Manganese-zinc ferrite / graphene composite aerogel material and preparation method thereof

Abstract

The application discloses a manganese-zinc ferrite / graphene composite aerogel material and a preparation method thereof. The raw materials of the material comprise manganese-zinc ferrite and graphene oxide; the mass ratio of the manganese-zinc ferrite to the graphene oxide is 0.06-0.18:1; and the manganese-zinc ferrite and the graphene oxide are combined into the composite aerogel material through a hydrothermal reaction and freeze drying. The technical scheme has the advantages of improving impedance matching of graphene aerogel, widening an effective absorption bandwidth and obtaining light weight and high efficiency.

Description

Technical Field

[0001] This application relates to the technical field of composite materials, and in particular to a manganese zinc ferrite / graphene composite aerogel material and its preparation method. Background Technology

[0002] Graphene aerogel, as a typical dielectric loss absorbing material, retains the inherent physicochemical properties of monolayer graphene while introducing other advantages, such as: good mechanical properties; porous structure further increases specific surface area while reducing density; three-dimensional structure improves mass and electron transport; pores provide numerous adsorption sites; and good thermal stability and hydrophobicity. Furthermore, the precursor of graphene aerogel is graphene oxide. After reduction treatment, its sheets have a large number of residual functional groups and defects. On the one hand, this can reduce conductivity, which is beneficial for improving impedance matching; on the other hand, defects and functional groups can act as polarization centers, contributing to polarization relaxation. Both of these promote electromagnetic wave attenuation, thus graphene aerogel has become a relatively ideal absorbing material. However, due to the high conductivity of graphene, graphene aerogel still suffers from poor impedance matching.

[0003] Due to its unique three-dimensional porous network structure, graphene aerogel can be doped with other substances. Combining graphene with other types of microwave absorbing materials can produce composite materials with better microwave absorption performance. Furthermore, by designing and controlling the structure of the composite material, not only can the dipole polarization of the material itself be enhanced, but interfacial polarization can also be generated, thereby enhancing its attenuation capability for electromagnetic waves.

[0004] Constructing composite materials of graphene aerogels with other different types of microwave absorbing materials is an effective method to enhance electromagnetic wave power. On the one hand, the increased polarization loss caused by the multi-interface structure of different components can improve dielectric loss capability. On the other hand, the synergistic effect of different loss mechanisms can significantly improve impedance matching and broaden the effective bandwidth, while the simultaneous addition of additives with different loss mechanisms can further enhance microwave absorption performance. However, many problems still exist: the microwave absorption mechanism of composite materials and the factors that broaden effective absorption are not yet clearly understood; the reflection loss value is still difficult to meet requirements; the material preparation process is still relatively cumbersome, and further improvements are needed in terms of cost reduction and environmental protection. Summary of the Invention

[0005] This application addresses the aforementioned shortcomings of the prior art by providing a material that can improve the impedance matching degree of graphene aerogel and broaden the effective absorption bandwidth, and can also produce a lightweight and efficient manganese-zinc ferrite / graphene composite aerogel material.

[0006] To solve the above-mentioned technical problems, the technical solution adopted in this application is: a manganese zinc ferrite / graphene composite aerogel material, the raw materials of which include: manganese zinc ferrite and graphene oxide; wherein the mass ratio of manganese zinc ferrite to graphene oxide is 0.06 to 0.18:1, and the manganese zinc ferrite and graphene oxide are obtained by hydrothermal reaction and freeze-drying to obtain the composite aerogel material.

[0007] Furthermore, the graphene oxide has a sheet diameter of 0.5–5 μm and a thickness of 0.8–1.2 nm.

[0008] Furthermore, the particle size of the manganese zinc ferrite is 60–80 μm.

[0009] Furthermore, the mass ratio of the manganese zinc ferrite to graphene oxide is 0.12 to 0.18:1.

[0010] This application also provides the above-mentioned manganese-zinc ferrite / graphene composite aerogel material and its preparation method, the steps of which include:

[0011] (1) Preparation of graphene oxide aqueous dispersion: Weigh the graphene oxide powder and add it to deionized water. Sonicate at room temperature until GO is completely dissolved. Adjust the pH to neutral and mechanically peel it off using a high-speed disperser to obtain the graphene oxide aqueous dispersion.

[0012] (2) Preparation of manganese zinc ferrite / graphene composite aerogel material: In step (1), manganese zinc ferrite is added to the aqueous dispersion of graphene oxide and ultrasonicated at room temperature to fully disperse the manganese zinc ferrite in the aqueous dispersion of graphene oxide. Then, it is transferred to a polytetrafluoroethylene liner and reacted in a reactor at 150-200℃ for 8-15 hours. After cooling to room temperature, it is transferred to a freeze dryer and freeze-dried for 24-96 hours to obtain the manganese zinc ferrite / graphene composite aerogel material.

[0013] Furthermore, the high-speed disperser described in step (1) has a rotation speed of 1000-2000 r / min and a peeling time of 10-15 min.

[0014] Furthermore, the concentration range of the graphene oxide in the dispersion in step (1) is 5–15 mg / ml.

[0015] Furthermore, the graphene oxide sheet in step (1) has a sheet diameter of 0.5–5 μm and a thickness of 0.8–1.2 nm.

[0016] Furthermore, the particle size of the manganese zinc ferrite described in step (2) is 60-80 μm.

[0017] Furthermore, the mass ratio of manganese zinc ferrite to graphene oxide in step (2) is 0.06 to 0.18:1.

[0018] Furthermore, the mass ratio of manganese zinc ferrite to graphene oxide in step (2) is 0.12 to 0.18:1.

[0019] Furthermore, step (2) involves reacting at 170-185°C in the reactor for 10-12 hours.

[0020] Furthermore, the freeze-drying time in step (2) is 24-48 hours, and the temperature is -55 to -60°C.

[0021] The advantages and beneficial effects of this application are as follows:

[0022] 1. The composite aerogel material of this application contains manganese zinc ferrite with high magnetic permeability but low dielectric constant, and graphene oxide with high dielectric constant but low magnetic permeability. Based on the properties of the two main raw materials, after being combined through a hydrothermal reaction, the manganese zinc ferrite can be uniformly distributed in the three-dimensional framework of graphene oxide. The electromagnetic parameters of the two can be complementary, thereby improving the impedance matching of the aerogel material, reducing the reflection of electromagnetic waves on the material surface, and increasing the amount of electromagnetic waves entering the material. The combination of the two not only improves the matching of electromagnetic parameters, but also enhances the multiple loss mechanism, so that the composite material exhibits excellent electromagnetic wave absorption capability in the X-band.

[0023] 2. The aerogel material of this application, by adjusting the ratio of manganese zinc ferrite to graphene oxide, achieves control over the electromagnetic parameters and impedance matching performance of the composite aerogel, thereby improving the loss of electromagnetic waves in the composite aerogel material. Moreover, the low density of the obtained graphene aerogel is also beneficial to improving the "heavy" problem of traditional wave-absorbing materials. The manganese zinc ferrite embedded in the graphene aerogel framework can also avoid the corrosion and oxidation of ferromagnetic materials during long-term use. The raw materials for preparation in this application mainly include manganese zinc ferrite and graphene oxide. The obtained wave-absorbing material can achieve wave absorption performance in a wide frequency range of 8.2-12.4GHz. In contrast, existing technologies generally contain multiple wave-absorbing agents, such as amino-modified cellulose fibers, activated carbon powder, nano-titanium dioxide, graphene oxide-manganese zinc ferrite composite materials, conductive micro powders, etc. There is interference between multiphase materials, and the content of graphene oxide-manganese zinc ferrite composite materials is low. Therefore, the obtained materials only have wave absorption performance in the low frequency band (such as 30MHz to 1.5GHz).

[0024] 3. The composite aerogel of this application employs a hydrothermal reaction and freeze-drying process, thus preserving the unique porous structure of the aerogel material (current technologies use drying at 80-90℃ for 10-12 hours without freeze-drying, therefore these processes cannot retain the three-dimensional structure of the gel and cannot obtain the porous graphene aerogel of this application). The pores and interfaces within this unique porous structure can reflect incident electromagnetic waves multiple times, extending the propagation path of electromagnetic waves within the material and thus improving energy dissipation. The porous structure can also adjust the dielectric constant and permeability of the material, making it more compatible with the impedance of free space, thereby reducing electromagnetic wave reflection on the material surface and increasing the energy of electromagnetic waves entering the material. Furthermore, this preparation process can optimize porosity, reducing the reflectivity of the material surface and allowing more electromagnetic waves to enter and be absorbed within the material. In addition, this porous structure significantly reduces the material's density, enabling it to be lightweight while maintaining excellent wave absorption performance, making it particularly suitable for aerospace, mobile devices, and other fields. For example, in the technical solution of this application, the density of the individual manganese-zinc ferrite is 5.2 g / cm³. 3 The density of graphene oxide alone is 2.2 g / cm³. 3 Furthermore, the aerogel material obtained by combining the two through the above processing technology—manganese-zinc ferrite / graphene composite aerogel—has a density of only 0.02 g / cm³. 3 about.

[0025] 4. In the preparation of the aqueous dispersion of graphene oxide, this application employs a high-speed disperser for mechanical exfoliation. This is because the van der Waals forces and hydrogen bonds between graphene oxide sheets make them prone to aggregation, affecting performance. The shear force of the high-speed disperser disperses them into single or fewer layers, ensuring uniform distribution. The dispersed graphene oxide has a larger specific surface area and more active sites, which is beneficial for the uniform distribution of manganese-zinc ferrite. Using a high-speed disperser to disperse graphene oxide is a key step in ensuring its performance and application effects. This application uses a hydrothermal reactor to provide a high-temperature and high-pressure environment, promoting π-π interactions between the graphene oxide sheets. The aerogel is self-assembled using van der Waals forces to form a three-dimensional network structure. The conditions in the hydrothermal reactor facilitate the formation of a stable cross-linked structure in the graphene sheets, enhancing the mechanical strength and stability of the aerogel. Under high temperature and pressure, some oxygen-containing functional groups in the graphene oxide are removed, restoring the conjugated π-bond structure, improving conductivity, dielectric constant, and dielectric loss, thus enhancing the interaction between the material and electromagnetic waves and improving its wave absorption performance. In contrast, existing technologies use crystallization for preparation, and subsequent filtration and drying processes cause shrinkage of the aerogel structure, increasing its overall density. The aerogel in this application has a density of only 0.02 g / cm³. 3 This improves upon the "heavy" nature of traditional microwave absorbing materials.

[0026] 5. The technical solution of this application prepares a flexible, lightweight material with high wave absorption performance by designing the structure of the wave-absorbing material and controlling the electromagnetic parameters; while the prior art does not involve the freeze-drying process, but dries at 80-90℃ for 10-12h. This process cannot retain the three-dimensional structure of the gel and cannot obtain the graphene aerogel product with the specific porous structure of this application. Attached Figure Description

[0027] Figure 1 The manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 (e.g.) Figure 1 -a) and the pure graphene oxide aerogel material prepared in Comparative Example 1 (as shown in Figure 1) Figure 1 The SEM image shown in -b).

[0028] Figure 2 The reflection loss curves of the manganese zinc ferrite / graphene composite aerogel material prepared in Example 1 at different thicknesses in the X-band (8.2-12.4 GHz) frequency range are shown.

[0029] Figure 3 This is a photograph of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1.

[0030] Figure 4 These are real images showing the results of post-processing composite aerogel materials using two methods: freeze-drying and oven-drying.

[0031] Figure 5 The attenuation constant (α) of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 varies with frequency in the X-band (8.2–12.4 GHz) frequency range.

[0032] Figure 6 The reflection loss curves of the manganese zinc ferrite / graphene composite aerogel material prepared in Example 2 at different thicknesses in the frequency range of 2 to 18 GHz are shown.

[0033] Figure 7 The graph shows the reflection loss curves of the manganese zinc ferrite / graphene composite aerogel material prepared in Example 3 at different thicknesses within the frequency range of 2–18 GHz.

[0034] Figure 8 Pure graphene oxide aerogel material prepared for Comparative Example 1 (e.g.) Figure 8 -a), Example 1: Manganese zinc ferrite / graphene composite aerogel material prepared with an addition amount of 30 mg of manganese zinc ferrite (as shown in Example 1). Figure 8 As shown in -b), Example 2 prepared a manganese zinc ferrite / graphene composite aerogel material with an addition amount of 60 mg of manganese zinc ferrite (as shown in -b). Figure 8-c), Example 3: Manganese zinc ferrite / graphene composite aerogel material prepared with an addition amount of 90 mg of manganese zinc ferrite (as shown in example c). Figure 8 The SEM image shown in Figure -d. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are merely preferred embodiments, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0036] Example 1:

[0037] A manganese-zinc ferrite / graphene composite aerogel material and its preparation method are disclosed, with the specific implementation steps as follows:

[0038] (1) Preparation of graphene oxide aqueous dispersion: Weigh 0.5g of graphene oxide powder and add it to 50mL of deionized water. Sonicate at room temperature for a period of time until GO is completely dissolved. Adjust the pH to neutral and mechanically exfoliate it using a high-speed disperser (the speed of the high-speed disperser is 1200r / min and the time is 12min) to obtain the graphene oxide aqueous dispersion.

[0039] (2) Preparation of manganese zinc ferrite / graphene composite aerogel material: 30 mg of manganese zinc ferrite was added to the aqueous dispersion of graphene oxide in step (1), and ultrasonicated at room temperature for 30 min to fully disperse the manganese zinc ferrite in the aqueous dispersion of graphene oxide. Then it was transferred to a polytetrafluoroethylene liner and reacted in a reactor at 180 °C for 12 h. After cooling to room temperature, it was transferred to a freeze dryer and freeze-dried at -55 to -60 °C for 48 h to obtain the manganese zinc ferrite / graphene composite aerogel material.

[0040] Comparative Example 1

[0041] The difference between Comparative Example 1 and Example 1 is that no magnetic material manganese zinc ferrite is added in the preparation process of the composite aerogel in step (2). That is, only the aqueous dispersion of graphene oxide is subjected to hydrothermal reaction. The rest of the process is exactly the same, so pure graphene oxide aerogel is obtained.

[0042] Figure 1 The manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 (e.g.) Figure 1 -a) and the pure graphene oxide aerogel material prepared in Comparative Example 1 (as shown in Figure 1) Figure 1 SEM image shown in -b). From Figure 1As shown in -a, manganese zinc ferrite (the red box in the figure represents manganese zinc ferrite, and the blue box represents graphene aerogel) is uniformly distributed in the three-dimensional graphene aerogel, indicating the successful preparation of the composite material.

[0043] The manganese zinc ferrite / graphene composite aerogel material prepared in Example 1 was added to molten paraffin and molded into cylinders and cylindrical rings, which were used for conductivity testing and microwave absorption (MA) measurement, respectively.

[0044] Figure 2 The graph shows the reflection loss curves of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 at different thicknesses within the X-band (8.2–12.4 GHz) frequency range. The reflection loss (RL) is shown across the entire frequency range. min The reflection loss is -46.8296dB, and it can also reach -16.1799dB with a low matching thickness of 3.2mm, which shows excellent absorption performance.

[0045] As attached Figure 3 The image shown is a physical photograph of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 of this application; the density of the manganese-zinc ferrite in this application is 5.2 g / cm³. 3 The density of graphene oxide is 2.2 g / cm³. 3 The final density of the prepared manganese-zinc ferrite / graphene composite aerogel was 0.02 g / cm³. 3 .

[0046] As attached Figure 4 The images shown are real pictures of the composite aerogel materials after being treated by freeze-drying and baking, respectively. As can be seen from the pictures, the aerogel material treated by the freeze-drying process of this application maintains a good structure and shape, and the structure is more stable. In contrast, the aerogel material treated by the baking process undergoes structural deformation and collapse, and it cannot be guaranteed that it obtains the specific porous aerogel structure of this application.

[0047] Figure 5 The attenuation constant (α) of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 1 varies with frequency in the X-band (8.2–12.4 GHz). The attenuation constant is the ability of an absorbing material to dissipate electromagnetic waves and is an important factor determining the absorption characteristics of microwave absorbers. The manganese-zinc ferrite / graphene composite aerogel material prepared by this method shows that the attenuation constant gradually increases with increasing frequency, reaching a maximum of 102.1697 Np / m at 9.439 GHz, demonstrating excellent electromagnetic wave dissipation capability.

[0048] Examples 2 and 3 investigated the effect of manganese-zinc ferrite on the structure of graphene composite aerogel by adjusting the amount of manganese-zinc ferrite added.

[0049] Example 2:

[0050] A manganese-zinc ferrite / graphene composite aerogel material and its preparation method are disclosed, with the specific implementation steps as follows:

[0051] (1) Preparation of graphene oxide aqueous dispersion: Weigh 0.5g of graphene oxide powder and add it to 50mL of deionized water. Sonicate at room temperature for a period of time until GO is completely dissolved. Adjust the pH to neutral and mechanically peel it off using a high-speed disperser to obtain the graphene oxide aqueous dispersion.

[0052] (2) Preparation of manganese zinc ferrite / graphene composite aerogel material: 60 mg of manganese zinc ferrite was added to the aqueous dispersion of graphene oxide in step (1), and ultrasonicated at room temperature for 30 min to fully disperse the manganese zinc ferrite in the aqueous dispersion of graphene oxide. Then it was transferred to a polytetrafluoroethylene liner and reacted in a reactor at 180 °C for 12 h. After cooling to room temperature, it was transferred to a freeze dryer and freeze-dried for 48 h to obtain the manganese zinc ferrite / graphene composite aerogel material.

[0053] The manganese-zinc ferrite / graphene composite aerogel material prepared in Example 2 was added to molten paraffin and molded into cylinders and cylindrical rings, which were used for conductivity testing and microwave absorption (MA) measurement, respectively.

[0054] Figure 6 The graph shows the reflection loss curves of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 2 at different thicknesses within the frequency range of 2–18 GHz. The reflection loss (RL) is shown across the entire frequency range. min The value is -42.3423dB, and the matching thickness is only 1.7mm.

[0055] Example 3:

[0056] A manganese-zinc ferrite / graphene composite aerogel material and its preparation method are disclosed, with the specific implementation steps as follows:

[0057] (1) Preparation of graphene oxide aqueous dispersion: Weigh 0.5g of graphene oxide powder and add it to 50mL of deionized water. Sonicate at room temperature for a period of time until GO is completely dissolved. Adjust the pH to neutral and mechanically peel it off using a high-speed disperser to obtain the graphene oxide aqueous dispersion.

[0058] (2) Preparation of manganese zinc ferrite / graphene composite aerogel material: 90 mg of manganese zinc ferrite was added to the aqueous dispersion of graphene oxide in step (1) and sonicated at room temperature for 30 min to fully disperse the manganese zinc ferrite in the aqueous dispersion of graphene oxide. Then it was transferred to a polytetrafluoroethylene liner and reacted in a reactor at 180 °C for 12 h. After cooling to room temperature, it was transferred to a freeze dryer and freeze-dried for 48 h to obtain the manganese zinc ferrite / graphene composite aerogel material.

[0059] The manganese-zinc ferrite / graphene composite aerogel material prepared in Example 3 was added to molten paraffin and molded into cylinders and cylindrical rings, which were used for conductivity testing and microwave absorption (MA) measurement, respectively.

[0060] Figure 7 The graph shows the reflection loss curves of the manganese-zinc ferrite / graphene composite aerogel material prepared in Example 3 at different thicknesses within the frequency range of 2–18 GHz. The reflection loss (RL) is shown across the entire frequency range. min The impedance was -16.3096 dB, and the matching thickness was only 1.6 mm. Compared with Examples 1 and 2, the matching thickness of the manganese zinc ferrite / graphene composite aerogel absorbing material prepared in Example 3 was even lower. However, due to the agglomeration of manganese zinc ferrite, the synergistic effect between the two was reduced, and the loss capability of incident electromagnetic waves was significantly reduced.

[0061] Figure 8 Pure graphene oxide aerogel material prepared for Comparative Example 1 (e.g.) Figure 8 -a), Example 1: Manganese zinc ferrite / graphene composite aerogel material prepared with an addition amount of 30 mg of manganese zinc ferrite (as shown in Example 1). Figure 8 As shown in -b), Example 2 prepared a manganese zinc ferrite / graphene composite aerogel material with an addition amount of 60 mg of manganese zinc ferrite (as shown in -b). Figure 8 -c), Example 3: Manganese zinc ferrite / graphene composite aerogel material prepared with an addition amount of 90 mg of manganese zinc ferrite (as shown in example c). Figure 8 The SEM image is shown in Figure d. The red box represents manganese-zinc ferrite. With the increase of manganese-zinc ferrite content, the distribution of manganese-zinc ferrite in the graphene composite aerogel is more uniform, which is beneficial to the synergistic effect of magnetic and dielectric materials and improves the microwave absorption performance of the composite material. However, when the amount of manganese-zinc ferrite added is 90 mg, the manganese-zinc ferrite exhibits a large degree of agglomeration in the graphene composite aerogel, which is not conducive to improving the impedance matching performance of the composite material.

[0062] As can be seen from the above embodiments and comparative examples, the above technical solution of this application uses manganese zinc ferrite and graphene oxide as the main raw materials, and then obtains an aerogel material through hydrothermal reaction and freeze-drying treatment. This material can maintain a specific porous structure. The pores and interfaces inside the porous structure can reflect incident electromagnetic waves multiple times, prolonging the propagation path of electromagnetic waves inside the material, thereby improving energy dissipation. The porous structure can adjust the dielectric constant and permeability of the material, making it more compatible with the impedance of free space, thereby reducing the reflection of electromagnetic waves on the material surface and increasing the energy of electromagnetic waves entering the material. By optimizing the porosity, the reflectivity of the material surface can be reduced, allowing more electromagnetic waves to enter the material and be absorbed. The porous structure significantly reduces the density of the material, enabling it to be lightweight while maintaining excellent wave absorption performance, making it particularly suitable for aerospace, mobile devices and other fields. The addition of zinc to the manganese zinc ferrite results in a wider absorption bandwidth. Manganese zinc ferrite is superior to manganese ferrite in terms of absorption bandwidth and temperature stability, making it suitable for broadband applications.

Claims

1. A method for preparing a manganese-zinc ferrite / graphene composite aerogel material, characterized in that: The steps of this method include: (1) preparing an aqueous dispersion of graphene oxide: weighing graphene oxide powder and adding it to deionized water, sonicating at room temperature until the graphene oxide is fully dispersed, adjusting the pH to neutral, and mechanically exfoliating it using a high-speed disperser to obtain an aqueous dispersion of graphene oxide; (2) preparing a manganese zinc ferrite / graphene composite aerogel material: adding manganese zinc ferrite to the aqueous dispersion of graphene oxide in step (1), and sonicating at room temperature to fully disperse the manganese zinc ferrite. The manganese zinc ferrite / graphene composite aerogel material is dispersed in an aqueous dispersion of graphene oxide and then transferred to a polytetrafluoroethylene liner. The reaction is carried out in a reactor at 150-200℃ for 8-15 hours. After cooling to room temperature, the material is transferred to a freeze dryer and freeze-dried for 24-96 hours to obtain the manganese zinc ferrite / graphene composite aerogel material. The particle size of the manganese zinc ferrite in step (2) is 60-80 μm. The mass ratio of the manganese zinc ferrite to the graphene oxide in step (2) is 0.06-0.18:

1.

2. The preparation method of the manganese-zinc ferrite / graphene composite aerogel material according to claim 1, characterized in that: The mass ratio of the manganese zinc ferrite to graphene oxide is 0.12 to 0.18:

1.

3. The preparation method of the manganese-zinc ferrite / graphene composite aerogel material according to claim 1, characterized in that: The high-speed disperser mentioned in step (1) has a rotation speed of 1000-2000 r / min and a peeling time of 10-15 min.

4. The preparation method of the manganese-zinc ferrite / graphene composite aerogel material according to claim 1, characterized in that: The concentration range of graphene oxide in the dispersion in step (1) is 5–15 mg / ml.

5. The preparation method of the manganese-zinc ferrite / graphene composite aerogel material according to claim 1, characterized in that: The graphene oxide sheet in step (1) has a sheet diameter of 0.5–5 μm and a thickness of 0.8–1.2 nm.

6. The preparation method of the manganese-zinc ferrite / graphene composite aerogel material according to claim 1, characterized in that: The reaction in step (2) is carried out at 170-185℃ for 10-12 hours in the reactor; the freeze-drying time in step (2) is 24-48 hours and the temperature is -55 to -60℃.

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