High-entropy sulfide and preparation method and application thereof

Abstract

The invention provides a high-entropy sulfide and a preparation method and application thereof, and relates to the technical field of high-entropy materials.The preparation method comprises the steps that a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide serves as a metal source, sulfur powder serves as a sulfur source, a second temperature zone and a third temperature zone are heated to 850-950 DEG C and 1050-1100 DEG C respectively in advance, and the mixture is heated to 850-950 DEG C and 1050-1100 DEG C respectively; then the metal source and the reaction substrate are placed in the second temperature zone and the third temperature zone respectively, rapid heating of the metal source and the reaction substrate can be achieved, after the reaction is finished, reaction products are rapidly cooled through liquid nitrogen, and element segregation of the prepared high-entropy sulfide can be avoided. In addition, the two-dimensional high-entropy sulfide provided by the invention has relatively good photoelectric response performance and has a wide application prospect in the technical field of photoelectricity.

Description

Technical Field

[0001] The present invention relates to the technical field of high entropy materials, and in particular to a high entropy sulfide and a preparation method and application thereof. Background Art

[0002] The controllable preparation of large-area, high-quality two-dimensional crystalline materials is an important basis for their application in optoelectronics, flexible devices and other fields; among them, two-dimensional high-entropy sulfide materials, as an emerging type of nanomaterial system, can combine the advantages of two-dimensional nanomaterials and high-entropy alloys, have unique metal components and adjustable band structures, and show excellent performance in the field of optoelectronic detection. At present, high-entropy sulfides can generally be prepared by high-temperature solid-phase method and solvothermal method, but because high-entropy sulfides contain multiple elements and each element has different physical properties, element segregation is prone to occur during nucleation and growth. Summary of the invention

[0003] The problem solved by the invention is that high entropy sulfide prepared by the existing method is prone to element segregation.

[0004] To solve the above problems, the present invention provides a method for preparing high entropy sulfide, based on a high temperature tube furnace having a first temperature zone, a second temperature zone and a third temperature zone, comprising:

[0005] Step S1, introducing a carrier gas into the high-temperature tube furnace, placing sulfur powder in the first temperature zone, and heating the first temperature zone, the second temperature zone, and the third temperature zone to a first temperature, a second temperature, and a third temperature, respectively;

[0006] Step S2, placing the metal source and the reaction substrate in the second temperature zone and the third temperature zone respectively, keeping them for a preset time, and cooling the obtained reaction product in liquid nitrogen to obtain high entropy sulfide;

[0007] Wherein, the metal source is a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide; the first temperature zone, the second temperature zone and the third temperature zone are arranged in sequence along the flow direction of the carrier gas, the first temperature is 300-350°C, the second temperature is 850-950°C, and the third temperature is 1050-1100°C.

[0008] Optionally, in the metal source, the mass ratio of the molybdenum trioxide, the tantalum pentoxide, the vanadium dioxide, the tungsten trioxide and the titanium dioxide is (4-6): (0.9-1.1): (0.9-1.1): (4-6):1.

[0009] Optionally, the mass ratio of the sulfur powder to the metal source is (4-6):1.

[0010] Optionally, in step S2, the preset time is 15-30 minutes.

[0011] Optionally, in step S1, the carrier gas is nitrogen.

[0012] Optionally, the flow rate of the carrier gas is 35-55 sccm.

[0013] Optionally, in step S2, the material of the reaction substrate includes one of sapphire, silicon and aluminum nitride.

[0014] Optionally, the reaction substrate is made of sapphire.

[0015] The present invention also provides a high entropy sulfide, which is prepared by the above-mentioned preparation method of the high entropy sulfide.

[0016] The present invention also provides an application of the high entropy sulfide in the field of optoelectronic technology.

[0017] Compared with the prior art, the present invention uses a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide as a metal source, and sulfur powder as a sulfur source. By preheating the second temperature zone and the third temperature zone to 850-950°C and 1050-1100°C respectively, and then placing the metal source and the reaction substrate in the second temperature zone and the third temperature zone respectively, the metal source and the reaction substrate can be quickly heated up, and the reaction product is quickly cooled by liquid nitrogen after the reaction is completed, so that element segregation of the obtained high entropy sulfide can be avoided. In addition, the two-dimensional high entropy sulfide provided by the present invention has better photoelectric response performance and has broad application prospects in the field of photoelectric technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the process for preparing high entropy sulfide in an embodiment of the present invention;

[0019] Figure 2 This is the XRD image of the high entropy sulfide prepared in Comparative Example 1;

[0020] Figure 3 This is an optical microscope image of the high entropy sulfide prepared in Example 1;

[0021] Figure 4 The scanning electron microscope and energy spectrum analysis diagram of the high entropy sulfide prepared in Example 1;

[0022] Figure 5 is a Raman spectrum of the high entropy sulfide prepared in Example 1;

[0023] Figure 6 This is a comparison chart of the output characteristics of the field effect transistor in the application example under the conditions of no light and laser irradiation with a wavelength of 405nm. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0026] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0027] like Figure 1 As shown, a method for preparing high entropy sulfide provided by an embodiment of the present invention is based on a high-temperature tube furnace having a first temperature zone, a second temperature zone and a third temperature zone, comprising:

[0028] Step S1, introducing a carrier gas into the high-temperature tube furnace, placing sulfur powder in the first temperature zone, and heating the first temperature zone, the second temperature zone, and the third temperature zone to a first temperature, a second temperature, and a third temperature, respectively;

[0029] Step S2, placing the metal source and the reaction substrate in the second temperature zone and the third temperature zone respectively, keeping them for a preset time, and cooling the obtained reaction product in liquid nitrogen to obtain high entropy sulfide;

[0030] Wherein, the metal source is a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide; the first temperature zone, the second temperature zone and the third temperature zone are arranged in sequence along the flow direction of the carrier gas, the first temperature is 300-350°C, the second temperature is 850-950°C, and the third temperature is 1050-1100°C.

[0031] It should be noted that, in the present invention, the first temperature zone, the second temperature zone, and the third temperature zone are heated to the first temperature, the second temperature, and the third temperature, respectively, which should be understood as: heating the first temperature zone to the first temperature, heating the second temperature zone to the second temperature, and heating the third temperature zone to the third temperature. In the present invention, placing the metal source and the reaction substrate in the second temperature zone and the third temperature zone, respectively, should be understood as: placing the metal source in the second temperature zone and placing the reaction substrate in the third temperature zone.

[0032] High entropy sulfides are generally prepared by high-temperature solid-phase method and solvent thermal method. There is no relevant report on the preparation of high entropy sulfides by CVD method. Moreover, when preparing materials by existing CVD, the reactants are generally placed in a tube furnace first, and then the reactants are heated from room temperature to a specified temperature. After the reaction, the reaction products are air-cooled or cooled with the furnace to room temperature.

[0033] The embodiment of the present invention improves the existing CVD method, uses a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide as a metal source, and uses sulfur powder as a sulfur source. The second temperature zone and the third temperature zone are heated to 850-950° C. and 1050-1100° C. in advance, and then the metal source and the reaction substrate are placed in the second temperature zone and the third temperature zone respectively, so that the metal source and the reaction substrate can be quickly heated up. After the reaction is completed, the reaction product is quickly cooled by liquid nitrogen, so that element segregation of the obtained high entropy sulfide can be avoided.

[0034] In some embodiments of the present invention, in the metal source, the mass ratio of the molybdenum trioxide, the tantalum pentoxide, the vanadium dioxide, the tungsten trioxide and the titanium dioxide is (4-6): (0.9-1.1): (0.9-1.1): (4-6):1.

[0035] In some embodiments of the present invention, the mass ratio of the sulfur powder to the metal source is (4-6):1.

[0036] In some embodiments of the present invention, in step S2, the preset time is 15-30 minutes.

[0037] In some embodiments of the present invention, in step S1, the carrier gas is nitrogen, and the flow rate of the carrier gas is 35-55 sccm.

[0038] In some embodiments of the present invention, in step S2, the material of the reaction substrate includes one of sapphire, silicon and aluminum nitride. Preferably, the material of the reaction substrate is sapphire.

[0039] The embodiment of the present invention further provides a high entropy sulfide, which is prepared by the above-mentioned method for preparing the high entropy sulfide.

[0040] The present invention also provides an application of the high entropy sulfide in the field of optoelectronic technology.

[0041] The present invention is further described below in conjunction with specific embodiments.

[0042] Embodiment 1: This embodiment is implemented using a high temperature tube furnace having a first temperature zone, a second temperature zone and a third temperature zone. The first temperature zone, the second temperature zone and the third temperature zone of the high temperature tube furnace are arranged in sequence along the flow direction of the carrier gas.

[0043] A1. Introduce carrier gas into a high-temperature tube furnace, place 5g of sulfur powder in the first temperature zone, heat the first temperature zone to 325°C, heat the second temperature zone to 900°C, and heat the third temperature zone to 1075°C; the carrier gas is nitrogen, and its flow rate is 45sccm

[0044] A2. Place 1 g of a metal source in the second temperature zone, place a reaction substrate in the third temperature zone, keep for 20 minutes, and cool the reaction product obtained on the reaction substrate in liquid nitrogen to obtain a high entropy sulfide; wherein the metal source is a mixture of molybdenum trioxide powder, tantalum pentoxide powder, vanadium dioxide powder, tungsten trioxide powder and titanium dioxide powder in a mass ratio of 5:1:1:5:1; and the reaction substrate is a sapphire substrate.

[0045] Embodiment 2: This embodiment is implemented using a high-temperature tube furnace having a first temperature zone, a second temperature zone and a third temperature zone. The first temperature zone, the second temperature zone and the third temperature zone of the high-temperature tube furnace are arranged in sequence along the flow direction of the carrier gas.

[0046] A1. Introduce carrier gas into a high-temperature tube furnace, place 5 g of sulfur powder in the first temperature zone, heat the first temperature zone to 300° C., heat the second temperature zone to 850° C., and heat the third temperature zone to 1050° C.; the carrier gas is nitrogen with a flow rate of 35 sccm.

[0047] A2. Place 1 g of a metal source in the second temperature zone, place a reaction substrate in the third temperature zone, keep for 20 minutes, and cool the reaction product obtained on the reaction substrate in liquid nitrogen to obtain a high entropy sulfide; wherein the metal source is a mixture of molybdenum trioxide powder, tantalum pentoxide powder, vanadium dioxide powder, tungsten trioxide powder and titanium dioxide powder in a mass ratio of 4:1:1:4:1; and the reaction substrate is a sapphire substrate.

[0048] Embodiment 3: This embodiment is implemented using a high-temperature tube furnace having a first temperature zone, a second temperature zone and a third temperature zone. The first temperature zone, the second temperature zone and the third temperature zone of the high-temperature tube furnace are arranged in sequence along the flow direction of the carrier gas.

[0049] A1. Introduce carrier gas into a high-temperature tube furnace, place 5 g of sulfur powder in the first temperature zone, heat the first temperature zone to 350°C, heat the second temperature zone to 950°C, and heat the third temperature zone to 1100°C; the carrier gas is nitrogen with a flow rate of 55 sccm.

[0050] A2. Place 1 g of a metal source in the second temperature zone, place a reaction substrate in the third temperature zone, keep for 20 minutes, and cool the reaction product obtained on the reaction substrate in liquid nitrogen to obtain a high entropy sulfide; wherein the metal source is a mixture of molybdenum trioxide powder, tantalum pentoxide powder, vanadium dioxide powder, tungsten trioxide powder and titanium dioxide powder in a mass ratio of 6:1:1:6:1; and the reaction substrate is a sapphire substrate.

[0051] Comparative Example 1: Synthesis of high entropy sulfide by high temperature solid phase method

[0052] 3 g of molybdenum powder, 6 g of tantalum powder, 2 g of vanadium powder, 6 g of tungsten powder, 2 g of titanium powder and 1 g of sulfur powder were mixed and ground evenly, and tableted using a ring-shaped mold to obtain a powder tablet.

[0053] The powder tablets were placed in a quartz tube and vacuumed. When the pressure in the quartz tube was 1.0×10 -3 When the temperature is 0.5 Pa, the quartz tube is encapsulated with a flame spray gun. The encapsulated quartz tube is placed in a muffle furnace, heated to 1000°C at a heating rate of 1°C / min, kept at this temperature for 100 h, and then cooled with the furnace to obtain MoWTiTaVS2 high entropy sulfide.

[0054] Application Examples

[0055] The high entropy sulfide prepared in Example 1 was used as a conductive channel to prepare a field effect transistor.

[0056] Experimental example

[0057] The high entropy sulfide prepared in Comparative Example 1 was characterized by XRD. Figure 2 ,from Figure 2 It can be seen that the high entropy sulfide prepared in Comparative Example 1 has V5S8 phase (PDF#04-008-3925) precipitated in the 2H phase (PDF#04-002-9908) of MoS2, indicating that there is element segregation in the high entropy sulfide prepared in Comparative Example 1.

[0058] The high entropy sulfide obtained in Example 1 was characterized by optical microscopy. Figure 3 ,from Figure 3It can be seen that the high entropy sulfide prepared in Example 1 is a sheet-like structure, belonging to a two-dimensional high entropy sulfide. Raman spectroscopy analysis of the high entropy sulfide prepared in Example 1 shows Figure 4 The high entropy sulfide obtained in Example 1 was subjected to scanning electron microscopy and energy spectrum analysis. Figure 5 ,from Figure 4 It can be seen that the characteristic peak of the product obtained in Example 1 is 382.5 cm -1 and 408.5cm -1 , corresponding to the 2H phase crystal structure, indicating that the high entropy sulfide prepared in Example 1 is a single phase. Figure 5 It can be seen that the molybdenum, tantalum, vanadium, tungsten, titanium and sulfur elements are evenly distributed in the high entropy sulfide prepared in Example 1, and no element segregation phenomenon occurs.

[0059] It should be noted that the high entropy sulfide obtained in the present invention is a two-dimensional thin film material, and its signal is weak during XRD detection, so XRD characterization cannot be performed.

[0060] The output characteristics of the field effect transistor in the corresponding use case were tested under the conditions of no light and laser irradiation with a wavelength of 405nm. The results are shown in Figure 6 ,from Figure 6 It can be seen that the high entropy sulfide prepared in Example 1 forms a good ohmic contact with the electrode. The carrier mobility of the high entropy sulfide is calculated to be as high as 1200 cm 2 / V·s, the high entropy sulfide prepared in Example 1 has excellent photoelectric response performance to the laser with a wavelength of 405 nm.

[0061] It should be noted that Figure 6 MediumDark(V BC ) series corresponds to the data under no light conditions, 405nm (V BC ) series corresponds to the data under the laser irradiation condition with a wavelength of 405nm.

[0062] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for preparing high entropy sulfide, characterized in that: Based on a high temperature tube furnace with a first temperature zone, a second temperature zone and a third temperature zone, comprising: Step S1, introducing a carrier gas into the high-temperature tube furnace, placing sulfur powder in the first temperature zone, and heating the first temperature zone, the second temperature zone, and the third temperature zone to a first temperature, a second temperature, and a third temperature, respectively; Step S2, placing the metal source and the reaction substrate in the second temperature zone and the third temperature zone respectively, keeping them for a preset time, and cooling the obtained reaction product in liquid nitrogen to obtain high entropy sulfide; Wherein, the metal source is a mixture of molybdenum trioxide, tantalum pentoxide, vanadium dioxide, tungsten trioxide and titanium dioxide; the first temperature zone, the second temperature zone and the third temperature zone are arranged in sequence along the flow direction of the carrier gas, the first temperature is 300-350°C, the second temperature is 850-950°C, and the third temperature is 1050-1100°C.

2. The method for preparing high entropy sulfide according to claim 1, characterized in that: In the metal source, the mass ratio of the molybdenum trioxide, the tantalum pentoxide, the vanadium dioxide, the tungsten trioxide and the titanium dioxide is (4-6): (0.9-1.1): (0.9-1.1): (4-6):

1.

3. The method for preparing high entropy sulfide according to claim 2, characterized in that: The mass ratio of the sulfur powder to the metal source is (4-6):

1.

4. The method for preparing high entropy sulfide according to claim 1, characterized in that: In step S2, the preset time is 15-30 minutes.

5. The method for preparing high entropy sulfide according to claim 1, characterized in that: In the step S1, the carrier gas is nitrogen.

6. The method for preparing high entropy sulfide according to claim 1, characterized in that: The flow rate of the carrier gas is 35-55 sccm.

7. The method for preparing high entropy sulfide according to claim 1, characterized in that: In the step S2, the material of the reaction substrate includes one of sapphire, silicon and aluminum nitride.

8. The method for preparing high entropy sulfide according to claim 7, characterized in that: The reaction substrate is made of sapphire.

9. A high entropy sulfide, characterized in that: The high entropy sulfide is prepared by the preparation method of the high entropy sulfide according to any one of claims 1 to 8.

10. Use of the high entropy sulfide according to claim 9 in the field of optoelectronic technology.

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