Preparation method of single-layer 1T-phase transition metal chalcogenide quantum chip material
The centrifugal purification process is optimized by hydrothermal or solvothermal method combined with ion embedding and liquid phase peeling methods, and the problem of preparation of single-layer 1T-phase transition metal chalcogenide quantum sheet materials is solved, and high-quality and low-cost large-scale production is achieved.
Patent Information
- Application Number
- CN202510538952.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2025-08-01
AI Technical Summary
It is difficult to efficiently prepare single-layer 1T-phase transition metal chalcogenide quantum sheet materials in the prior art, and there are problems such as harsh reaction conditions, small yield, difficult to regulate size, and poor repeatability.
The hydrothermal or solvothermal method is used to combine ion intercalation and liquid phase peeling methods, and the single-layer 1T-phase transition metal chalcogenide quantum sheet material is prepared by controlling the reaction temperature and centrifugal purification, including ion intercalation chemical method or electrochemical method, and the optimization of centrifugal speed and number of times is optimized, and the multi-layer material is removed to obtain a single-layer material.
The prepared single-layer 1T phase transition metal chalcogenide material has high quality, uniform size, and high 1T phase content. It is suitable for energy storage and catalytic applications. It has a simple method and low cost, and is suitable for large-scale production.
Smart Images
Figure CN120398006A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of inorganic nanomaterial preparation, and is a method for preparing monolayer 1T-phase transition metal chalcogenide quantum sheet materials. Background Art
[0002] Two-dimensional materials have unique monolayer crystal structures, and their quantum confinement characteristics in the thickness direction endow them with many physical and chemical properties different from those of their parent bulk materials. The two-dimensional materials that have been most widely studied mainly include graphene materials, transition metal chalcogenides, transition metal carbides, transition metal nitrides, etc. Among them, transition metal chalcogenides have important applications in many fields such as battery electrodes and photoelectrochemical hydrogen production due to their rich phase structures, large specific surface areas, and abundant element reserves. Generally, transition metal chalcogenides have three phase structures: 2H, 3R, and 1T. Among them, the 2H and 3R phases are semiconductor phases, while the 1T phase shows metallicity and has good conductivity. In terms of electrochemical energy storage capacity, chemical catalytic activity, etc., compared with the 2H-phase and 3R-phase chalcogenides, it shows more excellent performance. Further reducing the planar size of two-dimensional materials to the quantum size (<10 nm) will generate new physical and chemical properties due to their quantum size effect and edge effect, and have more reactive sites and a larger specific surface area than ordinary two-dimensional materials with larger planar sizes.
[0003] Currently, the methods for preparing monolayer 1T-phase transition metal chalcogenides mainly include chemical vapor deposition, mechanical exfoliation, thermal decomposition, and liquid-phase exfoliation, but these methods all have significant technical bottlenecks. Chemical vapor deposition has harsh reaction conditions, is selective to the substrate (i.e., subsequent complex transfer operations are required), has low yield, and it is difficult to prepare transition metal chalcogenides with adjustable sizes. Mechanical exfoliation has high requirements for crystal sizes, is difficult to control the number of layers, has poor repeatability, and extremely low yield. The process stability of thermal decomposition is poor. Therefore, the development of methods for preparing monolayer 1T-phase chalcogenide quantum sheet materials has attracted extensive attention from researchers. Summary of the Invention
[0004] Object of the Invention: The object of the present invention is to provide a method capable of preparing monolayer 1T-phase transition metal chalcogenide quantum sheet materials with good monolayer property, uniform size distribution, small sheet diameter, and high 1T-phase content.
[0005] Technical Solution: The method for preparing monolayer 1T-phase transition metal chalcogenide quantum sheet materials according to the present invention includes the following steps:
[0006] (1) Dissolve the reagent raw materials for preparing transition metal chalcogenides in a solvent, and mix them evenly to obtain a precursor solution;
[0007] (2) Hydrothermally or solvothermally react the precursor solution; after the reaction, take out the reaction product, wash and dry it to obtain a parent-phase multi-layer transition metal chalcogenide nanomaterial;
[0008] (3) Using the parent-phase multi-layer transition metal chalcogenide obtained in step (2) as a raw material, prepare an aqueous suspension of monolayer 1T-phase transition metal chalcogenide nanosheets by using ion intercalation combined with liquid-phase exfoliation method;
[0009] (4) Centrifuge and purify the aqueous suspension obtained in step (3) to obtain a suspension of monolayer 1T-phase transition metal chalcogenide quantum sheets;
[0010] (5) Wash and dry the suspension obtained in step (4) to obtain a powder material of monolayer 1T-phase transition metal chalcogenide quantum sheets.
[0011] Among them, in step (1), the transition metal chalcogenide is a transition metal sulfide or a transition metal selenide; the transition metal is molybdenum or tungsten.
[0012] In step (2), the reaction temperature is 100 - 300 °C, and the reaction time is 5 - 240 hours.
[0013] In step (3), the method of ion intercalation includes a chemical method or an electrochemical method; the intercalated ions include at least one of lithium, sodium, potassium, cesium, magnesium, calcium or aluminum ions.
[0014] In step (4), the process conditions for centrifugal purification are: the centrifugal speed is not less than 5000 rpm, the centrifugal time is not less than 3 minutes, and the number of centrifugations is not less than 3 times. Collect the suspension except for the precipitate. The purpose of centrifugal purification is to remove some multi-layer transition metal chalcogenides, so as to obtain an aqueous suspension of monolayer 1T-phase transition metal chalcogenide quantum sheets. If the centrifugal speed is lower than 5000 rpm, the time is less than 3 minutes, and the number of centrifugations is less than 3 times, the efficiency of removing multi-layer transition metal chalcogenides will be greatly reduced. The suspension of monolayer 1T-phase transition metal chalcogenide quantum sheet materials obtained in step (4) and the powder materials of quantum sheets obtained in step (5) can both be used as raw materials for applications such as energy storage and catalysis.
[0015] In step (5), the washing method includes one of filtration and dialysis, and the drying method includes one of natural drying, freeze drying or vacuum drying.
[0016] The method of the present invention is based on the fact that transition metal chalcogenides prepared by hydrothermal or solvothermal methods will generate nano-scale pores-rich defects, and then use ion intercalation combined with liquid-phase exfoliation to produce fragmentation to prepare monolayer 1T-phase transition metal chalcogenide quantum sheet materials.
[0017] Beneficial effects: Compared with the prior art, the present invention has the following remarkable effects: (1) The material products prepared by the method of the present invention have high quality, specifically manifested as: good monolayer property, uniform size distribution, small sheet diameter and high 1T phase content; it can provide extremely small monolayer 1T-phase chalcogenide quantum sheet materials with high electrochemical activity and high specific surface area for many energy storage and energy conversion devices, such as supercapacitors, ion batteries, catalysis, etc. (2) The present invention does not involve dangerous chemical reagents and special chemical reaction devices, the method process is simple, the cost is low, and the monolayer 1T-phase chalcogenide quantum sheet materials can be efficiently prepared. The hydrothermal or solvothermal reaction and ion insertion combined with liquid-phase exfoliation means in the preparation process can be scaled up for production, so it is suitable for large-scale preparation of monolayer 1T-phase two-dimensional quantum sheet materials. (3) The method of the present invention is simple to operate, has high production efficiency, low cost, is practical and feasible, and is green and environmentally friendly, with wide universality; the present invention can provide a material basis and implementation path for studying the basic physical properties of monolayer 1T-phase transition metal chalcogenide quantum sheet materials, exploring or expanding their applications, and achieving performance breakthroughs, etc. Description of the Drawings
[0018] Figure 1 It is a photograph of the suspension of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1;
[0019] Figure 2 It is a photograph of the powder of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1;
[0020] Figure 3 It is an XRD pattern of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1;
[0021] Figure 4 It is a transmission electron microscope image of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1;
[0022] Figure 5 It is a spherical aberration electron microscope photograph of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1;
[0023] Figure 6 It is a transmission electron microscope image of the monolayer 1T-phase tungsten sulfide quantum sheet material prepared in Example 2;
[0024] Figure 7 It is a transmission electron microscope image of the monolayer 1T-phase molybdenum selenide quantum sheet material prepared in Example 3;
[0025] Figure 8 It is a transmission electron microscope image of the monolayer 1T-phase tungsten selenide quantum sheet material prepared in Example 4. Detailed Embodiments
[0026] Example 1
[0027] A preparation method of a single-layer 1T-phase transition metal chalcogenide quantum sheet material, comprising the following steps:
[0028] (1) Take 236 mg of ammonium molybdate tetrahydrate and 508 mg of thiourea and add them to 40 mL of deionized water, and stir at room temperature for 20 minutes to form a precursor solution;
[0029] (2) Transfer the precursor solution to a high-pressure reaction kettle with a polytetrafluoroethylene liner, tighten the reaction kettle and place it in a forced-air drying oven for solvothermal reaction. The reaction conditions are 220 °C and the duration is 24 hours;
[0030] (3) After the reaction is completed, wait for the oven and the reaction kettle to cool naturally, and then take out the inner liner of the reaction kettle; pour out the product and wash it by centrifugation with deionized water. Freeze-dry the product obtained after centrifugal washing to obtain molybdenum sulfide nanopowder material;
[0031] (4) Using the obtained molybdenum sulfide nanopowder as the positive electrode raw material, mix acetylene black and PVDF (dissolved in NMP) according to the button battery electrode preparation method (the mixing mass ratio of molybdenum sulfide nanopowder, acetylene black, and PVDF is 8:1:1) to make an electrode slurry. Coat the electrode slurry on copper foil and vacuum dry it (100 °C, 8 hours) to make an electrode sheet; use the prepared electrode sheet as the positive electrode and a lithium sheet as the negative electrode to assemble a half-cell in a glove box; perform constant current discharge on the half-cell, and the discharge current density is 0.01 A / g. Stop discharging after the voltage drops to 0.6 V; then disassemble the discharged battery, take out the lithium-inserted MoS2 electrode sheet, and immediately put it into distilled water for ultrasonic exfoliation for 1 hour to obtain an aqueous suspension of 1T-phase molybdenum sulfide quantum sheets;
[0032] (5) Centrifuge and purify the obtained suspension. The centrifugation speed is 8000 rpm, the centrifugation time is 6 minutes, and the number of centrifugation times is 8 times. Collect the suspension except for the precipitate to obtain an aqueous suspension of a single-layer 1T-phase molybdenum sulfide quantum sheet material;
[0033] (6) Dialyze the suspension, collect the product, and perform freeze-drying to obtain a 1T-phase molybdenum sulfide quantum sheet powder material.
[0034] Figure 1 It is a photo of the suspension of the single-layer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1 (step 5), Figure 2 It is a photo of the powder of the single-layer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1. Figure 3 It is the X-ray diffraction pattern of the single-layer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1. By Figure 3 The results show that the phase structure of the obtained material is the 1T phase. Figure 4Transmission electron microscope image of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1. As can be seen from Figure 4 it, the obtained molybdenum sulfide quantum sheet material is monolayer, and the lateral size is the quantum size (<10 nm). Figure 5 Aberration-corrected electron microscope image of the monolayer 1T-phase molybdenum sulfide quantum sheet material prepared in Example 1, Figure 5 further proving that the phase structure of the material is the 1T phase.
[0035] Example 2
[0036] A preparation method of a monolayer 1T-phase transition metal chalcogenide quantum sheet material, comprising the following steps:
[0037] (1) Take 594 mg of tungsten hexachloride and 751 mg of thiourea and add them to 40 mL of deionized water, and stir at room temperature for 20 minutes to form a precursor solution;
[0038] (2) Transfer the precursor solution to a high-pressure reaction kettle with a polytetrafluoroethylene liner, tighten the reaction kettle and place it in a blast drying oven for hydrothermal reaction. The reaction conditions are 300 °C and the duration is 5 hours;
[0039] (3) After the reaction is completed, wait for the oven and the reaction kettle to cool naturally, and then take out the inner liner of the reaction kettle; pour out the product and wash it by centrifugation with deionized water, and freeze-dry the product obtained after centrifugal washing to obtain tungsten sulfide nanometer powder material;
[0040] (4) Weigh 500 mg of the tungsten sulfide nanometer powder material prepared in step (3) and add it to a Schlenk flask, seal the Schlenk flask and perform gas displacement with argon, add 8 mL of butyllithium solution (2.2 M) and 8 mL of anhydrous n-hexane to it, shake well, and react at 50 °C for 48 hours; after the reaction is completed, open the Schlenk flask, pour out all the solid and liquid in the flask after chemical lithium intercalation for filtration, and wash it twice by filtration with anhydrous n-hexane; after the filtration washing is completed, put the lithium-intercalated tungsten sulfide on the filter membrane together with the filter membrane into 500 mL of distilled water for ultrasonic exfoliation for 1 hour to obtain an aqueous suspension of 1T-phase tungsten sulfide quantum sheets;
[0041] (5) Centrifuge and purify the obtained suspension. The centrifuge speed is 10000 rpm, the centrifuge time is 5 minutes, and the number of centrifugations is 5 times. Collect the suspension except for the precipitate to obtain an aqueous suspension of monolayer 1T-phase tungsten sulfide quantum sheet material;
[0042] (6) Dialyze the suspension, collect the product, and freeze-dry it to obtain 1T-phase tungsten sulfide quantum sheet powder material.
[0043] Figure 6TEM image of the monolayer 1T-phase tungsten disulfide quantum sheet material prepared in Example 2. As can be seen from Figure 6 it, the obtained tungsten disulfide quantum sheet material is monolayer, and the lateral size is the quantum size (<10 nm).
[0044] Example 3
[0045] A method for preparing a monolayer 1T-phase transition metal chalcogenide quantum sheet material, comprising the following steps:
[0046] (1) Take 316 mg of selenium powder and 107 mg of sodium borohydride and add them to 40 mL of deionized water. After stirring at room temperature for 20 minutes, add 484 mg of sodium molybdate dihydrate thereto and continue stirring for 5 minutes to obtain a precursor solution;
[0047] (2) Transfer the precursor solution to a high-pressure reaction kettle with a polytetrafluoroethylene inner liner. Tighten the reaction kettle and place it in a forced-air drying oven for solvothermal reaction. The reaction conditions are 100 °C and the duration is 240 hours;
[0048] (3) After the reaction is completed, wait for the oven and the reaction kettle to cool naturally, and then take out the inner liner of the reaction kettle; pour out the product and wash it by centrifugation with deionized water. Freeze-dry the product obtained after centrifugal washing to obtain molybdenum selenide nanometer powder material;
[0049] (4) Weigh 500 mg of the molybdenum selenide nanometer powder material prepared in step (3) and add it to a round-bottom flask. Seal the round-bottom flask and replace the gas with argon. Add 10 mL of butyllithium solution (2.2 M) and 10 mL of anhydrous n-hexane thereto, shake well, and react at 30 °C for 96 hours; after the reaction is completed, open the round-bottom flask, pour out all the solid and liquid in the flask after chemical lithium intercalation for filtration, and wash it by filtration with anhydrous n-hexane twice; after the filtration washing is completed, put the lithium-intercalated molybdenum selenide on the filter membrane together with the filter membrane into 500 mL of distilled water for ultrasonic exfoliation for 1 hour to obtain an aqueous suspension of monolayer 1T-phase molybdenum selenide quantum sheets;
[0050] (5) Centrifuge and purify the obtained suspension. The centrifugation speed is 12,000 rpm, the centrifugation time is 3 minutes, and the number of centrifugations is 3 times. Collect the suspension except for the precipitate to obtain an aqueous suspension of monolayer 1T-phase molybdenum selenide quantum sheet material;
[0051] (6) Dialyze the suspension, collect the product, and freeze-dry it to obtain 1T-phase molybdenum selenide quantum sheet powder material.
[0052] Figure 7 TEM image of the monolayer 1T-phase molybdenum selenide quantum sheet material prepared in Example 3. As can be seen from Figure 7As can be seen, the obtained molybdenum selenide quantum sheet material is monolayer, and the lateral dimension is the quantum size (<10 nm).
[0053] Example 4
[0054] A preparation method of a monolayer 1T-phase transition metal chalcogenide quantum sheet material includes the following steps:
[0055] (1) Take 316 mg of selenium powder and 107 mg of sodium borohydride and add them to 40 mL of deionized water. After stirring at room temperature for 20 minutes, add 660 mg of sodium tungstate thereto and continue stirring for 5 minutes to obtain a precursor solution;
[0056] (2) Transfer the precursor solution to a high-pressure reaction kettle with a polytetrafluoroethylene inner liner. Tighten the reaction kettle and place it in a blast drying oven for solvothermal reaction. The reaction conditions are 200 °C and the duration is 100 hours;
[0057] (3) After the reaction is completed, wait for the oven and the reaction kettle to cool naturally, and then take out the inner liner of the reaction kettle; pour out the product and wash it by centrifugation with deionized water. Freeze-dry the product obtained after centrifugal washing to obtain tungsten selenide nanometer powder material;
[0058] (4) Weigh 500 mg of the tungsten selenide nanometer powder material prepared in step (3) and add it to a round-bottom flask. Seal the round-bottom flask and replace the gas with argon. Add 10 mL of butyllithium solution (2.2 M) and 8 mL of anhydrous n-hexane thereto, shake well, and keep reacting at 40 °C for 60 hours; after the reaction is completed, open the round-bottom flask, pour out all the solid and liquid in the flask after chemical lithium intercalation for filtration, and wash it twice by suction filtration with anhydrous n-hexane; after the suction filtration washing is completed, put the lithium-intercalated tungsten selenide on the filter membrane together with the filter membrane into 500 mL of distilled water for ultrasonic exfoliation for 1 hour to obtain an aqueous suspension of 1T-phase tungsten selenide quantum sheets;
[0059] (5) Centrifuge and purify the obtained suspension. The centrifuge speed is 5000 rpm, the centrifuge time is 10 minutes, and the number of centrifugations is 3 times. Collect the suspension except for the precipitate to obtain an aqueous suspension of monolayer 1T-phase tungsten selenide quantum sheet material;
[0060] (6) Dialyze the suspension, collect the product, and freeze-dry it to obtain 1T-phase tungsten selenide quantum sheet powder material.
[0061] Figure 8 Is the transmission electron microscope image of the monolayer 1T-phase tungsten selenide quantum sheet material prepared in Example 4. As can be seen from Figure 8 it, the obtained tungsten selenide quantum sheet material is monolayer, and the lateral dimension is the quantum size (<10 nm).
Claims
1. A preparation method of a single-layer 1T-phase transition metal chalcogenide quantum sheet material, characterized in that It includes the following steps: (1) Dissolve the reagent raw materials for preparing transition metal chalcogenides in a solvent, and after mixing evenly, obtain a precursor solution; (2) Carry out hydrothermal or solvothermal reaction on the precursor solution; after the reaction, take out the reaction product, wash and dry it to obtain a parent-phase multi-layer transition metal chalcogenide nanomaterial; (3) Using the parent-phase multi-layer transition metal chalcogenide obtained in step (2) as the raw material, prepare an aqueous suspension of monolayer 1T-phase transition metal chalcogenide nanosheets by using ion intercalation combined with liquid-phase exfoliation method; (4) Centrifuge and purify the aqueous suspension obtained in step (3) to obtain a suspension of monolayer 1T-phase transition metal chalcogenide quantum sheets; (5) Wash and dry the suspension obtained in step (4) to obtain a powder material of monolayer 1T-phase transition metal chalcogenide quantum sheets.
2. The preparation method according to claim 1, characterized in that: In step (1), the transition metal chalcogenide is a transition metal sulfide or a transition metal selenide.
3. The preparation method according to claim 2, characterized in that: The transition metal is molybdenum or tungsten.
4. The preparation method according to claim 1, characterized in that: In step (2), the reaction temperature is 100 - 300 °C, and the reaction time is 5 - 240 hours.
5. The preparation method according to claim 1, characterized in that: In step (3), the method of ion intercalation includes a chemical method or an electrochemical method.
6. The preparation method according to claim 5, characterized in that: The intercalated ions include at least one of lithium, sodium, potassium, cesium, magnesium, calcium or aluminum ions.
7. The preparation method according to claim 1, characterized in that: In step (4), the process conditions for centrifugal purification are: the centrifugal speed is not less than 5000 rpm, the centrifugal time is not less than 3 minutes, the number of centrifugations is not less than 3 times, collect the suspension except for the precipitate, and obtain an aqueous suspension of monolayer 1T-phase transition metal chalcogenide quantum sheets.
8. The preparation method according to claim 1, characterized in that: In step (5), the washing method includes filtration or dialysis.
9. The preparation method according to claim 1, characterized in that: In step (5), the drying method includes one of natural drying, freeze drying or vacuum drying.