A two-step partial oxidation method to improve the microwave absorption performance of MXene materials

Abstract

This invention belongs to the field of microwave absorbing material preparation technology, and discloses a two-step partial oxidation method to improve the microwave absorption performance of MXene materials. By performing hydrothermal pre-oxidation and heat treatment on MXene materials, oxide nanoparticles are grown in situ on their surface, achieving controllable partial oxidation. The MXene matrix retains a two-dimensional layered structure, and a heterogeneous interface is formed between the oxide nanoparticles and the MXene matrix. This adjusts the conductivity, optimizes impedance matching, enhances interface polarization, improves microwave absorption performance, and provides high-temperature stability.

Description

Technical Field

[0001] This invention belongs to the field of microwave absorbing material preparation technology, specifically relating to a two-step partial oxidation method for improving the microwave absorbing performance of MXene materials. Background Technology

[0002] With the rapid development of electronic information technology, electromagnetic pollution has become increasingly serious. Developing high-performance electromagnetic wave absorbing materials has become crucial for solving electromagnetic interference and electromagnetic protection problems. Ideal absorbing materials should possess characteristics such as thinness, light weight, strong absorption, wide bandwidth, and good stability.

[0003] Two-dimensional transition metal carbides / nitrides (MXenes) have shown great potential in the field of electromagnetic wave absorption due to their unique two-dimensional layered structure, high conductivity, abundant surface functional groups, and tunable surface chemistry. However, pure MXene materials have the following inherent drawbacks: First, their extremely high conductivity leads to a severe imbalance in impedance matching with free space, causing a large number of electromagnetic waves to be reflected at the material surface and difficult to penetrate and be consumed internally; second, their loss mechanism is relatively simple, mainly relying on conductive loss, lacking effective polarization relaxation and interfacial polarization loss mechanisms; finally, MXene materials, especially titanium-containing MXenes, have poor chemical stability at high temperatures or in air environments and are easily oxidized, which not only leads to the degradation of their electrical properties but also severely limits their application in harsh environments.

[0004] To overcome the above-mentioned shortcomings, existing technologies typically employ a strategy of combining MXene with other dielectric or magnetic components. For example, Xing et al. (Xing L, Cheng H, Li Y, et al. Simultaneous manipulation of constant and structure toward MOFs-derived hollow Co3O4 / Co / NC@MXene microspheres via pyrolysis strategy for high-performance microwave absorption[J]. Chemical Engineering Journal, 2024, 487: 150729.) grew ZIF-67 nanoparticles on a Ti3C2Tx MXene three-dimensional framework using a template method and electrostatic self-assembly. Hollow Co3O4 / Co / NC@MXene microspheres were obtained through pyrolysis, significantly optimizing impedance matching and attenuation capabilities. HCCM-800 achieved a reflection loss (RL) of -71.60 dB and an effective absorption bandwidth (EAB) of 5.14 GHz at a thickness of 2.25 mm. Li et al. (Li T, Ma L, Wang L, et al. Ultra-wideband electromagnetic wave absorption by decorating the magnetic particles on two-dimensional Ti3C2Tx[J]. Rare Metals, 2025, 44(3): 1844-1855.) proposed modifying Ti3C2Tx with magnetic FeNi nanoparticles. x Mxene composite material (FeNi-Ti3C2T) x Its effective absorption range is 170~220 GHz, and its absorption bandwidth reaches 50 GHz. (Bai et al. Achieving excellent microwave absorption performance in ultralight Ti3C2Tx MXene with M...) O bonds (M = Fe, Co, Ni) as surface terminating groups[J]. Chemical Engineering Journal, 2024, 501: 157715.) By doping magnetic elements into the precursor M–Ti3AlC2 (M = Fe, Co, Ni), M–Ti3C2T with M–O bonds as partial terminal groups was successfully prepared. x MXene materials, including Fe-Ti3C2T x RLmin is 53.01dB (2.47 mm), EAB value is 4.20GHz (1.34 mm).

[0005] As mentioned above, research on applying MXene to microwave absorbing materials has largely focused on single transition metal MXene and its composite / doping modification, without considering the performance degradation caused by the easy oxidation of MXene materials. In-situ partial oxidation is an effective method for preparing MXene composite materials by in-situ generating metal oxides on MXene materials through oxidation. This method can utilize the properties of oxides to reduce the material's conductivity and optimize impedance matching, while avoiding problems such as weak interfacial bonding and complex composite processes. Existing technology involves annealing Mo2TiC2T... X Surface growth of MoO3 / TiO2 oxide particles to construct a hierarchical heterostructure of "0D / 2D MXene" has improved microwave absorption performance to some extent. However, this method still has limitations: firstly, the size and dispersion of oxide particles are difficult to control precisely, resulting in insufficient heterostructure and limited improvement in polarization loss; secondly, the degree of oxidation of MXene lacks effective control, easily leading to uneven oxidation and significant differences in sample performance.

[0006] Therefore, developing a new method to precisely control the oxidation process of MXene, especially dual-transition metal MXene, in order to construct MXene materials with abundant heterostructures, optimized impedance matching, and excellent stability has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide a two-step partial oxidation method to improve the microwave absorption performance of MXene materials. Through a two-step oxidation process combining hydrothermal pre-oxidation and heat treatment, an oxide / MXene heterostructure is formed on the surface of the MXene material through controllable partial oxidation treatment, thereby adjusting the conductivity, enhancing the interfacial polarization, improving the microwave absorption performance, and providing high-temperature stability.

[0008] The specific technical solution to achieve the above-mentioned objectives is as follows:

[0009] This invention provides a method for improving the microwave absorption performance of MXene materials using a two-step partial oxidation process, comprising the following steps: performing preliminary oxidation of the MXene matrix by hydrothermal pre-oxidation; and then growing oxide nanoparticles in situ on the surface of the pre-oxidized MXene matrix by heat treatment.

[0010] The initial oxidation is a partial oxidation, which allows the MXene matrix in the final product to retain a two-dimensional layered structure, and a heterogeneous interface is formed between the oxide nanoparticles and the MXene matrix.

[0011] The MXene matrix includes Ti3C2T x TiN b CT x and TiVCT x Any one of them.

[0012] The method for improving the microwave absorption performance of MXene materials through two-step partial oxidation is characterized by comprising the following steps:

[0013] S1. Mix MXene powder with deionized water and carry out a hydrothermal reaction to obtain a pre-oxidized MXene suspension;

[0014] S2. The suspension obtained in S1 is washed, centrifuged and dried to obtain pre-oxidized MXene solid powder;

[0015] S3. The powder obtained in S2 is heat-treated in air at a temperature of 300-600℃ and kept at that temperature in air. The resulting mixture is then cooled to room temperature in the furnace to obtain the composite microwave absorbing material.

[0016] Preferably, the hydrothermal reaction temperature in S1 is 140-220℃, and the reaction time is 2-6 hours; the heating rate of the heat treatment in S3 is 2-10℃ / min, and the holding time is 1-4 hours; the heat treatment temperature in S3 is 300-500℃.

[0017] Preferably, the hydrothermal reaction in S1 is carried out at a temperature of 180°C for 4 hours.

[0018] Preferably, the heating rate of the heat treatment in S3 is 5°C / min, and the holding time is 2 hours.

[0019] Preferably, the heat treatment temperature in S3 is 400°C.

[0020] Preferably, the method for improving the microwave absorption performance of MXene materials through two-step partial oxidation includes the following steps:

[0021] S1, TiVCT x The powder was mixed with deionized water and subjected to a hydrothermal reaction to obtain pre-oxidized TiVCT. x (O) suspension;

[0022] S2. The suspension obtained in S1 is washed, centrifuged, and dried to obtain TiVCT. x (O) solid powder;

[0023] S3, the TiVCT obtained in S2 x (O) The powder is heat-treated in an air atmosphere at a temperature of 300-600℃ and kept at the air atmosphere. The resulting mixture is then cooled to room temperature in the furnace to obtain the composite microwave absorbing material.

[0024] The second objective of this invention is to provide an MXene composite absorbing material prepared by the method described above.

[0025] The third objective of this invention is to provide an application of the aforementioned MXene composite absorbing material in the fields of electromagnetic pollution, electromagnetic absorption stealth, or electromagnetic protection of electronic equipment.

[0026] The two-step partial oxidation method for improving the microwave absorption performance of MXene materials serves the following purposes: S1 involves stirring to uniformly disperse the powder in deionized water, achieving uniform pre-oxidation of the TiVC surface and interlayers through a hydrothermal process, forming oxygen-containing functional groups or a thin oxide layer, providing a uniform reaction starting point for subsequent calcination. S2 involves centrifuging, washing, and drying the reaction products to remove impurities, preparing for subsequent heat treatment. S3 involves precisely controlling the degree of oxidation and crystal phase evolution by changing the heat treatment temperature, effectively constructing oxide / TiVCT. x Heterogeneous structure optimizes impedance matching, enhances interface polarization and dipole polarization, and improves loss capability.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The two-step oxidation process proposed in this invention includes a hydrothermal reaction in a Teflon reactor and a heat-preserving oxidation process in a tube furnace. This process is characterized by its simplicity, low equipment requirements, and compliance with green and environmentally friendly principles.

[0029] (2) In the technical solution of the present invention, oxide particles are grown in situ on the surface of the MXene powder after oxidation treatment. The formation of these oxides reduces the conductivity of the MXene material, optimizes impedance matching, and allows more incident electromagnetic waves to enter the interior of the MXene. The electromagnetic wave energy entering the interior of the material is captured by electrons inside the MXene, and then this energy is converted into heat energy and consumed. In addition, the heterogeneous interface formed between the oxide and the MXene, as well as the defects generated during the oxidation process, can further enhance the interface polarization effect and relaxation loss, thus enriching the loss mechanism of the entire system.

[0030] (3) The oxidized MXene powder prepared in this invention exhibits improved microwave absorption performance compared to the unoxidized MXene powder. Specifically, TiVCT... x The lowest reflection loss value of the original powder is -10.98 dB, while after pre-oxidation treatment, the lowest reflection loss value of the material can reach the range of -30 to -45 dB. Attached Figure Description

[0031] Figure 1 For the original TiVCT x SEM images of powders;

[0032] Figure 2 TiVCT after oxidation treatment at 300℃ in Example 1 x SEM photos;

[0033] Figure 3 TiVCT after oxidation treatment at 400℃ in Example 2 x SEM photos;

[0034] Figure 4 TiVCT after oxidation treatment at 500℃ in Example 3 x SEM photos;

[0035] Figure 5 TiVCT after oxidation treatment at 600℃ in Example 4 x SEM photos;

[0036] Figure 6 For the original TiVCT x XRD diffraction pattern of powder;

[0037] Figure 7 TiVCT after oxidation treatment at 300℃ in Example 1 x XRD diffraction pattern;

[0038] Figure 8 TiVCT after oxidation treatment at 400℃ in Example 2 x XRD diffraction pattern;

[0039] Figure 9 TiVCT after oxidation treatment at 500℃ in Example 3 x XRD diffraction pattern;

[0040] Figure 10 TiVCT after oxidation treatment at 600℃ in Example 4 x XRD diffraction pattern;

[0041] Figure 11 For the original TiVCT x Reflection loss diagrams at different thicknesses;

[0042] Figure 12 TiVCT after oxidation treatment at 300℃ in Example 1 x Reflection loss diagrams at different thicknesses;

[0043] Figure 13 TiVCT after oxidation treatment at 400℃ in Example 2 x Reflection loss diagrams at different thicknesses;

[0044] Figure 14 TiVCT after oxidation treatment at 500℃ in Example 3 x Reflection loss diagrams at different thicknesses;

[0045] Figure 15 TiVCT after oxidation treatment at 600℃ in Example 4 x Reflection loss diagrams at different thicknesses. Detailed Implementation

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0047] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0048] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0049] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0050] TiVCT used in the embodiments of the present invention x Specifications: Multilayer TiVCT x Powder, manufacturer: Foshan Xinxi Technology Co., Ltd.

[0051] Example 1

[0052] Step 1: Add 1g TiVCT x The powder was placed in 150ml of deionized water and stirred for 30 minutes. The suspension was then poured into a 250ml Teflon autoclave and subjected to a hydrothermal reaction at 180°C for 4 hours.

[0053] Step 2: Thoroughly wash the obtained suspension with deionized water and ethanol, and centrifuge at 8000 rpm for 10 minutes to obtain oxidized TiVCT. x The product was vacuum dried at 60°C for 12 hours, and the resulting material was labeled as TiVCT. x (O).

[0054] Step 3: Place TiVCT x (O) Heat from room temperature to 300°C in a tube furnace at a heating rate of 5°C / min and hold for 2 hours in an air atmosphere. Then place the resulting mixture in the furnace to cool to room temperature.

[0055] The electromagnetic parameters of the synthesized samples were tested using a vector network analyzer (Agilent E5071C, USA) via the coaxial line method. The samples were melted and mixed with paraffin at a mass ratio of 3:1, then pressed into rings (inner diameter 3.04 mm, outer diameter 7.00 mm) using a custom mold. The electromagnetic parameters (ε) of the absorption rings were measured in the frequency range of 2–18 GHz under the selected test mode. r μ r ).

[0056] Figure 2 TiVCT prepared in Example 1 after oxidation treatment at 300°C x SEM images. (Compared to) Figure 1 Original TiVCT x Compared to other materials, TiVCT after oxidation treatment at 300℃ x The morphology of the particles did not change significantly, and the surface was covered with loose and dispersed oxide particles.

[0057] Figure 7 TiVCT after oxidation treatment at 300℃ in Example 1 xThe XRD diffraction pattern shows the presence of TiO2 diffraction peaks, confirming the TiO2 / TiVCT ratio. x The substances in the MXene complex coexist.

[0058] Figure 12 The TiVCT after oxidation treatment at 300℃ in Example 1 x Reflection loss diagrams at different thicknesses. Figure 11 In comparison, TiVCT after oxidation treatment x The microwave absorption capability is significantly enhanced. As shown in the figure, the minimum reflection loss (RLmin) for materials with a thickness greater than 2 mm all exceed -10 dB (more than 90% of electromagnetic waves are absorbed). When the thickness is 5.5 mm, the composite material has an RLmin of -30.55 dB at 4.17 GHz, and the effective absorption bandwidth of the material is 3.45 GHz, confirming that the sample has excellent microwave absorption performance. It is worth noting that adjusting the sample thickness can change the RLmin value and achieve excellent absorption throughout the 2-18 GHz band. For example, when the thickness is 4 mm, the sample has a reflection loss of -20.46 dB at 5.93 GHz; when the thickness is 2.5 mm, the sample has a reflection loss of -13.21 dB at 10.16 GHz.

[0059] Example 2

[0060] Step 1: Add 1g TiVCT x The powder was placed in 150ml of deionized water and stirred for 30 minutes. The suspension was then poured into a 250ml Teflon autoclave and subjected to a hydrothermal reaction at 180°C for 4 hours.

[0061] Step 2: Thoroughly wash the obtained suspension with deionized water and ethanol, and centrifuge at 8000 rpm for 10 minutes to obtain oxidized TiVCT. x The product was vacuum dried at 60°C for 12 hours, and the resulting material was labeled as TiVCT. x (O).

[0062] Step 3: Place TiVCT x (O) Heat from room temperature to 400°C in a tube furnace at a heating rate of 5°C / min and hold for 2 hours in air atmosphere. Place the resulting mixture in the furnace to cool to room temperature.

[0063] The electromagnetic parameters of the synthesized samples were tested using a vector network analyzer (Agilent E5071C, USA) via the coaxial line method. The samples were melted and mixed with paraffin at a mass ratio of 3:1, then pressed into rings (inner diameter 3.04 mm, outer diameter 7.00 mm) using a custom mold. The electromagnetic parameters (ε) of the absorption rings were measured in the frequency range of 2–18 GHz under the selected test mode. r μ r ).

[0064] Figure 3 TiVCT prepared in Example 2 after oxidation treatment at 400°C x SEM images. (Compared to) Figure 1 In comparison, TiVCT after oxidation treatment at 400℃ x More oxide particles are generated on the surface, and the interlayer spacing is reduced.

[0065] Figure 8 TiVCT after oxidation treatment at 400℃ in Example 2 x The XRD diffraction pattern shows the presence of TiO2 and V2O5 diffraction peaks, confirming that the oxidation degree is increased compared to the sample in Example 1, and the TiO2 / V2O5 ratio is higher. 5 / TiVCT x The substances in the MXene complex coexist.

[0066] Figure 13 The TiVCT after oxidation treatment at 400℃ in Example 2 x The graph shows the reflection loss at different thicknesses. As can be seen, the minimum reflection loss (RLmin) for material thicknesses greater than 2 mm all exceed -10 dB (more than 90% of electromagnetic waves are absorbed). When the matched thickness is 2.5 mm, the effective absorption bandwidth (RLmin ≤ -10 dB) reaches 1.1 GHz. At a thickness of 3 mm, the effective absorption bandwidth is 1.25 GHz. As the sample thickness increases from 4 mm to 5 mm, the effective absorption bandwidth increases from 1.58 GHz to 3.17 GHz. At 4.36 GHz, with a thickness of 5.5 mm, the minimum reflection loss reaches -45.72 dB, and the effective absorption bandwidth is 2.85 GHz, exhibiting ideal reflection loss and effective bandwidth, indicating that the sample has strong electromagnetic wave absorption capability.

[0067] Example 3

[0068] Step 1: Add 1g TiVCT x The powder was placed in 150ml of deionized water and stirred for 30 minutes. The suspension was then poured into a 250ml Teflon autoclave and subjected to a hydrothermal reaction at 180°C for 4 hours.

[0069] Step 2: Thoroughly wash the obtained suspension with deionized water and ethanol, and centrifuge at 8000 rpm for 10 minutes to obtain oxidized TiVCT. x The product was vacuum dried at 60°C for 12 hours, and the resulting material was labeled as TiVCT. x (O).

[0070] Step 3: Place TiVCT x (O) Heat the mixture from room temperature to 500°C in a tube furnace at a heating rate of 5°C / min and hold it in air for 2 hours. Then place the resulting mixture in the furnace to cool to room temperature.

[0071] The electromagnetic parameters of the synthesized samples were tested using a vector network analyzer (Agilent E5071C, USA) via the coaxial line method. The samples were melted and mixed with paraffin at a mass ratio of 3:1, then pressed into rings (inner diameter 3.04 mm, outer diameter 7.00 mm) using a custom mold. The electromagnetic parameters (ε) of the absorption rings were measured in the frequency range of 2–18 GHz under the selected test mode. r μ r ).

[0072] Figure 4 TiVCT prepared in Example 3 after oxidation treatment at 500°C x SEM images. (Compared to) Figure 1 In comparison, TiVCT after oxidation treatment at 500℃ x The layered structure of the particles is still preserved, and the oxide particles are neatly and tightly arranged in TiVCT. x On the surface, the oxide layer is relatively dense.

[0073] Figure 9 TiVCT after oxidation treatment at 500℃ in Example 3 x The XRD diffraction pattern shows the presence of diffraction peaks for TiO2 and V2O5, confirming the TiO2 / V2O5 / TiVCT ratio. x The substances in the MXene complex coexist.

[0074] Figure 14 The TiVCT after oxidation treatment at 500℃ in Example 3 x Reflection loss diagrams at different thicknesses. As shown in the diagrams, the minimum reflection loss (RLmin) for materials thicker than 3 mm all exceed -10 dB (more than 90% of electromagnetic waves are absorbed). This critical thickness is higher than that of samples in Examples 1 and 2, indicating a decrease in absorption performance. This may be due to excessive oxides disrupting the multi-interface morphology, leading to poor impedance matching and enhanced reflection characteristics. However, this performance is comparable to that of unoxidized TiVCT. xCompared to the sample, it still has a significant advantage. When the thickness is 5.5 mm, the composite material has an RLmin of -40.93 dB at 14.15 GHz and an effective absorption bandwidth of 2.61 GHz.

[0075] Example 4

[0076] Step 1: Add 1g TiVCT x The powder was placed in 150ml of deionized water and stirred for 30 minutes. The suspension was then poured into a 250ml Teflon autoclave and subjected to a hydrothermal reaction at 180°C for 4 hours.

[0077] Step 2: Thoroughly wash the obtained suspension with deionized water and ethanol, and centrifuge at 8000 rpm for 10 minutes to obtain oxidized TiVCT. x The product was vacuum dried at 60°C for 12 hours, and the resulting material was labeled as TiVCT. x (O).

[0078] Step 3: Place TiVCT x (O) Heat from room temperature to 600°C in a tube furnace at a heating rate of 5°C / min and hold for 2 hours in an air atmosphere. Place the resulting mixture in the furnace to cool to room temperature.

[0079] The electromagnetic parameters of the synthesized samples were tested using a vector network analyzer (Agilent E5071C, USA) via the coaxial line method. The samples were melted and mixed with paraffin at a mass ratio of 3:1, then pressed into rings (inner diameter 3.04 mm, outer diameter 7.00 mm) using a custom mold. The electromagnetic parameters (ε) of the absorption rings were measured in the frequency range of 2–18 GHz under the selected test mode. r μ r ).

[0080] Figure 5 TiVCT prepared in Example 4 after oxidation treatment at 600℃ x SEM images. (Compared to) Figure 1 In comparison, TiVCT after oxidation treatment at 600℃ x The layered structure completely collapsed, and oxide particles were generated on the lamellae.

[0081] Figure 10 TiVCT after oxidation treatment at 600℃ in Example 4 x The XRD diffraction pattern shows the presence of diffraction peaks for TiO2 and V2O5, confirming the TiO2 / V2O5 / TiVCT ratio. x The substances in the MXene complex coexist.

[0082] Figure 15The TiVCT after oxidation treatment at 600℃ in Example 4 x Reflection loss diagrams at different thicknesses are shown. It can be seen that the sample does not produce effective electromagnetic wave absorption up to a thickness of 4.5 mm. At a thickness of 5.5 mm, the minimum loss value of -45.52 dB is obtained at 15.11 GHz, with an effective frequency absorption range of 2.23 GHz. The decrease in absorption performance may be due to excessive oxidation damaging the TiVCT. x The layered structure leads to the deterioration of chemical composition, which in turn significantly reduces the interfacial polarization loss and conductivity loss of the material, eliminates the multiple reflection and scattering channels of electromagnetic waves, and destroys the impedance matching condition, ultimately resulting in a significant decrease in the absorption performance.

[0083] Comparative Example 1

[0084] Unoxidized TiVCT x powder

[0085] Using a vector network analyzer (Agilent E5071C, USA), the coaxial line method was employed to analyze the unoxidized TiVCT. x The electromagnetic parameters of the powder were tested. The sample was mixed with paraffin wax at a mass ratio of 3:1 and melted, then pressed into a ring using a custom mold (inner diameter 3.04 mm, outer diameter 7.00 mm). The electromagnetic parameters (ε) of the absorption ring were measured in the frequency range of 2–18 GHz under the selected test mode. r μ r ).

[0086] Figure 1 For the original TiVCT x SEM images of powder, raw TiVCT x The particles exhibit a smooth surface and a distinct accordion-like multi-layered structure.

[0087] Figure 6 TiVCT without oxidation treatment x The XRD diffraction pattern shows that only TiVCT is present in the image. x The diffraction peaks.

[0088] Figure 11 TiVCT without oxidation treatment x Reflection loss maps at different thicknesses. Original TiVCT. x The microwave absorption characteristics are optimal at a thickness of 1 mm, with a minimum reflection loss of -10.98 dB at 13.82 GHz. At other thicknesses, the reflection loss values ​​do not exceed -10 dB, indicating that the sample has poor electromagnetic wave absorption capability.

[0089] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

[0090] It should be particularly noted that the various embodiments listed in this specification and accompanying drawings are intended to illustrate the technical solutions and advantages of the present invention, and not to limit the scope of protection of the present invention. Without departing from the core ideas and technical effects of the present invention, those skilled in the art can make any form of improvement, substitution, combination, or modification to the structural arrangement, process parameters, material selection, control logic, etc., of the described embodiments; any obvious changes based on the same concept should be considered equivalent solutions of the present invention and should be included within the scope of protection defined by the claims of the present invention. The actual scope of protection of the present invention is determined by the appended claims and should be correctly understood in conjunction with the specification and accompanying drawings.

Claims

1. A method for improving the wave-absorbing performance of MXene material by two-step partial oxidation, characterized in that, The method comprises the following steps: S1, mixing MXene powder with deionized water and then performing hydrothermal reaction to obtain a preliminarily oxidized MXene suspension; S2, washing, centrifuging and drying the suspension obtained in S1 to obtain a preliminarily oxidized MXene solid powder; S3, performing heat treatment on the powder obtained in S2 in an air atmosphere, the heat treatment temperature is 300-600 DEG C, the obtained mixture is cooled to room temperature with the furnace, and a composite wave-absorbing material is obtained; The MXene is TiVCTx. After the heat treatment in S3, the TiVCTx matrix retains a two-dimensional layered structure, and TiO2 and V2O5 nanoparticles generated by partial oxidation of TiVCTx are in-situ grown on the surface of the TiVCTx matrix.

2. The method for improving the wave-absorbing performance of MXene material by two-step partial oxidation according to claim 1, characterized in that, The temperature of the hydrothermal reaction in S1 is 140-220 DEG C, and the reaction time is 2-6 hours; the heating rate of the heat treatment in S3 is 2-10 DEG C / min, and the holding time is 1-4 hours; the heat treatment temperature in S3 is 300-500 DEG C.

3. The method for improving the wave-absorbing performance of MXene material by two-step partial oxidation according to claim 2, characterized in that, The temperature of the hydrothermal reaction in S1 is 180 DEG C, and the reaction time is 4 hours.

4. The method for improving the wave-absorbing performance of MXene material by two-step partial oxidation according to claim 2, characterized in that, The heating rate of the heat treatment in S3 is 5 DEG C / min, and the holding time is 2 hours.

5. The method of claim 2, wherein the two-step partial oxidation enhances the wave-absorbing performance of the MXene material. The heat treatment temperature in S3 is 400 DEG C.

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