1 nanoflowers is 10 times that of spherical Au 99 Ag1 nanoparticles with similar particle sizes; however, the current green synthesis methods of precious metal alloys are usually used to synthesize nanoparticles. For example, using pomegranate seed juice as a reducing agent, AuAg alloy nanoparticles with different components can be controllably prepared. Using natural biopolymer kondagogu gum (GK) as a reducing agent and capping agent, various bimetallic alloy nanoparticles are synthesized by a simple and economical method; currently, there is a lack of research and reports on the green synthesis method of precious metal alloy nanoflowers. Summary of the Invention

[0004] In view of this, this application provides an AuM nanoflower and a green, efficient and low-cost preparation method and application thereof, which are used to solve the technical problem of the lack of a green synthesis method for precious metal alloy nanoflower structures in the prior art.

[0005] The first aspect of this application provides a green, efficient and low-cost preparation method for an AuM nanoflower, and the preparation method includes the steps:

[0006] Step S1: Mix green tea leaves and water and heat to boiling, and filter the green tea leaves to obtain a green tea aqueous solution;

[0007] Step S2: Stir and mix the green tea aqueous solution, the water-soluble compound of the first precious metal and the water-soluble compound of the second precious metal, and incubate to obtain AuM nanoflowers;

[0008] In step S2, the water-soluble compound of the first precious metal is chloroauric acid trihydrate.

[0009] Preferably, in step S1, the mass-volume ratio of the green tea leaves to water is 5 - 30 g:1 L.

[0010] Preferably, in step S1, the heating temperature is 100-150°C, and the boiling time is 0.5-1.5 h.

[0011] Preferably, in step S2, the water-soluble compound of the second noble metal is selected from at least one of silver nitrate, silver trifluoroacetate, chloroplatinic acid, potassium tetrachloroplatinate, and sodium tetrachloroplatinate.

[0012] Preferably, in step S2, the dosage of chloroauric acid trihydrate is 1-20 mmol / L, and the dosage of the water-soluble compound of the second noble metal is 1-20 mmol / L.

[0013] Preferably, in step S2, the incubation time is 1-3 h.

[0014] Preferably, after the incubation to obtain AuM nanoflowers, it further includes: step S3, washing the AuM nanoflowers with deionized water.

[0015] The second aspect of the present application provides an AuM nanoflower prepared by the green, efficient and low-cost preparation method described in the first aspect.

[0016] The third aspect of the present application provides the application of the AuM nanoflower prepared by the green, efficient and low-cost preparation method described in the first aspect in detecting hydrogen peroxide or glucose molecules.

[0017] Preferably, the application is to detect a hydrogen peroxide solution with a concentration of 100-900 mmol / L.

[0018] Preferably, the application is to detect a glucose solution with a concentration of 400-1000 mmol / L.

[0019] It should be noted that the AuM nanoflower provided by the present application can achieve a relatively high detection accuracy when detecting hydrogen peroxide solutions or glucose solutions within a specific concentration range.

[0020] In summary, the present application provides an AuM nanoflower, its green, efficient and low-cost preparation method and application. The AuM nanoflower is prepared by incubating a green tea aqueous solution and water-soluble compounds of at least two noble metals. The raw material used in the preparation method is a green tea aqueous solution, avoiding the use of toxic and harmful solvents; the process adopted in the preparation method is simple, easy to operate, has strong universality and high repeatability, improving the preparation process of noble metal alloy nanoflowers with cumbersome steps and complex operations; at the same time, the raw materials used in the preparation method are easily available, and the yield of preparing AuM nanoflowers is high, which is a green, efficient and low-cost preparation method for AuM nanoflowers, thus solving the technical problem of the lack of a green synthesis method for noble metal alloy nanoflower structures in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Transmission electron microscopy image of the AuM nanoflowers prepared by the green, efficient and low-cost preparation method described in Example 1 of the present application;

[0023] Figure 2 Transmission electron microscopy image of the AuM nanoflowers prepared by the green, efficient and low-cost preparation method described in Example 2 of the present application;

[0024] Figure 3 Working curve graph of the AuM nanoflowers prepared by the green, efficient and low-cost preparation method described in Example 1 of the present application for detecting the concentration and absorbance of H2O2;

[0025] Figure 4 Working curve graph of the AuM nanoflowers prepared by the green, efficient and low-cost preparation method described in Example 1 of the present application for detecting the concentration and absorbance of glucose;

[0026] Figure 5 Schematic diagram of the selective detection of glucose by the AuM nanoflowers prepared by the green, efficient and low-cost preparation method described in Example 1 of the present application. Specific embodiments

[0027] The present application provides an AuM nanoflower, a green, efficient and low-cost preparation method thereof and an application, which are used to solve the technical problem of the lack of a green synthesis method for noble metal alloy nanoflower structures in the prior art.

[0028] The following will clearly and completely describe the technical solutions of the present application with reference to the drawings. Obviously, the described embodiments are some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0029] Example 1

[0030] In view of the defect of the lack of a green synthesis method for noble metal alloy nanoflowers at present, Example 1 of the present application provides a green, efficient and low-cost preparation method for AuM nanoflowers. The preparation method includes the steps of preparing a green tea aqueous solution and incubating AuPt nanoflowers.

[0031] Among them, the steps of preparing the green tea aqueous solution include: weighing 15 mg of green tea and dissolving it in 3 mL of deionized water, then heating it to boiling for 1 h at a heating temperature of 100 - 150 °C, and filtering it through a filter pore to obtain the green tea aqueous solution.

[0032] The steps of incubating AuPt nanoflowers include: adding 1.0 mmol of HAuCl4·3H2O and 1.0 mmol of H2PtCl6 to each milliliter of the green tea aqueous solution at a dosage of 1 mmol / L, stirring at 600 rpm for 30 min, and then standing and incubating for 2 h to obtain AuPt nanoflowers in a uniformly suspended state.

[0033] Example 2

[0034] Example 2 of this application provides a green, efficient, and low-cost preparation method of AuM nanoflowers. The water-soluble compound of the second noble metal selected in the preparation method is AgNO3. The preparation method includes the steps of preparing the green tea aqueous solution and incubating AuAg nanoflowers.

[0035] Among them, the steps of preparing the green tea aqueous solution include: weighing 15 mg of green tea and dissolving it in 3 mL of deionized water, then heating it to boiling for 1 h at a heating temperature of 100 - 150 °C, and filtering it through a filter pore to obtain the green tea aqueous solution.

[0036] The steps of incubating AuPt nanoflowers include: adding 1.0 mmol of HAuCl4·3H2O and 1.0 mmol of AgNO3 to each milliliter of the green tea aqueous solution, stirring at 600 rpm for 30 min, and then standing and incubating for 2 h to obtain AuAg nanoflowers in a uniformly suspended state.

[0037] Example 3

[0038] Example 3 of this application provides a green, efficient, and low-cost preparation method of AuM nanoflowers. The preparation method includes the steps of preparing the green tea aqueous solution and incubating AuPt nanoflowers.

[0039] Among them, the steps of preparing the green tea aqueous solution include: weighing 15 mg of green tea and dissolving it in 3 mL of deionized water, then heating it to boiling for 1 h at a heating temperature of 100 - 150 °C, and filtering it through a filter pore to obtain the green tea aqueous solution.

[0040] The steps of incubating AuPt nanoflowers include: adding 1.5 mmol of HAuCl4·3H2O and 0.5 mmol of H2PtCl6 to each milliliter of the green tea aqueous solution, stirring at 600 rpm for 30 min, and then standing and incubating for 2 h to obtain AuPt nanoflowers in a uniformly suspended state.

[0041] Example 4

[0042] Example 4 of this application provides a green, efficient, and low-cost method for preparing AuM nanoflowers. The preparation method includes the steps of preparing a green tea aqueous solution and incubating AuPt nanoflowers.

[0043] Among them, the step of preparing the green tea aqueous solution includes: weighing 15 mg of green tea and dissolving it in 3 mL of deionized water, then heating it to boiling for 1 h at a heating temperature of 100 - 150 °C, and filtering it through a filter pore to obtain the green tea aqueous solution.

[0044] The step of incubating AuPt nanoflowers includes: adding 0.5 mmol of HAuCl4·3H2O and 1.5 mmol of H2PtCl6 to each milliliter of the green tea aqueous solution, stirring it at a speed of 600 rpm for 30 min, and then standing and incubating for 2 h to obtain AuPt nanoflowers in a state of a uniform suspension.

[0045] Experimental Example 1

[0046] This experimental example conducts microstructure characterization and performance testing on the AuM nanoflowers described in the examples.

[0047] Among them, the transmission electron microscope images of the AuM nanoflowers prepared in Examples 1 - 2 are as Figure 1-2 shown; from Figure 1 and 2 it can be seen that the green, efficient, and low-cost preparation method provided by the examples of this application can prepare AuM with a three-dimensional porous nanoflower-like structure, and the AuM nanoflowers have good dispersibility, uniform size and morphology; it avoids the defects of traditional synthesis methods such as the seed growth method, hydrothermal method, etching method, template method, and electrochemical method, which have cumbersome steps, complex operations, usually use toxic and harmful solvents, and low preparation efficiency, and are not suitable for large-scale industrial production.

[0048] Further referring to Figure 1 and 2 it can be seen that the sizes of the AuPt nanoflowers and AuAg nanoflowers provided in Examples 1 - 2 are 174.34 ± 48.3 nm and 117.6 ± 27.6 nm respectively, indicating that the composition and size of the AuM nanoflowers provided by this application can be adjusted, which is beneficial to improving the performance of the AuM nanoflowers subsequently; at the same time, as shown in Examples 3 and 4, the composition and size of the nanoflowers can also be adjusted by changing the dosages of HAuCl4·3H2O and H2PtCl6.

[0049] The performance of the AuM nanoflowers provided in Example 1 was tested by catalyzing the reaction of hydrogen peroxide with TMB (tetramethylbenzidine) solution to develop color, and detecting its absorbance. The concentration of hydrogen peroxide was quantitatively detected according to the linear relationship between the absorbance and hydrogen peroxide; the principle of detecting glucose was to construct a cascade reaction with the AuM nanoflowers provided in Example 1 and glucose oxidase. Glucose oxidase first oxidized glucose to gluconic acid and hydrogen peroxide, and then the AuM nanoflowers catalyzed the reaction of hydrogen peroxide with TMB solution to develop color. The concentration of glucose was quantitatively detected according to the linear relationship between the absorbance and hydrogen peroxide.

[0050] Among them, the experimental process directly for detecting hydrogen peroxide was as follows: 0.3 mL of 0.2 mol / L sodium acetate buffer solution (pH = 6), 100 μL of H2O2 solutions with concentration gradients including 0 / 0.1 / 0.2 / 0.3 / 0.4 / 0.5 / 0.6 / / 0.7 / 0.8 / 0.9 / 1.0 / 1.5 / 2.0 / / 2.5 / 3.0 mol / L, 0.1 mL of 10 mmol / L TMB solution and an appropriate amount of the AuPt nanoflower catalyst described in Example 1 were added into multiple 1.5 mL centrifuge tubes respectively. After mixing evenly, they were left standing for 5 min. The absorbance values of each group of samples at 652 nm were measured with a UV-visible spectrophotometer. Each experiment was measured in parallel 3 times, and the results were as Figure 3 shown; from Figure 3 it can be seen that the detection limit for the AuPt nanoflowers described in Example 1 to catalyze the reaction of H2O2 solution with TMB solution to develop color well was 100 mmol / L H2O2 solution. When the concentration of H2O2 solution was 100 - 900 mmol / L, the AuPt nanoflowers described in Example 1 could catalyze the reaction of H2O2 solution with TMB solution to develop color well, and the linear equation was A = 3.97053×10 -4 c + 0.254 (R 2 = 0.9989).

[0051] The experimental process for detecting glucose was as follows: in the presence of oxygen, 30 μL of 1.5 mg / mL glucose oxidase solution (both the glucose solution and the glucose oxidase solution were prepared with acetic acid-sodium acetate buffer solution with pH = 6) was added to 170 μL of glucose solutions with concentrations of 0 / 0.4 / 0.5 / 0.6 / 0.8 / 1.0 / 1.5 / 2.0 mol / L respectively, and incubated in a constant temperature water bath at 35 °C for 2 h; then 200 μL of sodium acetate buffer solution with pH = 6, 25 μL of 10 mmol / L TMB solution and an appropriate amount of the AuPt nanoflowers prepared in Example 1 were added, mixed evenly and reacted for 10 min, the color development phenomenon was observed and the UV absorbance at 652 nm was measured in parallel three times, and the results were as Figure 4 shown; from Figure 4It can be seen that the AuPt nanoflowers described in Example 1 can preferably catalyze the reaction between the H2O2 solution generated by the degradation of glucose and the TMB solution. The detection limit of the color reaction is a glucose solution with a concentration of 400 mmol / L. When the concentration of the H2O2 solution is 400 - 1000 mmol / L, the AuPt nanoflowers described in Example 1 can preferably catalyze the reaction between the H2O2 solution and the TMB solution to show color, and the linear equation is A = 2.053×10 -4 c + 0.118 (R 2 = 0.9805).

[0052] The process of selectively detecting glucose is as follows: Similar interfering substances of glucose such as maltose, fructose, sucrose, and lactose were selected and detected through the experimental process for detecting glucose. The addition amounts of maltose, fructose, sucrose, and lactose were all 2 mol / L, and the detection results are as Figure 5 shown. From Figure 5 it can be seen that the cascade reaction constructed by AuM nanoflowers and glucose oxidase has the function of selectively detecting the glucose concentration. This may be because it is difficult for glucose oxidase to catalyze and oxidize other sugars and unable to react with the TMB solution to show color.

[0053] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A green, efficient and low-cost preparation method of AuM nanoflowers, characterized in that, Comprising the steps of: Step S1: Mix green tea leaves and water and heat to boiling, then filter the green tea leaves to obtain a green tea aqueous solution. The heating temperature is 100 - 150 °C, and the boiling time is 0.5 - 1.5 h; Step S2: Stir and mix the green tea aqueous solution, the water-soluble compound of the first noble metal, and the water-soluble compound of the second noble metal, and incubate to obtain AuM nanoflowers; In step S2, the water-soluble compound of the first noble metal is chloroauric acid trihydrate; In step S1, the mass-volume ratio of the green tea leaves to water is 5 - 30 g:1 L; In step S2, the water-soluble compound of the second noble metal is selected from at least one of silver nitrate, silver trifluoroacetate, chloroplatinic acid, potassium tetrachloroplatinate, and sodium tetrachloroplatinate; The dosage of the chloroauric acid trihydrate is 1 - 20 mmol / L, and the dosage of the water-soluble compound of the second noble metal is 1 - 20 mmol / L; In step S2, the incubation time is 1 - 3 h.

2. An AuM nanoflower, characterized in that, Prepared by the green, efficient and low-cost preparation method of AuM nanoflowers as claimed in claim 1.

3. Application of the AuM nanoflowers prepared by the green, efficient and low-cost preparation method of AuM nanoflowers as claimed in claim 1 in detecting hydrogen peroxide or glucose.

4. The application according to claim 3, characterized in that, The application is for detecting a hydrogen peroxide solution with a concentration of 100 - 900 mmol / L.

5. The application according to claim 3, wherein The application is for detecting a glucose solution with a concentration of 400 - 1000 mmol / L.

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