A MOFs derived high-entropy alloy / carbon composite wave-absorbing material and a preparation method thereof

Abstract

The application discloses a MOFs-derived high-entropy alloy / carbon composite wave-absorbing material, which has a structure of a plurality of connected cluster structures; the cluster structures are composed of a plurality of connected porous hollow spherical structures; the porous hollow spherical structures are formed by accumulation of nanometer spherical particles; and the nanometer spherical particles are composed of amorphous carbon and FeCoNiCuCr high-entropy alloy nanoparticles uniformly distributed therein. The application also provides a preparation method of the MOFs-derived high-entropy alloy / carbon composite wave-absorbing material. Through component design of a MOFs precursor and carbonization process regulation, the high-entropy alloy is uniformly distributed in the carbon skeleton of the MOFs derivative, the skin effect caused by large-particle magnetic particles is effectively avoided, the electromagnetic wave loss capacity is improved, and the wave-absorbing performance is effectively improved. Meanwhile, the prepared wave-absorbing material has relatively small density, and the preparation process is simple.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic wave absorbing materials technology, specifically relating to a MOFs-derived high-entropy alloy / carbon composite absorbing material and its preparation method. Background Technology

[0002] The rapid development of electronic information technology has led to the widespread application of various electronic devices, and the resulting electromagnetic pollution has also affected people's health. At the same time, the rapid development of radar detection technology has placed higher demands on the radar stealth performance of weaponry. Therefore, high-performance electromagnetic wave absorbing materials have broad application prospects in both daily life and military equipment.

[0003] High-entropy alloys are a novel type of alloy composed of five or more elements in molar or near-molar ratios, exhibiting high mixed entropy. Compared to traditional alloys, high-entropy alloys possess thermodynamic high-entropy effects, structural lattice distortion effects, kinetic hysteresis diffusion effects, and performance-related cocktail effects, giving them significant advantages in electromagnetic wave absorption. FeCoNi-based high-entropy alloys typically exhibit high saturation magnetization and permeability, making them the preferred materials for designing high-entropy microwave absorbing materials based on the "cocktail effect." Furthermore, to further enhance electromagnetic wave loss capability, combining high-entropy alloys with carbon materials to achieve synergistic control of dielectric and magnetic losses is currently an important research direction.

[0004] Invention patents 202210806777.1 and 202111663064.6 respectively prepared high-entropy alloy / graphene composite materials and high-entropy alloy / carbon black composite materials using high-energy ball milling. Invention patent 202211742373.7 disclosed a method for preparing a pentagonal high-entropy alloy highly dispersed loaded carbon sponge microwave absorbing material, which loads the high-entropy alloy onto a layered porous carbon sponge through a chemical co-reducing agent heat treatment method. All of the above existing technologies achieve the preparation of high-entropy alloy / carbon composite microwave absorbing materials by blending and compounding with different types of carbon materials, which leads to the skin effect caused by large magnetic particles and reduces the microwave absorption performance of the material. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a MOF-derived high-entropy alloy / carbon composite microwave absorbing material and its preparation method. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] A first aspect of this invention provides a MOFs-derived high-entropy alloy / carbon composite microwave absorbing material, which consists of multiple interconnected cluster structures;

[0007] The clump-like structure is composed of multiple interconnected porous hollow spherical structures;

[0008] The porous hollow spherical structure is formed by the stacking of nanosphere particles;

[0009] The nanospheres are composed of amorphous carbon and FeCoNiCuCr high-entropy alloy nanoparticles uniformly distributed therein.

[0010] In one embodiment of the present invention, the particle size of the nanospheres is 50~100nm;

[0011] The hollow spherical structure has a particle size of 0.5~2.0μm.

[0012] A second aspect of this invention provides a method for preparing MOF-derived high-entropy alloy / carbon composite microwave absorbing materials, comprising the following steps:

[0013] Step 1: Dissolve the hydrates of metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions in an equimolar ratio in a solution of N,N-dimethylformamide, ethanol, and deionized water to form a first mixed solution.

[0014] Step 2: Add 2,5-dihydroxyterephthalic acid to the first mixed solution, disperse it by ultrasonication, add it to the reaction vessel, and carry out hydrothermal reaction at a preset temperature for a preset time. Then, perform centrifugation, washing and drying in sequence to obtain the multi-metal component MOF precursor.

[0015] Step 3: The multi-metal MOF precursor is placed in a tube furnace under a protective atmosphere for calcination treatment at a temperature of 700~1000℃ and a holding time of 1~8 h. After the holding time is completed, the furnace is cooled to room temperature to obtain the above-mentioned MOF-derived high-entropy alloy / carbon composite microwave absorbing material.

[0016] In one embodiment of the present invention, the hydrates of the metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions are respectively: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Cr(NO3)3·9H2O.

[0017] In one embodiment of the present invention, the hydrates of the metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions are respectively ferric chloride hydrate, cobalt chloride hydrate, nickel chloride hydrate, copper chloride hydrate, and chromium chloride hydrate.

[0018] In one embodiment of the present invention, the total molar ratio of the 2,5-dihydroxyterephthalic acid to the hydrates of the metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions is 0.5 to 1.5:1.

[0019] In one embodiment of the present invention, the volume ratio of the N,N-dimethylformamide, the ethanol and the deionized water is 15~25:1:1.

[0020] In one embodiment of the present invention, the preset temperature of the hydrothermal reaction is 100~200℃, and the preset time is 10~30h.

[0021] In one embodiment of the present invention, the heating rate of the tubular furnace is 1-5°C / min.

[0022] In one embodiment of the present invention, the protective atmosphere is nitrogen or argon, or a mixture of nitrogen and hydrogen or a mixture of argon and hydrogen; wherein the volume ratio of nitrogen to hydrogen and the volume ratio of argon to hydrogen are both X:(100-X), where X = 90~100.

[0023] The beneficial effects of this invention are:

[0024] This invention, through the design of MOF precursor component composition and the control of carbonization process, enables the high-entropy alloy to be uniformly distributed in the carbon framework of MOF derivatives, effectively avoiding the skin effect caused by large magnetic particles, improving electromagnetic wave loss capability, and effectively enhancing microwave absorption performance. Simultaneously, the prepared microwave absorbing material has a relatively low density and the preparation process is simple.

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 SEM image of the high-entropy alloy / carbon composite microwave absorbing material prepared in Example 3 of this invention;

[0027] Figure 2 SEM image of the high-entropy alloy / carbon composite microwave absorbing material prepared in Example 4 of this invention;

[0028] Figure 3 SEM image of the high-entropy alloy / carbon composite microwave absorbing material prepared in Example 5 of this invention;

[0029] Figure 4XRD spectra of the high-entropy alloy / carbon composite microwave absorbing materials prepared in Examples 3, 4 and 5 of this invention;

[0030] Figure 5 Electromagnetic parameter curves of the high-entropy alloy / carbon composite absorbing materials prepared in Examples 3 and 4 of this invention are provided for the present invention.

[0031] Figure 6 The reflectivity curve of the high-entropy alloy / carbon composite absorbing material prepared in Example 3 of this invention;

[0032] Figure 7 The reflectivity curve of the high-entropy alloy / carbon composite absorbing material prepared in Example 4 of this invention.

[0033] Figure 8 This invention provides a method for preparing MOFs-derived high-entropy alloy / carbon composite microwave absorbing materials. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0035] Example 1

[0036] The first aspect of the present invention provides a MOFs-derived high-entropy alloy / carbon composite microwave absorbing material in the form of a black powder, the structure of which is composed of multiple interconnected agglomerated structures; the agglomerated structures are composed of multiple interconnected porous hollow spherical structures; the porous hollow spherical structures are formed by the accumulation of nanosphere particles.

[0037] The nanospheres are composed of amorphous carbon and uniformly distributed FeCoNiCuCr high-entropy alloy nanoparticles.

[0038] The particle size of the nanospheres is 50~100nm; the particle size of the hollow spherical structure is 0.5~2.0μm.

[0039] In this embodiment, the composite material prepared by designing the MOF precursor components and controlling the carbonization process allows the high-entropy alloy to be uniformly distributed in the carbon framework of the MOF derivative, effectively avoiding the skin effect caused by large magnetic particles, improving electromagnetic wave loss capability, and effectively enhancing wave absorption performance. Simultaneously, the porous structure enhances the scattering of electromagnetic waves, thereby improving electromagnetic wave loss capability, and also reduces the density of the composite material.

[0040] Example 2

[0041] like Figure 8As shown, a second aspect of this invention provides a method for preparing MOFs-derived high-entropy alloy / carbon composite microwave absorbing materials, comprising the following steps:

[0042] Step 21: Dissolve the hydrates of metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions in an equimolar ratio in a solution of N,N-dimethylformamide (DMF), ethanol, and deionized water to form a first mixed solution.

[0043] Step 22: Add 2,5-dihydroxyterephthalic acid (H4DOT) to the first mixed solution, disperse it by ultrasonication, add it to the reaction vessel, and carry out hydrothermal reaction at a preset temperature for a preset time. Then, perform centrifugation, washing and drying in sequence to obtain the multi-metal component MOF precursor.

[0044] Step 23: The multi-metal MOF precursor is placed in a tube furnace under a protective atmosphere for calcination treatment at a temperature of 700~1000℃ and a holding time of 1~8 h. After the holding time is completed, the furnace is cooled to room temperature to obtain the MOF-derived high-entropy alloy / carbon composite microwave absorbing material of Example 1.

[0045] Furthermore, the hydrates of metal salts containing iron ions, cobalt ions, nickel ions, copper ions, and chromium ions are respectively: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Cr(NO3)3·9H2O.

[0046] Correspondingly, ferric chloride hydrate can be used to replace Fe(NO3)3·9H2O, while cobalt chloride hydrate can be used to replace Co(NO3)2·6H2O, nickel chloride hydrate can be used to replace Ni(NO3)2·6H2O, copper chloride hydrate can be used to replace Cu(NO3)2·3H2O, and chromium chloride hydrate can be used to replace Cr(NO3)3·9H2O.

[0047] Preferably, the molar ratio of 2,5-dihydroxyterephthalic acid to the hydrates of ferric, cobalt, nickel, copper, and chromium metal salts (total molar of all metal salts) is 0.5 to 1.5:1.

[0048] Preferably, the volume ratio of N,N-dimethylformamide, ethanol, and deionized water is 15~25:1:1.

[0049] Preferably, the preset temperature for the hydrothermal reaction is 100~200℃, and the preset time is 10~30h.

[0050] Preferably, the heating rate of the tube furnace is 1-5℃ / min.

[0051] Preferably, the protective atmosphere is nitrogen or argon, or a mixture of nitrogen and hydrogen or a mixture of argon and hydrogen; wherein the volume ratio of nitrogen to hydrogen is X:(100-X), the volume ratio of argon to hydrogen is X:(100-X), and X = 90~100.

[0052] In this embodiment, hollow spherical FeCoNiCuCr multi-metal MOF precursors are formed through hydrothermal self-assembly crystal growth using Fe, Co, Ni, Cu, Cr salts and the crosslinking agent 2,5-dihydroxyterephthalic acid (H4DOT). Then, by controlling process parameters such as the high-temperature carbonization atmosphere, heating rate, temperature, and time, the metal ions in the multi-metal MOF precursors are directly reduced to FeCoNiCuCr high-entropy alloy nanoparticles, and the organic ligands are carbonized to form a carbon framework. The FeCoNiCuCr high-entropy alloy is uniformly dispersed in the carbon framework as nanoparticles (without the need for separate preparation of the high-entropy alloy and carbon support), thus obtaining a high-entropy alloy / carbon composite microwave absorbing material. This composite microwave absorbing material can be applied in fields such as radar stealth protection for military equipment, electromagnetic radiation and leakage protection, and microwave anechoic chamber construction.

[0053] In this embodiment, hollow spherical FeCoNiCuCr multimetallic component MOFs precursors are used, and an optimized high-temperature carbonization process is employed to construct a high-entropy alloy / carbon composite material in which FeCoNiCuCr high-entropy alloy nanoparticles are highly dispersed and uniformly distributed within a hollow spherical carbon framework. This effectively avoids the skin effect caused by large magnetic particles, improves electromagnetic wave loss capability, and significantly enhances microwave absorption performance. This synergistic design and construction of dielectric and magnetic loss materials contributes to improving electromagnetic wave loss capability. The FeCoNiCuCr high-entropy alloy / carbon composite microwave absorbing material prepared in this embodiment exhibits excellent microwave absorption performance, has a relatively low density, and is simple to prepare, making it suitable for large-scale mass production.

[0054] Example 3

[0055] This embodiment provides a method for preparing MOF-derived high-entropy alloy / carbon composite microwave absorbing materials, including the following steps:

[0056] Step 31: Dissolve 2 mmol each of five metal salts, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and Cr(NO3)3·9H2O, in a solution of 400 mL N,N-dimethylformamide (DMF), 20 mL ethanol and 20 mL deionized water to form the first mixed solution;

[0057] Among them, Fe(NO3)3·9H2O can be replaced by ferric chloride hydrate, and correspondingly, Co(NO3)2·6H2O can be replaced by cobalt chloride hydrate, Ni(NO3)2·6H2O can be replaced by nickel chloride hydrate, Cu(NO3)2·3H2O can be replaced by copper chloride hydrate, and Cr(NO3)3·9H2O can be replaced by chromium chloride hydrate.

[0058] Step 32: Add 12 mmol of 2,5-dihydroxyterephthalic acid (H4DOT) to the first mixed solution, disperse it by ultrasonication for 30 min, add it to the reaction vessel, and carry out hydrothermal reaction at 130℃ for 24 h. Then, centrifuge, wash and dry in sequence to obtain the multi-metal component MOF precursor.

[0059] Step 33: The multi-metal MOF precursor is placed in a tube furnace under nitrogen atmosphere protection for calcination treatment. The heating rate of the tube furnace is 3℃ / min, the calcination treatment temperature is 900℃, and the holding time is 3 h. After the holding time is completed, the furnace is cooled to room temperature to obtain the MOF-derived high-entropy alloy / carbon composite microwave absorbing material of Example 1.

[0060] Example 4

[0061] This embodiment provides a method for preparing MOFs-derived high-entropy alloy / carbon composite microwave absorbing material, which is basically the same as the preparation process in Embodiment 3, except that: in this embodiment, the calcination temperature is 800℃ and the holding time is 5 h.

[0062] Example 5

[0063] This embodiment provides a method for preparing MOFs-derived high-entropy alloy / carbon composite microwave absorbing material, which is basically the same as the preparation process in Embodiment 3, except that: in this embodiment, the heating rate of the tube furnace is 5℃ / min, and the calcination temperature is 1000℃.

[0064] Example 6

[0065] This embodiment provides a method for preparing MOF-derived high-entropy alloy / carbon composite microwave absorbing materials, including the following steps:

[0066] Step 61: Dissolve 1 mmol each of five metal salts, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and Cr(NO3)3·9H2O, in a solution of 150 mL N,N-dimethylformamide (DMF), 10 mL ethanol and 10 mL deionized water to form the first mixed solution;

[0067] Among them, Fe(NO3)3·9H2O can be replaced by ferric chloride hydrate, and correspondingly, Co(NO3)2·6H2O can be replaced by cobalt chloride hydrate, Ni(NO3)2·6H2O can be replaced by nickel chloride hydrate, Cu(NO3)2·3H2O can be replaced by copper chloride hydrate, and Cr(NO3)3·9H2O can be replaced by chromium chloride hydrate.

[0068] Step 62: Add 2.5 mmol of 2,5-dihydroxyterephthalic acid (H4DOT) to the first mixed solution, disperse it by ultrasonication for 30 min, add it to the reaction vessel, and carry out hydrothermal reaction at 100℃ for 10 h. Then, centrifuge, wash and dry in sequence to obtain the multi-metal component MOF precursor.

[0069] Step 63: The multi-metal MOF precursor is placed in a tube furnace under nitrogen atmosphere protection for calcination treatment. The heating rate of the tube furnace is 1℃ / min, the calcination treatment temperature is 700℃, and the holding time is 1 h. After the holding time is completed, the furnace is cooled to room temperature to obtain the MOF-derived high-entropy alloy / carbon composite microwave absorbing material of Example 1.

[0070] Example 7

[0071] This embodiment provides a method for preparing MOF-derived high-entropy alloy / carbon composite microwave absorbing materials, including the following steps:

[0072] Step 71: Dissolve 2 mmol each of five metal salts, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and Cr(NO3)3·9H2O, in a solution of 500 mL N,N-dimethylformamide (DMF), 20 mL ethanol and 20 mL deionized water to form a first mixed solution;

[0073] Among them, Fe(NO3)3·9H2O can be replaced by ferric chloride hydrate, and correspondingly, Co(NO3)2·6H2O can be replaced by cobalt chloride hydrate, Ni(NO3)2·6H2O can be replaced by nickel chloride hydrate, Cu(NO3)2·3H2O can be replaced by copper chloride hydrate, and Cr(NO3)3·9H2O can be replaced by chromium chloride hydrate.

[0074] Step 72: Add 15 mmol of 2,5-dihydroxyterephthalic acid (H4DOT) to the first mixed solution, disperse it by ultrasonication for 30 min, add it to the reaction vessel, and carry out hydrothermal reaction at 200℃ for 30 h. Then, centrifuge, wash and dry in sequence to obtain the multi-metal component MOF precursor.

[0075] Step 73: The multi-metal MOF precursor is placed in a tube furnace under nitrogen atmosphere protection for calcination treatment. The heating rate of the tube furnace is 2℃ / min, the calcination treatment temperature is 950℃, and the holding time is 1 h. After the holding time is completed, the furnace is cooled to room temperature to obtain the MOF-derived high-entropy alloy / carbon composite microwave absorbing material of Example 1.

[0076] The MOFs-derived high-entropy alloy / carbon composite microwave absorbing material of this invention exhibits a synergistic effect between electrical and magnetic loss materials. The unique structure of the high-entropy alloy dispersed in a porous carbon framework not only reduces the density of the composite material but also modulates electromagnetic parameters, thereby improving electromagnetic wave loss capability. The preparation method of this MOFs-derived high-entropy alloy / carbon composite microwave absorbing material allows for control of the metal components of the MOFs precursor by adjusting the type of metal salt, thereby controlling the composition of the high-entropy alloy. This method can be applied to other metals and is a scalable synthesis strategy. The preparation process of the MOFs-derived high-entropy alloy / carbon composite microwave absorbing material of this invention is simple, requires no complex hardware equipment, is environmentally friendly, low-cost, and highly efficient, making it suitable for large-scale mass production.

[0077] Figures 1-3 The images shown are SEM images of the high-entropy alloy / carbon composite microwave absorbing materials prepared in Examples 3, 4 and 5, respectively. It can be seen that the high-entropy alloy / carbon composite microwave absorbing materials prepared under different conditions are all spherical particles with a particle size of 0.5~2.0μm, and some regions show that they have a hollow structure.

[0078] Figure 4 The XRD patterns of the high-entropy alloy / carbon composite microwave absorbing materials prepared in Examples 3, 4, and 5 are shown. As can be seen from the figures, the high-entropy alloy / carbon composite microwave absorbing materials prepared under different conditions all exhibit obvious characteristic diffraction peaks of a face-centered cubic lattice, indicating the formation of a FeCoNiCuCr high-entropy alloy phase. The XRD patterns of Examples 4 and 5 also show characteristic oxide peaks of Fe, Co, Ni, Cu, and Cr.

[0079] Figure 5The electromagnetic parameter curves of the high-entropy alloy / carbon composite absorbing materials prepared in Examples 3 and 4 are shown. The materials were mixed with paraffin wax at a mass ratio of 30% and pressed into ring-shaped samples (outer diameter 7 mm, inner diameter 3.04 mm, height 2-4 mm). Electromagnetic parameters were measured using the coaxial method. Figure 5 In the figures, (a) represents the dielectric constant and (b) represents the permeability. The real and imaginary parts of the dielectric constant of the high-entropy alloy / carbon composite microwave absorbing materials prepared in Examples 3 and 4 vary between 5 and 11 and 1.5 and 4.5, respectively, and both gradually decrease with increasing frequency, exhibiting significant dispersion characteristics. The real and imaginary parts of the permeability fluctuate around 1 and 0.1, respectively.

[0080] Figure 6 , Figure 7 The reflectivity curves of the high-entropy alloy / carbon composite absorbing materials prepared in Examples 3 and 4 are shown respectively. It can be seen that the high-entropy alloy / carbon composite absorbing materials possess excellent microwave absorption performance. Specifically, the composite material obtained in Example 3, with a thickness of 1.8 mm, achieves a minimum reflectivity of [value missing] at 16.1 GHz. 39.8 dB, with a maximum effective bandwidth of 5.8 GHz at a thickness of 2.1 mm. The composite material obtained in Example 4, with a thickness of 2.4 mm, achieved a minimum reflectivity of 13.4 GHz. 25.7dB, with a maximum effective bandwidth of 5.7 GHz.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0083] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A MOFs derived high-entropy alloy / carbon composite wave-absorbing material, characterized in that, The plurality of interconnected cluster structures; The cluster structure is composed of a plurality of interconnected porous hollow spherical structures; The porous hollow spherical structure is formed by accumulation of nanometer spherical particles; The nanometer spherical particles are composed of amorphous carbon and FeCoNiCuCr high-entropy alloy nanoparticles uniformly distributed therein; The preparation method of the MOFs derived high-entropy alloy / carbon composite wave-absorbing material comprises the following steps: Step one, dissolve the hydrates of metal salts containing iron ions, the hydrates of metal salts of cobalt ions, the hydrates of metal salts of nickel ions, the hydrates of metal salts of copper ions and the hydrates of metal salts of chromium ions in a solution of N,N-dimethylformamide, ethanol and deionized water in an equimolar ratio to form a first mixed solution; Step two, add 2,5-dihydroxyterephthalic acid to the first mixed solution, perform ultrasonic dispersion, then add it into a reaction kettle to perform hydrothermal reaction at a preset temperature for a preset time, then perform centrifugal separation, washing and drying treatment in sequence to obtain a multi-metal component MOFs precursor; The molar ratio of the total moles of 2,5-dihydroxyterephthalic acid to the hydrates of metal salts containing iron ions, the hydrates of metal salts of cobalt ions, the hydrates of metal salts of nickel ions, the hydrates of metal salts of copper ions and the hydrates of metal salts of chromium ions is 0.5-1.5:1; Step three, place the multi-metal component MOFs precursor in a tube furnace protected by a protective atmosphere for calcination treatment, the calcination treatment temperature is 700-1000℃, the holding time is 1-8 h, and the furnace is cooled to room temperature after the holding time ends to obtain the MOFs derived high-entropy alloy / carbon composite wave-absorbing material. 2.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The particle size of the nanometer spherical particles is 50-100 nm; The particle size of the hollow spherical structure is 0.5-2.0 μm. 3.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The hydrates of metal salts containing iron ions, the hydrates of metal salts of cobalt ions, the hydrates of metal salts of nickel ions, the hydrates of metal salts of copper ions and the hydrates of metal salts of chromium ions are Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and Cr(NO3)3·9H2O respectively. 4.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The hydrates of metal salts containing iron ions, the hydrates of metal salts of cobalt ions, the hydrates of metal salts of nickel ions, the hydrates of metal salts of copper ions and the hydrates of metal salts of chromium ions are iron chloride hydrate, cobalt chloride hydrate, nickel chloride hydrate, copper chloride hydrate and chromium chloride hydrate respectively. 5.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The volume ratio of the N,N-dimethylformamide, the ethanol and the deionized water is 15-25:1:

1. 6.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The preset temperature of the hydrothermal reaction is 100-200℃, and the preset time is 10-30 h. 7.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, characterized in that, The heating rate of the tube furnace is 1-5℃ / min. 8.The MOFs derived high-entropy alloy / carbon composite wave-absorbing material according to claim 1, wherein, The protective atmosphere is nitrogen or argon, or a mixture of nitrogen and hydrogen or a mixture of argon and hydrogen; the volume ratio of nitrogen and hydrogen and the volume ratio of argon and hydrogen are both X:(100-X), X=90-100.

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