Preparation method of micron-flower-shaped 1T / 2H phase molybdenum disulfide wave-absorbing material
By preparing micron-sized flower-shaped 1T/2H phase molybdenum disulfide absorbing materials, the problem of unclear dielectric modulation of transition metal sulfides was solved, and strong absorption performance with a wide bandwidth was achieved, making it suitable for electromagnetic wave absorbing materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2024-01-17
- Publication Date
- 2026-07-24
AI Technical Summary
The dielectric modulation mechanism of transition metal sulfide microwave absorbing materials is unclear, resulting in a narrow electromagnetic wave absorption bandwidth and weak absorption intensity.
A method for preparing micron-sized flower-shaped 1T/2H phase molybdenum disulfide microwave absorbing material was adopted. By controlling various phase transformations of MoS2, its dielectric properties and loss mechanism were adjusted. By utilizing the high conductivity of the 1T phase and the stability of the 2H phase, impedance matching and loss enhancement were achieved.
The prepared material has wide-bandwidth, strong absorption, and thin-matched-thickness absorption properties, with a maximum reflection loss of -59.8dB and an effective bandwidth of 6.8GHz (11.2-18GHz), making it suitable for electromagnetic wave absorbing materials.
Smart Images
Figure CN117963987B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite material preparation for electromagnetic wave absorption and electromagnetic pollution prevention. Background Technology
[0002] The research and development of radar-absorbing materials is crucial for advancing radar stealth technology. Radar-absorbing materials effectively absorb incident electromagnetic waves and convert electromagnetic energy into heat. In the increasingly important fields of radar stealth and electromagnetic compatibility, the role and importance of radar-absorbing materials are paramount, making the research and development of high-performance radar-absorbing materials a major issue in the military fields of various countries. Beyond military applications, radar-absorbing materials play an indispensable role in 5G networks, satellite communications, artificial intelligence, wearable electronics, autonomous vehicles and aircraft, medical protection, and electromagnetic pollution control. While the development of wireless technology has improved our quality of life, it has also inevitably caused serious electromagnetic pollution. On the one hand, it negatively impacts human health, especially cardiovascular health; on the other hand, it causes electromagnetic interference to electronic devices, leading to signal loss or interruption. This limits the performance of advanced electronic products, causing significant economic losses. For example, wireless charging technology and autonomous driving technology are severely constrained by electromagnetic interference, hindering their rapid development. Solving these problems depends on the rapid development and key breakthroughs in radar-absorbing materials. Summary of the Invention
[0003] This invention aims to address the technical problems of unclear dielectric modulation mechanism, narrow electromagnetic wave absorption bandwidth, and weak absorption intensity in transition metal sulfide microwave absorbing materials, and provides a method for preparing a micron-sized flower-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material.
[0004] A method for preparing a micron-sized flower-like 1T / 2H phase molybdenum disulfide microwave absorbing material, comprising the following steps:
[0005] Step 1: Dissolve ammonium molybdate tetrahydrate and thiourea in deionized water, stir to dissolve, and obtain a light blue clear reaction solution;
[0006] Step 2: Transfer the light blue clear reaction solution obtained in Step 1 to a hydrothermal reactor lined with polytetrafluoroethylene, heat it in a high-temperature drying oven with a forced airflow to carry out the hydrothermal reaction, cool it to room temperature after the reaction is completed, wash it by centrifugation with deionized water and anhydrous ethanol in sequence, and dry it to obtain 1T-MoS2 powder.
[0007] Step 3: Grind the 1T-MoS2 powder obtained in Step 2 thoroughly, place it in a high-temperature drying oven for heating and annealing, and the resulting powder is the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material, thus completing the preparation.
[0008] This invention utilizes the existence of multiple phases in MoS2, highlighting its multiphase nature. Optimizing the microwave absorption performance of pure MoS2 through phase engineering holds broad research potential. 1T-MoS2 is metastable under normal conditions, while 2H-MoS2 is stable. This greatly facilitates the quantitative adjustment of the 1T / 2H phase ratio to regulate its dielectric properties. The conductivity of the 1T phase is 10 times that of the 2H phase. 7 More than double. During the MoS2 phase transition, a gradual transition will occur from a strong-loss, weak-matching phase to a weak-loss, strong-matching phase, which will introduce a large number of defects and two-phase interfaces. While optimizing impedance matching, more loss mechanisms are introduced, such as dipole polarization, interface polarization, and defect-induced polarization losses, to enhance absorption performance.
[0009] The beneficial effects of this invention are:
[0010] I. The composite material is synthesized using commercial materials. The synthesis process does not require complex equipment or harsh experimental environments. The preparation process of this invention is low-cost, simple, and can be mass-produced.
[0011] II. A novel method for preparing a micron-sized flower-like 1T / 2H phase molybdenum disulfide microwave absorbing composite material is provided.
[0012] Third, the material prepared by the method of this invention is a broadband, strong-absorbing, and thin-matched microwave absorbing material. When the matching thickness is 2.68 mm, the maximum reflection loss is -59.8 dB, and when the matching thickness is 2.48 mm, the effective bandwidth is 6.8 GHz (11.2-18 GHz). This invention provides a good theoretical foundation for the development of molybdenum disulfide-based materials and offers good design ideas for the study of various loss mechanisms in electromagnetic wave absorbing materials.
[0013] IV. The micron-sized flower-like 1T / 2H phase molybdenum disulfide microwave absorbing material prepared by the method of this invention contains a 1T phase, which is a highly conductive phase with a strong loss effect on electromagnetic waves and is also a thermodynamically metastable phase. Through appropriate heat treatment, the metastable 1T phase gradually transforms into the stable 2H phase, adjusting the dielectric constant of the system, reducing impedance differences, and adjusting the loss capability to achieve a balance between impedance matching and loss capability. Furthermore, the disruption of the complete 1T phase structure introduces more S vacancies and heterogeneous interfaces, enhancing defect-induced dipole polarization and interfacial polarization losses. In summary, by adjusting the content of the MoS2 1T / 2H phase, good impedance matching is achieved while enhancing dielectric properties, thereby obtaining significant electromagnetic wave absorption performance.
[0014] The micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared by the method of this invention can be applied in the field of electromagnetic wave absorbing materials. Attached Figure Description
[0015] Figure 1 These are DSC diagrams of 1T-MoS2 powder obtained in step two of Example 1 at different heating rates;
[0016] Figure 2 The image shows the XRD patterns of the micron-shaped 1T / 2H phase molybdenum disulfide prepared in Example 1, compared with 1T-MoS2 and 2H-MoS2.
[0017] Figure 3 Raman diagrams of the micron-shaped 1T / 2H phase molybdenum disulfide prepared in Example 1 and the comparison samples of 1T-MoS2 and 2H-MoS2;
[0018] Figure 4 The image shows the XPS spectrum (Mo 3d sub-spectrum) of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1.
[0019] Figure 5 The image shows the XPS spectrum (S2p sub-spectrum) of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1.
[0020] Figure 6 The image shows the XPS spectrum (Mo 3d spectrum) of the 1T-MoS2 control sample prepared in Example 1.
[0021] Figure 7 The image shows the XPS spectrum (Mo 3d spectrum) of the 2H-MoS2 control sample prepared in Example 1.
[0022] Figure 8 This is a SEM image of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1;
[0023] Figure 9 This is a SEM image of the 1T-MoS2 control sample prepared in Example 1;
[0024] Figure 10 This is a SEM image of the 2H-MoS2 control sample prepared in Example 1;
[0025] Figure 11 This is an HRTEM image of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1;
[0026] Figure 12 This is a graph showing the electromagnetic parameter test results of the 1T-MoS2 control sample prepared in Example 1.
[0027] Figure 13 This is a reflection loss test curve of the 1T-MoS2 control sample prepared in Example 1;
[0028] Figure 14 This is a graph showing the electromagnetic parameter test results of the 2H-MoS2 control sample prepared in Example 1.
[0029] Figure 15 This is a reflection loss test curve of the 2H-MoS2 control sample prepared in Example 1;
[0030] Figure 16 This is a graph showing the electromagnetic parameter test curves of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1;
[0031] Figure 17 This is a reflection loss test curve of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1. Detailed Implementation
[0032] Specific Implementation Method 1: This implementation method describes a method for preparing a micron-sized flower-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material, which is carried out according to the following steps:
[0033] Step 1: Dissolve ammonium molybdate tetrahydrate and thiourea in deionized water, stir to dissolve, and obtain a light blue clear reaction solution;
[0034] Step 2: Transfer the light blue clear reaction solution obtained in Step 1 to a hydrothermal reactor lined with polytetrafluoroethylene, heat it in a high-temperature drying oven with a forced airflow to carry out the hydrothermal reaction, cool it to room temperature after the reaction is completed, wash it by centrifugation with deionized water and anhydrous ethanol in sequence, and dry it to obtain 1T-MoS2 powder.
[0035] Step 3: Grind the 1T-MoS2 powder obtained in Step 2 thoroughly, place it in a high-temperature drying oven for heating and annealing, and the resulting powder is the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material, thus completing the preparation.
[0036] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the molar ratio of Mo to S in the reaction solution described in step one is 1:5, and the concentration of Mo is 0.1–0.3 mol / L. Everything else is the same as in Specific Implementation Method One.
[0037] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: in step one, the stirring time is controlled to be 30-40 minutes, and the stirring speed is 300-500 rpm. Everything else is the same as in Specific Implementation Method One or Two.
[0038] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the hydrothermal reaction described in step two is controlled at a heating temperature of 160–200°C, and the holding time is 12–24 hours. Everything else is the same as in Specific Implementation Methods One to Three.
[0039] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the washing process described in step two involves washing with deionized water 2 to 3 times, followed by washing with anhydrous ethanol 2 to 3 times. Everything else is the same as in Specific Implementation Methods One to Four.
[0040] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the washing process described in step two employs centrifugal washing, with the centrifugal speed controlled at 6000–8000 rpm. Everything else is the same as in Specific Implementation Methods One to Five.
[0041] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that: after washing in step two, the product is air-dried in a cool, dark place for 12-16 hours. Everything else is the same as in Specific Implementation Methods One to Six.
[0042] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the powder described in step three is ground to 325-400 mesh. Everything else is the same as in Specific Implementation Methods One to Seven.
[0043] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the heating annealing temperature in step three is 140–240°C. Everything else is the same as in Specific Implementation Methods One to Eight.
[0044] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that the heating and annealing treatment time in step three is 5 to 120 minutes. Everything else is the same as in Specific Implementation Methods One to Nine.
[0045] The scope of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.
[0046] Example 1:
[0047] This embodiment describes a method for preparing a micron-sized, flower-like 1T / 2H phase molybdenum disulfide microwave absorbing material, which is carried out according to the following steps:
[0048] Step 1: Measure 60 mL of deionized water into a 250 mL beaker, stir magnetically at 300 rpm, weigh 2.119 g of ammonium molybdate tetrahydrate and 4.567 g of thiourea, dissolve them in the deionized water, and keep the system stirred for 30 min to form a light blue clear reaction solution.
[0049] Step 2: Transfer the light blue clear solution obtained in Step 1 to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor. Heat it to 200 °C in a high-temperature drying oven and maintain the temperature for 18 h to carry out the hydrothermal reaction. After the reaction is completed, cool it to room temperature, centrifuge and wash the obtained black powder. Wash it three times each with deionized water and anhydrous ethanol, and then dry it at room temperature for 12 h to obtain 1T-MoS2 powder.
[0050] Step 3: Grind the 1T-MoS2 powder obtained in Step 2 thoroughly, put it into a stainless steel crucible, and place it in a high-temperature drying oven for heating and annealing. Control the heating temperature to 185℃, the heating time to 60min, and the heating atmosphere to be air. The resulting black powder is the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material, thus completing the preparation.
[0051] Preparation of test samples:
[0052] The micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 was placed in paraffin at a mass ratio of 55%, heated to 65°C, and held for 15 minutes. The sample was then placed in a mold to obtain a coaxial ring with an outer diameter of 7 mm, an inner diameter of 3.04 mm, and a height of 2 mm.
[0053] Comparison of 1T-MoS2 and 2H-MoS2 samples:
[0054] The black 1T-MoS2 powder obtained in step two of Example 1 was carefully ground, placed in a stainless steel crucible, and heated in a high-temperature drying oven with forced air. The heating temperature was controlled at 220°C, the heating time was 60 minutes, and the heating atmosphere was air, resulting in a black powder, which became the 2H-MoS2 control sample. The black powder obtained in step two of Example 1, after careful grinding, did not undergo a heating process and became the 1T-MoS2 control sample.
[0055] The same test samples as in Example 1 were prepared for the 1T-MoS2 and 2H-MoS2 comparison samples.
[0056] The micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 was tested with 1T-MoS2 and 2H-MoS2 control samples.
[0057] Figure 1 The images show DSC diagrams of the 1T-MoS2 powder obtained in step two of Example 1 at different heating rates. It can be seen that the transformation from the 1T phase to the 2H phase is relatively slow and requires a certain amount of time, occurring in the temperature range of 160–270°C.
[0058] Figure 2The images show the XRD patterns of the micron-shaped 1T / 2H phase molybdenum disulfide prepared in Example 1, and the comparative samples of 1T-MoS2 and 2H-MoS2. The 1T-MoS2 comparative sample has a sharp diffraction peak at 9.4°, corresponding to the (002) crystal plane of the 1T-MoS2 comparative sample; the diffraction peak of the micron-shaped 1T / 2H phase molybdenum disulfide at 9.4° weakens, and the diffraction peak of the 2H phase (002) crystal plane appears at 14.1°, indicating that the phase composition gradually changes from the 1T phase to the 2H phase. In the XRD pattern of the 2H-MoS2 comparative sample, the diffraction peak of the 1T phase at 9.4° disappears, indicating a complete transformation to the 2H phase.
[0059] Figure 3 This is a Raman spectroscopy image of the micron-shaped 1T / 2H phase molybdenum disulfide prepared in Example 1, compared with 1T-MoS2 and 2H-MoS2 control samples. The values are located at 148, 237, 282, and 335 cm⁻¹. -1 J1, J2, E 1g The J3 vibration mode belongs to 1T-MoS2 and is located at 379 and 405 cm⁻¹. -1 E at the location 2g 1 and A 1g The vibrational mode is attributed to 2H-MoS2. Raman spectra also show that 1T-MoS2 gradually transforms into 2H-MoS2.
[0060] XPS spectrum (Mo 3d sub-spectrum) of the micron-flower-like 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 is shown below. Figure 4 As shown, the XPS spectrum (S2p sub-spectrum) of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 is as follows. Figure 5 As shown, the XPS spectra above characterize the chemical composition and elemental valence states of the micron-sized flower-like 1T / 2H phase molybdenum disulfide microwave absorbing material. Peak fitting of the Mo 3d spectrum revealed that the peaks at 232.8 eV, 229.6 eV, 231.9 eV, and 228.8 eV belong to the 2H-Mo 3d phase, respectively. 3 / 2 2H-Mo 3d 5 / 2 1T-Mo 3d 3 / 2 1T-Mo 3d 5 / 2 The 1T / 2H phase ratio can be obtained by comparing the signal integration areas of the 1T and 2H phases. Furthermore, a small amount of Mo produced by oxidation is observed at 236.1 eV. 6+ The signal exhibits S2s interference at 226.5 eV. Peak fitting of the S2p spectrum revealed peaks at 163.3 eV, 161.7 eV, 161.9 eV, and 160.9 eV, corresponding to 2H-S2p peaks. 1 / 2 2H-S2p 3 / 2 1T-S2p 1 / 2 1T-S2p3 / 2 There is a satellite peak (labeled "Sat") near 169.2 eV. The XPS spectrum (Mo 3d fraction) of the 1T-MoS2 control sample prepared in Example 1 is shown below. Figure 6 As shown, the XPS spectrum (Mo 3d spectrum) of the 2H-MoS2 control sample prepared in Example 1 is as follows. Figure 7 As shown, the 1T phase clearly occupies the majority in the 1T-MoS2 control sample, and calculations show that the mass proportion of the 1T phase is 76%. In the 2H-MoS2 control sample, the signal of the 1T phase disappears, and all of them are 2H phase.
[0061] Figure 8 The images show SEM images of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1, and SEM images of the 1T-MoS2 control sample prepared in Example 1. Figure 9 As shown, the SEM image of the 2H-MoS2 control sample prepared in Example 1 is as follows. Figure 10 As shown, the annealing process does not significantly alter the morphology of the samples. All samples exhibit a ping-pong ball-like daisy-shaped morphology, composed of MoS2 nanosheets, with a diameter of approximately 3 μm. This ping-pong ball-like daisy-shaped morphology facilitates multiple reflections and scattering of electromagnetic waves between the nanosheets, reduces the filling ratio, and builds a conductive network to enhance electromagnetic wave loss capability.
[0062] The HRTEM image of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 is shown below. Figure 11 As shown, both the 1T and 2H phases can be observed on the same MoS2 nanosheet. Due to the overlap of S atoms in the upper and lower layers along the Z-axis, signal superposition is enhanced, resulting in a certain contrast. The 2H phase exhibits a honeycomb structure, while the 1T phase shows a clear, independent triangular distribution of atoms. The MoS2 nanosheet also contains numerous regions of lattice distortion and discontinuous lattice fringes. These defects cause an imbalance in charge distribution within the system, introducing additional electric dipole moments and enhancing polarization losses.
[0063] The electromagnetic parameter test curves of the 1T-MoS2 comparison sample are shown below. Figure 12 As shown, from an electromagnetic parameter perspective, its dielectric constant has excessively high real and imaginary parts, which will cause significant impedance mismatch. Its permeability has a real part of 1 and an imaginary part of 0, indicating it is clearly a non-magnetic material. The microwave absorption performance test curves of the 1T-MoS2 comparison sample are shown below. Figure 13 As shown, the thicknesses, arranged in numerical order from 1 to 8, are 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, and 5.0 mm. Within the 1–18 GHz range and at thicknesses of 1.5–5 mm, it did not exhibit significantly superior absorption performance.
[0064] The electromagnetic parameter test curves of the 2H-MoS2 comparison sample are shown below. Figure 14 As shown, from the perspective of electromagnetic parameters, its permittivity has excessively low real and imaginary parts, resulting in insufficient electromagnetic wave attenuation. Its permeability has a real part of 1 and an imaginary part of 0, clearly indicating it is a non-magnetic material. The microwave absorption performance test curves of the 1T-MoS2 comparison sample are shown below. Figure 15 As shown, the thicknesses, arranged in numerical order from 1 to 8, are 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, and 5.0 mm. Within the 1–18 GHz range and at thicknesses of 1.5–5 mm, it did not exhibit significantly superior absorption performance.
[0065] The electromagnetic parameter test curves of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 are shown in the figure below. Figure 16 As shown, from the perspective of electromagnetic parameters, the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material exhibits excellent dielectric loss capability and obvious dielectric dispersion characteristics. The microwave absorption performance test curves of the micron-shaped 1T / 2H phase molybdenum disulfide microwave absorbing material prepared in Example 1 are shown in the figure. Figure 17 As shown. Curve 1 represents thicknesses of 1.5mm, 2.0mm, 2.48mm, 2.68mm, 3.0mm, 3.5mm, 4.0mm, and 4.5mm respectively, arranged sequentially from 1 to 8. It exhibits excellent absorption performance in the 1–18 GHz range. When the matched thickness is 2.68mm, the maximum reflection loss is -59.8dB, and the effective bandwidth is 6.8GHz (11.2–18GHz).
Claims
1. A method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material, characterized in that... This method is performed according to the following steps: Step 1: Dissolve ammonium molybdate tetrahydrate and thiourea in deionized water, stir to dissolve, and obtain a light blue clear reaction solution; Step 2: Transfer the light blue clear reaction solution obtained in Step 1 to a hydrothermal reactor lined with polytetrafluoroethylene, heat it in a high-temperature drying oven with a forced airflow to carry out the hydrothermal reaction, cool it to room temperature after the reaction is completed, wash it by centrifugation with deionized water and anhydrous ethanol in sequence, and dry it to obtain 1T-MoS2 powder. Step 3: Grind the 1T-MoS2 powder obtained in Step 2 thoroughly, place it in a high-temperature drying oven for heating and annealing in an air atmosphere, and the resulting powder is the micron-shaped 1T-2H phase molybdenum disulfide microwave absorbing material, thus completing the preparation. The molar ratio of Mo to S in the reaction solution described in step one is 1:5, and the concentration of Mo is 0.1~0.3 mol / L. The hydrothermal reaction described in step two is controlled at a heating temperature of 160~200 ℃ and a holding time of 12~24 h; The heating annealing process described in step three is performed at a temperature of 140~220 ℃.
2. The method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... Step 1: Control the stirring time to 30-40 minutes and the stirring speed to 300-500 rpm.
3. The method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... Step two involves washing with deionized water 2-3 times, followed by washing with anhydrous ethanol 2-3 times.
4. The method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... Step two washing process adopts centrifugal washing, and the centrifugal speed is controlled at 6000~8000 rpm.
5. The method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... After washing in step two, air dry in a cool, dark place for 12-16 hours.
6. The method for preparing a micron-shaped 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... The powder described in step three is ground to 325-400 mesh.
7. The method for preparing a micron-sized flower-like 1T-2H phase molybdenum disulfide microwave absorbing material according to claim 1, characterized in that... The heating and annealing process described in step three takes 5 to 120 minutes.