Ferrous sulfide-barium titanate wave-absorbing material and preparation method thereof

Abstract

The invention discloses a ferrous sulfide-barium titanate wave-absorbing material and a preparation method thereof, and belongs to the technical field of novel wave-absorbing materials.The wave-absorbing material is prepared through a two-step hydrothermal method, firstly, thiourea and ferrocene are mixed through the hydrothermal method to prepare ferrous sulfide, and then the ferrous sulfide and the ferrocene are mixed through a hydrothermal method to prepare the ferrous sulfide-barium titanate wave-absorbing material. Barium chloride, butyl titanate and the prepared ferrous sulfide are subjected to a reaction through a hydrothermal method, a ferrous sulfide-barium titanate composite material is obtained, and the wave absorbing performance of the composite material is adjusted by adjusting the content of barium titanate in the composite material. The ferrous sulfide-barium titanate composite wave-absorbing material prepared by the method has the advantages of lower density, wider effective absorption frequency band, higher electromagnetic wave absorption performance, simple preparation method, capability of regulating and controlling the morphology of the composite material and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of novel microwave absorbing materials, and particularly to a ferrous sulfide-barium titanate microwave absorbing material and a preparation method thereof. Background Art

[0002] With the development of science and technology in the current era, electromagnetic waves play a crucial role both in daily life and in the increasingly severe military field. The use of high-frequency electronic communication devices such as mobile phones and computers brings us convenience while also causing many potential hazards. The problem of electromagnetic pollution not only pollutes the environment but also harms people's living health. In order to reduce the harm of electromagnetic radiation, microwave absorbing structures, as a special performance material structure, have been widely studied by people.

[0003] In the current environment, the development trend of electromagnetic waves is gradually shifting from pursuing high microwave absorption performance to directions such as "wide frequency band", "multi-frequency band", and "light structure". Currently, it can mainly be approached from two aspects: 1) By effectively attenuating and absorbing the electromagnetic waves entering the material interior to increase the electromagnetic loss, thereby improving the electromagnetic loss ability of the microwave absorbing material. 2) As much as possible, when the electromagnetic waves pass through the surface of the microwave absorbing material, as much as possible is absorbed into the interior and the loss of reflection is reduced.

[0004] Single-phase material systems often have difficulty meeting multifunctional requirements due to the limitations of their intrinsic properties. Therefore, in the field of materials science, a multi-component composite strategy and micro-nano structure design are usually used to synergistically optimize the material properties. Research shows that by constructing new architectures such as core-shell heterojunctions and hollow topological structures, the electromagnetic parameters of the material can be effectively regulated and the interfacial polarization effect can be enhanced, thereby significantly improving the electromagnetic wave dissipation ability of the composite system.

[0005] However, the existing microwave absorbing materials still have certain deficiencies in performance. For example, the loss ability for electromagnetic waves needs to be further improved, and the microwave absorption frequency band is not wide enough. Therefore, it is urgent to achieve a key breakthrough in microwave absorption performance through structural innovation and component optimization. Summary of the Invention

[0006] The purpose of the present invention is to provide a ferrous sulfide-barium titanate microwave absorbing material and a preparation method thereof, and to prepare a ferrous sulfide-barium titanate microwave absorbing material with advantages such as a large specific surface area, a small density, a simple and safe preparation method, etc., to solve the above problems.

[0007] To achieve the above purpose, the present invention provides a preparation method of a ferrous sulfide-barium titanate microwave absorbing material, which composites ferrous sulfide and barium titanate, and barium titanate grows uniformly on the surface of ferrous sulfide. The specific preparation steps are as follows: 1) Weigh appropriate amounts of thiourea and ferrocene respectively and dissolve them in ethylene glycol solution. Stir magnetically, subject the mixed solution to ultrasonic treatment, and then heat the mixed solution using a heating stage. After stirring at room temperature, a pale yellow mixed solution is obtained. 2) Transfer the mixed solution obtained in step 1) to a hydrothermal reaction kettle for hydrothermal reaction. 3) Centrifuge and wash the solution obtained in step 2) several times, and dry it at 60 °C for 10 h in a blast drying oven to obtain iron sulfide powder particles. 4) Weigh appropriate amounts of tetrabutyl titanate and glacial acetic acid respectively and dissolve them in an appropriate amount of absolute ethanol. Stir magnetically for 30 min to obtain a pale yellow transparent organic solution. Add the iron sulfide powder obtained in step 3) to it, subject the mixed solution to ultrasonic treatment, and then heat the mixed solution using a heating stage. After stirring at room temperature, a pale yellow mixed solution is obtained. 5) Weigh an appropriate amount of barium chloride powder and dissolve it in deionized water. Stir magnetically for 5 min to obtain a clear and transparent solution. 6) Slowly drip the barium salt solution obtained in step 5) into the solution obtained in step 4), and adjust the pH value with sodium hydroxide solution simultaneously to form a colloidal mixed solution. 7) Transfer the colloidal solution obtained in step 6) to a hydrothermal reaction kettle for hydrothermal reaction. 8) Centrifuge and wash the powder obtained in step 7) several times, and then dry it at 60 °C for 10 h in a blast drying oven to obtain iron sulfide-barium titanate powder particles.

[0008] Preferably, in the above preparation method of an iron sulfide-barium titanate wave-absorbing material, the mass ratio of thiourea, ferrocene and ethylene glycol in step 1) is 1.2 - 3.6:0.7 - 2.1:50.

[0009] Preferably, in the above preparation method of an iron sulfide-barium titanate wave-absorbing material, the hydrothermal reaction temperature in step 2) is 180 - 220 °C, and the reaction time is 18 - 24 h.

[0010] Preferably, in the above preparation method of an iron sulfide-barium titanate wave-absorbing material, the mass ratio of tetrabutyl titanate, glacial acetic acid, absolute ethanol and iron sulfide in step 4) is 2.5 - 8.0:3.4 - 12:24:1.2 - 3.6.

[0011] Preferably, in the above preparation method of an iron sulfide-barium titanate wave-absorbing material, the mass ratio of barium chloride and deionized water in step 5) is 2.5 - 7.5:40.

[0012] Preferably, in the above preparation method of the iron sulfide-barium titanate wave-absorbing material, the concentration of the sodium hydroxide solution used to adjust the pH value in step 6) is 0.1 mol / L, and the pH value is adjusted to 6-8.

[0013] Preferably, in the above preparation method of the iron sulfide-barium titanate wave-absorbing material, the temperature of the hydrothermal reaction in step 7) is 180-220 °C, and the reaction time is 18-24 h.

[0014] The iron sulfide-barium titanate wave-absorbing material obtained by the above preparation method is a composite structure with wave-absorbing ability.

[0015] Therefore, the iron sulfide-barium titanate wave-absorbing material and its preparation method of the present invention have the following beneficial effects: (1) The iron sulfide-barium titanate wave-absorbing material first uses iron sulfide powder as a precursor. Subsequently, by adding the iron sulfide powder precursor to an anhydrous ethanol solution containing tetrabutyl titanate and glacial acetic acid and reacting, the titanate ions are attached to the surface of the iron sulfide. The structure of the wave-absorbing material not only facilitates the incident electromagnetic wave to enter the material interior but also can perform multiple losses on the electromagnetic wave entering the material interior, enhancing the loss ability of the material to the electromagnetic wave.

[0016] (2) By forming an iron sulfide-barium titanate composite structure, the iron sulfide-barium titanate wave-absorbing material introduces a heterojunction interface, which can generate interfacial polarization when the electromagnetic wave is incident, enhancing the loss ability of the material to the electromagnetic wave and achieving stronger wave-absorbing performance.

[0017] (3) After the titanate ions are attached to the surface of the iron sulfide in the preparation of the iron sulfide-barium titanate wave-absorbing material, barium chloride doping is used to prepare iron sulfide-barium titanate, and spherical barium titanate grows on the surface of flaky iron sulfide. Its unique structure can increase the transmission and loss paths of the incident electromagnetic wave and perform multiple reflections on the incident electromagnetic wave.

[0018] (4) The iron sulfide-barium titanate wave-absorbing material attaches non-metallic sulfur elements to the surface of barium titanate, increasing the number of defects inside the material. When the electromagnetic wave is incident, more dipole polarizations can be generated, thereby increasing the wave-absorbing performance of the iron sulfide-barium titanate wave-absorbing material.

[0019] (5) The iron sulfide-barium titanate wave-absorbing material modifies barium titanate with non-metallic sulfur elements. Some barium elements in barium titanate will combine with sulfur elements to obtain barium sulfide, enhancing the magnetic loss ability of the composite material. At the same time, the doping of sulfur elements can also adjust the dielectric properties of barium titanate and enhance its dielectric loss, thus forming a synergistic effect of multiple loss mechanisms and significantly improving the wave-absorbing ability of the composite material.

[0020] (6)Iron sulfide-barium titanate microwave absorbing material. When the thickness is 4.3 mm, the minimum reflection loss at 14.50 GHz reaches -54.40 dB. At this time, the widest effective absorption band (reflection loss less than -10 dB) reaches 2.2 GHz, and its loss ability to incident electromagnetic waves is significantly better than that of pure barium titanate powder and pure iron sulfide powder.

[0021] The following will further describe the technical solutions of the present invention in detail through the attached drawings and embodiments. Description of the Drawings

[0022] Figure 1 SEM image of iron sulfide powder in Comparative Example 1.

[0023] Figure 2 Microwave absorption performance graph of iron sulfide powder in Comparative Example 1.

[0024] Figure 3 SEM image of barium titanate powder in Comparative Example 2.

[0025] Figure 4 Microwave absorption performance graph of barium titanate powder in Comparative Example 2.

[0026] Figure 5 SEM image of iron sulfide-barium titanate powder in Example 1.

[0027] Figure 6 Microwave absorption performance graph of iron sulfide-barium titanate powder in Example 1.

[0028] Figure 7 SEM image of iron sulfide-barium titanate powder in Example 2.

[0029] Figure 8 Microwave absorption performance graph of iron sulfide-barium titanate powder in Example 2.

[0030] Figure 9 SEM image of iron sulfide-barium titanate powder in Example 3.

[0031] Figure 10 Microwave absorption performance graph of iron sulfide-barium titanate powder in Example 3. Detailed Embodiments

[0032] To better understand the above technical solutions, the following will describe the above technical solutions in detail in conjunction with the accompanying drawings of the specification and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0033] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. "Multiple" generally includes at least two.

[0034] It should also be noted that the term "comprises", "comprising", or any other variation thereof is intended to cover a non-exclusive inclusion, such that a commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such commodity or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the commodity or device comprising said element.

[0035] The present invention provides a preparation method of a ferrous sulfide-barium titanate wave-absorbing material, which composes ferrous sulfide and barium titanate, and grows barium titanate uniformly on the surface of ferrous sulfide. The specific preparation steps are as follows: 1) Weigh appropriate amounts of thiourea and ferrocene and dissolve them in an ethylene glycol solution, stir magnetically, after subjecting the mixed solution to ultrasonic treatment, heat the mixed solution using a heating table, stir at room temperature, and obtain a light yellow mixed solution; 2) Transfer the mixed solution obtained in step 1) to a hydrothermal reaction kettle for hydrothermal reaction; 3) Centrifuge and wash the solution obtained in step 2) several times, and dry it in a blast drying oven at 60 °C for 10 h to obtain ferrous sulfide powder particles; 4) Weigh certain amounts of tetrabutyl titanate and glacial acetic acid and dissolve them in an appropriate amount of absolute ethanol, stir magnetically for 30 min to obtain a light yellow transparent organic solution, add the ferrous sulfide powder obtained in step 3) thereto, after subjecting the mixed solution to ultrasonic treatment, heat the mixed solution using a heating table, stir at room temperature, and obtain a light yellow mixed solution; 5) Weigh an appropriate amount of barium chloride powder and dissolve it in deionized water, stir magnetically for 5 min to obtain a clear and transparent solution; 6) Slowly drop the barium salt solution obtained in step 5) into the solution obtained in step 4), and adjust the pH value with a sodium hydroxide solution to form a colloidal mixed solution; 7) Transfer the colloidal solution obtained in step 6) to a hydrothermal reaction kettle for hydrothermal reaction; 8) Centrifuge and wash the powder obtained in step 7) several times, and then dry it in a blast drying oven at 60 °C for 10 h to obtain ferrous sulfide-barium titanate powder particles.

[0036] To further optimize the above technical solution, in step 1), the mass ratio of thiourea, ferrocene and ethylene glycol is 1.2 - 3.6:0.7 - 2.1:50.

[0037] To further optimize the above technical solution, in step 2), the hydrothermal reaction temperature is 180 - 220 °C, and the reaction time is 18 - 24 h.

[0038] To further optimize the above technical solution, in step 4), the mass ratio of tetrabutyl titanate, glacial acetic acid, absolute ethanol and iron sulfide is 2.5 - 8.0:3.4 - 12:24:1.2 - 3.6.

[0039] To further optimize the above technical solution, in step 5), the mass ratio of barium chloride and deionized water is 2.5 - 7.5:40.

[0040] To further optimize the above technical solution, in step 6), the concentration of the sodium hydroxide solution used to adjust the pH value is 0.1 mol / L, and the pH value is adjusted to 6 - 8.

[0041] To further optimize the above technical solution, in step 7), the temperature of the hydrothermal reaction is 180 - 220 °C, and the reaction time is 18 - 24 h.

[0042] The iron sulfide - barium titanate absorbing material obtained by the above preparation method is a composite structure with wave - absorbing ability.

[0043] To introduce more clearly and in detail a kind of iron sulfide - barium titanate absorbing material and its preparation method provided by the embodiments of the present invention, the following will be described in combination with specific embodiments.

[0044] Comparative Example 1 1) Weigh 3.05 g of sodium sulfide and 1.86 g of ferrocene and dissolve them in 50 mL of ethylene glycol, stir magnetically for 30 min, transfer the solution to a hydrothermal reaction kettle, and react at 200 °C in a forced - air drying oven for 24 h.

[0045] 2) Wash the powder obtained after the reaction 3 times with deionized water, then wash it 2 times with absolute ethanol, and finally dry the centrifuged powder in a forced - air drying oven at 60 °C for 10 h.

[0046] 3) Prepare coaxial ring samples (the inner diameter of the coaxial ring sample is 3 mm and the outer diameter is 7 mm) according to the proportion that the doping amount of iron sulfide in paraffin is 50%. Measure the electromagnetic parameters of the sample through a vector network analyzer, and then calculate the wave - absorbing performance of the material through CST STUDIOSUITE software.

[0047] The SEM image of the pure iron sulfide sample is as Figure 1As shown, it can be seen from the figure that the prepared iron sulfide powder presents a petal-like flaky structure, and its wave absorption performance is as follows Figure 2 As shown, the minimum reflection loss in the range of 2 - 18 GHz is -12.44 dB, having certain wave absorption performance. However, its average effective absorption bandwidth is relatively narrow and cannot meet the actual application requirements.

[0048] Comparative Example 2 1) Weigh 2.500 g of tetrabutyl titanate and 5.525 g of glacial acetic acid and dissolve them in 24 g of absolute ethanol, and stir magnetically for 30 min. Separately, weigh 2.500 g of barium chloride and dissolve it in 40 g of deionized water, and stir magnetically for 5 min. Slowly add the prepared barium chloride solution dropwise to the mixed solution of tetrabutyl titanate and glacial acetic acid, transfer the mixed solution obtained to a hydrothermal reaction kettle, and react at 110 °C in a blast drying oven for 20 h.

[0049] 2) Wash the powder obtained after the reaction 3 times with deionized water, then wash it 3 times with absolute ethanol, and finally dry the centrifuged powder in a blast drying oven at 70 °C for 12 h.

[0050] 3) Put the dried powder in a crucible, place it in a tube furnace, and heat it to 500 °C at a heating rate of 5 °C·min -1 in an air atmosphere, and keep it at this temperature for 5 h. After the reaction is completed, let it cool naturally to room temperature.

[0051] 4) Prepare coaxial ring samples (the inner diameter of the coaxial ring samples is 3 mm and the outer diameter is 7 mm) according to the proportion that the doping amount of barium titanate in paraffin is 50%. Measure the electromagnetic parameters of the samples through a vector network analyzer, and then calculate the wave absorption performance of the material through CST STUDIO SUITE software.

[0052] The SEM of the pure barium titanate powder sample is as Figure 2 shown. It can be seen from the figure that the barium titanate powder presents, and its wave absorption performance is as Figure 3 shown. The minimum reflection loss in the range of 2 - 18 GHz is only -3.19 dB, and the overall wave absorption performance is poor and cannot meet the actual application requirements.

[0053] Example 1 1) Weigh 2.1 g of thiourea powder and 1.5 g of ferrocene powder and dissolve them in 50 g of ethylene glycol solution, stir magnetically for a certain time, transfer the solution to a hydrothermal reaction kettle, and react at 200 °C in a blast drying oven for 24 h.

[0054] 2) Wash the sample after the hydrothermal reaction 3 - 5 times with deionized water first, then wash it 1 - 2 times with absolute ethanol, and dry it in a blast drying oven at 60 °C for 10 h.

[0055] 3) Weigh 2.5 g of tetrabutyl titanate, 5.5 g of glacial acetic acid, and 1.2 g of iron sulfide and dissolve them in 24 g of absolute ethanol. Stir magnetically for 30 min. Weigh another 2.5 g of barium chloride and dissolve it in 40 g of deionized water. Stir magnetically for 5 min. Slowly add the prepared barium chloride solution dropwise to the mixed solution of tetrabutyl titanate, glacial acetic acid, and iron sulfide, and transfer the mixed solution obtained to a hydrothermal reaction kettle.

[0056] 4) Wash the sample after hydrothermal reaction with deionized water 3 - 5 times first, and then wash it with absolute ethanol 1 - 2 times. Dry it in a blast drying oven at 60 °C for 10 h.

[0057] 5) Prepare coaxial ring samples (the inner diameter of the coaxial ring sample is 3 mm and the outer diameter is 7 mm) from the powder according to the proportion that the doping amount of iron sulfide - barium titanate absorbing material in paraffin is 50%. Measure the electromagnetic parameters of the sample through a vector network analyzer, and then calculate the wave absorption performance of the material through CST STUDIO SUITE software.

[0058] The SEM image of the prepared iron sulfide - barium titanate absorbing material sample is as Figure 5 shown. It can be seen that the barium titanate absorbing material uniformly coats the surface of flaky iron sulfide. The wave absorption performance of the prepared iron sulfide - barium titanate absorbing material is as Figure 6 shown. It can be seen from the figure that when the thickness of the composite material is 3.0 mm, the minimum reflection loss at 10.2 GHz reaches - 12.78 GHz, and the widest effective absorption bandwidth at this time reaches 3.9 GHz. Compared with the two pure powders, the loss ability of the composite material to electromagnetic waves has been significantly enhanced.

[0059] Example 2 1) Weigh 3.2 g of thiourea powder and 1.9 g of ferrocene powder and dissolve them in 50 g of ethylene glycol solution. Stir magnetically for a certain time, transfer the solution to a hydrothermal reaction kettle, and react at 200 °C in a blast drying oven for 24 h.

[0060] 2) Wash the sample after hydrothermal reaction with deionized water 3 - 5 times first, and then wash it with absolute ethanol 1 - 2 times. Dry it in a blast drying oven at 60 °C for 10 h.

[0061] 3) Weigh 5.0 g of tetrabutyl titanate, 7.5 g of glacial acetic acid, and 2.4 g of iron sulfide and dissolve them in 24 g of absolute ethanol. Stir magnetically for 30 min. Weigh another 5.0 g of barium chloride and dissolve it in 40 g of deionized water. Stir magnetically for 5 min. Slowly add the prepared barium chloride solution dropwise to the mixed solution of tetrabutyl titanate, glacial acetic acid, and iron sulfide, and transfer the mixed solution obtained to the hydrothermal reaction kettle.

[0062] 4) Wash the sample after the hydrothermal reaction with deionized water 3 - 5 times, and then wash it with absolute ethanol 1 - 2 times, and dry it in a blast drying oven at 60 °C for 10 h.

[0063] 5) Prepare coaxial ring samples (the inner diameter of the coaxial ring sample is 3 mm and the outer diameter is 7 mm) according to the proportion that the doping amount of iron sulfide - barium titanate wave - absorbing material in paraffin is 50%. Measure the electromagnetic parameters of the samples through a vector network analyzer, and then calculate the wave - absorbing performance of the material through CST STUDIO SUITE software.

[0064] The SEM image of the prepared iron sulfide - barium titanate wave - absorbing material sample is as Figure 7 shown. It can be seen that the barium titanate wave - absorbing material uniformly coats the surface of flaky iron sulfide. The wave - absorbing performance of the prepared iron sulfide - barium titanate wave - absorbing material is as Figure 8 shown. It can be seen from the figure that when the thickness of the composite material is 1.8 mm, the minimum reflection loss at 10.27 GHz reaches - 39.17 dB, and the widest effective absorption band at this time reaches 3.2 GHz. Compared with the two pure powders, the loss ability of the composite material to electromagnetic waves has been significantly enhanced.

[0065] Example 3 1) Weigh 3.6 g of thiourea powder and 2.1 g of ferrocene powder, dissolve them in 50 g of ethylene glycol solution, stir magnetically for a certain time, transfer the solution to a hydrothermal reaction kettle, and react at 200 °C in a blast drying oven for 24 h.

[0066] 2) Wash the sample after the hydrothermal reaction with deionized water 3 - 5 times, and then wash it with absolute ethanol 1 - 2 times, and dry it in a blast drying oven at 60 °C for 10 h.

[0067] 3) Weigh 7.0 g of tetrabutyl titanate, 9.0 g of glacial acetic acid and 3.6 g of iron sulfide and dissolve them in 24 g of absolute ethanol, stir magnetically for 30 min. Separately, weigh 7.5 g of barium chloride and dissolve it in 40 g of deionized water, stir magnetically for 5 min. Slowly drip the prepared barium chloride solution into the mixed solution of tetrabutyl titanate, glacial acetic acid and iron sulfide, and transfer the mixed solution to a hydrothermal reaction kettle.

[0068] 4) Wash the sample after the hydrothermal reaction with deionized water 3 - 5 times, and then wash it with absolute ethanol 1 - 2 times, and dry it in a blast drying oven at 60 °C for 10 h.

[0069] 5) Prepare coaxial ring samples (the inner diameter of the coaxial ring sample is 3 mm and the outer diameter is 7 mm) from the powder according to the proportion that the doping amount of iron sulfide-barium titanate microwave absorbing material in paraffin is 50%. Measure the electromagnetic parameters of the samples by a vector network analyzer, and then calculate the microwave absorption performance of the material through CST STUDIO SUITE software.

[0070] The SEM image of the prepared iron sulfide-barium titanate microwave absorbing material sample is as Figure 9 shown. It can be seen that the barium titanate microwave absorbing material is uniformly coated on the surface of flaky iron sulfide. The microwave absorption performance of the prepared iron sulfide-barium titanate microwave absorbing material is as Figure 10 shown. It can be seen from the figure that when the thickness of the composite material is 4.3 mm, the minimum reflection loss at 14.46 GHz reaches -54.40 dB, and the widest effective absorption bandwidth at this time reaches 1.2 GHz. Compared with the two pure powders, the loss ability of the composite material to electromagnetic waves has been significantly enhanced.

[0071] Therefore, for an iron sulfide-barium titanate microwave absorbing material and its preparation method of the present invention, the iron sulfide-barium titanate microwave absorbing material first uses iron sulfide powder as a precursor, and then attaches titanate ions to the surface of iron sulfide by reacting the iron sulfide powder precursor in an anhydrous ethanol solution containing tetrabutyl titanate and glacial acetic acid. The structure of the microwave absorbing material is not only conducive to the incident electromagnetic wave entering the material interior, but also can perform multiple losses on the electromagnetic wave entering the material interior, enhancing the loss ability of the material to electromagnetic waves.

[0072] The iron sulfide-barium titanate microwave absorbing material forms an iron sulfide-barium titanate composite structure, introducing a heterojunction interface, which can generate interfacial polarization when the electromagnetic wave is incident, enhancing the loss ability of the material to electromagnetic waves and achieving stronger microwave absorption performance.

[0073] After the iron sulfide-barium titanate microwave absorbing material prepares to attach titanate ions to the surface of iron sulfide, iron sulfide-barium titanate is prepared by the method of barium chloride doping, and spherical barium titanate grows on the surface of flaky iron sulfide. Its unique structure can increase the transmission and loss paths of the incident electromagnetic wave and perform multiple reflections on the incident electromagnetic wave.

[0074] The iron sulfide-barium titanate microwave absorbing material attaches non-metallic sulfur elements to the surface of barium titanate, increasing the number of defects inside the material, and can generate more dipole polarizations when the electromagnetic wave is incident, thereby increasing the microwave absorption performance of the iron sulfide-barium titanate microwave absorbing material.

[0075] The iron sulfide-barium titanate microwave absorbing material modifies barium titanate with non-metallic sulfur element. Some barium elements in barium titanate will combine with sulfur element to obtain barium sulfide, enhancing the magnetic loss ability of the composite material. At the same time, the doping of sulfur element can also adjust the dielectric properties of barium titanate and enhance its dielectric loss, thus forming a synergistic effect of multiple loss mechanisms and significantly improving the microwave absorbing ability of the composite material.

[0076] For the iron sulfide-barium titanate microwave absorbing material, when the thickness is 4.3 mm, the minimum reflection loss at 14.50 GHz reaches -54.40 dB. At this time, the widest effective absorption band (reflection loss less than -10 dB) reaches 2.2 GHz, and its loss ability to incident electromagnetic waves is significantly better than that of pure barium titanate powder and pure iron sulfide powder.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements do not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of a ferrous sulfide-barium titanate microwave absorbing material, characterized in that, Composite iron sulfide with barium titanate by growing barium titanate uniformly on the surface of iron sulfide, which specifically includes the following preparation steps: 1) Weigh appropriate amounts of thiourea and ferrocene and dissolve them in ethylene glycol solution, stir magnetically, ultrasonically treat the mixed solution, and then heat the mixed solution using a heating stage. After stirring at room temperature, a pale yellow mixed solution is obtained; 2) Transfer the mixed solution obtained in step 1) to a hydrothermal reaction kettle for hydrothermal reaction; 3) Centrifuge and wash the solution obtained in step 2) several times, and dry it in a blast drying oven at 60 °C for 10 h to obtain iron sulfide powder particles; 4) Weigh certain amounts of tetrabutyl titanate and glacial acetic acid and dissolve them in appropriate amounts of absolute ethanol, stir magnetically for 30 min to obtain a pale yellow transparent organic solution. Add the iron sulfide powder obtained in step 3) to it, ultrasonically treat the mixed solution, and then heat the mixed solution using a heating stage. After stirring at room temperature, a pale yellow mixed solution is obtained; 5) Weigh appropriate amounts of barium chloride powder and dissolve it in deionized water, stir magnetically for 5 min to obtain a clear and transparent solution; 6) Slowly drip the barium salt solution obtained in step 5) into the solution obtained in step 4), and at the same time adjust the pH value with sodium hydroxide solution to form a colloidal mixed solution; 7) Transfer the colloidal solution obtained in step 6) to a hydrothermal reaction kettle for hydrothermal reaction; 8) Centrifuge and wash the powder obtained in step 7) several times, and then dry it in a blast drying oven at 60 °C for 10 h to obtain iron sulfide-barium titanate powder particles.

2. The preparation method of a ferrous sulfide-barium titanate microwave absorbing material according to claim 1, characterized in that In step 1), the mass ratio of thiourea, ferrocene, and ethylene glycol is 1.2 - 3.6:0.7 - 2.1:

50.

3. The preparation method of a ferrous sulfide-barium titanate wave-absorbing material according to claim 1, characterized in that, In step 2), the hydrothermal reaction temperature is 180 - 220 °C, and the reaction time is 18 - 24 h.

4. The preparation method of a ferrous sulfide-barium titanate wave-absorbing material according to claim 1, characterized in that, In step 4), the mass ratio of tetrabutyl titanate, glacial acetic acid, absolute ethanol, and iron sulfide is 2.5 - 8.0:3.4 - 12:24:1.2 - 3.

6.

5. The preparation method of an iron sulfide-barium titanate microwave absorbing material according to claim 1, characterized in that, In step 5), the mass ratio of barium chloride and deionized water is 2.5 - 7.5:

40.

6. The preparation method of an iron sulfide-barium titanate wave-absorbing material according to claim 1, characterized in that, In step 6), the concentration of the sodium hydroxide solution used to adjust the pH value is 0.1 mol / L, and the pH value is adjusted to 6 - 8.

7. The preparation method of an iron sulfide-barium titanate wave-absorbing material according to claim 1, wherein In step 7), the hydrothermal reaction temperature is 180 - 220 °C, and the reaction time is 18 - 24 h.

8. The iron sulfide-barium titanate wave-absorbing material obtained by the preparation method according to any one of claims 1 to 7, characterized in that, The obtained iron sulfide-barium titanate powder particles are a composite structure with wave-absorbing ability.

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