A molybdenum telluride carbon composite material, its preparation method and application

Abstract

This invention discloses a molybdenum telluride carbon composite material, its preparation method, and its applications, belonging to the fields of energy storage material preparation and sustainable environmental and energy development. The preparation method of this invention uses inexpensive and readily available industrial-grade products as raw materials, and synthesizes micron-sized hollow spheres of the molybdenum telluride carbon composite material through a simple calcination method. The preparation process has a short reaction time, mild reaction conditions, and simple operation, making it suitable for low-cost large-scale production. The preparation method of this invention allows for the control of the size of the micron-sized hollow spheres of the molybdenum telluride carbon composite material by changing the reaction parameters. The prepared product has stable morphology, does not agglomerate, and has high purity and high crystallinity. The molybdenum telluride carbon composite material of this invention has a spherical shell formed by the self-assembly of rolled nanosheets into a flower-like structure. Both the nanosheets and the hollow structure are conducive to rapid charge transport, making it promising for applications in energy storage, catalysis, sensing, optoelectronic devices, and many other fields.

Description

Technical Field

[0001] This invention belongs to the field of energy storage material preparation and sustainable development technology of environment and energy, specifically relating to a molybdenum telluride carbon composite material, its preparation method and application. Background Technology

[0002] Lithium-ion batteries have mature R&D technology and are widely used in commercial applications, but lithium resources are limited. Sodium-ion batteries (SIBs) have a similar energy storage mechanism to lithium-ion batteries, and sodium resources are widely distributed and inexpensive, which can further reduce production costs and improve the relationship between energy and the environment.

[0003] Molybdenum telluride (MoT) is an important member of the transition metal dichalcogenides (TMDs). Its unique catalytic and electronic properties make it promising for applications in energy storage, catalysis, sensing, and optoelectronic devices. MoT possesses a broad layered structure, with each layer composed of numerous robust Te-Mo-Te bonds connected by relatively weak van der Waals forces. Therefore, lithium and sodium ions can readily undergo reversible electrochemical insertion / extraction, thereby increasing the material's electrochemical storage capacity and rate performance.

[0004] Current methods for preparing molybdenum telluride nanomaterials include liquid-phase exfoliation, mechanical exfoliation, vapor deposition, and electrochemical deposition. However, these methods typically suffer from drawbacks such as complex reactions, high energy consumption, easy introduction of impurities, and difficulty in large-scale preparation. Furthermore, the hexagonal tellurium atoms readily form one-dimensional nanowires, nanotubes, and nanoribbons due to van der Waals forces, limiting their application in the fabrication of multidimensional telluride micro / nanostructures. Additionally, molybdenum telluride nanocrystals are prone to aggregation, and large agglomerates hinder the exposure of active edges, further impacting their cycle life as electrode materials. Moreover, the poor conductivity of molybdenum telluride often prevents the full utilization of its superior properties. Therefore, nanostructuring molybdenum telluride and combining it with highly conductive carbon materials is crucial for improving its electrochemical performance. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a molybdenum telluride carbon composite material, its preparation method and application, so as to solve the technical problems of existing preparation methods such as complex reaction, high energy consumption, easy introduction of impurities, and difficulty in large-scale preparation.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for preparing molybdenum telluride carbon composite material, comprising the following steps:

[0008] S1: Sodium carboxymethyl cellulose, sodium alginate, polymethyl methacrylate and sodium molybdate are dissolved in a mixed solution of deionized water and N,N-dimethylformamide. After stirring, the solid product is collected. The solid product is washed with water and dried to obtain product A.

[0009] S2: Calcine product A under vacuum conditions to obtain product B;

[0010] S3: After mixing product B and tellurium powder, the mixture is calcined under vacuum to obtain molybdenum telluride carbon composite material.

[0011] Further, in S1, the concentrations of sodium carboxymethyl cellulose, sodium alginate, polymethyl methacrylate, and sodium molybdate in the mixed solution are (0.01–0.05) mol / L, (0.001–0.005) mol / L, (0.01–0.03) mol / L, and (0.01–0.05) mol / L, respectively; the volume ratio of deionized water to N,N-dimethylformamide is 1:0.3–0.5.

[0012] Furthermore, in S1, the number of times the water is washed is 3 to 4 times; the drying temperature is 60 to 80°C, and the drying time is 7 to 9 hours.

[0013] Furthermore, in S2, the calcination treatment is carried out at a temperature of 600–700°C for 4–6 hours; the vacuum condition is in an argon atmosphere.

[0014] Furthermore, in S3, the mass ratio of product B to tellurium powder is 1:(7-8).

[0015] Furthermore, in S3, the calcination treatment is carried out at a temperature of 900–950°C for 5–6 hours.

[0016] Furthermore, in S3, the vacuum condition is in an argon atmosphere.

[0017] The present invention also discloses a molybdenum telluride carbon composite material prepared by the above preparation method.

[0018] Furthermore, the molybdenum telluride carbon composite material is shaped as a flower-shaped hollow structure formed by the self-assembly of rolled nanosheets, with a diameter of 1.4 μm and a wall thickness of 400–600 nm.

[0019] The present invention also discloses the application of the above-mentioned molybdenum telluride carbon composite material as an electrode material for a secondary battery.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention discloses a method for preparing molybdenum telluride carbon composite material. Using readily available and inexpensive industrial-grade products as raw materials, micron-sized hollow spheres of molybdenum telluride carbon composite material are synthesized for the first time via a simple calcination method. This method features a short reaction time, mild reaction conditions, and simple operation, making it suitable for low-cost large-scale production. Furthermore, the size of the micron-sized hollow spheres of the molybdenum telluride carbon composite material can be controlled by changing the reaction parameters. The prepared product exhibits stable morphology, does not agglomerate, has high purity, and high crystallinity.

[0022] The present invention also discloses a molybdenum telluride carbon composite material prepared by the above preparation method. The molybdenum telluride carbon composite material has a micron-sized flower-shaped hollow structure, and the product has stable morphology, does not agglomerate, has high purity, and high crystallinity.

[0023] This invention also discloses the application of the above-mentioned molybdenum telluride carbon composite material as a secondary battery electrode material. The nanosheet and hollow sphere structures are beneficial to electrolyte transport and rapid ion / electron transfer, and also play a certain role in promoting the structural stability of the electrode material. Attached Figure Description

[0024] Figure 1 This is a scanning electron microscope image of the molybdenum telluride carbon composite material prepared in this invention;

[0025] Figure 2 This is a transmission electron microscope (TEM) image of the molybdenum telluride carbon composite material prepared in this invention.

[0026] Figure 3 The image shows the XRD pattern of the molybdenum telluride carbon composite material prepared in this invention.

[0027] Figure 4 This is a charge-discharge diagram of the molybdenum telluride carbon composite material prepared in this invention. Detailed Implementation

[0028] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0029] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0030] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0031] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0032] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0033] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0034] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0035] Example 1

[0036] A method for preparing a molybdenum telluride carbon composite material includes the following steps:

[0037] Sodium carboxymethyl cellulose (0.05 mol / L), sodium alginate (0.005 mol / L), polymethyl methacrylate (0.03 mol / L), and sodium molybdate (0.05 mol / L) were dissolved in a mixed solution of deionized water and N,N-dimethylformamide (volume ratio 1:0.5). The mixture was stirred at room temperature and pressure for 12 h, and the product was collected, washed three times with water, and dried at 60 °C for 7 h to obtain product A. Product A was calcined at 600 °C for 4 h under an argon atmosphere to obtain product B. Product B and tellurium powder were placed in a tube furnace at a mass ratio of 1:7 and calcined at 900 °C for 5 h under an argon atmosphere to obtain molybdenum telluride carbon composite material.

[0038] See Figure 1 , Figure 1 The scanning electron microscope image of the hollow molybdenum telluride carbon composite material prepared in this invention shows that the prepared product has distinct morphological characteristics, and is formed by the self-assembly of rolled nanosheets into a flower-shaped structure.

[0039] See Figure 2 , Figure 2 The image shows a transmission electron microscope image of the hollow molybdenum telluride carbon composite material prepared according to the present invention, wherein the obtained product has a diameter of 1.4 μm and a thickness of 400–600 nm.

[0040] See Figure 3 , Figure 3 The XRD pattern of the prepared product indicates that the phase composition is MoTe2, corresponding to JCPDS card number 71-2157. Additionally, the peak around 2θ = 23° corresponds to the presence of amorphous carbon in the composite material.

[0041] See Figure 4 , Figure 4 Charge-discharge diagrams of hollow molybdenum telluride carbon composite material as a negative electrode material for sodium-ion batteries are presented. At a current density of 100 mA / g, the discharge specific capacity and charge specific capacity are 497 mAh / g and 318 mAh / g, respectively.

[0042] This invention utilizes inexpensive and readily available raw materials and simple and efficient preparation conditions to prepare molybdenum telluride carbon composite materials, obtaining micron-sized hollow spheres. This provides a sound theoretical basis and practical experience for the design and synthesis of molybdenum telluride and its composite materials.

[0043] Example 2

[0044] A method for preparing a molybdenum telluride carbon composite material includes the following steps:

[0045] Sodium carboxymethyl cellulose (0.01 mol / L), sodium alginate (0.001 mol / L), polymethyl methacrylate (0.01 mol / L), and sodium molybdate (0.01 mol / L) were dissolved in a mixed solution of deionized water and N,N-dimethylformamide (volume ratio 1:0.3). The mixture was stirred at room temperature and pressure for 8 h, and the product was collected, washed four times with water, and dried at 80 °C for 7 h to obtain product A. Product A was calcined at 700 °C for 5 h under an argon atmosphere to obtain product B. Product B and tellurium powder were placed in a tube furnace at a mass ratio of 1:8 and calcined at 950 °C for 5 h under an argon atmosphere to obtain molybdenum telluride carbon composite material.

[0046] Example 3

[0047] A method for preparing a molybdenum telluride carbon composite material includes the following steps:

[0048] Sodium carboxymethyl cellulose (0.02 mol / L), sodium alginate (0.002 mol / L), polymethyl methacrylate (0.02 mol / L), and sodium molybdate (0.02 mol / L) were dissolved in a mixed solution of deionized water and N,N-dimethylformamide (volume ratio 1:0.4). The solution was stirred at room temperature and pressure for 10 h, the product was collected, washed three times with water, and dried at 70 °C for 8 h to obtain product A. Product A was calcined at 650 °C for 6 h under an argon atmosphere to obtain product B. Product B and tellurium powder were placed in a tube furnace at a mass ratio of 1:7.5 and calcined at 930 °C for 6 h under an argon atmosphere to obtain molybdenum telluride carbon composite material.

[0049] Example 4

[0050] A method for preparing a molybdenum telluride carbon composite material includes the following steps:

[0051] Sodium carboxymethyl cellulose (0.04 mol / L), sodium alginate (0.004 mol / L), polymethyl methacrylate (0.04 mol / L), and sodium molybdate (0.04 mol / L) were dissolved in a mixed solution of deionized water and N,N-dimethylformamide (volume ratio 1:0.5). The mixture was stirred at room temperature and pressure for 10 h, the product was collected, washed three times with water, and dried at 60 °C for 7 h to obtain product A. Product A was calcined at 600 °C for 4 h under an argon atmosphere to obtain product B. Product B and tellurium powder were placed in a tube furnace at a mass ratio of 1:7 and calcined at 900 °C for 5 h under an argon atmosphere to obtain molybdenum telluride carbon composite material.

[0052] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for producing a molybdenum carbide telluride composite material, characterized by, The method comprises the following steps: S1: sodium carboxymethyl cellulose, sodium alginate, polymethyl methacrylate and sodium molybdate are dissolved in a mixed solution of deionized water and N,N-dimethylformamide, and the solid product is collected after stirring, and the solid product is sequentially washed with water and dried to obtain product A; S2: product A is subjected to calcination treatment under vacuum conditions to obtain product B; S3: product B and tellurium powder are mixed and subjected to calcination treatment under vacuum conditions to obtain a molybdenum telluride carbon composite material; In S1, the concentrations of sodium carboxymethyl cellulose, sodium alginate, polymethyl methacrylate and sodium molybdate in the mixed solution are (0.01-0.05) mol / L, (0.001-0.005) mol / L, (0.01-0.03) mol / L and (0.01-0.05) mol / L, respectively; the volume ratio of the deionized water to N,N-dimethylformamide is 1:0.3-0.5; In S2, the calcination treatment is performed at a temperature of 600-700 ℃ for 4-6 h, and the vacuum condition is in an argon atmosphere; In S3, the calcination treatment is performed at a temperature of 900-950 ℃ for 5-6 h.

2. The method of claim 1, wherein the molybdenum carbide-tellurium composite material is prepared by the steps of: preparing a mixture of molybdenum carbide and tellurium; and heating the mixture to a temperature of 600 to 800°C in a vacuum or an inert gas atmosphere. In S1, the water washing is performed for 3-4 times; the drying is performed at a temperature of 60-80 ℃ for 7-9 h.

3. The method for preparing a molybdenum telluride carbon composite material according to claim 1, characterized in that, In S3, the mass ratio of product B to tellurium powder is 1:(7-8).

4. The method for preparing a molybdenum telluride carbon composite material according to claim 1, characterized in that, In S3, the vacuum condition is in an argon atmosphere.

5. A molybdenum carbide telluride composite material, characterized by, The molybdenum telluride carbon composite material is prepared by the method of any one of claims 1-4.

6. A molybdenum carbide telluride composite material according to claim 5, characterized in that, The molybdenum telluride carbon composite material has a flower ball-shaped hollow structure formed by self-assembly of curled nanosheets, the diameter of the flower ball-shaped hollow structure is 1.4 μm, and the thickness of the ball wall is 400-600 nm.

7. Use of the molybdenum carbide telluride composite material according to claim 5 or 6, characterized in that The molybdenum telluride carbon composite material is used as an electrode material for a secondary battery.

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