A method for preparing high-entropy alloy by organic liquid-phase laser irradiation at normal temperature and pressure

Abstract

The application discloses a method for preparing high-entropy alloys by organic liquid phase laser irradiation at normal temperature and normal pressure, characterized in that 2-5 mg of metal or noble metal nanoparticles and non-noble metal oxide nanoparticles are respectively added into organic reagents such as ethanol, acetone, methanol or mixed liquid thereof, and are uniformly dispersed by sufficient ultrasonic and magnetic stirring; a 532 nm or 355 nm waveband nanosecond pulse laser is modulated, and the above-mentioned uniformly mixed colloidal solution is irradiated for 20 minutes, so that the final product of the high-entropy alloy with uneven size is obtained. The method realizes one-step preparation of series high-entropy alloys by co-irradiation of the uniformly mixed metal and oxide particles dispersed in the organic liquid phase medium.

Description

Technical Field

[0001] This invention relates to a method for preparing high-entropy alloys, and more particularly to a method for preparing high-entropy alloys by laser irradiation of an organic liquid phase under ambient temperature and pressure. Background Technology

[0002] High entropy alloys (HEAs) differ from the more mature binary or ternary alloys currently available. They represent a revolutionary new material that has experienced rapid development in recent years. In HEAs, multiple elements (≥5 types) of metals can be mixed in appropriate proportions to form single-phase solid solutions or intermetallic compounds under the stabilizing effect of configurational entropy. Due to the different elemental sizes, electron configurations, and crystal structures of the constituent elements, the uniformly mixed alloy single crystals exhibit rich surface electronic structures and significant lattice distortions. This results in a variety of excellent physicochemical properties, including high temperature resistance (high entropy effect), high hardness (lattice distortion effect), high thermal stability (hysteresis diffusion effect), and high catalytic activity (cocktail effect).

[0003] In the prior art:

[0004] Methods for preparing metal nanoparticles are mainly divided into two types: "top-down," which uses physical methods to break down bulk materials into nanoscale materials, and "bottom-up," which uses chemical methods to reduce metal ion salt precursors to their elemental form. The most common and mature wet chemical method can control the size and morphology of nanoparticles, but it is only suitable for preparing binary and a small number of ternary nanoalloy nanoparticles. This is because the reduction potential and thermal decomposition temperature of the various metal element ion salts in the precursor differ significantly, making it difficult to simultaneously decompose or reduce multiple ion salts. With the increase of elements, the final product often undergoes phase separation. High-entropy alloy particles prepared by low-temperature ball milling are consistently large and have low entropy.

[0005] Currently, a more reasonable synthesis method is to control the formation of high-entropy alloys through rapid heating and cooling kinetics, commonly using carbothermal shock and fast moving bed pyrolysis methods. However, these methods generally require complex operating procedures and high energy consumption to achieve rapid heating and cooling, and all rely on a support to achieve the loading and synthesis of high-entropy alloy nanoparticles.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a simple, safe, and rapid method for preparing high-entropy alloys by laser irradiation of organic liquid phase under ambient temperature and pressure, so as to solve the above-mentioned technical problems existing in the prior art.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] The method for preparing high-entropy alloys by laser irradiation of organic liquid phase under ambient temperature and pressure according to the present invention includes:

[0010] Weigh 2-5 mg of metal or noble metal nanoparticles and non-noble metal oxide nanoparticles and add them to organic reagents respectively. Disperse them evenly by thorough ultrasonic and magnetic stirring. The choice of nanoparticles is related to the distribution of element types in the final product.

[0011] By modulating a nanosecond pulse laser in the 532nm or 355nm band and irradiating the above-mentioned uniformly mixed colloidal solution for 20 minutes, a high-entropy alloy final product with uneven size can be obtained. The selection of laser band and parameter control are related to the ability of oxide particles to be reduced.

[0012] Compared with the prior art, the method for preparing high-entropy alloys by laser irradiation in an organic liquid phase at room temperature and pressure provided by the present invention prepares a series of high-entropy alloys by laser irradiation in an organic liquid phase at room temperature and pressure. It utilizes the photothermal effect of pulsed laser and nanoparticles and the reduction mechanism generated by the organic liquid phase medium under photothermal effect, and for the first time realizes the one-step preparation of a series of high-entropy alloys by co-irradiating uniformly mixed metal and oxide particles dispersed in the organic liquid phase medium. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the preparation of high-entropy alloys based on organic liquid phase laser irradiation technology according to an embodiment of the present invention;

[0014] Figure 2 TEM images of high-entropy alloys prepared by organic liquid-phase laser irradiation technology in this embodiment of the invention;

[0015] Figure 3 The EDS spectrum of AuIrRuCuCo in an embodiment of the present invention;

[0016] Figure 4 This is the EDS spectrum of AuPtFeCoNi in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them, and do not constitute a limitation on the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0018] First, the following explanations are provided for the terms that may be used in this article:

[0019] The term "and / or" means that either or both can be achieved simultaneously. For example, X and / or Y means that it includes both "X" or "Y" as well as the three cases of "X and Y".

[0020] The terms “including,” “comprising,” “containing,” “having,” or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example, “including a technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction conditions, processing conditions, parameter, algorithm, signal, data, product or article of manufacture, etc.)” should be interpreted as including not only the expressly listed technical feature element, but also other technical feature elements that are not expressly listed and are well-known in the art.

[0021] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0022] The contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments used in the embodiments of this invention are not specified, they are all conventional products that can be purchased commercially.

[0023] The method for preparing high-entropy alloys by laser irradiation of organic liquid phase under ambient temperature and pressure according to the present invention includes:

[0024] Weigh 2-5 mg of metal or noble metal nanoparticles and non-noble metal oxide nanoparticles and add them to organic reagents respectively. Disperse them evenly by thorough ultrasonic and magnetic stirring. The choice of nanoparticles is related to the distribution of element types in the final product.

[0025] By modulating a nanosecond pulse laser in the 532nm or 355nm band and irradiating the above-mentioned uniformly mixed colloidal solution for 20 minutes, a high-entropy alloy final product with uneven size can be obtained. The selection of laser band and parameter control are related to the ability of oxide particles to be reduced.

[0026] The nanosecond pulsed laser irradiates the above-mentioned uniformly mixed colloidal solution for 20 minutes.

[0027] The organic reagent includes any one or a mixture of the following: ethanol, acetone or methanol.

[0028] The metal or noble metal nanoparticles include Au, Ir, Ru and / or Pt, and the metal oxides involved include copper oxide, iron oxide, cobalt oxide, nickel oxide, aluminum oxide, iridium oxide, ruthenium oxide, zinc oxide, molybdenum oxide, tungsten oxide and / or tin oxide.

[0029] In summary, the method for preparing high-entropy alloys by laser irradiation in an organic liquid phase under ambient temperature and pressure, as described in this invention, can concisely and efficiently prepare high-entropy alloys in a single step at ambient temperature and pressure. Utilizing a "top-down" nanosecond pulsed laser to act on the surface of metal nanoparticles, the metal nanoparticles rapidly heat up and melt through photon-phonon energy transfer. The high-temperature nanoparticles then rapidly decompose the organic medium in the environment, generating reducing small molecules. Simultaneously, non-noble metal nanoparticles, co-dispersed with the metal nanoparticles in the organic medium, are reduced "bottom-up" into their corresponding non-noble metal elements under the synergistic effect of laser irradiation heating and reducing small molecules. Subsequently, continuous high-frequency nanosecond pulsed laser irradiation acts on the mixed colloid dispersed in the organic medium, causing the metal particles of each element in the solution to rapidly melt and alloy, and then condense and nucleate under the ultrafast quenching mechanism of the organic liquid phase medium, guiding the final rapid synthesis of the high-entropy alloy on a kinetic scale.

[0030] This invention organically combines the technical characteristics of "top-down" and "bottom-up" methods for preparing metal nanoparticles, and uses a one-step liquid-phase laser irradiation method to prepare high-entropy alloys, thus broadening the general technical route for the rapid and efficient preparation of high-entropy alloys.

[0031] To more clearly demonstrate the technical solution and its effects provided by the present invention, the embodiments of the present invention will be described in detail below with reference to specific examples.

[0032] Example 1

[0033] Specific experimental diagrams are shown below. Figure 1 As shown: Weigh appropriate masses of metal nanoparticles and non-precious metal oxide nanoparticles and add them separately to an organic reagent such as ethanol. Disperse them uniformly through thorough ultrasonic and magnetic stirring. Irradiate the uniformly mixed colloidal solution with a nanosecond pulsed laser with appropriate parameters for 20 minutes to obtain a high-entropy alloy final product with uneven size.

[0034] To characterize the morphology of the product, the sample was first analyzed by transmission electron microscopy (TEM), and the results showed that... Figure 2 The final product is a monodisperse, chain-like single-crystal sphere assembled together.

[0035] To further explore the versatility of this experiment, we irradiated Au and IrO2, RuO2, CuO, Co2O3 mixtures and Au, Pt mixed Fe2O3, Co2O3, NiO mixtures dispersed in ethanol under the same laser parameters.

[0036] Subsequently, we selected two prepared samples and performed X-ray energy dispersive spectroscopy (EDS) analysis on their metal single crystals. Figure 3 , Figure 4 The study found that the AuIrRuCuCo and AuPtFeCoNi elements in both samples were uniformly distributed within their respective single-crystal particles. This demonstrates that the experiment designed in this invention successfully prepared a gold-based high-entropy single-crystal solid solution alloy with uniform elemental distribution. Furthermore, this method is applicable to a wide range of metal particle types and oxide types, making it a general method for preparing high-entropy alloys.

[0037] This invention discloses a series of high-entropy alloys prepared by laser irradiation in an organic liquid phase at ambient temperature and pressure. Utilizing the photothermal interaction between pulsed laser and nanoparticles, and the reduction mechanism generated in the organic liquid medium under photothermal action, a series of high-entropy alloys were prepared in a one-step process for the first time by co-irradiating uniformly mixed metal and oxide particles dispersed in an organic liquid medium. The nanosecond pulsed laser interacts with the matter, generating high temperature and pressure locally only in the nanoparticle area, while the organic liquid medium is rapidly quenched and cooled. This not only provides excellent natural conditions for the kinetic control of high-entropy alloys but also avoids large-scale high-temperature and high-pressure environments and the introduction of excess chemical substances, thereby improving the operability and safety of the entire experiment. The final prepared high-entropy alloys exhibit stable physicochemical properties, clean surfaces, and a wide range of applicable elements, showing potential in mechanics, energy conversion, and biological fields. This synthesis method is safe, convenient, green, efficient, and highly versatile. It not only provides new pathways and ideas for the preparation and application of high-entropy alloys but also expands the new applications of liquid-phase laser irradiation technology. The metal oxides involved also include MoO3, WO3, SnO2, etc. The patent uses oxides such as IrO2, RuO2, CuO, Co2O3, Fe2O3, and NiO as examples for verification.

[0038] Nanosecond pulsed laser irradiation of the surface of metal nanoparticles can rapidly heat and melt the nanoparticles within a nanosecond timescale through photoacoustic interaction. Under this mechanism, the molten metal nanoparticle surface promotes the decomposition of organic liquid media (such as ethanol, methanol, acetone, and other common organic solvents) to generate reducing small molecules. Simultaneously, non-noble metal oxide nanoparticles co-dispersed with the metal nanoparticles in the organic medium are reduced to non-noble metal elements under the combined action of pulsed laser irradiation and the reducing small molecules generated by the organic reagents. Furthermore, the rapid heating mechanism unique to nanosecond pulsed laser irradiation and the rapid quenching mechanism of the organic liquid medium provide ideal conditions for the preparation of high-entropy alloys. Combining the above mechanisms, high-entropy alloys can be prepared simply and quickly in a single step at room temperature and pressure by irradiating a mixed colloidal solution of noble and non-noble metals uniformly dispersed in an organic solvent using nanosecond pulsed laser irradiation.

[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing high-entropy alloys by laser irradiation of organic liquid phase at room temperature and pressure, characterized in that, include: Weigh 2-5 mg of metal nanoparticles and metal oxide nanoparticles separately and add them to an organic reagent. Disperse them evenly by thorough ultrasonic and magnetic stirring. The choice of nanoparticles is related to the distribution of element types in the final product. By modulating a 532nm or 355nm nanosecond pulse laser and irradiating the above-mentioned uniformly mixed colloidal solution for 20 minutes, a high-entropy alloy final product with uneven size can be obtained. The selection of laser band and parameter control are related to the ability of metal oxide particles to be reduced. The nanosecond pulsed laser irradiates the above-mentioned uniformly mixed colloidal solution for 20 minutes; The organic reagent includes any one or more of the following mixtures: ethanol, acetone or methanol; The metal nanoparticles include: Au, Ir, Ru and / or Pt; The metal oxides include: copper oxide, iron oxide, cobalt oxide, nickel oxide, aluminum oxide, iridium oxide, ruthenium oxide, zinc oxide, molybdenum oxide, tungsten oxide, and / or tin oxide.

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