Two-dimensional molybdenum disulfide NANO material, preparation method therefor, and use thereof

Abstract

Provided in the present application are a two-dimensional 1T-phase molybdenum disulfide nano material, a preparation method therefor, and the use thereof. The two-dimensional 1T-phase molybdenum disulfide nano material satisfies the following conditions: the monolayer ratio of the molybdenum disulfide is 97% or above, the content of the 1T-phase molybdenum disulfide represented by X-ray photoelectron spectroscopy is 90% or above, and the surface has defects. The monolayer ratio of the two-dimensional molybdenum disulfide nano material being 97% or above indicates that the proportion of monolayer molybdenum disulfide nanosheets in the nano material is very high; the mass content of the 1T-phase molybdenum disulfide being 90% or above indicates that the nano material has good metallicity; and meanwhile, the presence of defects on the surface of the nano material indicates that the nano material has good dispersibility in solvents and also has good electrocatalytic performance, especially having excellent electrocatalytic hydrogen evolution performance under an industrial current density; the catalytic performance of the nano material is better than that of commercial Pt / C and even can be kept stable for 100 h without deterioration; thus, the nano material is one of the most superior non-precious-metal hydrogen evolution catalysts at present.

Description

A two-dimensional molybdenum disulfide nanomaterial, its preparation method and application Technical Field

[0001] The present application relates to the field of materials, and specifically to a two-dimensional molybdenum disulfide nanomaterial, a preparation method thereof, and applications. Background Art

[0002] Two-dimensional materials are nanomaterials composed of a single or several layers of atoms. These ultra-thin nanomaterials possess unique physical, chemical, and mechanical properties, giving them broad application prospects in optoelectronics, catalysis, energy storage, sensing, nanocomposites, and other fields. The transition metal sulfur compound molybdenum disulfide (MoS2) has a graphene-like layered structure, with van der Waals forces between the layers. MoS2 has three crystal structures: 1T, 2H, and 3R. The 1T-MoS2 structure has an octahedral coordination structure, exhibits metallic properties, and is a metastable structure. The 2H-MoS2 crystal contains two Mo-S units and is a stable structure. The 3R-MoS2 crystal contains one more Mo-S unit than the 2H-MoS2 crystal, meaning it contains three Mo-S units.

[0003] Two-dimensional MoS2 materials of different crystalline phases exhibit distinct properties. Due to its unique electronic structure, metallic 1T-MoS2 exhibits superior performance compared to the semiconducting 2H-MoS2 phase in electrochemical hydrogen production, field-effect transistors, and supercapacitors. Ultrathin single-layer MoS2 nanosheets also exhibit superior optoelectronic and catalytic properties. However, large-scale preparation of single-layer two-dimensional 1T-MoS2 materials remains challenging, particularly in terms of synthetic strategies for large-scale production, which severely limits their further application.

[0004] The alkali metal intercalation exfoliation method is a widely used strategy for preparing ultra-thin single-layer MoS2 nanosheets in the laboratory. It is to obtain a single-layer 1T-MoS2 nanosheet by exfoliating bulk MoS2 through intercalation chemistry or electrochemistry. Due to the activity of the alkali metal in its synthesis process, it is difficult to prepare it in large quantities, especially at the kilogram level. Moreover, the defects of the obtained 1T-MoS2 nanosheets cannot be controlled, and the dispersion is poor, the applicability is poor, and the industrial electrocatalytic application effect is also not ideal. At the same time, there are many alkali metal residues in the obtained nanosheets, which limits its application in catalysis and medical fields. For example, the Chinese patent with the authorization announcement number CN106311282B discloses a method for preparing and applying porous single-layer 1T-MoS2 nanosheets, which uses ultrasonic-assisted lithium ion intercalation to exfoliate multilayer MoS2 nanosheets to obtain single-layer 1T-MoS2 nanosheets. However, the reaction needs to be carried out under strictly anhydrous and oxygen-free conditions, and n-butyl lithium n-hexane solution is used to assist in the exfoliation. The experimental conditions are harsh, and the synthetic product contains Li +, large-scale preparation is difficult and has limited application. Hydrothermal or solvothermal methods have the advantages of mild reaction conditions and large-scale preparation, and can prepare 1T-MoS2 nanoflower balls, but the thickness of their nanosheets is generally several hundred nanometers, and further peeling is required to obtain ultra-thin single-layer nanosheets. Therefore, the use of hydrothermal methods to prepare single-layer MoS2 nanosheets is extremely challenging. For example, Chinese patent application publication number CN107651708A discloses a microwave hydrothermal method for preparing 1T@2H MoS2. It uses ammonium heptamolybdate and thiourea as raw materials to synthesize MoS2 nanospheres in a microwave hydrothermal method. The operation is simple and can be scaled up for production, but the 1T phase content of the obtained sample is not high, and the thickness cannot be controlled, resulting in nanoflower balls. Therefore, achieving large-scale preparation of single-layer 1T-MoS2 remains a huge challenge.

[0005] Summary of the Invention

[0006] The present application provides a two-dimensional 1T phase molybdenum disulfide nanomaterial, its preparation method and application, to solve the problems of low monolayer rate and 1T phase content of two-dimensional molybdenum disulfide nanomaterials.

[0007] The first aspect of the present application provides a two-dimensional molybdenum disulfide nanomaterial, and the two-dimensional 1T phase molybdenum disulfide nanomaterial meets the following conditions: the monolayer rate of molybdenum disulfide is above 97%, the content of 1T phase molybdenum disulfide characterized by X-ray photoelectron spectroscopy is above 90%, and the surface has defects.

[0008] In any embodiment of the first aspect of the present application, the water contact angle of the two-dimensional molybdenum disulfide nanomaterial is below 35°, preferably below 30°.

[0009] In any embodiment of the first aspect of the present application, the mass content of impurity ions in the two-dimensional molybdenum disulfide nanomaterial is less than 0.5%, preferably less than 100 ppm.

[0010] In any embodiment of the first aspect of the present application, the lateral size distribution of the two-dimensional molybdenum disulfide nanomaterials accounting for more than 90% of the number is between 75nm and 150nm.

[0011] The second aspect of the present application provides a method for preparing a two-dimensional 1T phase molybdenum disulfide nanomaterial, the preparation method comprising: step S1, inserting molybdate ions into the interlayer of a layered double hydroxide to obtain an LDH-molybdate intercalation complex; step S2, inserting a molybdate ion into a layered double hydroxide to obtain an LDH-molybdate intercalation complex; 2- The ionic compound undergoes a solvothermal reaction with the LDH-molybdate intercalation complex to obtain an LDH-MoS2 complex; in step S3, the LDH-MoS2 complex is etched with acid to remove the layered double hydroxide to obtain a two-dimensional 1T phase molybdenum disulfide nanomaterial.

[0012] In any embodiment of the second aspect of the present application, the above-mentioned step S1 includes: calcining the layered double metal hydroxide to obtain a layered bimetallic oxide, preferably at a calcination temperature of 400°C-600°C and a calcination time of 1h-5h; mixing the layered double metal oxide with an aqueous solution of molybdate, so that the molybdate ions are inserted into the interlayer of the layered double metal hydroxide during the reconstruction process of the layered double metal oxide into the layered double metal hydroxide, to obtain an LDH-molybdate intercalation complex, preferably mixing the layered double metal oxide and the aqueous solution of molybdate at 40°C-80°C under protective gas protection for 24h-60h, preferably the protective gas is nitrogen or an inert gas.

[0013] In any embodiment of the second aspect of the present application, the content of molybdate in the aqueous solution of molybdate is 0.1 mol / L-2 mol / L; preferably, the weight ratio of the layered bimetallic oxide to the molybdate is (0.5-3):1.

[0014] In any embodiment of the second aspect of the present application, step S1 comprises inserting molybdate ions into the interlayers of the layered double hydroxide using an ion exchange method or a coprecipitation method to obtain an LDH-molybdate intercalation complex.

[0015] In any embodiment of the second aspect of the present application, the layered hydroxide includes any one or more of calcium magnesium hydroxide, magnesium aluminum hydroxide and magnesium iron hydroxide.

[0016] In any embodiment of the second aspect of the present application, the molybdate ion is derived from molybdate, and the molybdate is selected from (NH4)6Mo7O 24 ·4H2O, Na2MoO4·2H2O, K2MoO4 or (NH4)3PO4·12MoO3 any one or more.

[0017] In any embodiment of the second aspect of the present application, step S2 comprises: 2- The ionic compound and the LDH-molybdate intercalation complex are dispersed in a solvent to form a reaction solution, preferably containing S 2- The ionic compound is selected from any one or more of thiourea, ammonium sulfide, or thioacetamide; the reaction solution is subjected to a solvent thermal reaction at 150°C-250°C to obtain an LDH-MoS2 complex, and the solvent thermal reaction time is preferably 6h-72h.

[0018] In any embodiment of the second aspect of the present application, the solvent is selected from any one or more of water and organic solvents.

[0019] In any embodiment of the second aspect of the present application, the organic solvent includes any one or more of an alcohol solvent, an ether solvent and a ketone solvent; preferably, the alcohol solvent includes any one or more of a C1-C6 monohydric alcohol and a C2-C6 dihydric alcohol; preferably, the alcohol solvent includes any one or more of methanol, ethanol, ethylene glycol and isopropanol.

[0020] In any embodiment of the second aspect of the present application, the LDH-molybdate intercalation complex is 2- The weight ratio of the ionic compound is 1:(0.5-10).

[0021] The third aspect of the present application also provides a two-dimensional molybdenum disulfide nanomaterial prepared by any one of the preparation methods of the second aspect.

[0022] The fourth aspect of the present application also provides a catalyst comprising a two-dimensional molybdenum disulfide material, wherein the two-dimensional molybdenum disulfide material comprises any one or more two-dimensional molybdenum disulfide nanomaterials provided in the first aspect or the third aspect.

[0023] The third aspect of the present application further provides a negative electrode material, comprising a two-dimensional molybdenum disulfide material, wherein the two-dimensional molybdenum disulfide material comprises any one or more two-dimensional molybdenum disulfide nanomaterials provided in the first aspect or the third aspect.

[0024] The third aspect of the present application also provides an application of any one or more of the two-dimensional molybdenum disulfide nanomaterials provided in the first aspect or the third aspect, wherein the application includes using the two-dimensional molybdenum disulfide nanomaterial as a drug carrier and / or drug additive.

[0025] The monolayer rate of the two-dimensional molybdenum disulfide nanomaterial of the present application is above 97%, indicating that the proportion of single-layer molybdenum disulfide nanosheets therein is extremely high; and the mass content of 1T phase molybdenum disulfide is above 90%, indicating that it has good metallic properties; its surface contains defects, so it has good dispersibility and good electrocatalytic performance, especially at industrial current density. It has excellent electrocatalytic hydrogen evolution performance, and its catalytic performance exceeds that of commercial Pt / C, and it is even stable for 100 hours without attenuation. It is one of the current excellent non-precious metal water decomposition hydrogen catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0027] Figure 1 shows the XRD spectra of the two-dimensional molybdenum disulfide nanomaterial powder of Example 1 of the present application and the molybdenum disulfide nanoflower ball of Comparative Example 1, as well as a photo of the kilogram-scale two-dimensional molybdenum disulfide nanosheet gel prepared in Example 1.

[0028] FIG2 shows the SEM image and TEM image of the two-dimensional molybdenum disulfide nanomaterial of Example 1 of the present application.

[0029] FIG3 shows a HRTEM image of the two-dimensional molybdenum disulfide nanomaterial according to Example 1 of the present application.

[0030] FIG4 shows dispersion photos of the two-dimensional molybdenum disulfide nanomaterial in different solvents and water contact angle test photos according to Example 1 of the present application.

[0031] FIG5 shows the AFM image and thickness statistics of the two-dimensional molybdenum disulfide nanomaterial of Example 1 of the present application.

[0032] FIG6 shows the lateral size distribution results of the two-dimensional molybdenum disulfide nanomaterial according to Example 1 of the present application based on AFM analysis.

[0033] FIG7 is an XPS characterization diagram of the two-dimensional molybdenum disulfide nanomaterial powder and commercial 2H phase MoS2 of Example 1.

[0034] FIG8 shows the EDS characterization results of the two-dimensional molybdenum disulfide nanomaterial of Example 1.

[0035] FIG9 shows the EPR spectra of the single-layer molybdenum disulfide material powders of Examples 1 and 2 of the present application.

[0036] FIG10 shows the EPR spectra of the single-layer molybdenum disulfide material powders of Examples 1 and 3 of the present application.

[0037] FIG11 shows an SEM spectrum of the two-dimensional molybdenum disulfide nanomaterial powder of Example 4 of the present application.

[0038] FIG12 shows the SEM and TEM images of the 1T-MoS2 bulk obtained in Comparative Example 1 of the present application.

[0039] FIG13 shows SEM images of the nano flower balls obtained in Example 1, Comparative Example 1, and Comparative Example 2.

[0040] Figure 14 shows the results of the electrocatalytic hydrogen evolution performance evaluation, wherein Figure 14a shows the LSV curves of Example 1 of the present application, carbon cloth, and commercial 20 wt% Pt / C at industrial current density; Figure 14b shows the Tafel slope comparison and overpotential comparison of Example 1 of the present application and other existing reported catalysts at industrial current density; Figure 14c shows the stability test results of Example 1 of the present application and commercial 20 wt% Pt / C at ultra-high current density. DETAILED DESCRIPTION

[0041] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The detailed description of the following examples is used to illustrate the principles of the present application, but is not intended to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0042] As analyzed in the background of this application, it is difficult to achieve the preparation of high-monolayer-rate two-dimensional 1T phase molybdenum disulfide nanomaterials using existing methods. To address this problem, this application provides a two-dimensional molybdenum disulfide nanomaterial, preparation method, and application.

[0043] In the first embodiment of the present application, a two-dimensional molybdenum disulfide nanomaterial is provided, which satisfies the following conditions: the monolayer rate of molybdenum disulfide is above 97%, the content of 1T phase molybdenum disulfide characterized by X-ray photoelectron spectroscopy is above 90%, and the surface has defects.

[0044] The monolayer rate of the two-dimensional molybdenum disulfide nanomaterial of the present application is above 97%, indicating that the proportion of single-layer molybdenum disulfide nanosheets therein is extremely high; and the content of 1T phase molybdenum disulfide is above 90%, indicating that it has good metallic properties; at the same time, its surface contains a large number of defects, so it has good dispersibility in the solvent and good electrocatalytic performance, especially at industrial current density. It has excellent electrocatalytic hydrogen evolution performance, and its catalytic performance exceeds that of commercial Pt / C, and is even stable for 100 hours without attenuation. It is one of the current superior non-precious metal water decomposition hydrogen catalysts.

[0045] As is understood in the art, such defects include but are not limited to sulfur defects and unsaturated coordinated molybdenum atoms (Mo 5+ ) and various structural defects.

[0046] In some embodiments, the water contact angle of the two-dimensional molybdenum disulfide nanomaterial is below 35°, preferably below 30°. The smaller the water contact angle, the better its hydrophilicity and the higher the defect concentration. Specifically, the surface of the single-layer MoS2 nanosheet of the two-dimensional molybdenum disulfide nanomaterial contains a large number of defects, including sulfur defects and unsaturated coordinated molybdenum atoms (Mo 5+) and various structural defects, wherein the surface contains a large number of defects and edge sulfur atoms, which will form more hydroxyl groups in the solvent dispersion, showing that the water contact angle is small, and the dispersibility is improved, and it can be dispersed in different solvents, so that it has a wider range of applications. At the same time, due to the presence of more defects and hydrophilic functional groups, it has a smaller water contact angle and better hydrophilicity, so it has a strong bubble-dispersing ability, which accelerates its mass transfer process in the catalytic process, and the hydrogen bubbles generated on the surface are quickly separated, so that it has higher catalytic performance and stability than commercial Pt / C at industrial current density, and has huge industrial value. For example, with reference to Figure 3, wherein the lattice defects are obvious, it shows that the degree of surface structural defects of the nanosheet is extremely high, and the EPR images of Figures 9 and 10 also show that there are many defect types (Mo defects and S defects) in its structure, so the nanosheet includes structural defects and a series of defect types such as S defects and Mo defects, which is beneficial to subsequent catalysis.

[0047] In some embodiments, the impurity ion content of the two-dimensional molybdenum disulfide nanomaterial is below 0.5% by mass (below the detection limit of the EDX instrument), preferably below 100 ppm. This indicates that the two-dimensional molybdenum disulfide nanomaterial has no other impurity ions on its surface (basic metal ions may remain after basic metal stripping), and has high purity, which is beneficial for applications in biological and medical fields.

[0048] In some embodiments, more than 90% of the two-dimensional molybdenum disulfide nanomaterials have a lateral size distribution between 75 nm and 150 nm. This indicates that the lateral size distribution of the two-dimensional molybdenum disulfide nanomaterials is narrower and more uniform. Existing exfoliation strategies produce nanosheets with a surface lateral size distribution ranging from 100 nm to 3 μm. To obtain products with a narrower lateral size distribution, complex lateral size screening is required, which is cumbersome and inefficient. This lateral size distribution can be measured using an atomic force microscope (AFM) and a scanning electron microscope (SEM).

[0049] Any two-dimensional molybdenum disulfide in the first embodiment of the present application can be prepared using the preparation method provided in the following second embodiment.

[0050] The second embodiment of the present application provides a method for preparing a two-dimensional molybdenum disulfide nanomaterial, which realizes the large-scale preparation of kilogram-level two-dimensional materials. The preparation method comprises: step S1, inserting molybdate ions into the interlayer of layered double hydroxide (LDH) to obtain LDH-molybdate intercalation complex; step S2, inserting S-containing 2- The ionic compound undergoes a solvothermal reaction with the LDH-molybdate intercalation complex to obtain an LDH-MoS2 complex; in step S3, the LDH-MoS2 complex is etched with acid to remove the layered double hydroxide to obtain a two-dimensional 1T phase molybdenum disulfide nanomaterial.

[0051] In the preparation method of the present application, since the layered double hydroxide contains a large amount of interlayer space, the confinement effect of the LDH layer can be used to transfer the hydrothermal reaction of MoS2 to the interlayer of LDH, that is, after the molybdate is inserted into the LDH, the molybdate-intercalated LDH is used as a precursor to react with the S-containing 2- The ionic compound undergoes a solvothermal reaction to form a layer-by-layer assembled LDH-MoS2 complex, which is then etched away to remove the template LDH, enabling the large-scale preparation of two-dimensional metallic phase 1T-MoS2 nanosheets with an ultra-high monolayer rate. This method achieves kilogram-scale mass production of two-dimensional 1T phase MoS2 nanomaterials with a high monolayer rate. The resulting two-dimensional molybdenum disulfide nanosheets have an extremely high 1T-molybdenum disulfide monolayer rate (e.g., over 97%), an extremely high 1T phase content (e.g., over 90%), and abundant defects, resulting in a water contact angle of less than 30° for the two-dimensional molybdenum disulfide nanomaterial, and the ability to be stably dispersed in different solvents. The resulting nanomaterials have relatively uniform lateral dimensions and superior catalytic performance.

[0052] At the same time, since the above preparation method does not require the presence of alkali metal ions for stripping, there is no residual alkali metal impurity ions in the obtained nanomaterials; and in the preparation process, after acid etching LDH, Mg 2+ and Al 3+ It is difficult for them to be adsorbed on MoS2, so the residual metal impurity ions on the surface are extremely low; at the same time, it solves the limitation of using basic metals to strip MoS2 materials and cannot achieve large-scale preparation, and during the synthesis process, its lateral size uniformity is strong.

[0053] The ultra-high monolayer rate two-dimensional 1T phase MoS2 nanomaterial obtained by the preparation method of the present application has a high monolayer rate of molybdenum disulfide and contains a large number of sulfur vacancies and unsaturated Mo on the surface. 5+ defect sites, and the 1T content is ultra-high, so the electrocatalytic performance is excellent, and the surface is highly hydrophilic and gas-repellent, showing excellent electrocatalytic hydrogen evolution performance under industrial current density.

[0054] In some embodiments of the present application, the above-mentioned step S1 includes: calcining a layered double metal hydroxide to obtain a layered double metal oxide (LDO); mixing the layered double metal oxide with an aqueous solution of molybdate, so that the molybdate ions are inserted into the interlayer of the layered double metal hydroxide during the reconstruction process of the layered double metal oxide into the layered double metal hydroxide, thereby obtaining an LDH-molybdate intercalation complex.

[0055] In the above embodiment, a layered double hydroxide is calcined to form a layered bimetallic oxide. This layered bimetallic oxide exhibits a "memory effect." Specifically, upon mixing with an aqueous solution containing molybdate, molybdate ions are efficiently adsorbed into the interlayers while the LDO undergoes structural reconstruction to form LDH, forming an LDH-molybdate intercalation complex. This embodiment exhibits high intercalation efficiency and a good intercalation effect.

[0056] In some embodiments, to remove anions from the LDH as much as possible while maintaining its layered structure, the calcination temperature is preferably 400°C-600°C and the calcination time is 1 hour-5 hours. Under these calcination conditions, as the calcination temperature increases or the calcination time increases, more anions in the layered double hydroxide are removed, thereby facilitating the efficient insertion of more molybdate ions and significantly increasing the yield.

[0057] In order to improve the intercalation efficiency of molybdate ions, in some embodiments, the above-mentioned mixing includes stirring the layered bimetallic oxide and the aqueous solution of molybdate at 40°C-80°C for 24h-60h under the protection of a protective gas to carry out structural reconstruction, preferably the protective gas is nitrogen or an inert gas, and the content of molybdate in the aqueous solution of molybdate is preferably 0.1mol / L-2.0mol / L; preferably, the weight ratio of the layered bimetallic oxide to the molybdate is (0.5-3):1.

[0058] In addition to using the above-mentioned reconstruction of the layered double metal oxide to achieve the insertion of molybdate ions, in some embodiments, the above-mentioned step S1 includes using an ion exchange method or a coprecipitation method to insert the molybdate ions into the interlayer of the layered double metal hydroxide to obtain an LDH-molybdate intercalation complex.

[0059] Ion exchange method: First, use high concentration sodium nitrate to replace the CO3 between the LDH layers 2- Ions (labeled as CO3 2- -LDH) to obtain NO3 - Intercalated LDH (labeled as NO3 - -LDH), and then further use high concentration molybdate to replace NO3 - -NO3 in LDH - , obtaining molybdate intercalated LDH. Among them, nitrate intercalated LDH is more suitable for replacing other ions, so a large amount of nitrate should be used in the replacement process to form concentration diffusion.

[0060] Co-precipitation method: It uses LDH metal salt, molybdate and alkali to directly mix, adjust the pH to 9-11, use molybdate as the anion in the LDH structure, and directly generate LDH with molybdate as the interlayer during the synthesis process.

[0061] The specific implementation process of the above ion exchange method or co-precipitation is based on conventional anion intercalation LDH, and the process and conditions are not described in detail here.

[0062] The layered double metal hydroxide used in the present application can be any conventional layered double metal hydroxide. In some embodiments, the layered double metal hydroxide is a layered calcium magnesium hydroxide or a layered magnesium aluminum hydroxide. The above-mentioned layered double metal hydroxide can be derived from existing materials or can be prepared by conventional methods. Taking the preparation of layered magnesium aluminum hydroxide as an example, the preparation process includes: dissolving Mg(NO3)2·6H2O, Al(NO3)3·9H2O and urea in water at a molar ratio of 3:1:30, and continuously stirring in an oil bath at 90°C-100°C for more than 24 hours, filtering and washing the obtained solid and drying it at 60°C to obtain layered magnesium aluminum hydroxide.

[0063] In some embodiments, the molybdate used in step S1 is derived from molybdate, and the molybdate is selected from (NH4)6Mo7O 24 ·4H2O, Na2MoO4·2H2O, K2MoO4 or (NH4)3PO4·12MoO3. 24 6- and MoO4 2- As molybdate ions. Moreover, experiments have shown that under the same reaction conditions, different molybdate ions will affect the defect concentration of the resulting nanomaterial. Therefore, different molybdates can be selected as needed to achieve the large-scale controllable preparation of single-layer 1T-MoS2 nanomaterials.

[0064] The solvothermal reaction of the present application can be used as a reference for the solvothermal reaction of conventional molybdenum disulfide. In order to improve the monolayer rate and 1T content of the monolayer 1T-molybdenum disulfide in the solvothermal reaction, in some embodiments, step S2 includes: 2- The ionic compound and the LDH-molybdate intercalation complex are dispersed in a solvent to form a reaction solution, preferably containing S 2- The ionic compound is selected from any one or more of thiourea, ammonium sulfide, or thioacetamide; the reaction solution is subjected to a solvothermal reaction at 150°C-250°C to obtain an LDH-MoS2 complex, preferably for 6 hours to 72 hours. By controlling the temperature of the solvothermal reaction, on the one hand, the 1T content can be increased, and on the other hand, the surface defects of the monolayer nanosheets can be regulated, thereby regulating their electrocatalytic performance. In some embodiments, the reaction solution can be preferably subjected to a solvothermal reaction at 150°C-210°C.

[0065] In some embodiments of the present application, the above-mentioned solvent is selected from any one or more of water and organic solvents.

[0066] In practice, it has been found that under the same conditions, when water is used as the solvent for the solvothermal reaction, compared to an organic solvent as the solvent for the solvothermal reaction, the intercalated molybdate ions diffuse from the interlayer into the water, thereby weakening the LDH template confinement effect, resulting in a higher proportion of nanospheres in the formed molybdenum disulfide, and reducing the monolayer rate. Therefore, in some embodiments, the solvent is preferably selected from any one or more of organic solvents. In some embodiments, the organic solvent includes any one or more of an alcohol solvent, an ether solvent, and a ketone solvent; preferably, the alcohol solvent includes any one or more of a C1-C6 monohydric alcohol and a C2-C6 dihydric alcohol; preferably, the alcohol solvent includes any one or more of methanol, ethanol, ethylene glycol, and isopropanol.

[0067] In some embodiments, the LDH-molybdate intercalation complex is 2- The weight ratio of the ionic compound is 1:(0.5-10).

[0068] In some embodiments, the acid used in step S3 includes an inorganic acid such as hydrochloric acid, nitric acid, or sulfuric acid. For example, the LDH-MoS2 complex is ultrasonicated in an acid, stirred, washed, and dried to obtain a monolayer of molybdenum disulfide nanomaterial.

[0069] A third embodiment of the present application provides a two-dimensional molybdenum disulfide nanomaterial prepared using any of the preparation methods provided in the second embodiment. The two-dimensional molybdenum disulfide nanomaterial has an extremely high monolayer ratio (greater than 97%), a high content of 1T phase molybdenum disulfide (greater than 90%), and a high concentration of sulfur vacancy defects, resulting in a water contact angle of less than 35° at 20°C-35°C. Furthermore, the two-dimensional molybdenum disulfide nanomaterial has a lateral size distribution between 75nm and 150nm, and / or an impurity ion content of less than 10ppm.

[0070] A fourth embodiment of the present application provides a catalyst comprising a two-dimensional molybdenum disulfide material, wherein the two-dimensional molybdenum disulfide material comprises any one of the two-dimensional molybdenum disulfide nanomaterials provided in the first or third embodiments. The catalyst comprising the two-dimensional molybdenum disulfide nanomaterial of the present application exhibits superior electrocatalytic hydrogen evolution performance at industrial current densities.

[0071] The fifth embodiment of the present application provides a negative electrode material, including a two-dimensional molybdenum disulfide material. The two-dimensional molybdenum disulfide material includes any one of the two-dimensional molybdenum disulfide nanomaterials provided in the first embodiment or the third embodiment.

[0072] The fifth embodiment of the present application provides an application of any one of the two-dimensional molybdenum disulfide nanomaterials provided in the first embodiment or the third embodiment, which includes using the two-dimensional molybdenum disulfide nanomaterial as a drug carrier or a drug additive.

[0073] The following examples and comparative examples will further illustrate the beneficial effects of the present application, but the scope of the present invention is not limited to these examples.

[0074] Example 1

[0075] (1) Al(NO3)3·9H2O, Mg(NO3)2·6H2O and urea were dissolved in deionized water at a molar ratio of 1:3:30 to obtain a mixed solution. The mixed solution was heated to 95°C and stirred for 24 hours, filtered and washed, and dried at 60°C to obtain LDH solid.

[0076] (2) LDH solid was calcined in a tube furnace at 450 °C for 2 h to obtain LDO, and (NH4)6Mo7O with a concentration of 0.5 mol / L was prepared. 24 ·5L of 4H2O aqueous solution, 1.0kg of LDO powder was dispersed in (NH4)6Mo7O 24 ·4H2O aqueous solution to obtain a mixed slurry, which was stirred at 60°C for 48 hours under nitrogen protection, filtered and washed, and dried at 60°C to obtain LDH-Mo7O 24 6- Among them, LDO and (NH4)6Mo7O 24 The weight ratio of 4H2O is 1:2.

[0077] (3) 2.0 kg LDH-Mo7O 24 6- and thiourea were uniformly dispersed in anhydrous ethanol, LDH-Mo7O 24 6- The weight ratio of thiourea to thiourea was 1:2, and a homogeneous suspension was obtained by ultrasonication and stirring. The homogeneous suspension was charged into a 10.0L reactor and reacted at 200°C for 24 hours. The mixture was then cooled to room temperature, filtered, and washed to obtain the LDH-MoS2 composite.

[0078] (4) The LDH-MoS2 complex was dispersed in a 0.5 mol / L hydrochloric acid solution, ultrasonicated and stirred for 24 h, filtered and washed to obtain gel-like MoS2 (solid content of 64%), and dried in a vacuum oven at 60 ° C for 12 h to obtain a two-dimensional molybdenum disulfide nanomaterial powder.

[0079] The two-dimensional molybdenum disulfide material powder obtained in the above steps is tested.

[0080] Figure 1a shows the XRD (X-ray diffraction) spectra of the two-dimensional molybdenum disulfide material (corresponding to the 1T-MoS2 monolayer in Figure 1) and the 1T-phase molybdenum disulfide nanosphere material (corresponding to the 1T-MoS2 bulk in Figure 1) from Comparative Example 1. The PDF (37-1439) is significantly different from that of the 2H-phase MoS2. Both the monolayer molybdenum disulfide material and the MoS2 spheres synthesized directly by hydrothermal synthesis in the comparative example belong to the 1T phase. Furthermore, the XRD crystallization peak (002) exhibits poor peak shape, demonstrating the presence of ultrathin nanosheets and disordered two-dimensional stacking. Figure 1b shows the kilogram-scale nanosheet gel obtained from large-scale production.

[0081] Figure 2 shows the SEM (scanning electron microscope) and TEM (transmission electron microscope) images of the two-dimensional molybdenum disulfide nanomaterial of Example 1. The left image is the SEM image and the right image is the TEM image, showing that the single-layer 1T-MoS2 nanosheets have an irregular sheet-like morphology, indicating that the nanosheets grow into ultra-thin nanosheets under LDH confinement.

[0082] FIG3 shows a HRTEM (high-resolution transmission electron microscope) image of the single-layer MoS 2 material, indicating that the irregular lattice diffraction of the nanosheets indicates that it contains a large number of defects and the crystal phase is a metallic 1T phase.

[0083] Figure 4a is a photograph of the dispersion of the two-dimensional molybdenum disulfide nanomaterial in Example 1 in different solvents. The dispersion concentration is 0.5 g / L. After 24 hours, there is no agglomeration, which proves that it can be stably dispersed in a variety of solvents with excellent dispersion performance. Figure 4b shows the water contact angle test results of the two-dimensional molybdenum disulfide nanomaterial in Example 1 of the present application and other materials. The water contact test method is to measure the pure water contact angle multiple times after solid powder tableting. As can be seen from Figure 4b, the two-dimensional molybdenum disulfide nanomaterial in Example 1 has an extremely small water contact angle and strong hydrophilicity, indicating that its surface catalytic defects and hydrophilic groups are numerous. At the same time, the ultra-low water contact angle is beneficial to the mass transfer process in the subsequent water decomposition application process.

[0084] Figure 5 shows the AFM (atomic force microscope) morphology and thickness statistics of the single-layer MoS2 material. The thickness statistics show that the single-layer rate of the two-dimensional molybdenum disulfide nanomaterial in Example 1 exceeds 97% and the thickness is only 0.8 nm.

[0085] FIG6 shows the lateral size distribution results of the two-dimensional molybdenum disulfide nanomaterial of Example 1 based on AFM analysis. It can be seen that the lateral size of the nanosheets is uniform, and the lateral size of the nanosheets is mainly distributed between 80 nm and 150 nm.

[0086] Figure 7 is the XPS (X-ray photoelectron spectroscopy) characterization of the two-dimensional molybdenum disulfide nanomaterial powder and commercial 2H phase MoS2 in Example 1, wherein the comparison of the areas of the 2H peak and the 1T peak in the XPS Mo 3d spectrum shows that the 1T phase content in the MoS2 synthesized in Example 1 exceeds 90%, and the synthesized MoS2 is a 1T phase.

[0087] FIG8 shows the EDS characterization results of the two-dimensional molybdenum disulfide nanomaterial of Example 1. It can be seen that no metal impurity ions Mg are detected, and the surface of the metal impurity ions Al is pure without any impurity ions remaining.

[0088] Example 2

[0089] The only difference from the preparation method of Example 1 is that in step (3), the homogeneous suspension is reacted at 180° C. for 24 hours to obtain the two-dimensional 1T phase molybdenum disulfide nanosheet powder of Example 2.

[0090] Figure 9 shows the EPR (electron paramagnetic resonance) graphs of the two-dimensional molybdenum disulfide materials obtained in Examples 1 and 2. Both samples have obvious peaks at g = 2.003 and g = 1.93, proving that the surfaces of both two-dimensional nanosheets contain extremely high Mo defects and S defects, and the defect concentration is adjustable with temperature.

[0091] Example 3

[0092] The difference from Example 1 is that an equal amount of Na2MoO4·2H2O is used to replace the (NH4)6Mo7O in Example 1. 24 ·4H2O, and the rest is the same as in Example 1, to obtain the two-dimensional molybdenum disulfide nanomaterial powder of Example 3.

[0093] Figure 10 shows the EPR (electron paramagnetic resonance) images of the two-dimensional 1T phase MoS2 materials obtained in Examples 1 and 3. Both samples have obvious peaks at g = 2.003 and g = 1.93, proving that both two-dimensional nanosheets contain extremely high Mo defects and S defects on their surfaces, and the defect concentration varies depending on the anion type. 24 When 4H2O is intercalated, the defect concentration of the resulting nanomaterial is greater.

[0094] Example 4

[0095] The only difference from the preparation method of Example 1 is that in step (3), LDH-Mo7O 24 6- and thiourea were uniformly dispersed in water. The two-dimensional molybdenum disulfide nanomaterial powder of Example 4 was obtained, and its SEM image is shown in Figure 11, which contains obvious nano-flower balls. 24 6-Partially intercalated Mo7O 24 6- Diffusion into water causes the growth of molybdenum disulfide to lose its restriction and form nano-flower balls, so its monolayer rate decreases, and it is a mixture of nano-flower balls and nano-sheets.

[0096] Example 5

[0097] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 400° C. for 2 hours to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 5 is obtained.

[0098] Example 6

[0099] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 600° C. for 2 hours to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 6 is obtained.

[0100] Example 7

[0101] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 650° C. for 2 hours to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 7 is obtained.

[0102] Example 8

[0103] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 350° C. for 2 hours to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 8 is obtained.

[0104] Example 9

[0105] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 500° C. for 1 hour to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 9 is obtained.

[0106] Example 10

[0107] The only difference from the preparation method of Example 1 is that in step (2), the LDH solid is calcined in a tube furnace at 600° C. for 5 hours to obtain LDO, and the rest is the same as Example 1. The two-dimensional molybdenum disulfide nanomaterial powder of Example 10 is obtained.

[0108] Example 11

[0109] The only difference from the preparation method of Example 1 is that in step (3), the homogeneous suspension is reacted at 150° C. for 24 hours. Thus, the two-dimensional molybdenum disulfide nanomaterial powder of Example 11 is obtained.

[0110] Example 12

[0111] The only difference from the preparation method of Example 1 is that in step (3), the homogeneous suspension is reacted at 250° C. for 24 hours to obtain the two-dimensional molybdenum disulfide nanomaterial powder of Example 12.

[0112] Example 13

[0113] The only difference from the preparation method of Example 1 is that in step (3), LDH-Mo7O 24 6- and thiourea were uniformly dispersed in ethylene glycol to obtain the two-dimensional molybdenum disulfide nanomaterial powder of Example 13.

[0114] Example 14

[0115] Use the same mass of Na2MoO4·2H2O to replace the (NH4)6Mo7O in Example 1 24 ·4H2O, and the remaining operations were the same as in Example 1 to obtain the two-dimensional molybdenum disulfide nanomaterial powder of Example 14.

[0116] Example 15

[0117] (1) Al(NO3)3·9H2O, Mg(NO3)2·6H2O and (NH4)6Mo7O 24 4H2O was dissolved in deionized water at a molar ratio of 1:3:1, and the pH was adjusted to 11.0 with NaOH. The mixed solution was then stirred and heated to 95°C for 24 hours, filtered and washed, and dried at 60°C to obtain LDH-Mo7O 24 6- .

[0118] (2) LDH-Mo7O 24 6- The thiourea was evenly dispersed in anhydrous ethanol, ultrasonicated and stirred, and the homogeneous suspension was placed in a reactor and reacted at 180°C for 24 hours. The mixture was then cooled to room temperature, filtered and washed to obtain the LDH-MoS2 composite.

[0119] (4) The LDH-MoS2 complex was dispersed in a 0.5 mol / L hydrochloric acid solution, ultrasonicated and stirred for 48 hours, filtered and washed to obtain a two-dimensional molybdenum disulfide material, and dried in a vacuum oven at 60°C for 12 hours to obtain a two-dimensional molybdenum disulfide nanomaterial powder.

[0120] Example 16

[0121] (1) Al(NO3)3·9H2O, Mg(NO3)2·6H2O and urea were dissolved in deionized water at a molar ratio of 1:3:30 to obtain a mixed solution. The mixed solution was heated to 95°C and stirred for 24 hours, filtered and washed, and dried at 60°C to obtain LDH solid. The obtained LDH was placed in a 1.0 mol / L sodium nitrate solution and the pH was adjusted to 2.0. Stirred at room temperature for 48 hours to remove the CO3 2- Ion exchange for NO3 - , filter, wash and dry to obtain NO3 - The LDH was then placed in a solution of (NH4)6Mo7O with a concentration of 1 mol / L. 24 ·4H2O aqueous solution to obtain a mixed slurry, which was stirred at 40°C for 24 hours under nitrogen protection, filtered and washed, and dried at 60°C to obtain LDH-Mo7O 24 6- Among them, nitrate intercalated LDH and (NH4)6Mo7O 24 ·4H2O weight ratio is 1:4.

[0122] (2) LDH-Mo7O 24 6- The thiourea was evenly dispersed in anhydrous ethanol, ultrasonicated and stirred, and the homogeneous suspension was placed in a reactor and reacted at 180°C for 24 hours. The mixture was then cooled to room temperature, filtered and washed to obtain the LDH-MoS2 composite.

[0123] (4) The LDH-MoS2 complex was dispersed in a 0.5 mol / L hydrochloric acid solution, ultrasonicated and stirred for 48 hours, filtered and washed to obtain a two-dimensional molybdenum disulfide material, and dried in a vacuum oven at 60°C for 12 hours to obtain a two-dimensional molybdenum disulfide nanomaterial powder.

[0124] Comparative Example 1

[0125] (NH4)6Mo7O 24 4H2O and thiourea were evenly dispersed in water, sonicated, and stirred. The homogeneous suspension was charged into a reactor and reacted at 200°C for 24 hours. The mixture was then cooled to room temperature, filtered, washed, and dried to obtain powdered 1T-MoS2 nanospheres. Figure 1 shows the 1T-MoS2 bulk obtained in Comparative Example 1, whose crystal phase is metallic. Figure 12 shows SEM and TEM images of the 1T-MoS2 bulk obtained in Comparative Example 1. The left image is the SEM image, showing distinct nanospheres; the right image is the TEM image, showing the nanospheres' high contrast and therefore their thickness.

[0126] Comparative Example 2

[0127] (NH4)6Mo7O 24 4H2O and thiourea were evenly dispersed in anhydrous ethanol, ultrasonically stirred, and the homogeneous suspension was placed in a reactor and reacted at 200°C for 24 hours. The mixture was then cooled to room temperature, filtered, washed, and dried to obtain powdered 1T-MoS2 nanospheres.

[0128] Figure 13 shows the SEM images of the nano flower balls obtained in Example 1, Comparative Example 1 and Comparative Example 2, wherein Figures a and b correspond to the SEM images of the two-dimensional molybdenum disulfide nanosheets of Example 1, and Figures c and d correspond to the SEM images of the nano flower balls obtained in Comparative Example 1 and Comparative Example 2, respectively. It can be seen that when there is no confinement effect of LDH, the generated MoS2 is flower-ball-shaped and the nanosheets are also thicker.

[0129] Performance Testing

[0130] The electrocatalytic hydrogen evolution performance of the two-dimensional molybdenum disulfide nanomaterial powder obtained in Example 1, the 1T-MoS2 block obtained in Comparative Example 1, and 20 wt% Pt / C were evaluated. The specific evaluation method is as follows:

[0131] The electrocatalytic samples were tested using a three-electrode system, with an Ag / AgCl (saturated) electrode as the reference electrode and a carbon rod as the counter electrode. The test was carried out in a H2SO4 (0.5M) electrode solution at a scan rate of 5mV / s, and the Shanghai Chenhua CHI660e electrochemical workstation was used for the test. Working electrode preparation method: 10.0mg of sample was dispersed in 1ml of a mixed solvent of water / ethanol (volume ratio 1:1), and then 30μL of a perfluorosulfonic acid membrane solution (Nafion) and 1.0mg of carbon black were added as a conductive agent. Ultrasonic treatment was performed for 30min to obtain a uniform catalyst dispersion, which was then placed on a carbon cloth electrode (1x 1cm 2 ) was coated with 0.5 mL of catalyst dispersion and the surface was dried to obtain a catalyst loading of 5.0 mg / cm 2 The working electrode was used. Linear sweep voltammetry (LSV) was used to measure the catalyst polarization curve at a scan rate of 5 mV / s. Chronoamperometry was also used to measure the IT curve. The results are shown in Figure 14.

[0132] Figure 14a shows the LSV curve of Example 1. It can be seen that the overpotential of the electrocatalytic hydrogen evolution of the monolayer MoS2 material is 154 mV, indicating that the monolayer 1T-MoS2 has excellent electrocatalytic performance. As the potential increases, its catalytic performance even exceeds that of the commercial precious metal Pt / C catalyst. Its corresponding Tafel and 1000 mA cm -2 The overpotential of the catalysts is compared with that of other catalysts as shown in Figure 14b. When the current density reaches 1000 mA·cm -2The required overpotential is only 316 mV, which is much smaller than that of other catalysts. At the same time, the corresponding Tafel slope is also small. Its catalytic performance at industrial current density exceeds that of almost all inorganic non-metallic catalysts, showing a strong electrocatalytic water splitting ability. The it curve in Figure 14c shows the stability of its catalysis at industrial current density. -2 The stability can be maintained for 100 hours, which is much stronger than the commercial Pt / C catalyst (the current density decays to 0 within 3 hours), demonstrating its stability in industrial electrocatalytic hydrogen evolution. Currently, the overpotential and stability of conventional two-dimensional materials and non-precious metal hydrogen evolution catalysts at high current densities are difficult to exceed those of commercial 20wt% Pt / C. Therefore, the single-layer 1T-MoS2 material with such high HER performance obtained in this application has very great industrial application prospects.

[0133] Specifically, the two-dimensional MoS2 nanomaterials generate a large number of H2 bubbles during the catalytic process. The higher hydrophilicity (compared to Pt / C, as shown in Figure 4b) gives the surface of the two-dimensional MoS2 nanomaterials super-bubble-repellent properties. These H2 bubbles quickly escape from the electrode surface, promoting bubble separation and mass transfer (which can greatly affect the HER performance at industrial current density), thereby achieving continuous H2 generation at high currents. In contrast, H2 bubbles strongly adhere to the Pt / C surface and merge into a larger size before separation, blocking many sites on the catalyst surface.

[0134] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A two-dimensional molybdenum disulfide nanomaterial, characterized in that: The two-dimensional molybdenum disulfide nanomaterial meets the following conditions: the monolayer rate of molybdenum disulfide is above 97%, the content of 1T phase molybdenum disulfide characterized by X-ray photoelectron spectroscopy is above 90%, and the surface has defects.

2. The two-dimensional molybdenum disulfide nanomaterial according to claim 1, characterized in that The water contact angle of the two-dimensional molybdenum disulfide nanomaterial is below 35°, preferably below 30°.

3. The two-dimensional molybdenum disulfide nanomaterial according to claim 1 or 2, characterized in that The mass content of impurity ions in the two-dimensional molybdenum disulfide nanomaterial is below 0.5%, preferably below 100 ppm.

4. The two-dimensional molybdenum disulfide nanomaterial according to any one of claims 1 to 3, characterized in that The lateral size distribution of the two-dimensional molybdenum disulfide nanomaterials, which accounts for more than 90% of the total amount, is between 75nm and 150nm.

5. A method for preparing a two-dimensional molybdenum disulfide nanomaterial, characterized in that: The preparation method comprises: Step S1, inserting molybdate ions into the interlayer of layered double hydroxide to obtain LDH-molybdate intercalation complex; Step S2, 2- The ionic compound undergoes a solvothermal reaction with the LDH-molybdate intercalation complex to obtain an LDH-MoS2 complex; Step S3, etching the LDH-MoS2 composite with acid to remove the layered double hydroxide to obtain the two-dimensional 1T phase molybdenum disulfide nanomaterial.

6. The preparation method according to claim 5, characterized in that The step S1 comprises: calcining the layered double metal hydroxide to obtain a layered double metal oxide, preferably at a temperature of 400° C. to 600° C. and for a time of 1 h to 5 h; The layered double metal oxide is mixed with an aqueous solution of molybdate, so that the molybdate ions are inserted into the interlayer of the layered double metal hydroxide during the reconstruction process of the layered double metal oxide into the layered double metal hydroxide to obtain the LDH-molybdate intercalation complex. Preferably, the mixing includes stirring the layered double metal oxide and the aqueous solution of molybdate at 40°C-80°C under protective gas protection for 24h-60h, and preferably the protective gas is nitrogen or an inert gas.

7. The preparation method according to claim 6, characterized in that The content of the molybdate in the aqueous solution of the molybdate is 0.1 mol / L-2 mol / L; preferably, the weight ratio of the layered bimetallic oxide to the molybdate is (0.5-3):

1.

8. The preparation method according to claim 5, characterized in that The step S1 includes inserting the molybdate ions into the interlayers of the layered double hydroxide using an ion exchange method or a coprecipitation method to obtain an LDH-molybdate intercalation complex.

9. The preparation method according to any one of claims 5 to 8, characterized in that The layered hydroxide includes any one or more of calcium magnesium hydroxide, magnesium aluminum hydroxide and magnesium iron hydroxide.

10. The preparation method according to any one of claims 5 to 9, characterized in that The molybdate ion is derived from molybdate, and the molybdate is selected from (NH4)6Mo7O 24 ·4H2O, Na2MoO4·2H2O, K2MoO4 or (NH4)3PO4·12MoO3 any one or more.

11. The preparation method according to any one of claims 5 to 10, characterized in that The step S2 comprises: Containing S 2- The ionic compound and the LDH-molybdate intercalation complex are dispersed in a solvent to form a reaction solution, preferably the S-containing 2- The ionic compound is selected from any one or more of thiourea, ammonium sulfide, or thioacetamide; The reaction solution is subjected to a solvothermal reaction at 150° C.-250° C. to obtain an LDH-MoS 2 complex. Preferably, the solvothermal reaction time is 6 h-72 h.

12. The preparation method according to claim 11, characterized in that The solvent is selected from any one or more of water and organic solvents.

13. The preparation method according to claim 12, characterized in that The organic solvent includes any one or more of an alcohol solvent, an ether solvent and a ketone solvent; preferably, the alcohol solvent includes any one or more of a C1-C6 monohydric alcohol and a C2-C6 dihydric alcohol; preferably, the alcohol solvent includes any one or more of methanol, ethanol, ethylene glycol and isopropanol.

14. The preparation method according to any one of claims 11 to 13, characterized in that The LDH-molybdate intercalation complex and the S-containing 2- The weight ratio of the ionic compound is 1:(0.5-10).

15. A two-dimensional molybdenum disulfide nanomaterial prepared by the preparation method according to any one of claims 5 to 14.

16. A catalyst comprising a two-dimensional molybdenum disulfide material, characterized in that: The two-dimensional molybdenum disulfide material includes the two-dimensional molybdenum disulfide nanomaterial according to any one of claims 1 to 4 and 15.

17. A negative electrode material comprising a two-dimensional molybdenum disulfide material, characterized in that: The two-dimensional molybdenum disulfide material includes the two-dimensional molybdenum disulfide nanomaterial according to any one of claims 1 to 4 and 15.

18. A use of the two-dimensional molybdenum disulfide nanomaterial according to any one of claims 1 to 4 and 15, the use comprising using the two-dimensional molybdenum disulfide nanomaterial as a drug carrier and / or drug additive.

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