Two-dimensional MBene-metal sulfide composite material as well as preparation method and application thereof

Abstract

The invention discloses a two-dimensional MBene-metal sulfide composite material and a preparation method and application thereof, and belongs to the technical field of electromagnetic wave-absorbing materials.Metal sulfide is used for controlling the stripping process of two-dimensional MBene, and a heterostructure of a two-dimensional MBene nanosheet loaded with evenly-dispersed metal sulfide particles is obtained through a high-temperature hydrothermal reaction; the two-dimensional MBene-metal sulfide composite material prepared by the preparation method disclosed by the invention has excellent electromagnetic performance due to the dielectric loss enhanced by the heterostructure and the nano effect of the metal sulfide. The metal sulfide intercalation strategy provided by the invention lays a foundation for the development of advanced two-dimensional electromagnetic absorption materials, and provides a universal method for the development of other two-dimensional nanosheets with adjustable structures.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wave absorbing materials, and particularly relates to a two-dimensional MBene-metal sulfide composite material, a preparation method thereof and an application thereof. Background Art

[0002] In the current era of rapid technological development, the importance of wave-absorbing materials has become increasingly prominent, which is driven by various factors. Wave-absorbing materials can absorb and convert unwanted electromagnetic waves into other forms of energy, such as heat energy, etc., thereby reducing electromagnetic interference and electromagnetic pollution, and having broad application prospects in the civilian field.

[0003] In recent years, due to their ultra-thin structure, high specific surface area and adjustable electromagnetic parameters, two-dimensional nanosheet materials have been widely used in electromagnetic interference shielding and electromagnetic wave absorption. Two-dimensional nanosheet materials include two-dimensional transition metal borides (MBene), two-dimensional carbon materials, and chalcogenide compounds such as transition metal disulfides. MBene is derived from ternary layered transition metal borides (MAB phase), and MBene can be obtained by chemically etching away the Al layer. MBene has metallic conductivity, excellent mechanical, optical and electronic properties, and has received great attention in the fields of optoelectronic devices, catalysis and energy. At the same time, because MBene has a relatively high complex dielectric constant and is a dielectric material with good electrical storage and dissipation capabilities, it is considered a promising excellent electromagnetic absorption material. The use of different two-dimensional material composites can provide a large number of interfaces beneficial to electromagnetic wave absorption. However, since two-dimensional MBene materials are prone to aggregation, more surface atoms cannot be exposed and the electron transport and migration are restricted, resulting in poor electromagnetic properties of two-dimensional MBene materials. Summary of the Invention

[0004] The present invention provides a two-dimensional MBene-metal sulfide composite material, a preparation method thereof and an application thereof, effectively solving the technical problem that the existing two-dimensional materials are easy to agglomerate and it is impossible to obtain two-dimensional materials with better electromagnetic properties. The present invention uses metal sulfide to manipulate the exfoliation process of two-dimensional MBene. Through a hydrothermal reaction at high temperature, a heterostructure of two-dimensional MBene nanosheets loaded with uniformly dispersed metal sulfide particles is obtained. Due to the enhanced dielectric loss of the heterostructure and the nano-effect of metal sulfide, the two-dimensional MBene-metal sulfide composite material prepared by the present invention has excellent electromagnetic properties. The metal sulfide intercalation strategy proposed by the present invention lays a foundation for the development of advanced two-dimensional electromagnetic absorption materials and provides a general method for the development of other two-dimensional nanosheets with adjustable structures.

[0005] The first object of the present invention is to provide a preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0006] The precursor MAB phase is etched using a hydrofluoric acid solution to obtain a multilayer MBene material;

[0007] Dissolve thiourea and soluble metal salt in water, add the multilayer MBene material, mix well, and perform hydrothermal reaction at 100°C to 250°C to obtain metal sulfide nanoparticles, which are in situ loaded on the multilayer nanomaterial to obtain a two-dimensional MBene-metal sulfide composite material.

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

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

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

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

[0012] As a preferred embodiment, the precursor MAB phase is MoAlB, WAlB, Cr 2 AB 2 , Fe 2 AB 2 , Mn 2 AB 2 or (Mo 2 / 3 Y 1 / 3 )AlB 2 .

[0013] As a preferred implementation manner, the etching time is 24 hours to 96 hours.

[0014] As a preferred embodiment, after the hydrothermal reaction, centrifuge at 5000r / min~10000r / min for 5min~30min, filter to obtain a primary product, wash the primary product with deionized water and ethanol, and dry it at 50℃~100℃ for 6h~24h to obtain a two-dimensional MBene-metal sulfide composite material.

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

[0016] The third object of the present invention is to provide an application of the above two-dimensional MBene-metal sulfide composite material in the preparation of electromagnetic wave absorbing materials.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention provides a preparation method of a two-dimensional MBene-metal sulfide composite material. The precursor MAB phase is etched with a hydrofluoric acid solution to obtain a multi-layer MBene material. Using thiourea and a soluble metal salt as raw materials, adding the multi-layer MBene material, mixing evenly and carrying out a hydrothermal reaction to obtain metal sulfide nanoparticles and load them on the multi-layer MBene material to obtain a two-dimensional MBene-metal sulfide composite material. The present invention utilizes the hydrothermal reaction to generate metal sulfide and in-situ load it in the interlayer of the multi-layer MBene material. The peeling of the multi-layer MBene material is realized by the gradual embedding of the metal sulfide in the multi-layer MBene material, thereby greatly increasing the specific surface area of the multi-layer MBene material and exposing more surface atoms. The interlayer distance of the peeled multi-layer MBene material increases, which is conducive to the transmission and migration of electrons. In the present invention, since the prepared multi-layer MBene material has fully exposed active sites, good conductive loss, high specific surface area, and a large number of surface-exposed atoms, the composite material of the present invention is endowed with excellent mechanical and electronic properties, can effectively regulate electromagnetic parameters and obtain excellent electromagnetic absorption performance. The metal sulfide obtained by the hydrothermal reaction is gradually embedded on the multi-layer MBene material. Due to the nano-size effect and dielectric properties of the metal sulfide particles, high-efficiency dielectric loss and dipole polarization are provided. The present invention significantly improves the electromagnetic properties of the composite material through the enhanced dielectric loss of the multi-layer MBene material heterostructure and the nano-effect of the metal sulfide. The two-dimensional MBene-metal sulfide composite material prepared by the present invention has potential application prospects in the field of electromagnetic protection. Description of the Drawings

[0019] Figure 1 It is the XRD pattern of the two-dimensional MBene-metal sulfide composite materials of Examples 1 to 5 of the present invention. Among them, 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 It is the XRD pattern of the two-dimensional MBene-metal sulfide composite materials prepared in Examples 1 to 3 of the present invention. Among them, MoB / MoS 2 is Example 1, CrB / CoS is Example 6, MnB / MoS2 This is Example 7.

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

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

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

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

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

[0026] Figure 8 This is the electromagnetic absorption performance diagram of two-dimensional MnB of Comparative Example 3 of the present invention. Detailed implementation manners

[0027] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the specific embodiments cited do not limit the present invention. The following test methods and detection methods are all conventional methods unless otherwise specified; the reagents and raw materials are all commercially available unless otherwise specified.

[0028] As mentioned in the background art of the present invention: In the field of electromagnetic wave absorbing materials, two-dimensional transition metal borides (MBene) are a new type of two-dimensional material with metallic conductivity, excellent mechanical, optical and electronic properties, and have received great attention in the fields of optoelectronic devices, catalysis and energy. Composite of different two-dimensional materials can provide a large number of interfaces beneficial to electromagnetic wave absorption. However, the existing two-dimensional materials have the problem of easy agglomeration, resulting in the inability to achieve layer-by-layer ordered embedding, thus affecting the electromagnetic properties of two-dimensional materials. Based on the above technical problems, the present invention provides a two-dimensional MBene-metal sulfide composite material, its preparation method and application.

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

[0030] The present invention first provides a preparation method of a two-dimensional MBene-metal sulfide composite material, including the following steps:

[0031] Etch the precursor MAB phase with a hydrofluoric acid solution to obtain a multi-layer MBene material;

[0032] Dissolve thiourea and soluble metal salts in water, add the multi-layer MBene material, mix well, and carry out a hydrothermal reaction at 100 °C to 250 °C to obtain metal sulfide nanoparticles, which are in-situ loaded on the multi-layer nanomaterial to obtain a two-dimensional MBene-metal sulfide composite material.

[0033] For the above hydrothermal reaction temperature, if it is less than 100 °C, the reaction will be insufficient and the multi-layer MBene material cannot be obtained; if the reaction temperature is higher than 250 °C, the temperature is too high, and the multi-layer MBene material will be severely oxidized.

[0034] In the above technical solution, since the prepared multi-layer MBene material has fully exposed active sites, good conductive loss, high specific surface area, and a large number of surface-exposed atoms, the composite material of the present invention is endowed with excellent mechanical and electronic properties, can effectively regulate electromagnetic parameters and obtain excellent electromagnetic absorption performance; on the other hand, the metal sulfide obtained by the hydrothermal reaction is gradually embedded on the multi-layer MBene material. Due to the nano-size effect and dielectric properties of the metal sulfide particles, high-efficiency dielectric loss and dipole polarization are provided.

[0035] In order to further improve the dielectric properties of the composite material, based on the mass of the two-dimensional MBene-metal sulfide composite material, the loading amount of the metal sulfide is 5% to 20%.

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

[0037] In order to obtain a multi-layer MBene material with better performance, the hydrothermal reaction time is 0.5 to 6 h. Combining the above hydrothermal reaction temperature, if the hydrothermal reaction time is less than 0.5 h, the reaction will also be insufficient and the multi-layer MBene material cannot be obtained. If the reaction time is greater than 6 h, the MBene material will be severely oxidized.

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

[0039] It should be noted that the precursor MAB phase of the present invention is selected from MoAlB, WAlB, Cr 2 AlB 2 、Fe 2 AlB 2 、Mn 2 AlB 2 or (Mo2 / 3 Y 1 / 3 )AlB 2 。

[0040] To fully etch the Al layer on the precursor MAB phase, the etching time is 24 h to 96 h. If the etching time is less than 24 h, the etching is insufficient and the proportion of the single-layer MBene material is too low; if the etching time is greater than 96 h, over-etching occurs, oxidation is severe, and the quality of the single-layer MBene material is not high.

[0041] To remove the influence of impurity substances, obtain a composite material with higher purity, and further improve the electromagnetic properties of the composite material, after the hydrothermal reaction, centrifuge at 5000 r / min to 10000 r / min for 5 min to 30 min, filter to obtain a primary product, wash the primary product with deionized water and ethanol, and dry it at 50 °C to 100 °C 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 examples and comparative examples.

[0043] Example 1

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

[0045] S1. Take 1.5 g of the precursor MoAlB, etch it in a hydrofluoric acid solution with a concentration of 40 wt.%, and then centrifuge and wash it at a speed of 7000 r / min to obtain multi-layer MBene powder, that is, multi-layer MoB material.

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

[0047] S3. Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 210 °C for 50 min, centrifuge at 5000 r / min for 5 min, filter to obtain a primary product, wash it several times with deionized water and ethanol respectively, and finally dry it in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS 2 composite material, and the mass ratio of MoB to MoS 2 is 1:1.4.

[0048] Example 2

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

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

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

[0052] S3. Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 210 °C for 50 min, centrifuge at 5000 r / min for 5 min, filter to obtain a primary product, wash it several times with deionized water and ethanol respectively, and finally dry it in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS 2 Composite material, the mass ratio of MoB to MoS 2 is 1:1.6.

[0053] Example 3

[0054] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

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

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

[0057] S3. Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 210 °C for 50 min, centrifuge at 5000 r / min for 5 min, filter to obtain a primary product, wash it several times with deionized water and ethanol respectively, and finally dry it in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS 2 Composite material, the mass ratio of MoB to MoS 2 is 1:1.2.

[0058] Example 4

[0059] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

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

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

[0062] S3. Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 210 °C for 50 min, centrifuge at 5000 r / min for 5 min, filter to obtain the primary product, wash it several times with deionized water and ethanol respectively, and finally dry it in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS 2 Composite material, the mass ratio of MoB to MoS 2 is 1:1.0.

[0063] Example 5

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

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

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

[0067] S3. Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 210 °C for 50 min, centrifuge at 5000 r / min for 5 min, filter to obtain the primary product, wash it several times with deionized water and ethanol respectively, and finally dry it in a vacuum oven at 70 °C for 12 h to obtain a two-dimensional MBene-metal sulfide composite material, denoted as MoB / MoS 2 Composite material, the mass ratio of MoB to MoS 2 is 1:0.75.

[0068] Example 6

[0069] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0070] S1, Take 1.5 g of the precursor Cr 2 AlB 2 , etch it in a hydrofluoric acid solution with a concentration of 40 wt.% for 48 h, and then centrifuge and wash it at a speed of 6000 r / min to obtain a multi-layer MBene material, that is, a multi-layer CrB material.

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

[0072] S3, Transfer the homogeneous solution to a 200 mL stainless steel autoclave with a polytetrafluoroethylene liner, carry out a hydrothermal reaction at 180 °C for 2 h, centrifuge at 7000 r / min for 5 min, filter to obtain a primary product, wash it several times with deionized water and ethanol respectively, and finally dry it 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 preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0075] Step 1: Take 1.5 g of the precursor Mn 2 AlB 2 , etch it in a 50 wt.% hydrofluoric acid solution for 56 hours, and then centrifuge and wash it at a speed of 6000 revolutions per minute to obtain multi-layer MBene, that is, multi-layer MnB material.

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

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

[0078] Step 4: The obtained product is centrifuged at 10000 revolutions per minute for 10 minutes and then filtered, washed several times with deionized water and ethanol respectively, and finally dried in a vacuum oven at 60 degrees for 12 hours to obtain a two-dimensional MnB / MoS 2 Composite material.

[0079] Example 8

[0080] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0081] Step 1: Take 1.5 g of the precursor (Mo 2 / 3 Y 1 / 3 )AlB 2 , etch it in a 40 wt.% hydrofluoric acid solution for 48 hours, and then centrifuge and wash it at a speed of 6000 revolutions per minute to obtain multi-layer MBene, that is, multi-layer MnB material.

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

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

[0084] Step 4: The obtained product is centrifuged at 10000 revolutions per minute for 10 minutes and then filtered, washed several times with deionized water and ethanol respectively, and finally dried in a vacuum oven at 60 °C for 12 hours to obtain a two-dimensional Mo 1.33 B 2 / CoS composite material.

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

[0086] Comparative Example 1

[0087] Compared with Example 1, the difference is that no metal sulfide is loaded.

[0088] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0089] S1, Take 1.5 g of the precursor MoAlB, etch it in a hydrofluoric acid solution with a concentration of 40 wt.% for 72 h, and then centrifuge and wash it at a speed of 7000 r / min to obtain a multi-layer MBene material, that is, multi-layer MoB material.

[0090] S2, The obtained product is centrifuged at 5000 r / min for 5 min and filtered to obtain a single-layer MBene material, denoted as MoB.

[0091] Comparative Example 2

[0092] Compared with Example 2, the difference is that no metal sulfide is loaded and a Cr-based MBene material is used.

[0093] A preparation method of a two-dimensional MBene-metal sulfide composite material, comprising the following steps:

[0094] S1, Take 1.5 g of the precursor Cr 2 AlB 2 , etch it in a hydrofluoric acid solution with a concentration of 40 wt.% for 48 h, and then centrifuge and wash it at a speed of 6000 r / min to obtain a multi-layer MBene material, that is, a multi-layer CrB material.

[0095] S2, Centrifuge the obtained product at 7000 r / min for 5 min, filter it to obtain a single-layer CrB material, denoted as CrB.

[0096] Comparative Example 3

[0097] Compared with Example 3, the difference lies in that no metal sulfide is loaded, and an Mn-based MBene material is used.

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

[0099] Step 1: Take 1.5 g of the precursor Mn 2 AlB 2 , etch it in a 50 wt.% hydrofluoric acid solution for 56 hours, and then centrifuge and wash it at a speed of 6000 revolutions per minute to obtain a multi-layer MnB material.

[0100] Step 2: Centrifuge the obtained product at 10000 revolutions per minute for 5 min, filter it to obtain a single-layer MnB material, denoted as MnB.

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

[0102] Figure 1 For the two-dimensional MoB / MoS of Examples 1 to 5 of the present invention 2 Composite material XRD pattern. From Figure 1 It can be seen that MoB has a characteristic peak of (001) within 10 degrees, and the (100) characteristic peak of MoS 2 also becomes significantly stronger with the increase in the proportion of MoS 2 , proving the effective combination of the two.

[0103] Figure 2 For the two-dimensional MoB / MoS prepared in Example 1 of the present invention 2 Composite material complex, the CrB / CoS complex prepared in Example 6, and the MnB / MoS prepared in Example 7 2 Composite material XRD spectrum. From Figure 2 It can be seen that MoB / MoS 2In the composite material, the characteristic peaks of MoB and MoS 2 can both be detected, indicating that MoS 2 is successfully loaded onto the surface of MoB. MBene has a characteristic peak of (001) within 10 degrees, and the characteristic peak of (100) of the sulfide is also confirmed, proving the effective combination of the two.

[0104] Figure 3 This is the SEM morphology diagram of the two-dimensional MoB / MoS 2 composite material of Example 1 of the present invention. It can be seen from Figure 3 that nanoparticles of MoS 2 are evenly loaded on the surface of MoB, obtaining a typical accordion structure, and the intercalation effect of MoS 2 is excellent.

[0105] Figure 4 This is the TEM electron micrograph of the two-dimensional MoB / MoS 2 composite material of Example 1 of the present invention. It can be seen from Figure 4 that the thickness of the obtained single-layer MoB nanosheets is less than 5 nm and there are no defect vacancies on the surface.

[0106] Figure 5 This is the electromagnetic absorption performance diagram of the two-dimensional MoB / MoS 2 composite material of Example 1 of the present invention. It can be seen from Figure 5 that the maximum absorption intensity of the two-dimensional MoB / MoS 2 composite material is -45 dB, and by adjusting the thickness, the effective absorption bandwidth can cover the range of 4.6 - 18 GHz.

[0107] Figure 6 This is the electromagnetic absorption performance diagram of two-dimensional MoB of Comparative Example 1 of the present invention. It can be seen from Figure 6 that the maximum absorption intensity of the two-dimensional pure MoB material is -18 dB, and the absorption intensity is significantly reduced.

[0108] Figure 7 This is the electromagnetic absorption performance diagram of two-dimensional CrB of Comparative Example 2 of the present invention. It can be seen from Figure 7 that the maximum absorption intensity of the two-dimensional pure CrB material is -12 dB, and the absorption intensity is significantly reduced.

[0109] Figure 8 This is the electromagnetic absorption performance diagram of two-dimensional MnB of Comparative Example 3 of the present invention. It can be seen from Figure 8 that the maximum absorption intensity of the two-dimensional pure MnB material is -23 dB, and the absorption intensity is significantly reduced.

[0110] In summary, the present invention significantly improves the electromagnetic properties of the composite material through the enhanced dielectric loss of the multi-layer MBene material heterostructure and the nano-effect of metal sulfide. The two-dimensional MBene / metal sulfide composite material prepared by the present 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 the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a two-dimensional MBene-metal sulfide composite material, characterized in that: The following steps are involved: The precursor MAB phase is etched using a hydrofluoric acid solution to obtain a multilayer MBene material; Dissolve thiourea and soluble metal salt in water, add the multilayer MBene material, mix well, and perform hydrothermal reaction at 100° C. to 250° C. to obtain metal sulfide nanoparticles, which are in-situ loaded on the multilayer MBene material to obtain a two-dimensional MBene-metal sulfide composite material.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the multilayer MBene material, thiourea and soluble metal salt is 1:1-50:0.5-30.

3. The preparation method according to claim 2, characterized in that: The soluble metal salt is sodium molybdate, cobalt nitrate, iron nitrate, nickel nitrate, copper nitrate, sodium acetate, cobalt acetate, iron acetate, nickel acetate or copper acetate.

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

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

6. The preparation method according to claim 5, characterized in that: The precursor MAB phase is MoAlB, WAlB, Cr2AlB2, Fe2AlB2, Mn2AlB2 or (Mo 2 / 3 Y 1 / 3 )AlB2.

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

8. The preparation method according to claim 1, characterized in that: After the hydrothermal reaction, centrifuge at 5000 r / min to 10000 r / min for 5 min to 30 min, filter to obtain a primary product, wash the primary product with deionized water and ethanol, dry at 50° C. to 100° C. for 6 h to 24 h to obtain a two-dimensional MBene-metal sulfide composite material.

9. A two-dimensional MBene-metal sulfide composite material prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the two-dimensional MBene-metal sulfide composite material according to claim 9 in preparing an electromagnetic absorbing material.

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