Method for in-situ preparation of molybdenum disulfide film on surface of metal molybdenum
By preparing molybdenum disulfide films in situ by hydrothermal reaction on the surface of metal molybdenum, the problems of complex processes and difficult to control film properties in the prior art are solved, and efficient and stable electrocatalytic hydrogen evolution performance is achieved, which is suitable for industrial-scale applications.
Patent Information
- Application Number
- CN202411861896.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-07
AI Technical Summary
The prior art When preparing molybdenum disulfide (MoS2) films, the process is complicated and it is difficult to accurately control the film structure and performance, which limits its application in the field of electrocatalytic hydrogen production.
Molybdenum disulfide film was prepared in situ on the surface of metal molybdenum by hydrothermal reaction, and the metal molybdenum was subjected to alkali washing and thermal oxidation treatment through sodium carbonate solution, and then hydrothermal reaction was carried out in sodium polysulfide solution to prepare a MoS2 film with high binding force and stability.
It improves the film-based binding force and stability of MoS2 film, enhances its electrocatalytic hydrogen evolution performance, simplifies the process, and is suitable for industrial-scale production.
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Figure CN119571304A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of electrocatalytic hydrogen evolution, and in particular to a method for in-situ preparing a molybdenum disulfide film on a metal molybdenum surface. Background Art
[0002] As an important way to produce clean energy, the efficiency and cost of electrocatalytic hydrogen production largely depend on the performance of catalytic materials. Platinum catalysts have excellent catalytic activity, but their high price limits their industrial application in large-scale catalytic hydrogen production. Molybdenum disulfide (MoS2) has unique physical and chemical properties. As a semiconductor material, it has a narrow band gap and strong electron transport capacity, making it one of the catalytic materials that has attracted much attention in the field of electrocatalytic hydrogen production. Traditional preparation methods mostly involve the synthesis of MoS2 powder and subsequent film-forming processes. The steps are cumbersome and it is difficult to accurately control the film structure and properties. For example, in "Boosting hydrogen evolution on MoS2 via co-confining selenium in surface and cobalt in inner layer", perfluorosulfonic acid resin was used to disperse cobalt and selenium-doped MoS2 nanomaterials and carbon black into a suspension, and then transferred to glassy carbon for drying to obtain a hydrogen evolution working electrode. An improved method was reported in "Aligned MoOx / MoS2 core-shell nanotubular structures with a high density of reactive sites based on self-ordered anodicmolybdenum oxide nanotubes". First, molybdenum metal was anodized in an ammonium fluoride solution, then vacuum heat treated at 350°C, and finally heat treated in a hydrogen sulfide atmosphere to obtain a tubular core-shell structure. Although this method does not require a transfer film forming process, it requires technically difficult preparation processes such as anodization, vacuum heat treatment, and hydrogen sulfide sulfidation treatment, and the process is cumbersome.
[0003] Therefore, developing a more efficient and direct in situ synthesis method is of great significance for improving the electrocatalytic performance and industrial-scale application potential of MoS2 thin films. Summary of the invention
[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface. The method prepares a molybdenum disulfide film in-situ on a metal molybdenum surface by a hydrothermal reaction, thereby improving the film-base bonding strength and stability of the film, and the film has a high electrocatalytic hydrogen evolution performance.
[0005] The technical solution of the present invention to solve the above technical problem is as follows: a method for in-situ preparing a molybdenum disulfide film on a metal molybdenum surface is provided, comprising the following steps: (1) The metal molybdenum is alkaline-washed with a sodium carbonate solution, then washed with distilled water, dried, heated to 400-600°C, kept warm for 0.5-2 h, and naturally cooled to room temperature to obtain an oxidized sample; (2) Heat the sodium sulfide solution to 70-90°C, then gradually add sulfur powder and stir to dissolve to obtain a sodium sulfide solution; (3) Immersing the oxidized sample obtained in step (1) in the sodium polysulfide solution obtained in step (2) for hydrothermal reaction, then cooling naturally, washing and drying, to obtain a molybdenum disulfide film on the surface of the metal molybdenum.
[0006] Furthermore, in step (1), the concentration of the sodium carbonate solution is 5-10 wt%.
[0007] The technical effect of adopting the further invention scheme is: the oxide and oil stain on the surface can be removed by alkaline washing of metal molybdenum with sodium carbonate solution.
[0008] Furthermore, in step (1), the metallic molybdenum is in the form of flakes, blocks, meshes or rods.
[0009] Furthermore, in step (1), the heating rate is 5-20°C / min.
[0010] Furthermore, in step (2), the concentration of the sodium sulfide solution is 0.1-5 mol / L.
[0011] Furthermore, in step (2), the molar ratio of sulfur powder to sodium sulfide is 0.5-3:1.
[0012] Furthermore, in step (3), the hydrothermal reaction is carried out at a temperature of 190-220° C. for 1-10 h.
[0013] Furthermore, in step (4), ultrasonic cleaning is performed in anhydrous ethanol.
[0014] The present invention also provides a molybdenum disulfide film prepared by the above method for in-situ preparing a molybdenum disulfide film on the surface of metallic molybdenum.
[0015] The present invention also provides application of the molybdenum disulfide film in electrocatalytic hydrogen production.
[0016] The present invention has the following beneficial effects: 1. The method of the present invention first performs thermal oxidation treatment on metal molybdenum, prepares a molybdenum oxide film on the surface of the metal molybdenum, participates in a subsequent hydrothermal reaction, and successfully synthesizes a molybdenum disulfide film in situ on the surface of the metal molybdenum. The molybdenum disulfide film prepared by this method has a strong bonding force with the substrate, which improves the adhesion and stability of the film.
[0017] 2. The present invention adopts a hydrothermal synthesis method, which is simple and efficient, and can evenly prepare a high-quality molybdenum disulfide film on the surface of metallic molybdenum. It is suitable for industrial-scale production and use and has great application value.
[0018] 3. The molybdenum disulfide film prepared by the method of the present invention has good electrocatalytic hydrogen evolution performance, and the morphology, structure and performance of the film can be controlled by adjusting the oxidation treatment time and other synthesis conditions to meet different application requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Schematic diagram of the preparation process of molybdenum disulfide film in Example 1; Figure 2 This is a macroscopic picture of the molybdenum sheet during the preparation process of Example 1; Figure 3 XRD comparison diagram of the in-situ MoS2 film and MoO3 prepared in Example 1; Figure 4 This is a scanning electron microscope image of the in-situ MoS2 film prepared in Example 1; Figure 5 This is a comparison diagram of the LSV hydrogen evolution curves of the in-situ MoS2 film and the carbon cloth self-supporting MoS2 film prepared in Example 1; Figure 6 This is a comparison chart of the Tafel slopes of the in-situ MoS2 film, the carbon cloth self-supporting MoS2 film and the metal Pt prepared in Example 1. DETAILED DESCRIPTION
[0020] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific conditions are specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.
[0021] Example 1 A method for in-situ preparation of molybdenum disulfide film on the surface of metal molybdenum, the preparation process schematic diagram is as follows Figure 1 As shown, the specific steps include: (1) The metal molybdenum (molybdenum sheet) was alkaline washed with 8 wt% sodium carbonate solution, then washed with distilled water, dried, heated to 500°C at a heating rate of 10°C / min, kept at this temperature for 1 h, and naturally cooled to room temperature to obtain an oxidized sample; (2) Heat 3 mol / L sodium sulfide solution to 80°C, then gradually add sulfur powder, the molar ratio of sulfur powder to sodium sulfide being 1:1, and stir to dissolve to obtain a sodium sulfide solution; (3) The oxidized sample obtained in step (1) is immersed in the sodium polysulfide solution obtained in step (2), and subjected to a hydrothermal reaction at 200° C. for 6 h, and then naturally cooled, and then ultrasonically cleaned in anhydrous ethanol and dried to obtain a molybdenum disulfide film on the surface of the metal molybdenum.
[0022] The macroscopic picture of the molybdenum sheet during the preparation process of Example 1 is as follows Figure 2 As shown, it can be seen that this method successfully prepared high-quality MoS2 thin film uniformly on the molybdenum sheet.
[0023] Example 2 A method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface comprises the following steps: (1) The metal molybdenum was alkaline-washed with a 5 wt% sodium carbonate solution, and then washed with distilled water. After drying, the metal molybdenum was heated to 400°C at a heating rate of 5°C / min, kept at this temperature for 0.5 h, and naturally cooled to room temperature to obtain an oxidized sample; (2) Heat 0.1 mol / L sodium sulfide solution to 70°C, then gradually add sulfur powder, the molar ratio of sulfur powder to sodium sulfide being 0.5:1, and stir to dissolve to obtain a sodium sulfide solution; (3) The oxidized sample obtained in step (1) is immersed in the sodium polysulfide solution obtained in step (2), and subjected to a hydrothermal reaction at 190° C. for 1 h, and then naturally cooled, and then ultrasonically cleaned in anhydrous ethanol and dried to obtain a molybdenum disulfide film on the surface of the metal molybdenum.
[0024] Example 3 A method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface comprises the following steps: (1) The metal molybdenum was alkaline washed with a 10 wt% sodium carbonate solution, then washed with distilled water, dried, and then heated to 600°C at a heating rate of 20°C / min, kept at this temperature for 2 h, and naturally cooled to room temperature to obtain an oxidized sample; (2) Heat 5 mol / L sodium sulfide solution to 90°C, then gradually add sulfur powder, the molar ratio of sulfur powder to sodium sulfide being 3:1, and stir to dissolve to obtain a sodium sulfide solution; (3) The oxidized sample obtained in step (1) is immersed in the sodium polysulfide solution obtained in step (2), and subjected to a hydrothermal reaction at 220° C. for 10 h, and then naturally cooled, and then ultrasonically cleaned in anhydrous ethanol and dried to obtain a molybdenum disulfide film on the surface of the metal molybdenum.
[0025] Test Example 1 (1) X-ray diffraction characterization was performed on the in-situ MoS2 film and MoO3 prepared in Example 1. The XRD pattern is shown in Figure 3 The results show that this method successfully synthesized MoS2 thin film in situ on the molybdenum sheet.
[0026] (2) The in-situ MoS2 film obtained in Example 1 was observed by scanning electron microscopy. The results are as follows: Figure 4 The results show that the surface of the in-situ MoS2 film is composed of micro-nano particles, which appear as nano-flocculated flakes under high magnification. This structure provides a larger specific surface area and more active sites for hydrogen evolution catalysis.
[0027] (2) The comparison of the Tafel slopes of the molybdenum disulfide film obtained in Example 1 and platinum (Pt) is shown in FIG. Figure 4 The results show that the Tafel slopes of the MoS2 film and Pt are 58 mV / dec and 41 mV / dec, respectively, indicating that the MoS2 film prepared by this method has good electrocatalytic hydrogen evolution performance, which is close to that of Pt catalyst.
[0028] Test Example 2 Referring to the literature "Vertically oriented MoS2and WS2nanosheets directly grown on carbon cloth as efficient and stable 3-dimensional hydrogen-evolvingcathodes", "A strategy to synergistically increase the number of active edgesites and the conductivity of MoS2nanosheets for hydrogen evolution" and "Hierarchical composite structure of few-layers MoS2nanosheets supported byvertical graphene on carbon cloth for high-performance hydrogen evolutionreaction", carbon cloth was placed as a support in the hydrothermal reaction system, and the same process conditions as the in-situ MoS2 film were used to prepare a carbon cloth self-supporting MoS2 hydrogen evolution electrode. The carbon cloth self-supporting MoS2 thin film electrode and the in-situ MoS2 thin film electrode were tested for hydrogen evolution, and the LSV curves and Tafel slopes were shown as follows: Figure 5 and Figure 6 shown.
[0029] The results show that the Tafel slopes of the in-situ MoS2 film and platinum are 58 mV / dec and 41 mV / dec respectively, while the Tafel slope of the carbon cloth self-supporting MoS2 film is 75 mV / dec. The hydrogen evolution catalytic performance of the in-situ MoS2 film prepared by the method of the present invention is better than that of the carbon cloth self-supporting MoS2 film and is close to that of the platinum catalyst.
[0030] The MoS2 film synthesized in situ by the method of the present invention did not fall off during multiple ultrasonic cleanings during the cleaning process, indicating that it has good bonding strength with the substrate, higher stability, is not easily damaged during use, and is more suitable for industrial-scale applications.
[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface, characterized in that: The following steps are involved: (1) The metal molybdenum is alkaline-washed with a sodium carbonate solution, then washed with distilled water, dried, heated to 400-600°C, kept warm for 0.5-2 h, and naturally cooled to room temperature to obtain an oxidized sample; (2) Heat the sodium sulfide solution to 70-90°C, then gradually add sulfur powder and stir to dissolve to obtain a sodium sulfide solution; (3) Immersing the oxidized sample obtained in step (1) in the sodium polysulfide solution obtained in step (2) for hydrothermal reaction, then cooling naturally, washing and drying, to obtain a molybdenum disulfide film on the surface of the metal molybdenum.
2. The method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface according to claim 1, characterized in that: In step (1), the concentration of the sodium carbonate solution is 5-10 wt%.
3. The method for in-situ preparing a molybdenum disulfide film on a metal molybdenum surface according to claim 1, characterized in that: In step (1), the metal molybdenum is in the form of flakes, blocks, meshes or rods.
4. The method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface according to claim 1, characterized in that: In step (1), the heating rate is 5-20°C / min.
5. The method for in-situ preparation of molybdenum disulfide film on a metal molybdenum surface according to claim 1, characterized in that: In step (2), the concentration of the sodium sulfide solution is 0.1-5 mol / L.
6. The method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface according to claim 1, characterized in that: In step (2), the molar ratio of the sulfur powder to sodium sulfide is 0.5-3:
1.
7. The method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface as claimed in claim 1, characterized in that: In step (3), the hydrothermal reaction is carried out at a temperature of 190-220° C. for 1-10 h.
8. The method for in-situ preparation of a molybdenum disulfide film on a metal molybdenum surface as claimed in claim 1, characterized in that: In step (4), ultrasonic cleaning is performed in anhydrous ethanol.
9. The molybdenum disulfide film obtained by the method for in-situ preparation of a molybdenum disulfide film on a metallic molybdenum surface according to any one of claims 1 to 8.
10. Use of the molybdenum disulfide film according to claim 9 in electrocatalytic hydrogen production.