Auagcufezn high-entropy alloy material with hollow structure and preparation method thereof

Abstract

The application discloses AuAgCuFeZn high-entropy alloy material with a hollow structure and a preparation method thereof, and comprises the following steps: preparing an organic solution containing cetyltrimethylammonium chloride; adding a precursor containing Au elements into the organic solution, and then stirring after ultrasonic homogenization; subsequently, adding precursors containing Ag, Cu, Fe and Zn elements respectively, and then stirring after ultrasonic treatment; then, adding excessive NaOH to perform stirring reaction; the mixture gradually changes from a solution into a paste, and the reaction is performed at room temperature; after the reaction is completed, drying is performed; after drying, the product is mixed with molybdenum hexacarbonyl, and high-temperature calcination is performed; after the calcination is completed, the product is crushed, washed and dried. The AuAgCuFeZn high-entropy alloy material with a size of about 1.5 microns and a hollow structure can be simply prepared in one-pot method, the material has a hollow structure inside, and Au, Ag, Cu, Fe and Zn elements are uniformly distributed on the outer shell. The AuAgCuFeZn high-entropy alloy is expected to be applied to the fields of drug delivery and biological catalysis.

Description

Technical Field

[0001] This invention belongs to the field of high-entropy alloy material preparation, specifically relating to a hollow AuAgCuFeZn high-entropy alloy material and its preparation method. Background Technology

[0002] For a long time, alloying has been used to endow materials with ideal properties. Traditional alloys usually add relatively small amounts of minor elements to the major elements, but their limited composition space is not conducive to the research and development of new properties. To overcome this limitation, high-entropy alloys with multiple major elements have attracted great attention. These are new alloy materials composed of five or more metallic elements, with each element accounting for 5%-35% of the alloy.

[0003] Currently, most existing methods for preparing high-entropy alloys are concentrated in fields such as physical metallurgy, including high-temperature melting methods like vacuum melting and laser additive manufacturing. The large mixing enthalpy between multiple immiscible elements leads to instability in the alloy system, easily causing segregation and phase separation. This results in high-entropy alloys mostly exhibiting a blocky structure, with difficult-to-control morphology and size, making it impossible to refine metals with low melting points. Furthermore, the preparation conditions are demanding, energy-intensive, and costly, significantly limiting the widespread application of high-entropy alloys. In addition, due to the limitations of high-entropy alloy preparation methods, current applications are mainly focused on the physical properties of the alloy materials, such as high-temperature melting resistant CoNiCuRuPd alloys and oxidation- and corrosion-resistant FeCoNiCuPt alloys. However, high-entropy alloys have great potential for development in biological applications, such as drug delivery, biocatalysis, and immunotherapy, which urgently requires the development of a simple and user-friendly method for preparing high-entropy alloys. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention innovatively develops a simple and user-friendly one-pot method for preparing hollow AuAgCuFeZn high-entropy alloy materials. The high-entropy alloy materials synthesized using this method exhibit a uniform size distribution of approximately 1.5 μm and possess a hollow internal structure with a uniform distribution of Au, Ag, Cu, Fe, and Zn elements in the outer shell. This AuAgCuFeZn high-entropy alloy shows promise for applications in drug delivery and biocatalysis.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] A high-entropy alloy material with a hollow structure, wherein the AuAgCuFeZn high-entropy alloy material has a hollow internal structure and five elements, Au, Ag, Cu, Fe and Zn, are uniformly distributed on its outer shell.

[0007] Preferably, the particle size of the AuAgCuFeZn high-entropy alloy material is 1.5 μm.

[0008] A method for preparing a hollow AuAgCuFeZn high-entropy alloy material as described above, comprising:

[0009] Prepare an organic solution containing hexadecyltrimethylammonium chloride;

[0010] First, a precursor containing Au is added to an organic solution, and after sonication and homogenization, the mixture is stirred. Then, precursors containing Ag, Cu, Fe and Zn are added separately, and after vigorous stirring and sonication, excess NaOH is added and the mixture is stirred and reacted. The mixture gradually changes from a solution to a paste and is allowed to stand at room temperature to react.

[0011] After the reaction is complete, the mixture is dried, then mixed with molybdenum hexacarbonyl and calcined at high temperature. After calcination, the product is crushed, washed, and dried to obtain a high-entropy alloy material with a hollow structure, AuAgCuFeZn.

[0012] Hexadecyltrimethylammonium chloride is used as a surfactant to prevent the self-polymerization and disordered reaction of various ionic precursors in the solvent.

[0013] The addition of NaOH is significant, serving to provide the strongly alkaline environment necessary for the intermolecular condensation reactions of various precursors and to participate in the reactions themselves. After the addition of NaOH, the organometallic precursors begin to undergo condensation reactions. Acetylacetone molecules in the solvent are deprotonated under strongly alkaline conditions, generating carbanions. These strongly activated carbanions act as nucleophiles, undergoing nucleophilic addition reactions with aldehydes and ketones. Specifically, the activated carbanions condense with organometallic precursors or acetylacetone molecules containing carbocations, forming new carbon-carbon bonds. During this process, the probability of condensation reactions occurring in the five metal organometallic precursors is random and uniform. Through repeated condensation reactions, the original small molecules and organometallic precursors transform into supramolecular polymers; the specific experimental phenomenon is that the mixture gradually changes from a solution to a paste.

[0014] Among them, molybdenum hexacarbonyl, as a weak reducing agent, generates reducing gas CO during high-temperature pyrolysis, which reduces the metal precursor into metastable metal ions, giving the prepared high-entropy alloy strong catalytic activity. At the same time, the generated gas gives the high-temperature molten alloy a hollow structure.

[0015] Among them, the supramolecular polymer formed by the ionic polymerization of organometallic precursors contains a large amount of organic matter, which is volatilized by high-temperature calcination.

[0016] Preferably, the method for preparing an organic solution containing hexadecyltrimethylammonium chloride is as follows: hexadecyltrimethylammonium chloride is added to an acetylacetone solution and dissolved by ultrasonication.

[0017] Preferably, the precursors containing Au, Ag, Cu, Fe and Zn are chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone and zinc acetylacetone, respectively.

[0018] Preferably, the molar ratio of hexadecyltrimethylammonium chloride, chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone, zinc acetylacetone, and molybdenum hexacarbonyl is 1.6:1:1:1:1:1:2.5.

[0019] Preferably, the molar ratio of NaOH, chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone, and zinc acetylacetone is (140-900):1:1:1:1:1.

[0020] Preferably, the reaction time at room temperature is 1-2 weeks.

[0021] Preferably, the drying conditions are: vacuum drying at a temperature of 60-100°C until completely dry.

[0022] Preferably, the high-temperature calcination conditions are: high-temperature calcination at a heating rate of 10-30℃ / min for 6-8 hours in a tube furnace at 700-900℃.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0024] 1. Existing synthesis methods are only suitable for preparing bulk high-entropy alloys and cannot precisely control the morphology of high-entropy alloys. The high-entropy alloy synthesized in this invention has an internal hollow structure and an outer shell in which five elements, Au, Ag, Cu, Fe, and Zn, are uniformly distributed.

[0025] 2. Existing synthesis methods produce high-entropy alloys with uneven size distribution. The high-entropy alloys prepared by this invention have a uniform size distribution of approximately 1.5 μm.

[0026] 3. Existing synthesis methods are complex, difficult to operate, and energy-intensive. This invention adopts a one-pot, stepwise synthesis method, which is simple and easy to operate, avoiding the safety hazards present in traditional high-temperature melting methods.

[0027] 4. Existing synthetic methods for preparing high-entropy alloys are mostly limited to developing the physical properties of the alloy materials. The AuAgCuFeZn high-entropy alloy with a hollow structure synthesized in this invention expands its application potential in the field of biopharmaceutical delivery. Attached Figure Description

[0028] Figure 1The images show the TEM dark field image and elemental mapping of the AuAgCuFeZn high-entropy alloy material prepared in Example 1 of this invention.

[0029] Figure 2 The images show the TEM dark field image and elemental mapping of the AuAgCuFeZn high-entropy alloy material prepared in Example 2 of this invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples. However, these should not be construed as limiting the present invention and are merely examples.

[0031] Unless otherwise specified, the test methods or experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are obtained from conventional commercial sources or prepared by conventional methods.

[0032] Example 1

[0033] This embodiment provides a method for preparing a high-entropy alloy material with a hollow structure, including:

[0034] Weigh 50 mg of hexadecyltrimethylammonium chloride (CTAC) and 60 ml of acetylacetone solution into a 100 ml three-necked flask and dissolve by sonication. After the CTAC is completely dissolved, add 100 μl of chloroauric acid (23.6%) solution to the above solution, sonicate to form a homogeneous solution, and stir for 5 min. Then add 0.5 mmol of silver acetylacetone, copper acetylacetone, iron acetylacetone, and zinc acetylacetone respectively, stir vigorously for 10 min, and sonicate for 40 min until completely dissolved. Then add 2.8 g of NaOH and stir for 30 min. During this process, the mixture gradually changes from a solution to a paste. Remove the magnet and let it stand at room temperature for 1 week.

[0035] After the above mixture reacted completely, it was dried under vacuum at 60°C. After complete drying, 60 mg of molybdenum hexacarbonyl was added and mixed, and then calcined in a tube furnace at 900°C with a heating rate of 10°C / min for 6 hours. After calcination, the product was crushed and washed three times with ethanol and H2O, and then dried to obtain a high-entropy alloy material of AuAgCuFeZn with a hollow structure.

[0036] Example 2

[0037] This embodiment provides a method for preparing a high-entropy alloy material with a hollow structure, including:

[0038] Weigh 80 mg of hexadecyltrimethylammonium chloride (CTAC) and 40 mL of acetylacetone solution into a 100 mL three-necked flask and dissolve by sonication. After the CTAC is completely dissolved, add 50 μL of chloroauric acid (23.6%) solution to the above solution, sonicate to form a homogeneous solution, and stir for 10 min. Then add 0.1 mmol of silver acetylacetone, copper acetylacetone, iron acetylacetone, and zinc acetylacetone respectively, stir vigorously for 5 min, and sonicate for 30 min until completely dissolved. Then add 3.6 g of NaOH and stir for 60 min. During this process, the mixture gradually changes from a solution to a paste. Remove the magnetic flask and let it stand at room temperature for 2 weeks.

[0039] After the above mixture reacted completely, it was dried under vacuum at 80°C. After complete drying, 70 mg of molybdenum hexacarbonyl was added and mixed, and then calcined in a tube furnace at 800°C with a heating rate of 30°C / min for 7 hours. After calcination, the product was crushed and washed three times with ethanol and H2O, and then dried to obtain a high-entropy alloy material of AuAgCuFeZn with a hollow structure.

[0040] Example 3

[0041] This embodiment provides a method for preparing a high-entropy alloy material with a hollow structure, including:

[0042] Weigh 100 mg of hexadecyltrimethylammonium chloride (CTAC) and 80 mL of acetylacetone solution into a 100 mL three-necked flask and dissolve by sonication. After the CTAC is completely dissolved, add 70 μL of chloroauric acid (23.6%) solution to the above solution, sonicate to form a homogeneous solution, and stir for 7 min. Then add 0.2 mmol of silver acetylacetone, copper acetylacetone, iron acetylacetone, and zinc acetylacetone respectively, stir vigorously for 8 min, and sonicate for 60 min until completely dissolved. Then add 3.0 g of NaOH and stir for 45 min. During this process, the mixture gradually changes from a solution to a paste. Remove the magnetic flask and let it stand at room temperature for 2 weeks.

[0043] After the above mixture reacted completely, it was dried under vacuum at 100℃. After complete drying, 65 mg of molybdenum hexacarbonyl was added and mixed, and then calcined in a tube furnace at 700℃ with a heating rate of 20℃ / min for 8 hours. After calcination, the product was crushed and washed three times with ethanol and H2O, and then dried to obtain a high-entropy alloy material of AuAgCuFeZn with a hollow structure.

[0044] This invention will use the AuAgCuFeZn high-entropy alloy materials prepared in Examples 1 and 2 as examples to characterize and illustrate the preparation results. Example 3 has also been successfully synthesized, and will not be described in detail here.

[0045] Figure 1 The images show the TEM dark-field image and elemental mapping of the AuAgCuFeZn high-entropy alloy material prepared in Example 1. The TEM dark-field image shows that the particle size of a single AuAgCuFeZn high-entropy alloy is approximately 1.5 μm. It is also clear that the contrast in the central part is significantly lower than that at the edges, a characteristic of the hollow structure of high-entropy alloys. The elemental mapping of Au, Ag, Cu, Fe, and Zn shows a uniform distribution of the five elements, perfectly matching the TEM dark-field image of the high-entropy alloy, indicating that each particle contains all five elements with a uniform content distribution. The elemental mapping clearly shows that the elemental distribution in the central part is significantly less than that at the edges, further confirming the successful synthesis of the hollow AuAgCuFeZn high-entropy alloy.

[0046] Figure 2 The images show the TEM dark-field image and elemental mapping of the AuAgCuFeZn high-entropy alloy material prepared in Example 2. The TEM dark-field image shows that the particle size of a single AuAgCuFeZn high-entropy alloy is approximately 1.5 μm. It is also clear that the contrast in the central part is significantly lower than that at the edges, a characteristic of the hollow structure of high-entropy alloys. The elemental mapping of Au, Ag, Cu, Fe, and Zn shows a uniform distribution of the five elements, perfectly matching the TEM dark-field image of the high-entropy alloy, indicating that each particle contains all five elements with uniform content distribution. The relatively low content of Au and Cu explains their lower brightness in the elemental mapping, while the relatively high content of Ag, Fe, and Zn results in brighter elemental mappings. Furthermore, the elemental mapping clearly shows that the elemental distribution in the central part is significantly less than that at the edges, further confirming the successful synthesis of the hollow AuAgCuFeZn high-entropy alloy.

[0047] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-entropy alloy material of AuAgCuFeZn with a hollow structure, characterized in that, The AuAgCuFeZn high-entropy alloy material has a hollow internal structure, and five elements, Au, Ag, Cu, Fe and Zn, are uniformly distributed on its outer shell. The preparation method of the AuAgCuFeZn high-entropy alloy material includes: Prepare an organic solution containing hexadecyltrimethylammonium chloride; First, a precursor containing Au is added to an organic solution, and after sonication and homogenization, the mixture is stirred. Then, precursors containing Ag, Cu, Fe and Zn are added separately, and after vigorous stirring and sonication, excess NaOH is added and the mixture is stirred and reacted. The mixture gradually changes from a solution to a paste and is allowed to stand at room temperature to react. After the reaction is complete, the product is dried, mixed with molybdenum hexacarbonyl, and calcined at high temperature. After calcination, the product is crushed, washed, and dried to obtain AuAgCuFeZn high-entropy alloy material with a hollow structure. The precursors containing Au, Ag, Cu, Fe and Zn are chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone and zinc acetylacetone, respectively.

2. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 1, characterized in that, The AuAgCuFeZn high-entropy alloy material has a particle size of 1.5 μm.

3. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 1, characterized in that, The method for preparing an organic solution containing hexadecyltrimethylammonium chloride is as follows: add hexadecyltrimethylammonium chloride to an acetylacetone solution and dissolve it by sonication.

4. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 3, characterized in that, The molar ratio of hexadecyltrimethylammonium chloride, chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone, zinc acetylacetone, and molybdenum hexacarbonyl is 1.6:1:1:1:1:1:2.

5.

5. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 3, characterized in that, The molar ratio of NaOH, chloroauric acid solution, silver acetylacetone, copper acetylacetone, iron acetylacetone, and zinc acetylacetone is (140-900):1:1:1:1:

1.

6. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 1, characterized in that, The reaction time is 1-2 weeks at room temperature.

7. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 1, characterized in that, The drying conditions are: vacuum drying at 60-100 ℃ until completely dry.

8. The AuAgCuFeZn high-entropy alloy material with a hollow structure according to claim 1, characterized in that, The conditions for high-temperature calcination are: calcination at a temperature of 700-900 ℃ in a tubular furnace at a heating rate of 10-30 ℃ / min for 6-8 h.

Images