Hierarchical porous high-entropy alloy electrode material for hydrogen peroxide detection, preparation method and application

Abstract

This invention provides a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide. The electrode material uses a transition metal high-entropy alloy as a matrix, with a first channel interconnected with a metal ligament. The metal ligament has a second channel. Both the first and second channels are located within the grains of the high-entropy alloy crystal, and the average pore size of the first channel is significantly larger than that of the second channel. The first and second channels distributed on the matrix form a hierarchical porous structure. This invention also provides a method for preparing the hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide and its application. The electrode material of this invention is a high-entropy alloy with a hierarchical porous structure, possessing a larger specific surface area, more catalytic active sites, and a faster electron transport rate. Furthermore, the hierarchical pores are all located within the crystal grains, resulting in a stable structure that is not easily broken.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials functional materials, and more specifically to a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide, its preparation method, and its application. Background Technology

[0002] H2O2 has bactericidal and disinfecting properties and is often used in dairy product packaging. However, if the packaging contains high levels of H2O2, it can cause a range of diseases if ingested through dairy products, such as Alzheimer's disease, myocardial infarction, atherosclerosis, Parkinson's disease, and cancer. Therefore, accurate and rapid methods for detecting H2O2 are crucial.

[0003] Currently, methods for detecting H2O2 mainly focus on non-enzymatic electrochemical methods due to their advantages such as simple equipment, speed, low cost, and high sensitivity. The key to H2O2 detection lies in the electrocatalytic decomposition of H2O2, relying on the electrical signal generated by the reaction to measure the H2O2 concentration. Therefore, the design of electrocatalysts is crucial.

[0004] Typically, a good catalyst requires both high conductivity and good catalytic activity. Therefore, most catalysts employ organometallic frameworks to improve their conductivity; however, organometallic frameworks have poor toughness, limiting their practical applications. Noble metal powders can provide good catalytic activity; however, their high cost and complexity of modification limit their application.

[0005] Recently, many researchers have turned their attention to abundant transition metal materials. Due to their atomic structure, transition metals possess catalytic activity comparable to noble metals. Currently, many transition metals and their oxides have been reported as H2O2 sensors, such as Co-, Fe-, Co3O4, NiO, Cu2O, Fe3O4, and MnO2. However, these transition metal catalysts are mainly in powder form and require binders to be modified onto glassy carbon electrodes or carbon cloth for electrochemical testing. Thicker catalyst layers deposited on glassy carbon electrodes (GCEs) increase electrical and mass transfer resistance, leading to poor sensing performance and thus limiting the sensitivity and detection limit for H2O2 detection.

[0006] High-entropy alloys can be adapted to any desired response through almost limitless combinations and modifications of elements. In the field of catalysis, high-entropy alloys can incorporate a variety of transition metal elements, combining the properties of multiple elements to create a composite effect, thereby enhancing catalytic activity.

[0007] High-entropy alloys are currently mainly used in catalysis fields such as solid-state ethanol fuel cells, water splitting (hydrogen evolution reaction (HER) and oxygen evolution reaction (OER)), and CO oxidation. High-entropy alloys have already demonstrated excellent performance in multiple aspects of catalysis. For example, Chinese patent CN113061925A discloses a method for preparing a hierarchical porous high-entropy alloy water electrolysis catalyst. This catalyst is a self-supporting bulk electrode with a hierarchical porous structure. The macropore size is 500 nm to 2 μm, and the micropore size is 40-200 nm. The synergistic effect between the main transition metals and the hierarchical porous structure improve the oxygen production performance of the material during water electrolysis.

[0008] However, high-entropy alloys have not yet been applied to the detection of H2O2 in current technology. Summary of the Invention

[0009] The present invention aims to provide a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide, so as to expand the application field of high-entropy alloys. The electrode material is a high-entropy alloy strip with a hierarchical porous structure, which has a larger specific surface area, more catalytic active sites and a faster electron transport rate. Moreover, the hierarchical pores are all located within the crystal grains, and the structure is stable and not easily broken.

[0010] According to a first aspect of the present invention, a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide is provided. The electrode material uses a high-entropy alloy containing transition metals as a matrix, the matrix having a first channel interconnected with a metal ligament, the metal ligament having a second channel, both the first and second channels being located within the grains of the high-entropy alloy crystal, and the average pore size of the first channel being much larger than the average pore size of the second channel, the first and second channels distributed on the matrix forming a hierarchical porous structure.

[0011] Preferably, the average pore size of the first channel is in the submicron to micron range, and the average pore size of the second channel is in the nanometer range.

[0012] Preferably, the average pore size of the first channel is 300 nm to 3 μm, and the average pore size of the second channel is 5 nm to 30 nm.

[0013] Preferably, the composition of the transition metal high-entropy alloy is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are not the same; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2.

[0014] Preferably, the transition metal high-entropy alloy is in strip form.

[0015] Preferably, in the transition metal high-entropy alloy, Co, Cr, and Fe elements exist in the forms of Co3O4, Cr2O3, and Fe3O4.

[0016] According to a second aspect of the present invention, a method for preparing the aforementioned hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide is provided, comprising the following steps:

[0017] Weigh out the corresponding transition metal elements in proportion and smelt them to obtain a transition metal master alloy. Then, rapidly cool and spin the master alloy through copper rollers to obtain a high-entropy transition metal alloy strip. The composition of the high-entropy transition metal alloy strip is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are different; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2;

[0018] The transition metal high-entropy alloy strips were dealloyed, washed with deionized water until neutral, and dried at room temperature to obtain a hierarchical porous high-entropy alloy electrode material.

[0019] Preferably, chemical dealloying is used for dealloying, and the specific process is as follows: the high entropy alloy strip of the transition metal is placed in a container of H2SO4 solution, and the container is placed in a water bath shaker for dealloying.

[0020] Preferably, the concentration of the H2SO4 solution is 0.5–3 M, and the dealloying time is 10 min–72 h.

[0021] In a third aspect of the present invention, the application of the aforementioned hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide in a non-enzymatic H2O2 sensor is provided.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The hierarchical porous high-entropy alloy electrode material of the present invention can be used to detect H2O2, and has high sensitivity and low detection limit. The electrode material of the present invention has a first channel with an average pore size of 300 nm to 3 μm and a second channel with an average pore size of 5 nm to 30 nm. The two types of channels constitute a hierarchical porous structure. The first channel with a larger pore size has a larger channel size, which is conducive to the transport of molecules / ions in the solution and provides high conductivity. The second channel with a smaller pore size provides a larger specific surface area, thereby providing more catalytic active sites. On the other hand, the first and second channels are surrounded by Fe-Cr grain boundaries, which are high electron transport channels and can provide high conductivity for catalytic H2O2, avoiding the disadvantage of poor conductivity of metal oxides. Furthermore, the oxides of cobalt, chromium and iron further promote the decomposition of H2O2. Thus, through its unique structure and materials, the electrode material of the present invention has both the catalytic activity and conductivity required for a highly efficient electrocatalyst, and has good sensitivity and low detection limit when detecting H2O2.

[0024] 2. The hierarchical porous high-entropy alloy electrode material of the present invention has a strip-shaped self-supporting structure, which avoids the pretreatment of conventional catalytic electrode materials and can be used directly as an electrode. By controlling the precursor, the crystal form of the high-entropy alloy is adjusted to equiaxed hexagonal grains, and most of the easily corroded elements are concentrated inside the grains, while the less reactive elements are concentrated at the grain boundaries. By controlling the time and concentration of dealloying, dealloying only occurs inside the grains, and the small amount of highly corrosion-resistant elements at the grain boundaries are not corroded, thereby keeping the grains intact, ensuring the stability of the structure, and solving the problem of easy breakage of the strip-shaped self-supporting structure.

[0025] 3. The electrode material preparation process of the present invention is simple, low-cost, and time-saving, making it easy to industrialize and widely used. It has better practicality and uses a simple dealloying method instead of the metal salt reduction method, with a metal recovery rate close to 100%, without wasting metal elements. Attached Figure Description

[0026] Figure 1 This is a SEM image of the electrode material obtained in Example 1.

[0027] Figure 2 This is a TEM image of the electrode material obtained in Example 1.

[0028] Figure 3 This is a SEM image of the electrode material obtained in Comparative Example 1.

[0029] Figure 4 This is a SEM image of the electrode material obtained in Comparative Example 2.

[0030] Figure 5 This is a SEM image of the electrode material obtained in Comparative Example 3.

[0031] Figure 6 This is a SEM image of the electrode material obtained in Comparative Example 4.

[0032] Figures 7a-7f They are respectively for Figure 2 EDS surface scans of Al, Co, Cr, Fe, Ni, and O were performed, where the position of the line containing 1 is... Figure 2 The central cross is located at position 1.

[0033] Figure 8 The CV curves of the electrode materials in Examples 1-3 and Comparative Examples 1-4 are fitted curves of the difference in peak current density between the oxidation peak and the reduction peak at a potential of -0.25V and the scan rate.

[0034] Figure 9 The current-time response curve of the electrode material obtained in the example catalyzing H2O2 is shown.

[0035] Figure 10 The graph shows the relationship between the peak current and H2O2 concentration obtained by CA testing of the electrode material in Example 1.

[0036] Figure 11 The current-time response curve and fitted curve of the electrode material for H2O2 catalysis in Comparative Example 2 are shown.

[0037] Figure 12 The current-time response curve and fitted curve of the electrode material for H2O2 catalysis in Comparative Example 3 are shown.

[0038] Figure 13 The current-time response curve and fitted curve of the electrode material for H2O2 catalysis in Comparative Example 4 are shown. Detailed Implementation

[0039] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0040] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described below in more detail, can be implemented in any of a number of ways.

[0041] This invention provides a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide. The electrode material has a hierarchical pore structure, which gives it a larger specific surface area, more catalytic active sites, and a faster electron transport rate. Moreover, the pore structure is formed within the grains of the alloy crystal, ensuring the integrity of the crystal structure and avoiding material breakage, thus forming an electrode material with high catalytic activity and self-supporting properties.

[0042] In an exemplary embodiment of the present invention, a hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide is provided. The electrode material uses a high-entropy alloy containing transition metals as a matrix. The matrix has a first channel, which is interconnected with a metal ligament. The metal ligament has a second channel. Both the first and second channels are located within the grains of the high-entropy alloy crystal. The average pore size of the first channel is much larger than the average pore size of the second channel. The first and second channels distributed on the matrix form a hierarchical porous structure.

[0043] It should be understood that the first and second channels being located within the grains of the high-entropy alloy crystal means that the first and second channels do not disrupt the grain boundaries and are completely located within the grain boundaries.

[0044] The average diameter of the first channel is much larger than that of the second channel, meaning that the average diameters of the first channel and the second channel differ by at least one level.

[0045] In a preferred embodiment, the average pore size of the first channel is from the submicron to the micron level, and the average pore size of the second channel is the nanometer level.

[0046] In a more preferred embodiment, the average pore size of the first channel is 300 nm to 3 μm, and the average pore size of the second channel is 5 nm to 30 nm.

[0047] In a preferred embodiment, the composition of the transition metal high-entropy alloy is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are not the same; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2.

[0048] In a more preferred embodiment, the composition of the transition metal high-entropy alloy is CoCrFeNiAl. x The system, where x is the molar ratio and x = 1.2 to 2.

[0049] In a preferred embodiment, the transition metal high-entropy alloy is in strip form.

[0050] In a preferred embodiment, in the transition metal high-entropy alloy, Co, Cr, and Fe elements mainly exist in the form of oxides; specifically, the oxides are Co3O4, Cr2O3, and Fe3O4, respectively.

[0051] In another preferred embodiment, a method for preparing the aforementioned hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide is provided, comprising the following steps:

[0052] Weigh out the corresponding transition metal elements in proportion and smelt them to obtain a transition metal master alloy. Then, rapidly cool and spin the master alloy through copper rollers to obtain a high-entropy transition metal alloy strip. The composition of the high-entropy transition metal alloy strip is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are different; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2;

[0053] The transition metal high-entropy alloy strips were dealloyed, washed with deionized water until neutral, and dried at room temperature to obtain a hierarchical porous high-entropy alloy electrode material.

[0054] In a preferred embodiment, a chemical dealloying method is used for dealloying, and the specific process is as follows: the high-entropy alloy strip of the transition metal is placed in a container of H2SO4 solution, and the container is placed in a water bath shaker for dealloying.

[0055] In a preferred embodiment, the concentration of the H2SO4 solution is 0.5–3 M, and the dealloying time is 10 min–72 h.

[0056] In a preferred embodiment, the temperature of the water bath shaker is 30–50°C, and the shaking speed is 100–200 rpm.

[0057] In another preferred embodiment, the washing time with deionized water is 30-60 seconds to achieve neutrality.

[0058] In other preferred embodiments, the process of obtaining the transition metal master alloy is as follows: the mass of the metal element is converted into the required mass according to the target alloy composition, the metal element is washed with anhydrous ethanol and then placed in an electric arc melting furnace. The alloy is repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure that the alloy elements are mixed evenly, thus obtaining the transition metal master alloy.

[0059] In another preferred embodiment, the process of obtaining the transition metal high-entropy alloy strip is as follows: the oxide layer on the surface of the transition metal master alloy is removed by grinding and placed in a quartz tube. Under the conditions of high-purity argon gas and copper roller rotation speed of 2200-3500 rpm, the transition metal high-entropy alloy strip is prepared by spinning.

[0060] In this invention, the crystal structure of the high-entropy alloy is controlled to form equiaxed hexagonal grains by controlling the precursor, and most of the easily corroded elements are concentrated inside the grains, while the less reactive elements are concentrated at the grain boundaries. The specific precursor system, combined with the control of the time and concentration of dealloying, ensures that dealloying only occurs inside the grains, and the small number of easily corroded elements at the grain boundaries are not corroded.

[0061] Meanwhile, by regulating the alternating distribution of easily corroded and inactive phases within the grains, and by controlling the content of active phases in the precursor, during dealloying, the easily corroded phase (e.g., Al-Ni phase) detaches over a large area, while the inactive phase (e.g., Fe-Cr phase) within the grains also detaches, forming the first channel with a larger average pore size. Meanwhile, the less abundant and sporadic easily corroded phases at the metal ligaments detach, forming the second channel with a smaller average pore size.

[0062] In other preferred embodiments, the aforementioned hierarchical porous high-entropy alloy electrode material for detecting hydrogen peroxide is also provided for use in a non-enzymatic H2O2 sensor. It can be directly fabricated as an electrode for detecting H2O2, has excellent catalytic performance, and is structurally stable and not easily broken.

[0063] To facilitate better understanding, the present invention will be further described below with reference to specific examples, but the preparation method is not limited thereto, and the content of the present invention is not limited thereto.

[0064] Unless otherwise specified, all raw materials used in the following examples were purchased commercially.

[0065]

Example 1

[0066] First, according to the target alloy composition CoCrFeNiAl 1.5 (1.5 is the molar ratio) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.86g, Cr: 7.82g, Fe: 8.40g, Ni: 8.83g, and Al: 6.09g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere. At the same time, magnetic stirring is turned on to ensure that the alloy elements are mixed evenly, and an alloy ingot is obtained.

[0067] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.5 (1.5 is the molar ratio) Alloy strip sample.

[0068] The prepared CoCrFeNiAl 1.5 The alloy strip was cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 h of dealloying. After dealloying, the sample was removed and washed with deionized water for 60 s to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a hierarchical porous structure.

[0069] For CoCrFeNiAl 1.5 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 1.5 .

[0070]

Example 2

[0071] First, according to the target alloy composition CoCrFeNiAl 1.2 (1.2 is the molar ratio) Convert to the required mass of each element. Based on 40g of alloy for one melting, the mass of the elemental metals are Co: 9.15g, Cr: 8.07g, Fe: 8.67g, Ni: 9.11g, and Al: 5.00g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere. At the same time, magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0072] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.2 (1.2 is the molar ratio) Alloy strip sample.

[0073] The prepared CoCrFeNiAl 1.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 0.5 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 48 h. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0074] For CoCrFeNiAl1.2 The sample after high-entropy alloy strips were dealloyed in 0.5M H2SO4 solution was designated as NPCCF-Al. 1.2 .

[0075]

Example 3

[0076] First, the required mass of each element was calculated according to the target alloy composition CoCrFeNiAl2 (2 being the molar ratio). Based on a 40g alloy melt per batch, the mass of the elemental metals were Co: 8.43g, Cr: 7.43g, Fe: 8.00g, Ni: 8.43g, and Al: 7.71g. After cleaning with anhydrous ethanol, the alloy was placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere while simultaneously turning on magnetic stirring to ensure uniform mixing of the alloy elements.

[0077] Take out the alloy ingot, grind off the oxide layer on the surface, put it into a quartz tube (5g), set the copper roller speed to 3000 rpm, and spin the strip in a high-purity argon atmosphere to prepare a CoCrFeNiAl2 (2 is the molar ratio) alloy strip sample with a width of 4mm and a thickness of 40μm.

[0078] The prepared CoCrFeNiAl 1.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0079] The sample after dealloying the CoCrFeNiAl2 high-entropy alloy strip in 1M H2SO4 solution is designated as NPCCF-Al2.

[0080]

Example 4

[0081] First, according to the target alloy composition CoCrFeNiAl 0.4 Mn 0.8 (0.4 and 0.8 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.42g, Cr: 7.42g, Fe: 7.96g, Ni: 8.38g, Al: 5.82g, Mn: 6.27g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0082] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.4 Mn 0.8 (0.4 and 0.8 are molar ratios) Alloy strip samples.

[0083] The prepared CoCrFeNiAl 0.4 Mn 0.8 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0084] For CoCrFeNiAl 0.4 Mn 0.8 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 0.4 Mn 0.8 .

[0085]

Example 5

[0086] First, according to the target alloy composition CoCrFeNiAl 0.8 Ti 0.6 (0.8 and 0.6 are molar ratios) Converted to the required element masses, based on a 40g alloy melt per batch, the metal element masses are Co: 8.56g, Cr: 7.54g, Fe: 8.09g, Ni: 8.51g, Al: 3.13g, and Ti: 4.16g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while simultaneously turning on magnetic stirring to ensure uniform mixing of alloy elements.

[0087] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.8 Ti 0.6 (0.8 and 0.6 are molar ratios) Alloy strip samples.

[0088] The prepared CoCrFeNiAl 0.8 Ti 0.6The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0089] For CoCrFeNiAl 0.8 Ti 0.6 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 0.8 Ti 0.6 .

[0090]

Example 6

[0091] First, according to the target alloy composition CoCrFeNiAl 1.2 Zr 0.4 (1.2 and 0.4 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.02g, Cr: 7.07g, Fe: 7.58g, Ni: 7.98g, Al: 4.40g, Zr: 4.96g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0092] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.2 Zr 0.4 (1.2 and 0.4 are molar ratios) Alloy strip samples.

[0093] The prepared CoCrFeNiAl 1.2 Zr 0.4 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0094] For CoCrFeNiAl 1.2 Zr 0.4 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 1.2 Zr0.4 .

[0095]

Example 7

[0096] First, according to the target alloy composition CoCrFeNiAl 1.6 Cu 0.2 (1.6 and 0.2 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.39g, Cr: 7.39g, Fe: 7.93g, Ni: 8.34g, Al: 6.14g, Cu: 1.81g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0097] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.6 Cu 0.2 (1.6 and 0.2 are molar ratios) Alloy strip samples.

[0098] The prepared CoCrFeNiAl 1.6 Cu 0.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0099] For CoCrFeNiAl 1.6 Cu 0.2 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 1.6 Cu 0.2 .

[0100]

Example 8

[0101] First, according to the target alloy composition CoCrFeNiMn 1.8 Ti 0.2(1.8 and 0.2 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 7.07g, Cr: 6.23g, Fe: 6.68g, Ni: 7.03g, Mn: 11.85g, and Ti: 1.15g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while simultaneously turning on magnetic stirring to ensure uniform mixing of the alloy elements.

[0102] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiMn alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.8 Ti 0.2 (1.8 and 0.2 are molar ratios) Alloy strip samples.

[0103] The prepared CoCrFeNiMn 1.8 Ti 0.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0104] CoCrFeNiMn 1.8 Ti 0.2 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Mn. 1.8 Ti 0.2 .

[0105]

Example 9

[0106] First, according to the target alloy composition CoCrFeNiMn 0.8 Zr 0.4 (0.8 and 0.4 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 7.71g, Cr: 6.80g, Fe: 7.30g, Ni: 7.67g, Mn: 5.75g, Zr: 4.77g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0107] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiMn alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.8 Zr 0.4 (0.8 and 0.4 are molar ratios) Alloy strip samples.

[0108] The prepared CoCrFeNiMn 0.8 Zr 0.4 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0109] CoCrFeNiMn 0.8 Zr 0.4 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Mn. 0.8 Zr 0.4 .

[0110]

Example 10

[0111] First, according to the target alloy composition CoCrFeNiMn 0.6 Cu 0.8 (0.6 and 0.8 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 7.63g, Cr: 6.73g, Fe: 7.22g, Ni: 7.59g, Mn: 4.26g, Cu: 6.57g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0112] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiMn alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.6 Cu 0.8 (0.6 and 0.8 are molar ratios) Alloy strip samples.

[0113] The prepared CoCrFeNiMn 0.6 Cu 0.8The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0114] CoCrFeNiMn 0.6 Cu 0.8 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Mn. 0.6 Cu 0.8 .

[0115]

Example 11

[0116] First, according to the target alloy composition CoCrFeNiTi 0.4 Zr 1.2 (0.4 and 1.2 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 6.67g, Cr: 5.88g, Fe: 6.31g, Ni: 6.63g, Ti: 2.16g, Zr: 12.37g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0117] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiTi alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.4 Zr 1.2 (0.4 and 1.2 are molar ratios) Alloy strip samples.

[0118] The prepared CoCrFeNiTi 0.4 Zr 1.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0119] CoCrFeNiTi 0.4 Zr 1.2 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Ti. 0.4 Zr1.2 .

[0120]

Example 12

[0121] First, according to the target alloy composition CoCrFeNiTi 0.2 Cu 1.6 (0.2 and 1.6 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 7.00g, Cr: 6.18g, Fe: 6.63g, Ni: 6.97g, Ti: 1.14g, Cu: 12.07g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0122] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiTi alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.2 Cu 1.6 (0.2 and 1.6 are molar ratios) Alloy strip samples.

[0123] The prepared CoCrFeNiTi 0.2 Cu 1.6 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0124] CoCrFeNiTi 0.2 Cu 1.6 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Ti. 0.2 Cu 1.6 .

[0125]

Example 13

[0126] First, according to the target alloy composition CoCrFeNiZr 0.2 Cu 1.8(0.2 and 1.8 are molar ratios) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 6.59g, Cr: 5.81g, Fe: 6.23g, Ni: 6.56g, Zr: 2.04g, Cu: 12.77g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure uniform mixing of the alloy elements.

[0127] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiZr strip with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.2 Cu 1.8 (0.2 and 1.8 are molar ratios) Alloy strip samples.

[0128] The prepared CoCrFeNiZr 0.2 Cu 1.8 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0129] For CoCrFeNiZr 0.2 Cu 1.8 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Zr. 0.2 Cu 1.8 .

[0130]

Example 14

[0131] First, according to the target alloy composition CoCrFeNiMn 1.2 (1.2 is the molar ratio) Convert to the required mass of each element. Based on 40g of alloy for one melting, the mass of the metal elements are Co: 8.10g, Cr: 7.14g, Fe: 7.66g, Ni: 8.06g, Mn: 9.05g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere. At the same time, magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0132] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiMn alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.2(1.2 is the molar ratio) Alloy strip sample.

[0133] The prepared CoCrFeNiMn 1.2 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0134] CoCrFeNiMn 1.2 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Mn. 1.2 .

[0135]

Example 15

[0136] First, according to the target alloy composition CoCrFeNiTi 1.4 (1.4 is the molar ratio) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.07g, Cr: 7.11g, Fe: 7.63g, Ni: 8.03g, Ti: 9.16g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0137] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller was set to a speed of 3000 rpm, and a CoCrFeNiTi alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.4 (1.4 is the molar ratio) Alloy strip sample.

[0138] The prepared CoCrFeNiTi 1.4 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0139] CoCrFeNiTi 1.4 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Ti. 1.4 .

[0140]

Example 16

[0141] First, according to the target alloy composition CoCrFeNiZr 1.8 (1.8 is the molar ratio) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 6.06g, Cr: 5.34g, Fe: 5.73g, Ni: 6.03g, Zr: 16.85g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0142] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiZr strip with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 1.8 (1.8 is the molar ratio) Alloy strip sample.

[0143] The prepared CoCrFeNiZr 1.8 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0144] For CoCrFeNiZr 1.8 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Zr. 1.8 .

[0145]

Example 17

[0146] First, the required element masses were calculated according to the target alloy composition CoCrFeNiCu2 (2 being the molar ratio). Based on a 40g alloy melt per batch, the mass of the elemental metals were Co: 6.70g, Cr: 5.90g, Fe: 6.33g, Ni: 6.66g, and Cu: 14.41g. After cleaning with anhydrous ethanol, the alloy was placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere while simultaneously turning on magnetic stirring to ensure uniform mixing of the alloy elements.

[0147] Take out the alloy ingot, grind off the oxide layer on the surface and put it into a quartz tube. Set the copper roller speed to 3000 rpm and spin the strip in a high-purity argon atmosphere to prepare a CoCrFeNiCu2 (2 is the molar ratio) alloy strip sample with a width of 4 mm and a thickness of 40 μm.

[0148] The prepared CoCrFeNiCu2 alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H2SO4 solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 h of dealloying. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0149] The sample after dealloying the CoCrFeNiCu2 high-entropy alloy strip in 1M H2SO4 solution is designated as NPCCF-Cu2.

[0150] Comparative Example 1

[0151] First, according to the target alloy composition CoCrFeNiAl 0.9 (0.9 is the molar ratio) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 9.44g, Cr: 8.33g, Fe: 8.94g, Ni: 9.40g, and Al: 3.90g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0152] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 0.9 (0.9 is the molar ratio) Alloy strip sample.

[0153] The prepared CoCrFeNiAl 0.9 The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0154] For CoCrFeNiAl 0.9 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 0.9 .

[0155] Comparative Example 2

[0156] First, the required element masses were converted according to the target alloy composition CoCrFeNiAl. Based on a 40g alloy melt per batch, the mass of the elemental metals were Co: 9.34g, Cr: 8.24g, Fe: 8.85g, Ni: 9.30g, and Al: 4.28g. After cleaning with anhydrous ethanol, the alloy was placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere while magnetic stirring was turned on to ensure uniform mixing of the alloy elements.

[0157] Take out the alloy ingot, grind off the oxide layer on the surface, put it into a quartz tube (5g), set the copper roller speed to 3000 rpm, and spin the strip in a high-purity argon atmosphere to prepare a CoCrFeNiAl alloy strip sample with a width of 4mm and a thickness of 40μm.

[0158] The prepared CoCrFeNiAl alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H2SO4 solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 h. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0159] The sample after dealloying the CoCrFeNiAl high-entropy alloy strip in 1M H2SO4 solution is designated as NPCCF-Al.

[0160] Comparative Example 3

[0161] First, according to the target alloy composition CoCrFeNiAl 2.5 (2.5 is the molar ratio) Converted to the required mass of each element, based on a 40g alloy for one melting, the mass of the elemental metals are Co: 8.04g, Cr: 7.09g, Fe: 7.63g, Ni: 8.04g, and Al: 9.20g. After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere, while magnetic stirring is turned on to ensure that the alloy elements are mixed evenly.

[0162] The alloy ingot was removed, the oxide layer on the surface was removed by grinding, and 5g was placed in a quartz tube. The copper roller speed was set to 3000 rpm, and a CoCrFeNiAl alloy with a width of 4 mm and a thickness of 40 μm was prepared by spinning in a high-purity argon atmosphere. 2.5 (2.5 is the molar ratio) Alloy strip sample.

[0163] The prepared CoCrFeNiAl 2.5The alloy strips were cut into 2 cm lengths and immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker at a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 hours. After dealloying, the samples were removed and washed with deionized water to remove residual liquid from the surface, yielding a self-supporting three-dimensional hierarchical nanoporous high-entropy alloy with a porous structure.

[0164] For CoCrFeNiAl 2.5 The sample after high-entropy alloy strips were dealloyed in 1M H2SO4 solution was designated as NPCCF-Al. 2.5 .

[0165] Comparative Example 4

[0166] First, according to the target alloy composition CoCrFeNiAl 1.5 (1.5 is the molar ratio) Converted to the required mass of each element, Co: 8.86g, Cr: 7.82g, Fe: 8.40g, Ni: 8.83g, Al: 6.09g (based on 40g of alloy per melting). After cleaning with anhydrous ethanol, the alloy is placed in an electric arc melting furnace and repeatedly melted 5 times in a high-purity argon atmosphere. At the same time, magnetic stirring is turned on to ensure that the alloy elements are mixed evenly, and an alloy ingot is obtained.

[0167] Remove the alloy ingot, grind off the surface oxide layer, and place 5g into a quartz tube. Select a water-cooled copper mold with a diameter of 2-5mm, and perform injection molding in a high-purity argon atmosphere to prepare a CoCrFeNiAl alloy with a diameter of 4mm and a length of 4cm. 1.5 (1.5 is the molar ratio) Rod-shaped cast alloy sample.

[0168] The prepared CoCrFeNiAl 1.5 Rod-shaped alloys were wire-cut to obtain alloy ingots with a diameter of 4 mm and a thickness of 2 mm. The alloy ingots were then immersed in a container containing 1 M H₂SO₄ solution. The container was placed in a water bath shaker with a shaking speed of 150 rpm and a water bath temperature of 40 °C for 12 h of dealloying. After dealloying, the sample was removed and washed with deionized water for 60 s to remove residual liquid from the surface, thus obtaining a rod-shaped, hierarchical porous CoCrFeNiAl high-entropy alloy.

[0169] SEM and TEM tests

[0170] For NPCCF-AI 1.5 NPCCF-AI 0.9 NPCCF-AI, NPCCF-AI 2.5 and rod-shaped hierarchical porous CoCrFeNiAl 1.5 The samples were subjected to SEM and TEM tests, from Figure 1 It can be seen from NPCCF-AI 1.5 The material surface has a uniformly distributed structure of large and small pores. There is a large pore at position #1 (inside the circle), and a small pore at position #2 (inside the circle), which is the ligament of the large pore.

[0171] from Figure 2 You can see NPCCF-AI 1.5 It exhibits macropores with hexagonal equiaxed crystals as boundaries, and micropores exist at the macropore ligaments. Both macropores and micropores are located inside the grains, and the grain boundaries are clear and undamaged, which is conducive to the structural stability of the material and makes it less prone to breakage when made into thin strips.

[0172] Figure 3 , Figure 4 , Figure 5 and Figure 6 NPCCF-AI 0.9 NPCCF-AI, NPCCF-AI 2.5 and rod-shaped hierarchical porous CoCrFeNiAl 1.5 The surface morphology images of the samples all show the formation of channels. Figure 3 and Figure 4 (in the box in the middle), at the same time, from Figure 3-5 The arrow clearly shows that the grain boundaries were destroyed after the sample was de-alloyed. This is because if the Al content is low, there is not enough Al to cause preferential corrosion to form large pores during de-alloying. Instead, due to the difference in element content at the grain boundaries, crevice corrosion occurs preferentially at the grain boundaries, so the grain boundaries are corroded first, leading to their destruction. If the Al content is high, it is preferentially corroded in H2SO4 solution, causing the Al-Ni phase to detach. The detachment of a large amount of Al-Ni phase leads to the detachment of the inactive matrix along with the Al phase, forming large pores and destroying the grain boundaries.

[0173] and Figure 6 Rod-shaped hierarchical porous CoCrFeNiAl 1.5 As can be seen from the figure, the channels are unevenly distributed, and the channels are formed by the shedding of dendrites larger than the grains. Therefore, the grain boundaries are inevitably disrupted. Furthermore, statistical analysis shows that rod-shaped hierarchical pores in CoCrFeNiAl... 1.5 The average pore size is 8.69 μm, which is significantly larger than that of the strip NPCCF-Al. 1.5 The pore size of the sample.

[0174] EDS

[0175] For NPCCF-AI 1.5 The elements of a single grain are scanned by line.

[0176] like Figures 7a-7f As shown in the image, the area scan reveals that in NPCCF-AI...1.5 The presence of Co, Cr, Fe, and O elements in the metal ligaments indicates that Co, Cr, and Fe exist in oxide form and are attached around the pores, synergistically enhancing catalytic performance. Simultaneously, it can be observed that the Al and Ni content at the grain boundaries is in the range of 100–500, significantly lower than the Co, Cr, Fe, and O content (1000–5000). Furthermore, at the grain boundaries (at 800 nm), the Cr and Fe content is both above 3000, indicating that the grain boundaries are rich in inert Cr and Fe elements, with virtually no easily corroded Al and Ni elements. This demonstrates that easily corroded elements are primarily concentrated within the grains, thus ensuring that the pores are located within the grains and maintaining the integrity of the grain boundaries.

[0177] Preparation of working electrode

[0178] The electrode materials of Examples 1-3 and Comparative Examples 1-4 were used to make working electrodes.

[0179] One end of the materials from Examples 1-3 and Comparative Examples 1-4 was welded to a nickel wire using a spot welding machine. The welded sample joints and the nickel wire immersed in the solution were coated with an insulating material to ensure precise control of the electrode area. After the insulating material dried, it was ready for use to obtain the required working electrode.

[0180] Catalytic performance

[0181] For the electrode materials of Examples 1-3 and Comparative Examples 1-4, a double-layer capacitor (C) is used. DL The electrochemically active surface area (ECSA) of each electrode material in 0.1 M PBS solution (pH 7.4) was determined using a method based on scan rate-dependent CV curves. The C0 value was calculated. DL Value, then, use the formula ECSA=C DL / C s (C s The value is 0.040 mF cm -2 The ECSA value is calculated based on the specific capacitance.

[0182] The results are as follows Figure 8 As shown in the figure, the CV curves of the seven electrode materials at a potential of -0.25V show the fitting curves of the difference in peak current density between the oxidation and reduction peaks and the scan rate.

[0183] The slope of the fitted curve can be used to derive NPCCF-Al 0.9 NPCCF-AI, NPCCF-AI 2.5 Rod-shaped hierarchical porous CoCrFeNiAl 1.5 NPCCF-AI 1.2 NPCCF-AI 1.5C of NPCCF-Al2 electrode DL The values ​​were 12 μF, 18.5 μF, 19 μF, 32 μF, 63 μF, 65.5 μF, and 94.5 μF, respectively. Therefore, the NPCCF-Al values ​​were calculated. 0.9 NPCCF-AI, NPCCF-AI 2.5 Rod-shaped hierarchical porous CoCrFeNiAl 1.5 NPCCF-AI 1.2 NPCCF-AI 1.5 The ECSA values ​​of the NPCCF-Al2 electrode and the NPCCF-Al2 electrode were 0.30 cm⁻¹. -2 0.46cm -2 0.48cm -2 0.8cm -2 1.58cm -2 1.64cm -2 and 2.36cm -2 Clearly, the electrochemically active surface area of ​​Comparative Examples 1-4 is not as large as that of Examples 1-3, indicating that the hierarchical nanoporous structure with preserved grain boundaries has a larger electrochemically active surface area and can provide more catalytic active sites, which is one of the main reasons for its good H2O2 catalytic performance.

[0184] Sensitivity, detection limit and detection range

[0185] Using NPCCF-AI 1.5 Working electrode, NPCCF-Al working electrode, NPCCF-Al 2.5 Working electrode, and rod-shaped hierarchical porous CoCrFeNiAl 1.5 Working electrode for detecting H2O2 in phosphate buffer solution

[0186] NPCCF-AI 1.5 The titration test results of the working electrode on H2O2 are as follows: Figure 9 As shown in the figure, NPCCF-AI 1.5 When H2O2 is added to the working electrode, a rapid current response is generated, and the electrode reaches a stable state within 5 seconds, indicating that the electrode material has good sensitivity to H2O2.

[0187] from Figure 9 As can be seen from the illustration, a significant step in current is also observed when 50 μM H₂O₂ is added, indicating that NPCCF-Al 1.5 The working electrode can detect low concentrations of H2O2, with a wide detection range of 50 μM to 49.95 mM.

[0188] For NPCCF-AI 1.5 The titration results of the working electrode were fitted, and the results are as follows: Figure 10 As shown in the figure, when the H2O2 concentration is in the range of 0.05-11.95 mM, NPCCF-Al 1.5 The sensitivity of the electrode material is 510.4 μA mM. -1 cm -2 (correlation coefficient R) 2 =0.9946), with a detection limit of 0.7 μM (signal-to-noise ratio S / N = 3), indicating good H2O2 catalytic performance.

[0189] NPCCF-Al, NPCCF-Al 2.5 And rod-shaped hierarchical porous CoCrFeNiAl 1.5 The titration test of the sample with H2O2 and its fitting results are as follows: Figure 11-13 As shown, from Figure 11 It can be seen that when the H2O2 concentration is in the range of 0.95-17.65 mM, the sensitivity of the NPCCF-Al electrode material is 225.1 μA mM. -1 cm -2 (correlation coefficient R) 2 =0.9978), detection limit is 2μM (signal-to-noise ratio S / N = 3); from Figure 12 It can be seen that when the H2O2 concentration is in the range of 0.95-17.65 mM, NPCCF-Al 2.5 The sensitivity of the electrode material is 259.5 μA mM. -1 cm -2 (correlation coefficient R) 2 =0.9978), detection limit is 1μM (signal-to-noise ratio S / N = 3); from Figure 13 It can be seen that when the H2O2 concentration is in the range of 0.95-9.65 mM, the rod-shaped hierarchical porous CoCrFeNiAl 1.5 The sensitivity of the electrode material is 482.1 μA mM. -1 cm -2 (correlation coefficient R) 2 =0.9909), the detection limit is 0.71μM (signal-to-noise ratio S / N = 3).

[0190] As can be seen from the above, NPCCF-Al, NPCCF-Al 2.5 And rod-shaped hierarchical porous CoCrFeNiAl 1.5 The sensitivity of the electrode materials is lower than that of NPCCF-Al. 1.5 The detection limit is higher than that of NPCCF-Al. 1.5 Furthermore, the addition of a small concentration of 50 μM H2O2 showed no significant current response, indicating that NPCCF-Al... 2.5And rod-shaped hierarchical porous CoCrFeNiAl 1.5 The electrode material has a smaller detection range, and its catalytic performance for H2O2 is inferior to that of NPCCF-Al. 1.5 Therefore, the hierarchical porous high-entropy alloy electrode material of the present invention can be considered to have higher sensitivity, lower detection limit, and wider detection range.

[0191] In summary, the hierarchical porous high-entropy alloy electrode material of the present invention can be used to detect H2O2 and has excellent catalytic performance.

[0192] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. The application of a hierarchical porous high-entropy alloy electrode material in a non-enzymatic H2O2 sensor, characterized in that, The electrode material uses a high-entropy alloy containing transition metals as a matrix. The matrix has a first channel, which is connected to a metal ligament. The metal ligament has a second channel. Both the first and second channels are located within the grains of the high-entropy alloy crystal. The average pore size of the first channel is much larger than that of the second channel. The first and second channels distributed on the matrix form a hierarchical porous structure. The composition of the transition metal high-entropy alloy is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are different; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2; By controlling the precursor, the crystal structure of the high-entropy alloy is adjusted to equiaxed hexagonal grains, and most of the easily corroded elements are concentrated inside the grains, while the less reactive elements are concentrated at the grain boundaries. Then, by controlling the time and concentration of dealloying, dealloying is made to occur only inside the grains, and the small number of highly corrosion-resistant elements at the grain boundaries are not corroded, thus keeping the grains intact and ensuring the stability of the structure.

2. The application of the hierarchical porous high-entropy alloy electrode material according to claim 1 in a non-enzymatic H2O2 sensor, characterized in that, The average pore size of the first channel is in the submicron to micron range, and the average pore size of the second channel is in the nanometer range.

3. The application of the hierarchical porous high-entropy alloy electrode material according to claim 1 or 2 in a non-enzymatic H2O2 sensor, characterized in that, The average pore size of the first channel is 300 nm to 3 μm, and the average pore size of the second channel is 5 nm to 30 nm.

4. The application of the hierarchical porous high-entropy alloy electrode material according to claim 1 in a non-enzymatic H2O2 sensor, characterized in that, The transition metal high-entropy alloy is in strip form.

5. The application of the hierarchical porous high-entropy alloy electrode material according to claim 1 in a non-enzymatic H2O2 sensor, characterized in that, In high-entropy alloys of transition metals, Co, Cr, and Fe elements exist in the forms of Co3O4, Cr2O3, and Fe3O4.

6. The application of the hierarchical porous high-entropy alloy electrode material according to claim 1 in a non-enzymatic H2O2 sensor, characterized in that, The preparation method of the hierarchical porous high-entropy alloy electrode material includes the following steps: Weigh out the corresponding transition metal elements in proportion and smelt them to obtain a transition metal master alloy. Then, rapidly cool and spin the master alloy through copper rollers to obtain a high-entropy transition metal alloy strip. The composition of the high-entropy transition metal alloy strip is CoCrFeNiA. x B y The system is defined as follows: A and B are Al, Mn, Ti, Zr or Cu, and A and B are one or two of them, and A and B are different; x and y are molar ratios, and x+y=1.2~2, x=0~2, y=0~2; The transition metal high-entropy alloy strips were dealloyed, washed with deionized water until neutral, and dried at room temperature to obtain a hierarchical porous high-entropy alloy electrode material.

7. The application of the hierarchical porous high-entropy alloy electrode material according to claim 6 in a non-enzymatic H2O2 sensor, characterized in that, The chemical dealloying method was used for dealloying, and the specific process is as follows: the high-entropy alloy strip of the transition metal was placed in a container of H2SO4 solution, and the container was placed in a water bath shaker for dealloying.

8. The application of the hierarchical porous high-entropy alloy electrode material according to claim 7 in a non-enzymatic H2O2 sensor, characterized in that, The concentration of the H2SO4 solution is 0.5~3M, and the dealloying time is 10min~72h.

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