Universal multi-element alloy nanoparticle preparation method

Abstract

The invention discloses a universal preparation method of multi-element alloy nanoparticles. The preparation method comprises the following steps: respectively preparing a precursor of a main catalyst gold, at least one reducing agent metal precursor and one or more metal precursors capable of being fused through electrostatic interaction into precursor material solutions; uniformly mixing the obtained precursor material solutions; standing the mixed solution for 3-24 hours until colloidal particles or precipitates appear in the mixed solution; and washing the solution after standing by respectively with hot water and hot absolute ethyl alcohol through a centrifugal method to obtain the multi-element alloy nanoparticles. According to the preparation method, the reduction step in the existing gold catalysis nanoparticle synthesis process is improved, the metal precursor is directly used as a reducing agent of the gold precursor, introduction of impurities is reduced, synthesis of the multi-element alloy nanoparticles at normal temperature and normal pressure is achieved, the preparation method is not limited by the types and the number of elements, and the preparation method is suitable for industrial production. And the multi-element alloy nano-particles with various different element combinations can be flexibly prepared.

Description

Technical Field

[0001] The invention relates to the technical field of nano materials, and in particular to a universal method for preparing multi-element alloy nano particles. Background Art

[0002] The design and development of new materials are very important for promoting the further development of various applications, and the introduction of multi-element alloys has effectively broadened the design and exploration space of current materials. In traditional metal materials, the properties of the materials are mostly determined by their main elements. In order to overcome this limitation, scientists have proposed the concept of multi-element alloys. A multi-element alloy is an alloy material containing four or more metal elements. Generally speaking, these elements need to be evenly distributed in the alloy and form a single-phase or amorphous solid solution structure. Compared with single metals, multi-element alloys have superior optical, electrical, magnetic and mechanical properties. This is due to the complex interaction between multiple elements (cocktail effect), which also makes multi-element alloys applicable to a variety of fields, such as catalysis, plasmonics, bioimaging, drug therapy and electronic devices.

[0003] The traditional preparation technology of bulk multi-element alloys is already very mature, so the current research bottleneck is how to achieve uniform fusion of multiple elements at the nanoscale. Scientists have proposed a variety of methods for preparing multi-element alloy nanoparticles, such as carbon thermal shock method, laser shock method, physical deposition method, hydrothermal method, etc. In these methods, high temperature, high-energy shock or strong reducing environment are indispensable. This is because the melting points, mixing enthalpy and reduction potential of different metal elements are different, and extreme experimental conditions are required to overcome the energy barrier of multi-element alloy formation. However, this also limits the application environment and output of these methods, and increases energy consumption and carbon emissions in practical applications. Therefore, this field urgently needs to develop a more gentle and convenient preparation technology to batch synthesize multi-element alloy nanoparticles.

[0004] Gold is a very unique metal element with the largest electronegativity among metals (2.54), and it is one of the few metal elements with a stable -1 valence. Researchers have found that gold can be used as a catalyst in the synthesis of other materials. For example, when synthesizing nanoparticles or clusters, after the gold precursor is reduced with a reducing agent, the gold seed can catalyze the subsequent reduction of the gold precursor or other metal precursors. However, although gold-based catalytic research has shown good application prospects, it still faces many challenges that need to be solved, and there is still a lack of multi-element alloy nanoparticle preparation processes using gold as a catalyst. Summary of the invention

[0005] In order to overcome the above problems in the prior art, the purpose of the present invention is to provide a universal method for preparing multi-element alloy nanoparticles. The method utilizes the effect of gold catalyzing the chemical bond breaking and electron redistribution in other metal precursor molecules, as well as the electrostatic adsorption effect of gold on other metal elements, to prepare multi-element alloy nanoparticles. The method improves the reduction step in the existing gold-catalyzed nanoparticle synthesis process, directly uses the metal precursor as a reducing agent for the gold precursor, reduces the introduction of impurities, and realizes the synthesis of multi-element alloy nanoparticles at room temperature and pressure.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A general method for preparing multi-element alloy nanoparticles comprises the following steps:

[0008] S1: preparing a precursor of a main catalyst gold, at least one reducing agent metal precursor, and one or more metal precursors capable of being incorporated by electrostatic action into precursor material solutions respectively;

[0009] S2: uniformly mixing the precursor material solutions obtained in step S1 to obtain a mixed solution;

[0010] S3: leaving the mixed solution obtained in step S2 to stand for 3 to 24 hours until colloidal particles or precipitation are observed in the mixed solution;

[0011] S4: washing the solution obtained in step S3 after standing with hot water and hot anhydrous ethanol respectively by centrifugation to obtain multi-element alloy nanoparticles.

[0012] Furthermore, the precursor of the main catalyst gold is AuCl3.

[0013] Furthermore, the reducing agent metal precursor includes VCl3, CrCl3, MnCl2, MoCl5, RuCl3, RhCl3, PdCl2, ReCl3, and IrCl4.

[0014] Furthermore, the metal precursors that can be integrated through electrostatic action include ScCl3, FeCl3, CoCl2, NiCl2, CuCl2, ZnCl2, YCl3, ZrCl4, NbCl5, TaCl5, WCl6, and PtCl4.

[0015] Furthermore, in step S1, the concentration of each precursor material solution is any concentration.

[0016] Furthermore, in step S4, the solution obtained in step S3 after standing is washed with hot water and hot anhydrous ethanol for no less than three times respectively.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The preparation method of the present invention is not limited by the type and quantity of elements, and can flexibly prepare multi-element alloy nanoparticles of various element combinations. Whether it is a binary, ternary or multi-element alloy, whether it is a common element or a rare element, it can be successfully prepared by this method. In contrast, the existing technology can often only be prepared for a few specific element combinations, and the scope of application is extremely limited. The versatility of this method provides a broad space for the research and development and innovation of new materials, and can meet the diverse needs of different fields for multi-element alloy nanoparticles.

[0019] 2) The multi-element alloy nanoparticles prepared by the method of the present invention can show excellent performance in different application scenarios. Whether in the fields of catalysis, energy storage, electronic devices or biomedicine, the nanoparticles prepared by this method can meet the corresponding performance requirements without the need to develop specific preparation processes for different application scenarios. This wide compatibility makes this preparation method have higher practical value and market competitiveness.

[0020] 3) The method of the present invention improves the reduction step in the existing gold catalytic nanoparticle synthesis process, directly uses a metal precursor as a reducing agent for the gold precursor, reduces the introduction of impurities, and realizes the synthesis of multi-element alloy nanoparticles at room temperature and pressure, and most of the raw materials used and the by-products produced in the preparation process have good recycling value. Through simple separation and treatment processes, unreacted raw materials and by-products can be recycled and reused. This not only reduces resource waste, but also further reduces production costs, achieving the dual goals of efficient resource utilization and environmental friendliness.

[0021] 4) The preparation method of the present invention abandons the cumbersome pretreatment and post-treatment steps in the prior art, and the process flow is concise and clear. The traditional method often involves complex operations, while the method of the present invention simplifies the steps to four steps, reduces the operation links, reduces the probability of errors caused by complex operations, and the process flow is user-friendly and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 These are the SEM images and EDS images (scale is 200 nm) of the AuMoNbZrSc multi-element alloy nanoparticles prepared in Example 1 of the present invention.

[0023] Figure 2 This is the XRD diagram of the AuMoNbZrSc multi-element alloy nanoparticles prepared in Example 1 of the present invention.

[0024] Figure 3 This is the XPS graph of the AuMoNbZrSc multi-element alloy nanoparticles prepared in Example 1 of the present invention.

[0025] Figure 4 These are the SEM images and EDS images (scale is 200 nm) of the AuMoTaWZn multi-element alloy nanoparticles prepared in Example 2 of the present invention.

[0026] Figure 5 This is the XRD diagram of the AuMoTaWZn multi-element alloy nanoparticles prepared in Example 2 of the present invention.

[0027] Figure 6 This is the XPS graph of the AuMoTaWZn multi-element alloy nanoparticles prepared in Example 2 of the present invention.

[0028] Figure 7 These are the SEM images and EDS images (scale is 200 nm) of the AuIrPtPdRu multi-element alloy nanoparticles prepared in Example 3 of the present invention.

[0029] Figure 8 This is the XRD diagram of the AuIrPtPdRu multi-element alloy nanoparticles prepared in Example 3 of the present invention.

[0030] Fig. 9 This is the XPS graph of the AuIrPtPdRu multi-element alloy nanoparticles prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention, and the present invention is not limited thereto.

[0032] The present invention provides a general method for preparing multi-element alloy nanoparticles, which comprises the following steps:

[0033] S1: preparing a precursor of a main catalyst gold, at least one reducing agent metal precursor, and one or more metal precursors capable of being incorporated by electrostatic action into precursor material solutions respectively;

[0034] S2: uniformly mixing the precursor material solutions obtained in step S1 to obtain a mixed solution;

[0035] S3: leaving the mixed solution obtained in step S2 to stand for 3 to 24 hours until colloidal particles or precipitation are observed in the mixed solution;

[0036] S4: washing the solution obtained in step S3 after standing with hot water and hot anhydrous ethanol respectively by centrifugation to obtain multi-element alloy nanoparticles.

[0037] Among them, the precursor of the main catalyst gold is AuCl3.

[0038] Preferably, the reducing agent metal precursor includes VCl3, CrCl3, MnCl2, MoCl5, RuCl3, RhCl3, PdCl2, ReCl3, IrCl4.

[0039] Preferably, the metal precursors that can be incorporated by electrostatic action include ScCl3, FeCl3, CoCl2, NiCl2, CuCl2, ZnCl2, YCl3, ZrCl4, NbCl5, TaCl5, WCl6, PtCl4, wherein the precursors of Cu, W, and Pt can be reduced under the catalytic action of Au. The concentration of each precursor material solution is any concentration. In theory, the reaction can occur regardless of the concentration, and the solution concentration or the amount of the precursor substance only affects the yield of the generated particles.

[0040] Example 1

[0041] This embodiment provides a method for preparing AuMoNbZrSc multi-element alloy nanoparticles, which comprises the following steps:

[0042] S1: AuCl3, MoCl5, NbCl5, ZrCl4 and ScCl3 are respectively prepared into precursor material solutions with a concentration of 4 mmol / L. The solvent used in the preparation of each precursor material solution is water or anhydrous ethanol, as long as the solute used is soluble in the solvent;

[0043] S2: adding 1 mL of each 4 mmol / L precursor material solution AuCl3, MoCl5, NbCl5, ZrCl4 and ScCl3 solution obtained in step S1 to a beaker, stirring for 10 min to mix the precursor material solutions evenly to obtain a mixed solution;

[0044] S3: leaving the mixed solution obtained in step S2 to stand for 24 hours;

[0045] S4: washing the static solution obtained in step S3 with ultrapure water at 60° C. and anhydrous ethanol at 60° C. respectively by centrifugation, discarding the supernatant, and obtaining the precipitate as AuMoNbZrSc multi-element alloy nanoparticles.

[0046] The SEM images and EDS images of the AuMoNbZrSc multi-element alloy nanoparticles prepared in this example are shown in FIG. Figure 1 As shown, the particles are spherical and it can be observed that the elements are evenly distributed in the particles, proving the uniform mixing of the elements. Figure 2 and 3The XRD and XPS graphs of the AuMoNbZrSc multi-element alloy nanoparticles prepared in this embodiment are shown in the figure. The results of XRD show that the AuMoNbZrSc multi-element alloy nanoparticles are single-phase alloy nanoparticles, and the single-phase structure is the characteristic structure of the multi-element alloy. The crystal structure of the AuMoNbZrSc multi-element alloy nanoparticles is fcc, which conforms to the crystal structure of pure Au. At the same time, XRD shows that the lattice parameters have changed slightly (the peak position has shifted), which proves that Au, as the main structure, allows a variety of metal elements to be evenly mixed, resulting in lattice distortion. The XPS results show the valence states of each element: Au (0), Mo (+6), Nb (+5), Zr (+4), Sc (+3). It can be observed that the valence states of Au and Mo have changed, proving that their precursors have undergone redox reactions, and MoCl5 provides electrons; while the valence states of Nb, Zr, and Sc have not changed, proving that the three are incorporated into the multi-element alloy nanoparticles through electrostatic adsorption.

[0047] Example 2

[0048] This embodiment provides a method for preparing AuMoTaWZn multi-element alloy nanoparticles, which comprises the following steps:

[0049] S1: AuCl3, MoCl5, TaCl5, WCl6 and ZnCl2 are respectively prepared into precursor material solutions with a concentration of 5 mmol / L. The solvent used in the preparation of each precursor material solution is water or anhydrous ethanol, as long as the solute used is soluble in the solvent;

[0050] S2: adding 1 mL of each 5 mmol / L precursor material solution AuCl3, MoCl5, TaCl5, WCl6 and ZnCl2 solution obtained in step S1 to a beaker, stirring for 10 min to mix the precursor material solutions evenly to obtain a mixed solution;

[0051] S3: leaving the mixed solution obtained in step S2 to stand for 24 hours;

[0052] S4: washing the static solution obtained in step S3 with ultrapure water at 60° C. and anhydrous ethanol at 60° C. respectively by centrifugation, discarding the supernatant, and obtaining the precipitate as AuMoTaWZn multi-element alloy nanoparticles.

[0053] The SEM images and EDS images of the AuMoTaWZn multi-element alloy nanoparticles prepared in this example are as follows: Figure 4 As shown, the particles are spherical and it can be observed that the elements are evenly distributed in the particles, proving the uniform mixing of the elements. Figure 5 and 6The XRD and XPS graphs of the AuMoTaWZn multi-element alloy nanoparticles prepared in this embodiment are shown in the figure. The results of XRD show that the AuMoTaWZn multi-element alloy nanoparticles are single-phase alloy nanoparticles, and the single-phase structure is the characteristic structure of the multi-element alloy. The crystal structure of the AuMoTaWZn multi-element alloy nanoparticles is fcc, which is consistent with the crystal structure of pure Au. At the same time, XRD shows that the lattice parameters have changed slightly (the peak position has shifted), which proves that Au, as the main structure, allows a variety of metal elements to be evenly mixed, resulting in lattice distortion. The XPS results show the valence states of each element: Au (0), Mo (+6), Ta (+5), W (+4), Sc (Zn). It can be observed that the valence states of Au, Mo and W have changed, proving that the precursors of the three have undergone redox reactions, MoCl5 provides electrons, and Au and W obtain electricity; while the valence states of Ta and Zn have not changed, proving that the two are integrated into the multi-element alloy nanoparticles through electrostatic adsorption.

[0054] Example 3

[0055] This embodiment provides a method for preparing AuIrPtPdRu multi-element alloy nanoparticles, which comprises the following steps:

[0056] S1: AuCl3, IrCl4, PtCl4, PdCl2 and RuCl3 are respectively prepared into AuCl3 solution with a concentration of 5mmol / L, IrCl4 solution with a concentration of 1mmol / L, PtCl4 solution with a concentration of 2mmol / L, PdCl2 solution with a concentration of 2mmol / L and RuCl3 solution with a concentration of 5mmol / L. The solvent used in the preparation of each precursor material solution is water or anhydrous ethanol, as long as the solute used is soluble in the solvent;

[0057] S2: Add 1 mL of AuCl3 solution, 4 mL of IrCl4 solution, 2 mL of PtCl4 solution, 2 mL of PdCl2 solution, and 5 mL of RuCl3 solution obtained in step S1 into a beaker, and stir for 10 min to mix the precursor material solutions evenly to obtain a mixed solution;

[0058] S3: leaving the mixed solution obtained in step S2 to stand for 8 hours;

[0059] S4: washing the static solution obtained in step S3 with ultrapure water at 60° C. and anhydrous ethanol at 60° C. respectively by centrifugation, discarding the supernatant, and obtaining the precipitate as AuIrPtPdRu multi-element alloy nanoparticles.

[0060] The SEM images and EDS images of the AuIrPtPdRu multi-element alloy nanoparticles prepared in this example are shown in Figure 7As shown, the particles are spherical and it can be observed that the elements are evenly distributed in the particles, proving the uniform mixing of the elements. Figure 8 and 9 The XRD and XPS images of the AuIrPtPdRu multi-element alloy nanoparticles prepared in this embodiment are shown in the figure. The result of XRD shows that the AuIrPtPdRu multi-element alloy nanoparticles are single-phase alloy nanoparticles, and the single-phase structure is the characteristic structure of the multi-element alloy. The crystal structure of the AuIrPtPdRu multi-element alloy nanoparticles is fcc, which conforms to the crystal structure of pure Au. At the same time, XRD shows that the lattice parameters have changed slightly (the peak position has shifted), which proves that Au, as the main structure, allows a variety of metal elements to be evenly mixed, thereby causing lattice distortion. The XPS results show the valence states of each element: Au (-1), Ir (+3), Pt (0), Pd (0), Ru (0). It can be observed that the valence states of all elements have changed, and Au is -1 valence, which proves that under the catalytic action of Au, a redox reaction has occurred between the precursor molecules, and the chemical bonds of all precursor molecules have been broken and reorganized.

[0061] It should be noted that the above-described embodiments are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, the present invention may be modified, improved and replaced with equivalents, and these modifications, improvements and equivalent replacements are also considered to fall within the scope of protection of the claims of the present invention.

Claims

1. A general method for preparing multi-element alloy nanoparticles, characterized in that: The steps include: S1: preparing a precursor of a main catalyst gold, at least one reducing agent metal precursor, and one or more metal precursors capable of being dissolved by electrostatic action into precursor material solutions respectively; S2: uniformly mixing the precursor material solutions obtained in step S1 to obtain a mixed solution; S3: leaving the mixed solution obtained in step S2 to stand for 3 to 24 hours until colloidal particles or precipitation are observed in the mixed solution; S4: washing the solution obtained in step S3 after standing with hot water and hot anhydrous ethanol respectively by centrifugation to obtain multi-element alloy nanoparticles.

2. The general method for preparing multi-element alloy nanoparticles according to claim 1, characterized in that: The precursor of the main catalyst gold is AuCl3.

3. The general method for preparing multi-element alloy nanoparticles according to claim 1, characterized in that: The reducing agent metal precursors include VCl3, CrCl3, MnCl2, MoCl5, RuCl3, RhCl3, PdCl2, ReCl3, and IrCl4.

4. The general method for preparing multi-element alloy nanoparticles according to claim 1, characterized in that: The metal precursors that can be integrated through electrostatic action include ScCl3, FeCl3, CoCl2, NiCl2, CuCl2, ZnCl2, YCl3, ZrCl4, NbCl5, TaCl5, WCl6, and PtCl4.

5. The general method for preparing multi-element alloy nanoparticles according to claim 1, characterized in that: In step S1 , the concentration of each precursor material solution is arbitrary.

6. The universal method for preparing multi-element alloy nanoparticles according to claim 1, characterized in that: In step S4, the solution obtained in step S3 after standing is washed with hot water and hot anhydrous ethanol for no less than three times respectively.

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