FeTe1-xOx electromagnetic wave-absorbing material and preparation method and application thereof

Abstract

The invention provides a FeTe1-xOx electromagnetic wave-absorbing material as well as a preparation method and application thereof. The method comprises the following steps: S1, placing a quartz boat containing Te nano powder in an upstream temperature zone of a tubular furnace; s2, placing a certain amount of FeCl2 powder in another quartz boat, and placing the quartz boat in a central temperature zone of a tubular furnace; s3, respectively heating the temperature zones in which the quartz boat in the S1 and the other quartz boat in the S2 to reaction temperatures, keeping the temperature until the FeCl2 powder and the Te powder fully react, and preparing two-dimensional FeTe nanosheets in batches by utilizing a chemical vapor deposition technology; and S4, placing the two-dimensional FeTe nanosheets obtained in S3 in an oxygen plasma treatment instrument, and preparing the oxygen-doped two-dimensional FeTe < 1-x > Ox electromagnetic wave-absorbing material with tellurium vacancies with different concentrations by regulating and controlling performance parameters of the plasma treatment instrument. The product provided by the invention can activate basal plane inert sites of FeTe, and effectively optimizes dielectric relaxation loss, thereby realizing improvement of electromagnetic wave-absorbing performance.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic protection materials and relates to two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping. 1- x O x Electromagnetic absorbing material, preparation method and application thereof. Background Art

[0002] Due to the development of electronic communication equipment and technology, electromagnetic pollution is increasing and posing a threat to national security and human health. Therefore, there is an urgent need for electromagnetic absorbing materials that can effectively mitigate electromagnetic radiation. As a typical representative of transition metal chalcogenides, two-dimensional transition metal tellurides have aroused widespread research interest in related fields such as electronic devices and energy due to their high specific surface area and diverse physicochemical properties. Especially in the field of electromagnetic protection, transition metal tellurides show great potential for electromagnetic protection due to their unique phase change characteristics, spin polarization, ferromagnetism and topological state. For example, Chinese invention patent CN 116875958 B publicly reported a highly efficient Cr5Te8@expanded graphite heterojunction electromagnetic absorbing material.

[0003] In addition to the method of building a heterogeneous interface with external elements to enhance the interface polarization loss and then induce the optimal dielectric loss, regulating dipole polarization is another key method to optimize the absorption performance by adjusting the intrinsic properties of the material. Based on the existing technology, there is still a lack of effective strategies to enhance the dipole polarization of transition metal tellurides. Therefore, how to provide a simple and effective dipole polarization promotion process based on the intrinsic components of transition metal tellurides in order to further improve the electromagnetic absorption performance of two-dimensional transition metal tellurides has become the main problem faced at this stage. Summary of the invention

[0004] In view of this, the present invention provides a two-dimensional FeTe with different tellurium vacancies and oxygen doping concentrations. 1-x O x Preparation method of electromagnetic wave absorbing materials. An effective double defect model based on electronic polarization relaxation was established on iron telluride (FeTe) flakes by one-step O2 plasma treatment. Tellurium vacancies and oxygen doping activated the basal inert sites of FeTe, effectively optimizing the dielectric relaxation loss, thereby achieving improved electromagnetic wave absorbing performance.

[0005] Specifically, on one hand, the present invention provides a method for preparing an electromagnetic absorbing material, which comprises the following steps: S1: placing a quartz boat containing Te nanopowder in an upstream temperature zone of a tube furnace; S2: placing a certain amount of FeCl2 powder in another quartz boat, and placing it in the central temperature zone of the tube furnace; S3: raising the temperature zones where the quartz boat described in S1 and the other quartz boat described in S2 are located to the reaction temperature respectively, and keeping the temperature until the FeCl2 powder and the Te powder are fully reacted, and using chemical vapor deposition technology to batch prepare two-dimensional FeTe nanosheets; S4: placing the two-dimensional FeTe nanosheets obtained in S3 in an oxygen plasma treatment instrument, and preparing two-dimensional FeTe nanosheets with different concentrations of tellurium vacancies and oxygen doping by adjusting the performance parameters of the plasma treatment instrument. 1-x O x Electromagnetic absorbing materials.

[0006] Optionally, the reaction temperature in the upstream temperature zone of S1 is 450-550°C.

[0007] Optionally, the reaction temperature in the central temperature zone of S2 is 590-670°C.

[0008] Optionally, the holding time in S3 is adjusted according to the input amount of the reactants. When 1-100 parts by mass of FeCl2 powder is taken to participate in the reaction, the holding time ranges from 10 to 60 minutes.

[0009] Optionally, the performance parameters of the oxygen plasma treatment instrument in S4 specifically include: one or more of processing power, processing time, gas flow rate, and vacuum degree.

[0010] Optionally, the adjustment range of the processing power is 60-150W; the adjustment range of the processing time is 20-60min; the adjustment range of the oxygen gas flow rate is 150-500sccm; and the adjustment range of the vacuum degree is 10-90Pa.

[0011] Preferably, the processing power is 70W; the processing time is 40min; the gas flow rate is 200sccm; and the vacuum degree is 50Pa.

[0012] Alternatively, the two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping is obtained as described in S4 1-x O x Electromagnetic absorbing material, defect level FeTe 1-x O x -1~FeTe 1-x O x -4.

[0013] The second aspect of the present invention provides a two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping prepared according to the preparation method.1-x O x Electromagnetic absorbing materials.

[0014] The third aspect of the present invention provides a two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping. 1-x O x Application of electromagnetic absorbing materials in the field of electromagnetic protection.

[0015] The beneficial effects of the present invention are:

[0016] (1) Double defect engineering achieved through oxygen plasma intentionally activates the inert sites on the basal plane of the two-dimensional FeTe nanosheets, further enhancing their space charge polarization and dipole polarization activities.

[0017] (2) The dual polarization centers formed by Te vacancies and O doping lead to charge redistribution and increased dipole site density, which enhances dielectric polarization relaxation and significantly improves the electromagnetic wave absorption performance of the product.

[0018] Therefore, the present invention provides a two-dimensional FeTe with different tellurium vacancies and oxygen doping concentrations. 1-x O x Electromagnetic absorbing materials have potential application prospects in the field of electromagnetic protection.

[0019] In addition, additional advantages, objects, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures and method steps specifically pointed out in the written description and claims and the accompanying drawings.

[0020] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention.

[0022] Figure 1 The two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping in the embodiment of the present invention is shown in FIG. 1-x O x Schematic diagram of the steps of the preparation method of electromagnetic absorbing material;

[0023] Figure 2 FeTe with double defect sites obtained by oxygen plasma treatment of FeTe 1-x Ox Atomic diagram

[0024] Figure 3 The XPS spectra of Fe 2p of Examples 1-4 and Comparative Examples of the present invention;

[0025] Figure 4 The electron paramagnetic resonance spectra of Examples 1-4 and Comparative Examples of the present invention are shown in FIG.

[0026] Figure 5 FeTe of Example 2 of the present invention 1-x O x 3D reflection loss results of absorbing materials in the 2-18GHz frequency range;

[0027] Figure 6 FeTe of Example 3 of the present invention 1-x O x 3D reflection loss results of absorbing materials in the 2-18GHz frequency range;

[0028] Figure 7 This is a 3D reflection loss result diagram of the FeTe absorbing material of the comparative example of the present invention in the frequency range of 2-18 GHz;

[0029] Figure 8 FeTe of Example 3 of the present invention 1-x O x 3D radar reflection signal diagram of absorbing materials in the radar band. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention. It should also be noted that, in order to avoid blurring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0031] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0032] Combined with Figure 1As shown, an embodiment of the present invention provides a method for preparing an electromagnetic absorbing material, which comprises the following steps: S1: placing a quartz boat containing Te nanopowder in the upstream temperature zone of a tube furnace; S2: placing a certain amount of FeCl2 powder in another quartz boat, and placing it in the central temperature zone of the tube furnace; S3: raising the temperature zones of the S1 quartz boat and the S2 quartz boat to the reaction temperature, respectively, and keeping them warm until the FeCl2 powder and the Te powder react fully, and using chemical vapor deposition technology to prepare two-dimensional FeTe nanosheets in batches; S4: placing the two-dimensional FeTe nanosheets obtained in S3 in an oxygen plasma treatment instrument, and preparing two-dimensional FeTe nanosheets with different concentrations of tellurium vacancies and oxygen doping by adjusting the performance parameters of the oxygen plasma treatment instrument, such as the duration of the action, the oxygen gas flow rate, the oxygen plasma action power, etc. 1-x O x Electromagnetic absorbing materials. Figure 2 As shown, FeTe with double defect sites is obtained by oxygen plasma treatment 1-x O x Atomic diagram

[0033] Optionally, the reaction temperature in the upstream temperature zone of S1 is 450-550°C.

[0034] Optionally, the reaction temperature in the central temperature zone of S2 is 590-670°C.

[0035] Optionally, the holding time in S3 is adjusted according to the input amount of the reactants. When 1-100 parts by mass of FeCl2 powder is taken to participate in the reaction, the holding time ranges from 10 to 60 minutes.

[0036] Optionally, the performance parameters of the plasma processing instrument in S4 specifically include: one or more of processing power, processing time, gas flow rate, and vacuum degree.

[0037] Optionally, the adjustment range of the processing power is 60-150W; the adjustment range of the processing time is 20-60min; the adjustment range of the oxygen gas flow rate is 150-500sccm; and the adjustment range of the vacuum degree is 10-90Pa.

[0038] Preferably, the processing power is 70W; the processing time is 40min; the gas flow rate is 200sccm; and the vacuum degree is 50Pa.

[0039] Specifically, the determination of the preferred parameters in the performance parameters of the plasma treatment instrument is based on the physical properties of FeTe in this experiment and the advantages and disadvantages of the wave absorption performance in the experimental results. On the one hand, due to the strong interaction between Fe atoms and Te atoms, the parameters such as the time and power of the oxygen plasma action will not be at too low a level. In addition, the concentration of double defects is crucial to the wave absorption performance. The dual polarization centers formed by Te vacancies and O doping lead to charge redistribution and increased dipole site density, which enhances dielectric polarization relaxation, thereby significantly improving the electromagnetic wave absorption performance of the product.

[0040] Alternatively, two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping can be obtained in S4. 1-x O x Electromagnetic absorbing material, defect level FeTe 1-x O x -1~FeTe 1-x O x -4.

[0041] Specifically, during the oxygen plasma treatment process, oxygen molecules collide, dissociate, ionize and recombine under the impact of high-speed electrons and the action of the photoelectric effect, thereby forming oxygen plasma. There are many kinds of particles in oxygen plasma, mainly positive ions, negative ions, O + , O 2+ , O - , O 2- , O 3- , ground state particles, excited state particles, etc. At the same time, these active groups can also recombine into new substances. These high-energy particles will bombard the surface of the material, causing the chemical bonds to break, thereby removing some elements. In addition, a large number of oxygen active groups will combine with the elements exposed on the surface of the material to achieve oxygen doping.

[0042] Combined with the above analysis, by controlling the parameters such as the power, time, and oxygen flow rate of the plasma treatment instrument, the material surface bombarded to different degrees, that is, FeTe with different degrees of defects, can be obtained. 1-x O x Obviously, too low defect concentration (FeTe 1-x O x -1) caused by low dipole polarization loss, the improvement of wave absorption performance is not obvious; too high defect concentration (FeTe 1- x O x -4), which will seriously damage the surface of the material and even cause the collapse of the structure, damage the basic physical properties of the material, and lead to a decrease in the absorption performance. 1-x O x -2,FeTe 1-x Ox -3), while retaining the original good structure and intrinsic properties, active sites are injected into the surface of FeTe material, enhancing its space charge polarization and dipole polarization relaxation, thereby improving the electromagnetic wave absorption ability.

[0043] A second aspect of an embodiment of the present invention provides a two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping prepared according to a preparation method 1-x O x Electromagnetic absorbing materials.

[0044] A third aspect of an embodiment of the present invention provides a two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping. 1-x O x Application of electromagnetic absorbing materials in the field of electromagnetic protection.

[0045] The present invention is further described in detail below through specific implementation methods and related comparative examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0046] Example 1

[0047] Place the quartz boat containing Te powder in the upstream temperature zone of the tube furnace, then place the FeCl2 crystal powder in another quartz boat and place it in the central temperature zone of the tube furnace, raise the above temperature zones to the reaction temperature of 500℃ and 650℃ respectively, and keep them warm for 20 minutes. After the reaction is completed, open the furnace cover and cool it naturally to room temperature. Use chemical vapor deposition technology to prepare two-dimensional FeTe nanosheets in batches. Subsequently, place the obtained two-dimensional FeTe nanosheets in an oxygen plasma treatment machine, control the power of the oxygen plasma treatment machine to 60W, the vacuum degree to 60Pa, the treatment time to 20 minutes, and the gas flow rate to 150sccm. Preparation of FeTe 1-x O x -1Electromagnetic absorbing materials.

[0048] Example 2

[0049] Place the quartz boat containing Te powder in the upstream temperature zone of the tube furnace, then place the FeCl2 crystal powder in another quartz boat and place it in the central temperature zone of the tube furnace, raise the above temperature zones to the reaction temperature of 500℃ and 620℃ respectively, and keep them warm for 30 minutes. After the reaction is completed, open the furnace cover and cool it naturally to room temperature. Use chemical vapor deposition technology to prepare two-dimensional FeTe nanosheets in batches. Subsequently, place the obtained two-dimensional FeTe nanosheets in an oxygen plasma treatment machine, control the power of the oxygen plasma treatment machine to 70W, the vacuum degree to 70Pa, the treatment time to 30 minutes, and the gas flow rate to 300sccm. Preparation of FeTe 1-x O x -2Electromagnetic absorbing materials.

[0050] Example 3

[0051] Place the quartz boat containing Te powder in the upstream temperature zone of the tube furnace, then place the FeCl2 crystal powder in another quartz boat and place it in the central temperature zone of the tube furnace, raise the above temperature zones to the reaction temperature of 500℃ and 630℃ respectively, and keep them warm for 40 minutes. After the reaction is completed, open the furnace cover and cool it naturally to room temperature. Use chemical vapor deposition technology to prepare two-dimensional FeTe nanosheets in batches. Subsequently, place the obtained two-dimensional FeTe nanosheets in an oxygen plasma treatment machine, control the power of the oxygen plasma treatment machine to 70W, the vacuum degree to 50Pa, the treatment time to 40 minutes, and the gas flow rate to 200sccm. Preparation of FeTe 1-x O x -3Electromagnetic absorbing materials.

[0052] Example 4

[0053] Place the quartz boat containing Te powder in the upstream temperature zone of the tube furnace, then place the FeCl2 crystal powder in another quartz boat and place it in the central temperature zone of the tube furnace, raise the above temperature zones to the reaction temperature of 500℃ and 630℃ respectively, and keep them warm for 40 minutes. After the reaction is completed, open the furnace cover and cool it naturally to room temperature. Use chemical vapor deposition technology to prepare two-dimensional FeTe nanosheets in batches. Subsequently, place the obtained two-dimensional FeTe nanosheets in an oxygen plasma treatment machine, control the power of the oxygen plasma treatment machine to 100W, the vacuum degree to 80Pa, the treatment time to 60 minutes, and the gas flow rate to 400sccm. Preparation of FeTe 1-x O x -4Electromagnetic absorbing materials.

[0054] Comparative Example

[0055] The quartz boat containing Te powder was placed in the upstream temperature zone of the tube furnace, and then the FeCl2 crystal powder was placed in another quartz boat and placed in the central temperature zone of the tube furnace. The above temperature zones were raised to the reaction temperature of 500℃ and 630℃ respectively, and kept warm for 40 minutes. After the reaction was completed, the furnace cover was opened and cooled naturally to room temperature. Two-dimensional FeTe nanosheets were prepared in batches using chemical vapor deposition technology. They were directly used for electromagnetic absorption test without oxygen plasma treatment.

[0056] Table 1. FeTe with different defect levels 1-x O x Comparison of wave absorption performance

[0057]

[0058] from Figure 3It can be seen that after oxygen plasma treatment, the binding energy of Fe 2p shows an obvious blue shift, resulting in an increase in the work function of FeTe, implying the implantation of oxygen atoms into FeTe. Figure 4 It can be seen from the electron paramagnetic resonance spectrum that compared with the original FeTe, FeTe 1-x O x The degree of defects gradually increases. Figure 5-Figure 7 It can be concluded from the absorption performance results that the FeTe with different defect levels prepared by the present invention 1-x O x It has better wave absorption performance than the original FeTe and has excellent radar reflection cross-sectional area reduction capability ( Figure 8 ). This is due to the effective double defect model based on electronic polarization relaxation constructed by oxygen plasma treatment. Te vacancies and O doping activate the basal inert sites of FeTe, effectively optimizing the dielectric relaxation loss, thereby achieving an improvement in electromagnetic absorption performance.

[0059] The present invention modifies the intrinsic components of transition metal tellurides through defect engineering to customize the local electronic structure, thereby effectively promoting dipole polarization. Oxygen plasma technology, as a unique defect nanofabrication tool, can play two different roles based on the intrinsic oxidative nature of active oxygen ions: one is to remove surface components to produce elemental vacancies; the other is to introduce new units, such as p-type oxygen doping; its dual functions enable dual defect engineering modulation to be achieved using a single processing step, that is, to simultaneously promote and maintain self-organization and self-assembly.

[0060] In addition, the FeTe prepared in the present invention has different defect concentrations. 1-x O x The preparation method is simple, easy to operate, has a short production cycle, and has the potential for large-scale production.

[0061] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0062] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0063] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A FeTe 1-x O x The method for preparing an electromagnetic absorbing material is characterized in that: The method comprises the following steps: S1: placing the quartz boat containing Te nanopowder in the upstream temperature zone of the tube furnace; S2: Place a certain amount of FeCl2 powder in another quartz boat and place it in the central temperature zone of the tube furnace; S3: Raise the temperature zones of the quartz boat in S1 and the other quartz boat in S2 to the reaction temperature respectively, and keep the temperature until the FeCl2 powder and the Te powder react fully, and prepare two-dimensional FeTe nanosheets in batches by chemical vapor deposition technology; S4: The two-dimensional FeTe nanosheets obtained in S3 are placed in an oxygen plasma treatment instrument, and two-dimensional FeTe nanosheets with different concentrations of tellurium vacancies and oxygen doping are prepared by adjusting the performance parameters of the plasma treatment instrument. 1-x O x Electromagnetic absorbing materials.

2. The method according to claim 1, characterized in that: The reaction temperature in the upstream temperature zone of S1 is 450-550°C.

3. The method according to claim 1, characterized in that: The reaction temperature in the central temperature zone of S2 is 590-670°C.

4. The method according to claim 2 or 3, characterized in that: The holding time in S3 is adjusted according to the input amount of the reactants. When 1-100 parts by mass of FeCl2 powder is taken to participate in the reaction, the holding time ranges from 10 to 60 minutes.

5. The method according to claim 1, characterized in that The performance parameters of the oxygen plasma treatment instrument in S4 specifically include: one or more of processing power, processing time, gas flow rate, and vacuum degree.

6. The method according to claim 5, characterized in that: The adjustment range of the processing power is 60-150W; the adjustment range of the processing time is 20-60min; the adjustment range of the oxygen gas flow rate is 150-500sccm; and the adjustment range of the vacuum degree is 10-90Pa.

7. The method according to claim 6, characterized in that: Preferably, the processing power is 70W; the processing time is 40min; the gas flow rate is 200sccm; and the vacuum degree is 50Pa.

8. The method according to claim 1, characterized in that: The two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping as described in S4 1-x O x Electromagnetic absorbing material, defect level FeTe 1-x O x -1~FeTe 1-x O x -4.

9. A two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping prepared by the preparation method according to any one of claims 1 to 8 1-x O x Electromagnetic absorbing materials.

10. A two-dimensional FeTe with different concentrations of tellurium vacancies and oxygen doping according to claim 9. 1-x O x Application of electromagnetic absorbing materials in the field of electromagnetic protection.

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