A two-dimensional MBene-metal sulfide composite material and its preparation method and application

Abstract

This invention discloses a two-dimensional MBene-metal sulfide composite material, its preparation method, and its applications, belonging to the field of electromagnetic absorbing materials technology. This invention utilizes metal sulfides to manipulate the exfoliation process of two-dimensional MBene. Through a high-temperature hydrothermal reaction, a heterostructure of two-dimensional MBene nanosheets loaded with uniformly dispersed metal sulfide particles is obtained. Benefiting from the enhanced dielectric loss of the heterostructure and the nano-effect of the metal sulfides, the two-dimensional MBene-metal sulfide composite material prepared by this invention exhibits excellent electromagnetic properties. The metal sulfide intercalation strategy proposed in this invention lays the foundation for the development of advanced two-dimensional electromagnetic absorbing materials and provides a general method for the development of other two-dimensional nanosheets with tunable structures.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic wave absorbing materials technology, specifically to a two-dimensional MBene-metal sulfide composite material, its preparation method, and its application. Background Technology

[0002] In today's era of rapid technological advancement, the importance of electromagnetic wave absorbing materials is becoming increasingly prominent, driven by a variety of factors. These materials can absorb unwanted electromagnetic waves and convert them into other forms of energy, such as heat, thereby reducing electromagnetic interference and pollution. They have broad application prospects in the civilian sector.

[0003] In recent years, two-dimensional nanosheet materials have found wide applications in electromagnetic interference shielding and electromagnetic wave absorption due to their ultrathin structure, high specific surface area, and tunable electromagnetic parameters. Two-dimensional nanosheet materials include two-dimensional transition metal borides (MBene), two-dimensional carbon materials, and chalcogenides such as transition metal dichalcogenides. MBene is derived from ternary layered transition metal borides (MAB phase), obtained by chemically etching away the Al layer. MBene possesses metallic conductivity and excellent mechanical, optical, and electronic properties, attracting significant attention in optoelectronic devices, catalysis, and energy fields. Furthermore, due to its high composite dielectric constant, MBene is a dielectric material with good electrical storage and dissipation capabilities, and is considered a promising electromagnetic absorption material. Combining different two-dimensional materials can provide numerous interfaces conducive to electromagnetic wave absorption. However, because two-dimensional MBene materials tend to stack, they cannot expose more surface atoms, and electron transport and migration are restricted, resulting in poor electromagnetic performance. Summary of the Invention

[0004] This invention provides a two-dimensional MBene-metal sulfide composite material, its preparation method, and its applications. It effectively solves the technical problem that existing two-dimensional materials are prone to agglomeration, making it difficult to obtain two-dimensional materials with superior electromagnetic properties. This invention utilizes metal sulfides to manipulate the exfoliation process of two-dimensional MBene. Through a high-temperature hydrothermal reaction, a heterostructure of two-dimensional MBene nanosheets loaded with uniformly dispersed metal sulfide particles is obtained. Benefiting from the enhanced dielectric loss of the heterostructure and the nano-effect of the metal sulfides, the two-dimensional MBene-metal sulfide composite material prepared by this invention achieves excellent electromagnetic properties. The metal sulfide intercalation strategy proposed in this invention lays the foundation for the development of advanced two-dimensional electromagnetic absorbing materials and provides a general method for the development of other two-dimensional nanosheets with tunable structures.

[0005] The first objective of this invention is to provide a method for preparing a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0006] The precursor MAB phase was etched using hydrofluoric acid solution to obtain multilayer MBene materials;

[0007] Thiourea and soluble metal salts were dissolved in water, and the multilayer MBene material was added and mixed. The mixture was then subjected to a hydrothermal reaction at 100℃~250℃ to obtain metal sulfide nanoparticles, which were then in situ loaded onto the multilayer nanomaterials to obtain a two-dimensional MBene-metal sulfide composite material.

[0008] In a preferred embodiment, the mass ratio of the multilayer MBene material, thiourea, and soluble metal salt is 1:1 to 50:0.5 to 30.

[0009] In a preferred embodiment, the soluble metal salt is sodium molybdate, cobalt nitrate, ferric nitrate, nickel nitrate, copper nitrate, sodium acetate, cobalt acetate, ferric acetate, nickel acetate, or copper acetate.

[0010] In a preferred embodiment, the hydrothermal reaction time is 0.5h to 6h.

[0011] In a preferred embodiment, the concentration of the hydrofluoric acid solution is 30wt% to 60wt%, and the ratio of the precursor MAB phase to the hydrofluoric acid solution is 1g:10mL to 200mL.

[0012] In a preferred embodiment, the precursor MAB phase is MoAlB, WAlB, Cr2AlB2, Fe2AlB2, Mn2AlB2, or (Mo 2 / 3 Y 1 / 3 )AlB2.

[0013] In a preferred embodiment, the etching time is 24h to 96h.

[0014] As a preferred embodiment, after the hydrothermal reaction, the product is centrifuged at 5000 r / min to 10000 r / min for 5 min to 30 min, filtered, and the primary product is obtained. The primary product is washed with deionized water and ethanol, and dried at 50℃ to 100℃ for 6 h to 24 h to obtain a two-dimensional MBene-metal sulfide composite material.

[0015] The second objective of this invention is to provide a two-dimensional MBene-metal sulfide composite material prepared by the above-described preparation method.

[0016] A third objective of this invention is to provide an application of the above-mentioned two-dimensional MBene-metal sulfide composite material in the preparation of electromagnetic absorbing materials.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention provides a method for preparing a two-dimensional MBene-metal sulfide composite material. The method involves etching the precursor MAB phase with hydrofluoric acid solution to obtain a multilayer MBene material. Thiourea and a soluble metal salt are added to the multilayer MBene material, mixed, and subjected to a hydrothermal reaction to obtain metal sulfide nanoparticles, which are then loaded onto the multilayer MBene material to obtain the two-dimensional MBene-metal sulfide composite material. This invention utilizes a hydrothermal reaction to generate metal sulfides, which are then in situ loaded into the intercalations of the multilayer MBene material. The layer-by-layer intercalation of the metal sulfides in the multilayer MBene material achieves the exfoliation of the multilayer MBene material, thereby significantly increasing the specific surface area and exposing more surface atoms. The increased interlayer distance after exfoliation facilitates electron transport and migration. In this invention, the prepared multilayer MBene material possesses fully exposed active sites, good conductivity loss, high specific surface area, and a large number of exposed surface atoms, thus endowing the composite material with excellent mechanical and electronic properties. Electromagnetic parameters can be effectively controlled to obtain excellent electromagnetic absorption performance. Metal sulfides obtained through hydrothermal reaction are progressively embedded into multilayer MBene materials. Due to the nanoscale effect and dielectric properties of the metal sulfide particles, highly efficient dielectric loss and dipole polarization are provided. This invention significantly improves the electromagnetic properties of the composite material through the enhanced dielectric loss of the multilayer MBene material's heterostructure and the nanoscale effect of the metal sulfides. The two-dimensional MBene-metal sulfide composite material prepared by this invention has potential applications in the field of electromagnetic protection. Attached Figure Description

[0019] Figure 1 The images show the XRD patterns of the two-dimensional MBene-metal sulfide composite materials of Examples 1 to 5 of the present invention, wherein MBene-MoS1:1.4 is Example 1, MBene-MoS1:1.6 is Example 2, MBene-MoS1:1.2 is Example 3, MBene-MoS1:1.0 is Example 4, and MBene-MoS1:0.75 is Example 5.

[0020] Figure 2 The images show the XRD patterns of the two-dimensional MBene-metal sulfide composite materials prepared in Examples 1 to 3 of this invention, wherein MoB / MoS2 is Example 1, CrB / CoS is Example 6, and MnB / MoS2 is Example 7.

[0021] Figure 3 This is a SEM image of the two-dimensional MBene-metal sulfide composite material of Example 1 of the present invention.

[0022] Figure 4 This is a TEM image of the two-dimensional MBene-metal sulfide composite material of Example 1 of the present invention.

[0023] Figure 5 This is a graph showing the electromagnetic absorption performance of the two-dimensional MBene-metal sulfide composite material in Example 1 of the present invention.

[0024] Figure 6 This is a graph showing the electromagnetic absorption performance of two-dimensional MoB in Comparative Example 1 of the present invention.

[0025] Figure 7 This is a graph showing the electromagnetic absorption performance of two-dimensional CrB in Comparative Example 2 of the present invention.

[0026] Figure 8 This is a graph showing the electromagnetic absorption performance of two-dimensional MnB in Comparative Example 3 of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention is further described below with reference to specific embodiments. However, the embodiments are not intended to limit the invention. Unless otherwise specified, the following test methods and detection methods are conventional methods; unless otherwise specified, the reagents and raw materials are commercially available.

[0028] As mentioned in the background section of this invention, two-dimensional transition metal borides (MBene) are a novel type of two-dimensional material in the field of electromagnetic wave absorbing materials. They possess metallic conductivity and excellent mechanical, optical, and electronic properties, attracting significant attention in optoelectronic devices, catalysis, and energy. Composites of different two-dimensional materials can provide numerous interfaces conducive to electromagnetic wave absorption. However, existing two-dimensional materials suffer from a tendency to aggregate, hindering the achievement of layer-by-layer ordered embedding and thus affecting their electromagnetic properties. Based on these technical problems, this invention provides a two-dimensional MBene-metal sulfide composite material, its preparation method, and its applications.

[0029] The technical solution of the present invention will be analyzed and described in detail below.

[0030] This invention first provides a method for preparing a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0031] The precursor MAB phase was etched using hydrofluoric acid solution to obtain multilayer MBene materials;

[0032] Thiourea and soluble metal salts were dissolved in water, and the multilayer MBene material was added and mixed. The mixture was then subjected to a hydrothermal reaction at 100℃~250℃ to obtain metal sulfide nanoparticles, which were then in situ loaded onto the multilayer nanomaterials to obtain a two-dimensional MBene-metal sulfide composite material.

[0033] If the hydrothermal reaction temperature is below 100℃, the reaction will be incomplete and multilayer MBene material cannot be obtained; if the reaction temperature is above 250℃, the multilayer MBene material will undergo severe oxidation.

[0034] In the above technical solution, the prepared multilayer MBene material has fully exposed active sites, good conductivity loss, high specific surface area, and a large number of exposed surface atoms, which endow the composite material of the present invention with excellent mechanical and electronic properties, and can effectively control electromagnetic parameters and obtain excellent electromagnetic absorption performance. On the other hand, the metal sulfide obtained by hydrothermal reaction is embedded layer by layer into the multilayer MBene material. Due to the nano-size effect and dielectric properties of the metal sulfide particles, it provides efficient dielectric loss and dipole polarization.

[0035] To further improve the dielectric properties of the composite material, the loading of the metal sulfide in the two-dimensional MBene-metal sulfide composite material is 5% to 20%.

[0036] It should be noted that the soluble metal salts used in this invention are selected from sodium molybdate, cobalt nitrate, ferric nitrate, nickel nitrate, copper nitrate, and the corresponding acetates.

[0037] To obtain multilayer MBene materials with better performance, the hydrothermal reaction time is 0.5–6 hours. Considering the hydrothermal reaction temperature mentioned above, if the reaction time is less than 0.5 hours, the reaction will be incomplete, and multilayer MBene materials cannot be obtained. If the reaction time is greater than 6 hours, the MBene material will undergo severe oxidation.

[0038] In order to etch away the Al layer on the precursor MAB phase, the acid solution includes a 30wt% to 60wt% hydrofluoric acid solution and a 37% hydrochloric acid solution, and the ratio of the precursor MAB phase to the hydrofluoric acid solution is 1g:10 to 200mL.

[0039] It should be noted that the precursor MAB phase described in this invention is selected from MoAlB, WAlB, Cr2AlB2, Fe2AlB2, Mn2AlB2, or (Mo 2 / 3 Y 1 / 3 )AlB2.

[0040] To ensure sufficient etching of the Al layer on the precursor MAB phase, the etching time is 24h to 96h. If the etching time is less than 24h, the etching is insufficient, resulting in a low proportion of monolayer MBene material; if the etching time is greater than 96h, over-etching occurs, leading to severe oxidation and low quality of the monolayer MBene material.

[0041] To remove the influence of impurities and obtain a composite material with higher purity, and to further improve the electromagnetic properties of the composite material, after hydrothermal reaction, the mixture was centrifuged at 5000 r / min to 10000 r / min for 5 min to 30 min, filtered, and a primary product was obtained. The primary product was washed with deionized water and ethanol, and dried at 50℃ to 100℃ for 6 h to 24 h to obtain a two-dimensional MBene-metal sulfide composite material.

[0042] The technical effects of the present invention will be described in detail below through specific embodiments and comparative examples.

[0043] Example 1

[0044] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0045] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene powder, i.e., multilayer MoB material.

[0046] S2, dissolve 2.8g thiourea and 1.4g sodium molybdate in 100mL deionized water, add 100mg of multilayer MoB material and mix, stir magnetically for 1h to obtain a homogeneous solution.

[0047] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 210 °C for 50 min. After centrifugation at 5000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS2 composite material, with a mass ratio of MoB to MoS2 of 1:1.4.

[0048] Example 2

[0049] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0050] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene powder, i.e., multilayer MoB material.

[0051] S2, dissolve 2.8g thiourea and 1.6g sodium molybdate in 100mL deionized water, add 100mg of multilayer MoB material and mix, stir magnetically for 1h to obtain a homogeneous solution.

[0052] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 210 °C for 50 min. After centrifugation at 5000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS2 composite material, with a mass ratio of MoB to MoS2 of 1:1.6.

[0053] Example 3

[0054] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0055] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene powder, i.e., multilayer MoB material.

[0056] S2, dissolve 2.8g thiourea and 1.2g sodium molybdate in 100mL deionized water, add 100mg of multilayer MoB material and mix, stir magnetically for 1h to obtain a homogeneous solution.

[0057] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 210 °C for 50 min. After centrifugation at 5000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS2 composite material, with a mass ratio of MoB to MoS2 of 1:1.2.

[0058] Example 4

[0059] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0060] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene powder, i.e., multilayer MoB material.

[0061] S2, dissolve 2.8g thiourea and 1.0g sodium molybdate in 100mL deionized water, add 100mg of multilayer MoB material and mix, stir magnetically for 1h to obtain a homogeneous solution.

[0062] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 210 °C for 50 min. After centrifugation at 5000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS2 composite material, with a mass ratio of MoB to MoS2 of 1:1.0.

[0063] Example 5

[0064] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0065] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene powder, i.e., multilayer MoB material.

[0066] S2, dissolve 2.8g thiourea and 0.75g sodium molybdate in 100mL deionized water, add 100mg of multilayer MoB material and mix, stir magnetically for 1h to obtain a homogeneous solution.

[0067] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 210 °C for 50 min. After centrifugation at 5000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS2 composite material, with a mass ratio of MoB to MoS2 of 1:0.75.

[0068] Example 6

[0069] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0070] S1, take 1.5g of precursor Cr2AlB2, etch it in a 40wt.% hydrofluoric acid solution for 48h, and then centrifuge and wash it at 6000r / min to obtain multilayer MBene material, i.e. multilayer CrB material.

[0071] S2, dissolve 1.4g thiourea and 0.5g cobalt nitrate in 50mL deionized water, add 60mg of multilayer CrB material and mix, stir magnetically for 2h to obtain a homogeneous solution.

[0072] S3. The homogeneous solution was transferred to a 200 mL stainless steel autoclave lined with polytetrafluoroethylene and hydrothermally reacted at 180 °C for 2 h. After centrifugation at 7000 r / min for 5 min, the mixture was filtered to obtain the primary product. The primary product was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 70 °C for 24 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as CrB / CoS.

[0073] Example 7

[0074] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0075] Step 1: Take 1.5g of precursor Mn2AlB2, etch it in 50wt.% hydrofluoric acid solution for 56 hours, and then centrifuge and wash it at 6000 rpm to obtain multilayer MBene, i.e., multilayer MnB material.

[0076] Step 2: Dissolve 2.0g thiourea and 0.9g cobalt nitrate in 50mL of deionized water, mix with 100mg MBene material, and stir vigorously with magnetic stirring for 2 hours to obtain a homogeneous solution.

[0077] Step 3: Transfer the mixture to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and react at 160 degrees Celsius for 4 hours.

[0078] Step 4: The obtained product was centrifuged at 10,000 rpm for 10 minutes and then filtered. It was washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 60 degrees Celsius for 12 hours to obtain a two-dimensional MnB / MoS2 composite material.

[0079] Example 8

[0080] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0081] Step 1: Take 1.5g of precursor (Mo) 2 / 3 Y 1 / 3 AlB2 was etched in a 40 wt.% hydrofluoric acid solution for 48 hours, and then centrifuged and washed at 6000 rpm to obtain multilayer MBene, i.e., multilayer MnB material.

[0082] Step 2: Dissolve 1.0g thiourea and 0.5g cobalt nitrate in 50mL of deionized water, mix with 100mg MBene material, and stir vigorously with magnetic stirring for 2 hours to obtain a homogeneous solution.

[0083] Step 3: Transfer the mixture to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and react at 160 degrees Celsius for 4 hours.

[0084] Step 4: The obtained product was centrifuged at 10,000 rpm for 10 minutes, filtered, washed several times with deionized water and ethanol, and finally dried in a vacuum oven at 60 degrees Celsius for 12 hours to obtain two-dimensional Mo. 1.33 B2 / CoS composite material.

[0085] To further illustrate the technical effects of the present invention, a comparative example is also provided, as follows:

[0086] Comparative Example 1

[0087] The difference compared to Example 1 is that it does not contain metal sulfides.

[0088] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0089] S1, take 1.5g of precursor MoAlB, etch it in a 40wt.% hydrofluoric acid solution for 72h, and then centrifuge and wash it at 7000r / min to obtain multilayer MBene material, i.e. multilayer MoB material.

[0090] S2, the obtained product was centrifuged at 5000 r / min for 5 min, filtered, and a monolayer MBene material was obtained, denoted as MoB.

[0091] Comparative Example 2

[0092] The difference from Example 2 is that it does not load metal sulfides and uses Cr-based MBene material.

[0093] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0094] S1, take 1.5g of precursor Cr2AlB2, etch it in a 40wt.% hydrofluoric acid solution for 48h, and then centrifuge and wash it at 6000r / min to obtain multilayer MBene material, i.e. multilayer CrB material.

[0095] S2, the obtained product was centrifuged at 7000 r / min for 5 min, filtered, and a single-layer CrB material was obtained, denoted as CrB.

[0096] Comparative Example 3

[0097] The difference compared to Example 3 is that it does not support metal sulfides and uses Mn-based MBene material.

[0098] A method for preparing a two-dimensional MBene-metal sulfide composite material includes the following steps:

[0099] Step 1: Take 1.5g of precursor Mn2AlB2, etch it in 50wt.% hydrofluoric acid solution for 56 hours, and then centrifuge and wash it at 6000 rpm to obtain multilayer MnB material.

[0100] Step 2: The obtained product is centrifuged at 10,000 rpm for 5 min, filtered, and a single-layer MnB material is obtained, denoted as MnB.

[0101] The performance test results of the two-dimensional MBene-metal sulfide composite materials prepared in Examples 1 to 8 of this invention and the two-dimensional pure MBene nanosheets prepared in Comparative Examples 1 to 3 are as follows.

[0102] Figure 1 These are XRD patterns of the two-dimensional MoB / MoS2 composite materials from Examples 1 to 5 of this invention. Figure 1 It can be seen that MoB has a characteristic peak of (001) within 10 degrees, and the characteristic peak of MoS2 (100) also becomes significantly stronger with the increase of the proportion of MoS2, proving the effective recombination of the two.

[0103] Figure 2 The images show the XRD patterns of the two-dimensional MoB / MoS2 composite material obtained in Example 1, the CrB / CoS composite material obtained in Example 6, and the MnB / MoS2 composite material obtained in Example 7. Figure 2 As can be seen from the data, the characteristic peaks of both MoB and MoS2 can be detected in the MoB / MoS2 composite material, indicating that MoS2 was successfully loaded onto the MoB surface. MBene has a characteristic peak of (001) within 10 degrees, and the characteristic peak of sulfide (100) is also confirmed, proving the effective composite of the two.

[0104] Figure 3 This is a SEM image of the two-dimensional MoB / MoS2 composite material from Example 1 of the present invention. Figure 3 It can be seen that the MoB surface is uniformly loaded with MoS2 nanoparticles, resulting in a typical accordion structure, and the MoS2 intercalation effect is excellent.

[0105] Figure 4 This is a TEM image of the two-dimensional MoB / MoS2 composite material from Example 1 of the present invention. Figure 4 It can be seen that the thickness of the obtained monolayer MoB nanosheets is less than 5 nm, and there are no defects or vacancies on the surface.

[0106] Figure 5 This is a graph showing the electromagnetic absorption properties of the two-dimensional MoB / MoS2 composite material of Example 1 of the present invention. Figure 5It is known that the maximum absorption intensity of the two-dimensional MoB / MoS2 composite material is -45dB, and by adjusting the thickness, the effective absorption bandwidth can cover the range of 4.6-18GHz.

[0107] Figure 6 This is a graph showing the electromagnetic absorption performance of two-dimensional MoB as described in Comparative Example 1 of this invention. (The graph is derived from...) Figure 6 It can be seen that the maximum absorption intensity of the two-dimensional pure MoB material is -18dB, and the absorption intensity is significantly reduced.

[0108] Figure 7 This is a graph showing the electromagnetic absorption performance of two-dimensional CrB in Comparative Example 2 of this invention. (From...) Figure 7 It can be seen that the maximum absorption intensity of the two-dimensional pure CrB material is -12dB, and the absorption intensity is significantly reduced.

[0109] Figure 8 This is a graph showing the electromagnetic absorption performance of two-dimensional MnB in Comparative Example 3 of this invention. (From...) Figure 8 It can be seen that the maximum absorption intensity of the two-dimensional pure MnB material is -23dB, and the absorption intensity is significantly reduced.

[0110] In summary, this invention significantly improves the electromagnetic properties of composite materials by enhancing dielectric loss through the heterostructure of multilayer MBene materials and the nano-effect of metal sulfides. The two-dimensional MBene / metal sulfide composite material prepared by this invention has potential application prospects in the field of electromagnetic protection.

[0111] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a two-dimensional MBene-metal sulfide composite material, characterized in that, Includes the following steps: The precursor MAB phase was etched with hydrofluoric acid solution to obtain a multilayer MBene material; the precursor MAB phase was MoAlB, WAlB, Cr2AlB2, Fe2AlB2 or Mn2AlB2. Thiourea and a soluble metal salt are dissolved in water, and the multilayer MBene material is added and mixed. The mixture is then subjected to a hydrothermal reaction at 100℃~250℃ to obtain metal sulfide nanoparticles, which are then in situ loaded onto the multilayer MBene material to obtain a two-dimensional MBene-metal sulfide composite material. The mass ratio of the multilayer MBene material, thiourea, and soluble metal salt is 1:1~50:0.5~30. The soluble metal salt is sodium molybdate, cobalt nitrate, ferric nitrate, nickel nitrate, copper nitrate, cobalt acetate, ferric acetate, nickel acetate, or copper acetate.

2. The preparation method according to claim 1, characterized in that, The hydrothermal reaction time is 0.5h to 6h.

3. The preparation method according to claim 1, characterized in that, The concentration of the hydrofluoric acid solution is 30wt%~60wt%, and the ratio of the precursor MAB phase to the hydrofluoric acid solution is 1g:10mL~200mL.

4. The preparation method according to claim 1, characterized in that, The etching time is 24h~96h.

5. The preparation method according to claim 1, characterized in that, After hydrothermal reaction, the product is centrifuged at 5000r / min~10000r / min for 5min~30min, filtered, and the primary product is obtained. The primary product is washed with deionized water and ethanol, and dried at 50℃~100℃ for 6h~24h to obtain a two-dimensional MBene-metal sulfide composite material.

6. A two-dimensional MBene-metal sulfide composite material prepared by the preparation method according to any one of claims 1 to 5.

7. The application of the two-dimensional MBene-metal sulfide composite material of claim 6 in the preparation of electromagnetic absorbing materials.

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