A multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material, its preparation method and application

Abstract

This invention discloses a multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material, its preparation method, and its applications. The technical solution of this invention utilizes oxidative polymerization to generate a conductive polymer layer on the surface of WS2. The conductive polymer and WS2 are structurally and functionally designed, and the thickness of the conductive polymer layer is controlled by adjusting the organic monomer content and reaction time, thereby improving microwave absorption performance. The multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material prepared based on the above approach exhibits excellent conductivity and EMW absorption performance. The WS2 / WO3 / PPy material is lightweight, low-cost, and has good microwave absorption performance. It can be used as an absorbing agent; when the matching thickness is 2.3 mm, the effective absorption bandwidth can reach 6.72 GHz; when the matching thickness is 3.3 mm, the minimum reflection loss can reach -55.87 dB. When mixed with cellulose to prepare a thin film, the minimum reflection loss can reach -38 dB at a thickness of 0.5 mm.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials, and more particularly to a multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material. Background Technology

[0002] With the rapid advancement of 5G technology and the increasing prevalence of electronic devices, electromagnetic environment issues are becoming increasingly prominent. On the one hand, the protection of personal information security and the stable operation of precision equipment place higher demands on the resistance of equipment to external electromagnetic interference; on the other hand, the convenient use of everyday electronic products and the intelligent development of wearable devices emphasize reducing the harmful effects of electromagnetic radiation from the devices themselves. Therefore, seeking an efficient and lightweight electromagnetic wave (EMW) absorption solution has become particularly urgent, aiming to balance the dual needs of electromagnetic protection and the lightweight and intelligent design of equipment.

[0003] Two-dimensional tungsten disulfide (WS2) is a nanomaterial with a two-dimensional layered structure, where each layer consists of alternating layers of tungsten and sulfur atoms connected by van der Waals interactions. Its unique two-dimensional structure, large specific surface area, and high reactivity have led to its widespread application in optoelectronic devices, sensors, and catalysis. However, its semiconductor properties prevent it from being a promising candidate for microwave absorbing materials. Wang et al. synthesized flower-like WS2 nanomaterials via a hydrothermal method. The abundant defects on the flower-like WS2 significantly improved the dipole polarization loss of the material, resulting in excellent microwave absorption performance (J. Wang, Y. Wang, J. Cheng, Y. Fu, Y. Li, W. Nie, J. Wang, J. Wang, B. Liu, D. Zhang, G. Zheng, M. Cao, Abundant vacancies induced highpolarization-attenuation effects in flower-like WS2 microwave absorbers, Journal of Materials Science & Technology 194 (2024).). However, the hydrothermal process limits the possibility of large-scale production of the material, and because this method only improves the dipole planning loss of the material by creating defects, it is difficult to significantly improve the dielectric loss capability of the material. Similarly, Liu et al. prepared NCFs@WS2 composites by hydrothermal method and carbonization. Although the composites exhibited good microwave absorption performance, the production cost of carbonization reduced the feasibility of large-scale application (X. Liu, S. Zhang, M. Yu, X. Zhao, Y. Jia, Y. Huang, M. Zong, WS2 nanosheets anchored on N-doped carbon fibers for superior electromagnetic wave absorption, Chemical Engineering Journal 465 (2023).). Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material and its preparation method. The technical solution of this invention is described below:

[0005] A method for preparing a multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material includes the following steps:

[0006] S1, oxidizing WS2 to obtain WS2 / WO3 containing a heterogeneous interface;

[0007] S2, add the WS2 / WO3 obtained in S1 to water, and disperse it evenly to obtain a WS2 / WO3 dispersion; add the obtained WS2 / WO3 dispersion to potassium persulfate solution, ammonium persulfate solution, and sodium persulfate solution, disperse it evenly, and then pre-cool it at low temperature to obtain an oxidizing solution;

[0008] S3, the oxidizing solution obtained in S2 is added to the pyrrole ethanol solution to carry out the oxidation reaction. After the reaction is completed, the solution is filtered, washed and dried to obtain the multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material.

[0009] Preferably, the oxidation treatment in S1 involves heating WS2 from room temperature to 500-600°C at a heating rate of 10-15°C / min; and then calcining it in air at 550-600°C for 15-30 min.

[0010] Preferably, the mass ratio of WS2 / WO3 to potassium persulfate solution, ammonium persulfate solution, and sodium persulfate solution in the oxidation solution of S2 is 1:8 to 1:10.

[0011] Preferably, the low-temperature precooling treatment in S2 is to freeze the mixture at -100~-80℃ for 10~15 minutes.

[0012] Preferably, the mass ratio of WS2 / WO3 to pyrrole in the mixture of pyrrole ethanol solution and oxidizing solution in S3 is 1:1 to 1:5.

[0013] Preferably, the oxidation reaction is carried out at a temperature of 20-30°C for 6-12 hours.

[0014] Preferably, the preparation method adopts the following steps:

[0015] S1, take WS2 and heat it from room temperature to 500℃ at a heating rate of 10℃ / min; then calcine it in air at 500℃ for 30min to obtain WS2 / WO3 containing a heterogeneous interface;

[0016] S2, WS2 / WO3 is uniformly dispersed in water to prepare a 20 g / L WS2 / WO3 dispersion; potassium persulfate is dissolved in water to prepare a 120 g / L potassium persulfate solution; the prepared WS2 / WO3 dispersion is added in equal volume to the prepared potassium persulfate solution, and after uniform dispersion, it is frozen at -80℃ for 10 min to obtain an oxidizing solution;

[0017] S3, pyrrole is added to ethanol to obtain a pyrrole ethanol solution of 40 g / L; the oxidizing liquid obtained in S2 is added to the pyrrole ethanol solution at a volume ratio of 2:1, and the oxidation reaction is carried out at 25°C for 6 h to obtain the multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material.

[0018] This invention provides an application of the multi-interface WS2 / WO3 / PPy nanocomposite absorbing material. The multi-interface WS2 / WO3 / PPy nanocomposite absorbing material has a WS2 / WO3 interface and a WO3 / PPy interface;

[0019] The WS2 / WO3 interface is obtained by oxidizing the outer surface of WS2; the oxidation treatment is to heat WS2 from room temperature to 500~600℃ at a heating rate of 10~15℃ / min; and then calcine it in air at 550~600℃ for 15~30min.

[0020] The WO3 / PPy interface is obtained by coating pyrrole onto the surface of WS2 / WO3 through oxidative polymerization. The oxidative polymerization method involves mixing WS2 / WO3 with potassium persulfate solution, ammonium persulfate solution, and sodium persulfate solution, freezing it at -100~-80℃ for 10~15min, and then reacting it with pyrrole ethanol for oxidation.

[0021] This invention provides an application of a multi-interface WS2 / WO3 / PPy nanocomposite absorbing material, which is used for electromagnetic wave absorption and shielding.

[0022] Preferably, the multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material is mixed with cellulose at a mass ratio of 1:2 to 1:5 and then dispersed in water, and the microwave absorbing film is prepared by vacuum filtration.

[0023] Beneficial effects

[0024] Compared with existing technologies, we utilize oxidative polymerization to generate a conductive polymer layer on the surface of WS2. We then design the structure and function of the conductive polymer and WS2, and adjust the thickness of the conductive polymer layer by regulating the organic monomer content and reaction time, thereby improving microwave absorption performance. The oxidative polymerization method involves polymerizing organic monomers through an oxidation reaction at room temperature. Compared with traditional high-temperature polymerization, oxidative polymerization offers advantages such as simple operation and energy efficiency. In the technical solution provided by this invention, the room-temperature liquid-phase reaction environment reduces the chemical requirements of the coating material for the conductive polymer. The multi-interface WS2 / WO3 / PPy nanocomposite microwave absorbing material prepared based on the above approach exhibits excellent conductivity and EMW absorption performance. This invention has the following advantages:

[0025] (1) The preparation method of the present invention is simple, safe and controllable, and the surface polypyrrole of the prepared WS2 / WO3 is intact and uniform. The surface of the WS2 / WO3 after polypyrrole coating does not peel or fall off, and the whole is dark blue. The conductivity of WS2 / WO3 / PPy can reach the order of 10. 1 The S / m ratio is 133% higher than that of WS2. Therefore, WS2 / WO3 / PPy is also suitable for applications such as electrochemical devices.

[0026] (2) The advantages of the multi-interface preparation technology adopted in this invention are: First, the process is simple and easy to operate. Since there are active sites on the surface of WS2, the reaction activity is high, and the WS2 / WO3 interface can be formed by calcination in air; Second, the oxidative polymerization of polypyrrole can react at room temperature to form a conductive polymer layer with good conductivity.

[0027] (3) This invention coats PPy onto the surface of WS2 / WO3. The two-dimensional layered structure and large specific surface area of ​​WS2 / WO3 allow for the deposition of more polypyrrole on the surface. This not only improves its conductivity but also promotes the separation of charges in the electromagnetic field, thereby improving the polarization loss of the material. In addition, the non-uniform heterogeneous interface between WS2 and WO3 inside the composite material significantly improves the interfacial polarization loss and electromagnetic wave absorption performance of the material.

[0028] (4) This invention utilizes an oxidative polymerization strategy to prepare a WS2 / WO3 / PPy nanocomposite microwave absorbing material. The WS2 / WO3 / PPy material is lightweight, low-cost, and exhibits excellent microwave absorption performance, making it suitable for use as an absorbing agent. Testing showed that when the matched thickness of the material is 2.3 mm, the effective absorption bandwidth reaches 6.72 GHz; when the matched thickness is 3.3 mm, the minimum reflection loss reaches -55.62 dB. When mixed with cellulose to prepare a thin film, the minimum reflection loss reaches -38 dB at a thickness of 0.5 mm. Attached Figure Description

[0029] Figure 1 The X-ray diffraction pattern of WS2 / WO3 obtained in step 1 of Example 1;

[0030] Figure 2 The X-ray diffraction pattern of WS2 / WO3 / PPy-1 obtained in Example 1;

[0031] Figure 3 Transmission electron microscope (TEM) images of WS2 / WO3 prepared in step 1 of Example 1 and WS2 / WO3 / PPy-1 prepared in Example 1;

[0032] Figure 4Conductivity diagrams of WS2 / WO3 prepared in step 1 of Example 1 and WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 prepared in Examples 1-4;

[0033] Figure 5 The absorption performance of WS2 / WO3 prepared in step 1 of Example 1, with a matching thickness of 4.8 mm, shows a minimum reflection loss of -12.36 dB.

[0034] Figure 6 The absorption performance of WS2 / WO3 / PPy-1 prepared in Example 1, with a matching thickness of 2.5 mm, shows a minimum reflection loss of -27.57 dB.

[0035] Figure 7 The absorption performance of WS2 / WO3 / PPy-2 prepared in Example 2, with a matching thickness of 4.1 mm, shows a minimum reflection loss of -47.68 dB.

[0036] Figure 8 The absorption performance of WS2 / WO3 / PPy-3 prepared in Example 3, with a matching thickness of 2.8 mm, shows a minimum reflection loss of -36.82 dB.

[0037] Figure 9 The absorption performance of WS2 / WO3 / PPy-4 prepared in Example 4, with a matching thickness of 3.3 mm, shows a minimum reflection loss of -58.62 dB.

[0038] Figure 10 This is an example of preparing a cellulose microwave absorbing film by combining WS2 / WO3 / PPy-4 obtained in Example 4 with cellulose;

[0039] Figure 11 The electromagnetic absorption properties of cellulose absorbing films prepared by compositing WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 obtained in Examples 1-4 with cellulose are shown in the figure. Detailed Implementation

[0040] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods. Example

[0041] A multi-interface WS2 / WO3 / PPy-1 nanocomposite microwave absorbing material, the preparation method of which includes the following steps:

[0042] (1) To prepare WS2 / WO3, 2g of solid WS2 was weighed and placed in a tube furnace and heated in air at 500°C for 15min to obtain WS2 / WO3 containing a heterogeneous interface; the WS2 was two-dimensional WS2 (molecular weight 247.97, purity >99.8%, particle size 1-3μm).

[0043] (2) To prepare the dispersion, add 50 mL of deionized water to a beaker, weigh 1 g of the prepared WS2 / WO3 using an electronic balance, add it to the above deionized water, place the beaker in an ultrasonic instrument and ultrasonically disperse it at 25°C for 1 h until the powder is evenly dispersed, and obtain a well dispersed WS2 / WO3 dispersion.

[0044] (3) To prepare the oxidizing solution, add 50 ml of deionized water to a beaker, weigh 8 g of solid potassium persulfate using an analytical balance and add it to dissolve, stirring until completely dissolved; add the WS2 / WO3 dispersion obtained in step (2) to the potassium persulfate solution, and stir electromagnetically at 25°C for 30 min at a speed of 500 r / min; place the above solution in a refrigerator and freeze at -80°C for 10 min to obtain the oxidizing solution;

[0045] (4) Prepare a pyrrole ethanol solution and carry out an oxidative polymerization reaction. Weigh 1g of pyrrole with an analytical balance and add 50ml of ethanol to disperse it. Place the oxidative solution obtained in step (3) into the pyrrole solution and stir it electromagnetically at 25℃ with a speed of 500 r / min for 6h.

[0046] After the oxidative polymerization reaction is completed, the reaction product is repeatedly washed and filtered until the filtrate is colorless and dried to finally obtain WS2 / WO3 / PPy-1.

[0047] X-ray diffraction and transmission electron microscopy measurements were performed on the WS2 / WO3 prepared in step (1) of Example 1 and the WS2 / WO3 / PPy-1 prepared in Example 1. The results are as follows: Figures 1-3 As shown:

[0048] Figure 1 The image shows the X-ray diffraction pattern of WS2 / WO3 obtained in step (1) of Example 1. It can be seen from the image that WS2 and WO3 have obvious diffraction peaks at the same time.

[0049] Figure 2The image shows the X-ray diffraction pattern of WS2 / WO3 / PPy-1 in Example 1. The image shows that WS2 / WO3 exhibits obvious characteristic peaks after being coated with polypyrrole, and the characteristic peaks correspond to the PDF cards of WS2 and WO3, confirming that PPy is generated on the surface of WS2 / WO3.

[0050] Figure 3 The images show scanning electron microscope (SEM) images of WS2 / WO3 prepared in step (1) of Example 1 and WS2 / WO3 / PPy-1 prepared in Example 1. The left image shows the unique two-dimensional layered structure of WS2 / WO3 nanomaterials, and the right image shows that WS2 / WO3 forms a conductive polymer layer on the surface after the polypyrrole reaction.

[0051] Example 2

[0052] A multi-interface WS2 / WO3 / PPy-2 nanocomposite microwave absorbing material, the preparation method of which includes the following steps:

[0053] (1) To prepare WS2 / WO3, 2g of solid WS2 was weighed and placed in a tube furnace and heated in air at 550°C for 15min to obtain WS2 / WO3 containing a heterogeneous interface; the WS2 was two-dimensional WS2 (molecular weight 247.97, purity >99.8%, particle size 1-3μm).

[0054] (2) To prepare the dispersion, add 50 mL of deionized water to a beaker, weigh 1 g of the prepared WS2 / WO3 using an electronic balance, add it to the above deionized water, place the beaker in an ultrasonic instrument and ultrasonically disperse it at 25°C for 1 h until the powder is evenly dispersed, and obtain a well dispersed WS2 / WO3 dispersion.

[0055] (3) To prepare the oxidizing solution, add 50 ml of deionized water to a beaker, weigh 8 g of solid potassium persulfate using an analytical balance and add it to dissolve, stirring until completely dissolved; add the WS2 / WO3 dispersion obtained in step (2) to the potassium persulfate solution, and stir electromagnetically at 25°C for 30 min at a speed of 550 r / min; place the above solution in a refrigerator and freeze at -80°C for 10 min to obtain the oxidizing solution;

[0056] (4) Prepare a pyrrole ethanol solution and carry out an oxidative polymerization reaction. Weigh 2g of pyrrole with an analytical balance and add 50ml of ethanol to disperse it. Place the oxidative solution obtained in step (3) into the pyrrole solution and stir it electromagnetically at 25℃ with a speed of 550 r / min for 6h.

[0057] After the oxidative polymerization reaction is completed, the reaction product is repeatedly washed and filtered until the filtrate is colorless and dried to finally obtain WS2 / WO3 / PPy-2.

[0058] Example 3

[0059] A multi-interface WS2 / WO3 / PPy-3 nanocomposite microwave absorbing material, the preparation method of which includes the following steps:

[0060] (1) To prepare WS2 / WO3, 2g of solid WS2 was weighed and placed in a tube furnace and heated in air at 500°C for 30min to obtain WS2 / WO3 containing a heterogeneous interface; the WS2 was two-dimensional WS2 (molecular weight 247.97, purity >99.8%, particle size 1-3μm).

[0061] (2) To prepare the dispersion, add 50 mL of deionized water to a beaker, weigh 1 g of the prepared WS2 / WO3 using an electronic balance, add it to the above deionized water, place the beaker in an ultrasonic instrument and ultrasonically disperse it at 20 °C for 1 h until the powder is evenly dispersed, and obtain the well dispersed WS2 / WO3 dispersion.

[0062] (3) To prepare the oxidizing solution, add 50 ml of deionized water to a beaker, weigh 8 g of solid potassium persulfate using an analytical balance and add it to dissolve, stirring until completely dissolved; add the WS2 / WO3 dispersion obtained in step (2) to the potassium persulfate solution, and stir electromagnetically at 20°C for 30 min at a speed of 600 r / min; place the above solution in a refrigerator and freeze at -75°C for 10 min to obtain the oxidizing solution;

[0063] (4) Prepare a pyrrole ethanol solution and carry out an oxidative polymerization reaction. Weigh 1g of pyrrole with an analytical balance and add 50ml of ethanol to disperse it. Place the oxidative solution obtained in step (3) into the pyrrole solution and stir it electromagnetically at 25℃ with a speed of 600 r / min for 10h.

[0064] After the oxidative polymerization reaction is completed, the reaction product is repeatedly washed and filtered until the filtrate is colorless. After drying, WS2 / WO3 / PPy-3 is finally obtained.

[0065] Example 4

[0066] A multi-interface WS2 / WO3 / PPy-4 nanocomposite microwave absorbing material, the preparation method of which includes the following steps:

[0067] (1) To prepare WS2 / WO3, 2g of solid WS2 was weighed and placed in a tube furnace and heated in air at 500°C for 30min to obtain WS2 / WO3 containing a heterogeneous interface; the WS2 was two-dimensional WS2 (molecular weight 247.97, purity >99.8%, particle size 1-3μm).

[0068] (2) To prepare the dispersion, add 50 mL of deionized water to a beaker, weigh 1 g of the prepared WS2 / WO3 using an electronic balance, add it to the above deionized water, place the beaker in an ultrasonic instrument and ultrasonically disperse it at 25°C for 1 h until the powder is evenly dispersed, and obtain a well dispersed WS2 / WO3 dispersion.

[0069] (3) To prepare the oxidizing solution, add 50 ml of deionized water to a beaker, weigh 8 g of solid potassium persulfate using an analytical balance and add it to dissolve, stirring until completely dissolved; add the WS2 / WO3 dispersion obtained in step (2) to the potassium persulfate solution, and stir electromagnetically at 25°C for 30 min at a speed of 550 r / min; place the above solution in a refrigerator and freeze at -85°C for 10 min to obtain the oxidizing solution;

[0070] (4) Prepare a pyrrole ethanol solution and carry out an oxidative polymerization reaction. Weigh 2g of pyrrole with an analytical balance and add 50ml of ethanol to disperse it. Place the oxidative solution obtained in step (3) into the pyrrole solution and stir it magnetically at 25℃ with a speed of 600 r / min for 6h.

[0071] After the oxidative polymerization reaction is completed, the reaction product is repeatedly washed and filtered until the filtrate is colorless. After drying, WS2 / WO3 / PPy-4 is finally obtained.

[0072] Example 5

[0073] The electromagnetic parameters of WS2 / WO3 obtained in step (1) of Example 1 and WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3 and WS2 / WO3 / PPy-4 obtained in Examples 1 to 4 were tested in the 2-18 GHz frequency band using a network analyzer (VNA, N5245A, Agilent, USA).

[0074] The WS2 / WO3 obtained in step (1) of Example 1, and the WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 obtained in Examples 1-4, were respectively prepared into samples with paraffin wax at a mass ratio of 6:4. All samples were pressed into a standard annulus using the same mold. f in 3.04 mm f out (7.00 mm) to maintain geometric certainty. The thickness of all annular spaces is maintained at 2.5 mm. Agilent PNA software automatically outputs the relevant electromagnetic parameters based on the Nicolson, Ross, and Weir algorithm. The result is as follows: Figures 4-9 The results shown are as follows:

[0075] Figure 4 The graph shows the conductivity test results of WS2 / WO3 prepared in step (1) of Example 1 and WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 prepared in Examples 1-4. The conductivity of WS2 / WO3, WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 in the graph are 0.08 S / m, 1.51 S / m, 3.62 S / m, 1.49 S / m, and 3.61 S / m, respectively. Figure 4 It can be seen that the conductivity of WS2 / WO3 is significantly enhanced after being coated with polypyrrole. The conductivity can be controlled by changing the mass ratio of pyrrole to WS2 / WO3. The thickness of polypyrrole coated on the surface of WS2 / WO3 increases with the increase of pyrrole addition.

[0076] from Figures 5-9 As can be seen from the data: the minimum reflection loss of WS2 / WO3 obtained in step (1) of Example 1 is -16.84 dB; the minimum reflection loss of WS2 / WO3 / PPy-1 is -27.57 dB; the minimum reflection loss of WS2 / WO3 / PPy-2 is -47.68 dB; the minimum reflection loss of WS2 / WO3 / PPy-3 is -36.82 dB; and the minimum reflection loss of WS2 / WO3 / PPy-4 is -58.62 dB.

[0077] Example 6

[0078] 1 g of WS2 / WO3 / PPy-4 and 2 g of cellulose were dispersed in 10 ml of water, and a cellulose microwave absorbing material film was prepared by vacuum filtration. An example of the resulting film is shown in the figure below. Figure 10 As shown in the figure, the WS2 / WO3 / PPy composite material has the ability to be fabricated into devices and has broad application prospects.

[0079] Electromagnetic parameters of cellulose absorbing films prepared by combining WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 with cellulose were tested in the 2-18 GHz frequency band using a network analyzer (VNA, N5245A, Agilent, USA). The test results are as follows. Figure 11 As shown in the figure, it can be seen that the performance of the prepared cellulose microwave absorbing film is positively correlated with the performance of the powder, that is, the better the performance of the filler, the better the electromagnetic wave absorption performance of the film.

[0080] In summary, the electromagnetic parameters of the composite material can be adjusted by changing the thickness of the conductive polymer and by oxidizing WS2 in air, thereby altering the interface structure and thus improving microwave absorption performance. Comparative analysis of the test data from WS2 / WO3 / PPy-1, WS2 / WO3 / PPy-2, WS2 / WO3 / PPy-3, and WS2 / WO3 / PPy-4 in the examples reveals that increasing the thickness of the polypyrrole increases the conductivity of the composite material, correspondingly increasing the real part of the dielectric constant. Simultaneously, the increased internal oxidation time forms a significant heterogeneous interface, increasing the dielectric loss of the material and further enhancing its electromagnetic absorption performance.

[0081] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection of the present invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of the present invention, or equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of patent protection of the present invention.

Claims

1. A multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material, characterized in that, the multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material has WS2 / WO3 interfaces and WO3 / PPy interfaces; the WS2 / WO3 interfaces are obtained by oxidizing the outer surface of WS2; the WO3 / PPy interfaces are obtained by wrapping pyrrole on the surface of WS2 / WO3 through an oxidative polymerization method; the oxidizing treatment is heating WS2 from room temperature to 500-600 ℃ at a heating rate of 10-15 ℃ / min, and then calcining in air at 550-600 ℃ for 15-30 min; the oxidative polymerization method is mixing WS2 / WO3 with a potassium persulfate solution, an ammonium persulfate solution, or a sodium persulfate solution, and then freezing the mixture at-100--80 ℃ for 10-15 min, and then performing an oxidation reaction with pyrrole ethanol. 2.A preparation method of the multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material according to claim 1, characterized in that, the method comprises the following steps: S1, oxidizing WS2 to obtain WS2 / WO3 containing heterogeneous interfaces; S2, adding the WS2 / WO3 obtained in S1 to water, and uniformly dispersing to obtain a WS2 / WO3 dispersion liquid; adding the WS2 / WO3 dispersion liquid to a potassium persulfate solution, an ammonium persulfate solution, or a sodium persulfate solution, and uniformly dispersing to obtain an oxidation liquid after precooling treatment; S3, adding the oxidation liquid obtained in S2 to a pyrrole ethanol solution to perform an oxidation reaction for 6-12 h to obtain the multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material. 3.The preparation method according to claim 2, characterized in that: the oxidizing treatment in S1 is heating WS2 from room temperature to 500-600 ℃ at a heating rate of 10-15 ℃ / min, and then calcining in air at 550-600 ℃ for 15-30 min; and / or the precooling treatment in S2 is freezing the mixture at-100--80 ℃ for 10-15 min. 4.The preparation method according to claim 2, characterized in that: the mass ratio of WS2 / WO3 to the potassium persulfate solution, the ammonium persulfate solution, or the sodium persulfate solution in the oxidation liquid in S2 is 1:8-1:

10. 5.The preparation method according to claim 2, characterized in that: the mass ratio of WS2 / WO3 to pyrrole in the mixture of the pyrrole ethanol solution and the oxidation liquid in S3 is 1:1-1:

5. 6.The preparation method according to claim 2, characterized in that: the preparation method comprises the following steps: S1, heating WS2 from room temperature to 500 ℃ at a heating rate of 10 ℃ / min, and then calcining in air at 500 ℃ for 30 min to obtain WS2 / WO3 containing heterogeneous interfaces; S2, uniformly dispersing WS2 / WO3 into water to configure a 20 g / L WS2 / WO3 dispersion liquid; dissolving potassium persulfate in water to configure a 120 g / L potassium persulfate solution; adding the prepared WS2 / WO3 dispersion liquid into the prepared potassium persulfate solution in equal volume, uniformly dispersing and then freezing at-80℃ for 10 min to obtain an oxidation liquid; S3, adding pyrrole into ethanol to obtain a 40 g / L pyrrole ethanol solution; adding the oxidation liquid prepared in S2 into the pyrrole ethanol solution in a volume ratio of 2:1, and performing oxidation reaction at 25℃ for 6 h to obtain the multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material. 7.A multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material, characterized in that: The multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material is prepared according to the preparation method of any one of claims 2-6. 8.Use of the multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material according to claim 7, characterized in that: The multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material is used for electromagnetic wave absorption and shielding. 9.The use according to claim 8, characterized in that: The multi-interface WS2 / WO3 / PPy nanocomposite wave-absorbing material is mixed with cellulose in a mass ratio of 1:2-1:5, and then dispersed in water to prepare a wave-absorbing film by suction filtration.

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