Preparation method and application of a magnetic material trivanadium tetrasulfide

Abstract

This invention belongs to the field of materials preparation technology, and relates to a method for preparing and applying the magnetic material vanadium tetrasulfide. The method for preparing vanadium tetrasulfide involves using elemental vanadium and sulfur powder as raw materials, mixing them with a transport agent, and preparing them in the high-temperature region of a vacuum-sealed quartz tube using a chemical vapor transport method. The transport agent is selected from iodine, ammonium chloride, and vanadium trichloride. When the transport agent is selected from iodine, hexagonal plate-shaped vanadium tetrasulfide is synthesized; when the transport agent is selected from ammonium chloride, rod-shaped vanadium tetrasulfide is synthesized; and when the transport agent is selected from vanadium trichloride, irregular plate-shaped vanadium tetrasulfide is synthesized. This invention utilizes a chemical vapor transport method to controllably synthesize large-area vanadium tetrasulfide single crystals with different morphologies, representing a highly efficient, controllable, and simple process.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation technology, and relates to a method for preparing and applying the magnetic material trivanadium tetrasulfide. Background Technology

[0002] Vanadium tetrasulfide (V3S4), a layered transition metal sulfide, has attracted widespread attention in recent years in fields such as energy storage, catalysis, and electronic devices due to its unique crystal structure and excellent electrochemical performance. It exhibits good reversible capacity and rate performance as an anode material in sodium-ion, potassium-ion, and aluminum-ion batteries, and demonstrates excellent catalytic activity in the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). Furthermore, V3S4 has been investigated for applications in electronic devices such as field-effect transistors and gas sensors.

[0003] In traditional synthesis techniques, the synthesis of vanadium tetrasulfide is relatively complex, requiring high-temperature or even high-pressure sealed vacuum sintering, making it impossible to synthesize the desired morphology in a directional manner. Different morphologies preferentially expose different crystal planes, resulting in varying numbers of active sites and intrinsic activities on different crystal planes. Moreover, large-area vanadium tetrasulfide can provide a larger active area. However, large-area vanadium tetrasulfide is more difficult to synthesize. Although vanadium tetrasulfide has broad application prospects, further research and optimization are needed in terms of synthesis methods and stability.

[0004] Therefore, methods for synthesizing large-area vanadium tetrasulfide single crystals with different morphologies are particularly important. Summary of the Invention

[0005] The main objective of this invention is to overcome the deficiencies in the prior art and provide a method for preparing and applying the magnetic material trivanadium tetrasulfide.

[0006] To achieve the above objectives, the specific technical solution is as follows: This invention provides a method for preparing vanadium tetrasulfide, a magnetic material, by using elemental vanadium and sulfur powder as raw materials, mixing them with a transport agent, and preparing them by chemical vapor transport (CVT); the transport agent is selected from iodine, ammonium chloride, and vanadium trichloride.

[0007] This invention employs a chemical vapor transport method to synthesize large-area vanadium tetrasulfide single crystals with different morphologies. When the transport agent is selected from iodine, hexagonal plate-shaped vanadium tetrasulfide is synthesized. When the transport agent is selected from ammonium chloride, rod-shaped vanadium tetrasulfide is synthesized. When the transport agent is selected from vanadium trichloride, irregular plate-shaped vanadium tetrasulfide is synthesized. This method is an efficient, controllable, and simple process.

[0008] The vanadium tetrasulfide prepared by this invention is an important vanadium sulfide material, with three single crystal morphologies: hexagonal plate-shaped, rod-shaped, and irregular plate-shaped, each with its own characteristics. The hexagonal plate-shaped vanadium tetrasulfide has a diameter of 100-300 micrometers, has a high specific surface area and good electrochemical performance, and is mainly used in supercapacitors and lithium-ion battery anode materials. The rod-shaped vanadium tetrasulfide has a length of 100-900 micrometers, has excellent conductivity and fast ion diffusion channels, and performs outstandingly in battery anodes and electrocatalysis. The irregular plate-shaped vanadium tetrasulfide has a diameter of 500-1500 micrometers, providing more active sites, and is suitable as a composite material matrix and for catalytic applications.

[0009] Furthermore, the high-temperature zone of the quartz tube has a temperature of 800-1100℃, and the low-temperature zone has a temperature of 700-1000℃; the temperature difference between the high-temperature zone and the low-temperature zone is 100-150℃, and the heat preservation time is 4-10 days.

[0010] This invention employs a chemical vapor transport method, with the reactant end being a high-temperature zone and the product end being a low-temperature zone. Under the action of the temperature gradient between the high-temperature and low-temperature zones, the transport agent transports the raw materials from the high-temperature zone to the low-temperature zone for growth, thus producing vanadium tetrasulfide single crystals from powdered elemental raw materials in one step. The temperature is easy to control and the repeatability is good.

[0011] Furthermore, the molar ratio of the vanadium to the sulfur powder is 1:(2-5), and / or the vanadium and sulfur powder are mixed evenly by grinding.

[0012] Within this molar ratio range, the vanadium and sulfur powder of the present invention facilitate the formation of trivanadium tetrasulfide.

[0013] Furthermore, the purity of the vanadium and sulfur powder is not less than 99.9%.

[0014] Furthermore, the amount of iodine used is 50-150 mg / mmol vanadium.

[0015] The use of iodine within this range in this invention helps to ensure efficient transport during the reaction process and experimental safety.

[0016] Furthermore, the amount of ammonium chloride used is 30-60 mg / mmol vanadium.

[0017] The use of ammonium chloride within this range in this invention helps to ensure efficient transport of the reaction process and experimental safety.

[0018] Furthermore, the amount of vanadium chloride used is 10-50 mg / mmol of elemental vanadium.

[0019] The use of vanadium chloride within this range in this invention contributes to the efficient transport of vanadium chloride in the reaction process.

[0020] Furthermore, the vacuum degree of the quartz tube is less than or equal to 1*10. -2 Pa.

[0021] The vacuum level used in this invention helps to produce a pure phase free of impurities.

[0022] Furthermore, the temperature rise rate of the high-temperature zone and the low-temperature zone is 1-5℃ / min.

[0023] The present invention further provides the application potential of vanadium tetrasulfide prepared by the above-mentioned method for preparing vanadium tetrasulfide in the preparation of capacitors, electrode materials, catalytic materials or composite matrix.

[0024] For example, vanadium tetrasulfide with a hexagonal sheet structure is used in supercapacitors and lithium-ion battery anode materials; vanadium tetrasulfide with a rod-shaped structure is used in battery anodes and electrocatalysis; and vanadium tetrasulfide with an irregular sheet structure is used as a composite matrix or in catalytic applications.

[0025] In one specific embodiment of the present invention, a method for preparing a magnetic material, vanadium tetrasulfide, includes the following steps: (1) Grind and mix vanadium and sulfur powder raw materials in a molar ratio of 1:(2-3) evenly, add 90-110 mg / mmol of vanadium as transport agent, and pack into a quartz tube; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa is placed in a dual-temperature zone tube furnace with a heating rate of 1-2℃ / min. The reactant end is in a high-temperature zone with a temperature of 1000-1100℃, and the product end is in a low-temperature zone with a temperature of 900-1000℃. The temperature difference between the high-temperature and low-temperature zones is 100-150℃. The mixture is kept at this temperature for 4-10 days and then cooled in the furnace to obtain hexagonal plate-shaped vanadium tetrasulfide.

[0026] In one specific embodiment of the present invention, a method for preparing a magnetic material, vanadium tetrasulfide, includes the following steps: (1) Grind and mix vanadium and sulfur powder raw materials in a molar ratio of 1:(2-3) evenly, add 45-55 mg / mmol of ammonium chloride as a transport agent, and pack it into a quartz tube; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa is placed in a dual-temperature zone tube furnace with a heating rate of 1-2℃ / min. The reactant end is in a high-temperature zone with a temperature of 1000-1100℃, and the product end is in a low-temperature zone with a temperature of 900-1000℃. The temperature difference between the high-temperature and low-temperature zones is 100-150℃. The mixture is held at this temperature for 4-10 days and then cooled with the furnace to obtain vanadium tetrasulfide with a rod-like structure.

[0027] In one specific embodiment of the present invention, a method for preparing a magnetic material, vanadium tetrasulfide, includes the following steps: (1) Grind and mix vanadium and sulfur powder raw materials in a molar ratio of 1:(2-3) evenly, add 40-50 mg / 1 mmol of vanadium chloride as a transport agent, and pack it into a quartz tube; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa is placed in a dual-temperature zone tube furnace with a heating rate of 1-2℃ / min. The reactant end is in a high-temperature zone with a temperature of 1000-1100℃, and the product end is in a low-temperature zone with a temperature of 900-1000℃. The temperature difference between the high-temperature and low-temperature zones is 100-150℃. The mixture is held at this temperature for 4-10 days and then cooled with the furnace to obtain vanadium tetrasulfide with an irregular sheet-like structure.

[0028] Compared with the prior art, the present invention has the following significant advantages: This invention employs a chemical vapor transport method to controllably synthesize large-area vanadium tetrasulfide single crystals with different morphologies. When the transport agent is selected from iodine, hexagonal plate-shaped vanadium tetrasulfide is synthesized; when the transport agent is selected from ammonium chloride, rod-shaped vanadium tetrasulfide is synthesized; and when the transport agent is selected from vanadium trichloride, irregular plate-shaped vanadium tetrasulfide is synthesized. This is a highly efficient, controllable, and simple process. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the growth of hexagonal vanadium tetrasulfide using iodine as the transport agent in this invention; Figure 2 This is a schematic diagram of the growth of rod-shaped vanadium tetrasulfide synthesized using ammonium chloride as a transport agent in this invention; Figure 3 This is a schematic diagram of the growth of sheet-like vanadium tetrasulfide synthesized using vanadium chloride as a transport agent in this invention; Figure 4 This invention uses iodine as a transport agent to synthesize vanadium tetrasulfide, and the resulting image is shown in the scanning electron microscope image and elemental distribution map. Top left: Scanning electron microscope image; top right: Vanadium elemental distribution map; bottom left: Sulfur elemental distribution map; bottom right: Overlay of scan image and elemental distribution map. Figure 5This invention uses ammonium chloride as a transport agent to synthesize vanadium tetrasulfide using scanning electron microscopy and elemental distribution diagram. From left to right: Scanning electron microscope; overlay of scan image and elemental distribution map; sulfur elemental distribution map; vanadium elemental distribution map; Figure 6 This is a scanning electron microscope image of vanadium tetrasulfide synthesized using vanadium chloride as a transport agent in this invention; Figure 7 This invention uses vanadium tetrasulfide as a transport agent to synthesize vanadium trisulfide using vanadium chloride as a scanning electron microscope image and elemental distribution map. From left to right: scanning electron microscope; sulfur distribution map; vanadium distribution map. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0032] Unless otherwise specified in the embodiments of the present invention, the techniques or conditions described in the literature in this field or the product instructions shall be followed; if the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased through legitimate channels.

[0033] The vanadium and sulfur powder used in this invention have a purity of 99.9%.

[0034] Example 1 like Figure 1 As shown, this embodiment provides a method for preparing hexagonal sheet-shaped magnetic material vanadium tetrasulfide, including the following steps: (1) Grind and mix 1 mmol of vanadium and 2 mmol of sulfur powder evenly, add 100 mg of elemental iodine, and pack into a quartz tube with a size of 23 cm; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa was placed in a dual-temperature zone tube furnace with a heating rate of 1℃ / min; the reactant end was in the high-temperature zone at 1050℃, and the product end was in the low-temperature zone at 950℃; after holding at this temperature for 7 days, the product was cooled with the furnace to obtain hexagonal plate-shaped vanadium tetrasulfide.

[0035] Example 2 like Figure 2 As shown, this embodiment provides a method for preparing rod-shaped magnetic material vanadium tetrasulfide, including the following steps: (1) Grind and mix 1 mmol of vanadium and 2 mmol of sulfur powder evenly, add 50 mg of ammonium chloride, and pack into a quartz tube with a size of 23 cm; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa was placed in a dual-temperature zone tube furnace with a heating rate of 1℃ / min; the reactant end was in the high-temperature zone at 1050℃, and the product end was in the low-temperature zone at 950℃; after holding at this temperature for 7 days, the product was cooled with the furnace to obtain rod-shaped vanadium tetrasulfide.

[0036] Example 3 like Figure 3 As shown, this embodiment provides a method for preparing sheet-like magnetic material vanadium tetrasulfide, including the following steps: (1) Grind and mix 1 mmol of elemental vanadium and 2 mmol of sulfur powder evenly, add 50 mg of vanadium chloride, and pack into a quartz tube with a size of 23 cm; (2) Vacuum the quartz tube and seal it. The vacuum degree of the quartz tube is 1*10. -2 Pa was placed in a dual-temperature zone tube furnace with a heating rate of 1℃ / min; the reactant end was in the high-temperature zone at 1050℃, and the product end was in the low-temperature zone at 950℃; after holding at this temperature for 7 days, the product was cooled with the furnace to obtain flake-shaped vanadium tetrasulfide.

[0037] The scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) spectra of the trivanadium tetrasulfide (TTS) prepared in Examples 1-3 are shown in Tables 1-3.

[0038] Table 1. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) content of vanadium tetrasulfide synthesized with iodine as the transport agent.

[0039] Table 2. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) content of vanadium tetrasulfide synthesized with ammonium chloride as the transport agent.

[0040] Table 3. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) content of vanadium tetrasulfide synthesized with vanadium chloride as the transport agent.

[0041] Table 1 shows that the hexagonal plate-shaped vanadium tetrasulfide contains sulfur and vanadium, and its chemical formula is V3S4 based on the normalized atomic ratio. Table 2 shows that the rod-shaped vanadium tetrasulfide contains sulfur and vanadium, and its chemical formula is V3S4 based on the normalized atomic ratio. Table 3 shows that the plate-shaped vanadium tetrasulfide contains sulfur and vanadium, and its chemical formula is V3S4 based on the normalized atomic ratio.

[0042] from Figure 4The scanning electron microscope (SEM) images of hexagonal plate-shaped vanadium tetrasulfide and the corresponding vanadium and sulfur element distribution maps, as well as the overlay of the SEM images and element distribution maps, show that the vanadium and sulfur elements in the hexagonal plate-shaped vanadium tetrasulfide are uniformly distributed and there is no phase separation.

[0043] from Figure 5 Scanning electron microscope (SEM) images of rod-shaped vanadium tetrasulfide and corresponding vanadium and sulfur element distribution maps, as well as overlay images of the scan and element distribution maps, show that vanadium and sulfur elements are uniformly distributed in hexagonal plate-shaped vanadium tetrasulfide, without phase separation.

[0044] from Figure 6 and Figure 7 Scanning electron microscope (SEM) images of plate-shaped vanadium tetrasulfide and corresponding vanadium and sulfur element distribution diagrams, along with scanning images, demonstrate that vanadium and sulfur elements are uniformly distributed in the hexagonal plate-shaped vanadium tetrasulfide, without phase separation.

[0045] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing vanadium tetrasulfide, a magnetic material, characterized in that, It is prepared by chemical vapor transport method using vanadium and sulfur powder as raw materials, mixed with a transport agent; the transport agent is selected from iodine, ammonium chloride or vanadium trichloride.

2. The method for preparing the magnetic material vanadium tetrasulfide according to claim 1, characterized in that, The reaction vessel is a vacuum-sealed quartz tube. The temperature of the high-temperature zone of the quartz tube is 800-1100℃, and the temperature of the low-temperature zone is 700-1000℃. The temperature difference between the high-temperature zone and the low-temperature zone is 100-150℃, and the heat preservation time is 4-10 days.

3. The method for preparing the magnetic material vanadium tetrasulfide according to claim 1 or 2, characterized in that, The molar ratio of vanadium to sulfur powder is 1:(2-5), and / or the vanadium and sulfur powder are mixed evenly by grinding.

4. The method for preparing the magnetic material vanadium tetrasulfide according to claim 3, characterized in that, The purity of the vanadium and sulfur powder is not less than 99.9%.

5. The method for preparing the magnetic material vanadium tetrasulfide according to claim 1, 2, or 4, characterized in that, The amount of iodine used is 50-150 mg / mmol of vanadium.

6. The method for preparing vanadium tetrasulfide magnetic material according to claim 1, 2, or 4, characterized in that, The amount of ammonium chloride used is 30-60 mg / mmol vanadium.

7. The method for preparing vanadium tetrasulfide magnetic material according to claim 1, 2, or 4, characterized in that, The amount of vanadium chloride used is 10-50 mg / mmol of elemental vanadium.

8. The method for preparing vanadium tetrasulfide magnetic material according to claim 1, 2, or 4, characterized in that, The vacuum degree of the quartz tube is less than or equal to 1*10. -2 Pa.

9. The method for preparing the magnetic material vanadium tetrasulfide according to claim 8, characterized in that, The temperature rise rate in the high-temperature zone and the low-temperature zone is 1-5℃ / min.

10. The application of vanadium tetrasulfide prepared by the method for preparing magnetic material vanadium tetrasulfide according to any one of claims 1-9 in the preparation of capacitors, electrode materials, catalytic materials or composite matrix.

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