A molybdenum-manganese-carbon composite material, its preparation method and application

Abstract

The application provides a molybdenum-manganese-carbon composite material and a preparation method and application thereof, and belongs to the technical field of inorganic functional material preparation.The disclosed method has low price of reaction raw materials, simple preparation process, and forms unique nanotube-shaped molybdenum-manganese-carbon composite material through self-assembly of nanoparticles, and has low cost of raw materials and preparation process, is free of environmental pollution, is suitable for batch production, and has wide application prospect.The prepared tubular molybdenum-manganese-carbon composite material has distinct morphological characteristics, high purity and good crystallinity, and has wide application prospect in the fields of photoelectric catalysis, sensing, semiconductors, secondary battery electrode materials and the like.

Description

Technical Field

[0001] This invention belongs to the field of inorganic functional material preparation technology, specifically relating to a molybdenum-manganese-carbon composite material, its preparation method, and its application. Background Technology

[0002] With technological advancements and human development, the continuous consumption of non-renewable energy sources such as coal, oil, and natural gas has resulted in the emission of large amounts of toxic gases that pollute the environment. Therefore, there is an urgent need to find renewable energy sources to replace non-renewable ones. Secondary batteries, as a new type of energy storage device, offer advantages such as a wide operating temperature range, lightweight construction, and environmental friendliness, and have been successfully applied in smart electronic devices such as laptops, electric vehicles, and digital cameras. As the demand for smart devices increases, there is an urgent need to develop secondary batteries with advantages such as high energy density, long lifespan, and fast charging and discharging speeds. Among these, the negative electrode material is an indispensable component of secondary batteries.

[0003] Binary metal oxides, as a type of anode material, have attracted researchers' attention due to their diverse crystal structures, rich and varied physicochemical properties, and wide range of applications. In recent years, with the popularization of new electronic devices, binary metal oxides have shown great promise in sensors, nanogenerators, and energy storage and conversion. Transition metal molybdates, as a type of binary metal oxide, are used in luminescence, photoelectrocatalysis, and energy storage and conversion.

[0004] The design and fabrication of transition metal molybdate micro / nano structures are beneficial for increasing specific surface area and electrochemical active sites. For example, Chinese patent CN201110347430.7 discloses a method for preparing manganese molybdate materials assembled from nanosheets into microrod structures; Chinese patent CN201110048928.3 discloses a method for preparing hierarchical heterostructured nanowires of manganese molybdate and cobalt molybdate. However, molybdates, as electrode materials, exhibit significant volume changes during charge-discharge processes, which is detrimental to their cycle stability. To address this issue, carbon materials with good conductivity are typically used for coating. For instance, Chinese patent CN202011505651.8 describes the preparation of carbon-coated manganese molybdate single-crystal microrods using a co-precipitation method combined with high-temperature calcination. As a sodium-ion battery anode material, these microrods exhibit better electrochemical performance compared to uncoated manganese molybdate microrods. The aforementioned reports on MnMoO4 and its composite materials demonstrate the crucial role of micro / nano structure design and carbon material composites in the electrochemical performance of molybdates. Mn2Mo3O8 is a member of the binary molybdenum-manganese compounds with a unique hexagonal structure. It has important application prospects in photoelectrocatalysis, sensors, and electrochemical energy storage materials. However, there are relatively few reports on the structural design of this type of molybdate and its composite with carbon materials. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a molybdenum-manganese-carbon composite material, its preparation method and application, to solve the technical problem that there is no relatively mature and stable preparation method for molybdate structure design.

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

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

[0008] S1: Dissolve the molybdenum source and manganese source in deionized water to obtain solution A and solution B;

[0009] S2: Add solution B dropwise to solution A, stir, and a mixed solution is obtained;

[0010] S3: Humic acid and tris(hydroxymethyl)aminomethane are added to a mixed solution and stirred to obtain a precipitate. The precipitate is then filtered, washed with water, and dried to obtain product C.

[0011] S4: After calcining product C, a molybdenum-manganese-carbon composite material is obtained.

[0012] Furthermore, in S1, the concentration of molybdate ions in solution A is 0.005–0.008 mol / L; and the concentration of manganese ions in solution B is 0.004–0.007 mol / L.

[0013] Furthermore, in S1, the molybdenum source and manganese source are molybdic acid and manganese nitrate, respectively.

[0014] Furthermore, in S2, the volume ratio of solution B to solution A is 1:(1~3).

[0015] Furthermore, in S2, the stirring is carried out at room temperature and pressure for 6–8 hours.

[0016] Furthermore, in S3, the concentrations of humic acid and tris(hydroxymethyl)aminomethane in the mixed solution are 0.003–0.006 mol / L and 0.001–0.003 mol / L, respectively.

[0017] Furthermore, in S3, 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 10 hours.

[0018] Furthermore, in S4, the calcination treatment is carried out under an argon or nitrogen atmosphere, and the calcination temperature is 600-700°C for 1-2 hours.

[0019] The present invention also discloses a molybdenum-manganese-carbon composite material prepared by the above preparation method.

[0020] The present invention also discloses the application of the above-mentioned molybdenum-manganese-carbon composite material, which is used as a photoelectrocatalytic material, a sensing material, a semiconductor material, or an electrode material for a secondary battery.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention discloses a method for preparing a molybdenum-manganese-carbon composite material. Using molybdenum source, manganese source, humic acid, and tris(hydroxymethyl)aminomethane as raw materials, and by adjusting the proportions of the reactants and process parameters such as calcination, nanoparticles are self-assembled to form a unique nanotube-shaped molybdenum-manganese-carbon composite material for the first time. The main components of molybdenum and manganese are Mn₂Mo₃O₈, and the carbon is amorphous and uniformly composited with Mn₂Mo₃O₈. The addition of humic acid and tris(hydroxymethyl)aminomethane in this invention plays a certain auxiliary role in the formation of the unique morphology of the tubular molybdenum-manganese-carbon composite material. After appropriate calcination, the purity and crystallinity of the product are further improved. This preparation method is simple and easy to operate, has low energy consumption, and the raw materials and preparation process are environmentally friendly, making it suitable for mass production.

[0023] The present invention also discloses a molybdenum-manganese-carbon composite material prepared by the above preparation method, which has the characteristics of distinct morphological features, high purity, and high crystallinity. The uniform composite of amorphous carbon layers further improves the electronic conductivity and structural stability of the composite material.

[0024] Due to their excellent properties, the above-mentioned molybdenum-manganese-carbon composite material has broad application prospects in fields such as photoelectrocatalysis, sensing, semiconductors, and secondary battery electrode materials. Attached Figure Description

[0025] Figure 1 The XRD pattern of the molybdenum-manganese-carbon composite material prepared in Example 1;

[0026] Figure 2 The image shows a scanning electron microscope (SEM) image of the molybdenum-manganese-carbon composite material prepared in Example 1.

[0027] Figure 3 The charge-discharge curves are shown for the molybdenum-manganese-carbon composite material prepared in Example 1. 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-manganese-carbon composite material includes the following steps:

[0037] Molybdic acid and manganese nitrate were dissolved in deionized water to prepare solutions A and B, respectively, with molybdate ion concentrations of 0.005 mol / L and manganese ion concentrations of 0.004 mol / L. Solution B was added dropwise to solution A at a volume ratio of 1:1, and the mixture was stirred at room temperature and pressure for 6 hours. Humic acid and tris(hydroxymethyl)aminomethane were added to the above aqueous solution at concentrations of 0.003 mol / L and 0.001 mol / L, respectively, and the mixture was stirred at room temperature and pressure for 8 hours. The resulting precipitate was filtered, washed three times with water, and dried at 80°C for 7 hours to obtain product C. Product C was calcined at 700°C for 1 hour under an argon atmosphere to obtain a molybdenum-manganese-carbon composite material.

[0038] See Figure 1 , Figure 1 XRD patterns of the products prepared for this invention, from Figure 1 The product's phase composition was determined to be Mn2Mo3O8 and amorphous carbon, with the peak between 2θ = 22 and 26° corresponding to the presence of amorphous carbon in the composite material. The absence of other impurity peaks indicates that the prepared product has high purity.

[0039] See Figure 2 , Figure 2 The transmission electron microscope image of the product prepared in this invention shows that the prepared molybdenum-manganese-carbon composite material has distinct morphological characteristics and exhibits a nanotube structure.

[0040] See Figure 3 , Figure 3 The charge-discharge curves of the product prepared according to this invention are shown. As a sodium-ion battery anode material, this product achieves a first discharge and charge specific capacity of 346 and 206 mAh g, respectively. -1 .

[0041] Example 2

[0042] A method for preparing a molybdenum-manganese-carbon composite material includes the following steps:

[0043] Molybdic acid and manganese nitrate were dissolved in deionized water to prepare solutions A and B, respectively, with molybdate ion concentrations of 0.008 mol / L and manganese ion concentrations of 0.007 mol / L. Solution B was added dropwise to solution A at a volume ratio of 1:3, and the mixture was stirred at room temperature and pressure for 8 hours. Humic acid and tris(hydroxymethyl)aminomethane were added to the above aqueous solution at concentrations of 0.006 mol / L and 0.003 mol / L, respectively, and the mixture was stirred at room temperature and pressure for 10 hours. The resulting precipitate was filtered, washed four times with water, and dried at 60°C for 10 hours to obtain product C. Product C was calcined at 600°C for 2 hours under a nitrogen atmosphere to obtain a molybdenum-manganese-carbon composite material.

[0044] Example 3

[0045] A method for preparing a molybdenum-manganese-carbon composite material includes the following steps:

[0046] Molybdic acid and manganese nitrate were dissolved in deionized water to prepare solutions A and B, respectively, with molybdate ion concentrations of 0.006 mol / L and manganese ion concentrations of 0.005 mol / L. Solution B was added dropwise to solution A at a volume ratio of 1:2, and the mixture was stirred at room temperature and pressure for 7 h. Humic acid and tris(hydroxymethyl)aminomethane were added to the above aqueous solution at concentrations of 0.004 mol / L and 0.002 mol / L, respectively, and the mixture was stirred at room temperature and pressure for 9 h. The resulting precipitate was filtered, washed four times with water, and dried at 70 °C for 8 h to obtain product C. Product C was calcined at 650 °C for 1.5 h under a nitrogen atmosphere to obtain a molybdenum-manganese-carbon composite material.

[0047] Example 4

[0048] A method for preparing a molybdenum-manganese-carbon composite material includes the following steps:

[0049] Molybdic acid and manganese nitrate were dissolved in deionized water to prepare solutions A and B, respectively, with molybdate ion concentrations of 0.007 mol / L and manganese ion concentrations of 0.006 mol / L. Solution B was added dropwise to solution A at a volume ratio of 1:3, and the mixture was stirred at room temperature and pressure for 8 hours. Humic acid and tris(hydroxymethyl)aminomethane were added to the above aqueous solution at concentrations of 0.005 mol / L and 0.003 mol / L, respectively, and the mixture was stirred at room temperature and pressure for 10 hours. The resulting precipitate was filtered, washed three times with water, and dried at 80°C for 7 hours to obtain product C. Product C was calcined at 600°C for 1 hour under an argon atmosphere to obtain a molybdenum-manganese-carbon composite material.

[0050] 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-manganese-carbon composite material, characterized by, The method comprises the following steps: S1: Dissolve a molybdenum source and a manganese source in deionized water respectively to obtain solution A and solution B; the concentration of molybdate ions in solution A is 0.005-0.008 mol / L; the concentration of manganese ions in solution B is 0.004-0.007 mol / L; the molybdenum source and the manganese source are molybdic acid and manganese nitrate respectively; S2: Add solution B to solution A dropwise, and obtain a mixed solution after stirring; S3: Add humic acid and tris-hydroxymethyl aminomethane to the mixed solution, and obtain a precipitate after stirring; the precipitate is sequentially subjected to filtration, water washing and drying treatment to obtain product C; S4: After calcination treatment of product C, a molybdenum-manganese-carbon composite material is obtained; In S3, the concentrations of humic acid and tris-hydroxymethyl aminomethane in the mixed solution are 0.003-0.006 mol / L and 0.001-0.003 mol / L respectively.

2. The method of claim 1, wherein the molybdenum-manganese-carbon composite material is prepared by the steps of: preparing a mixture of molybdenum oxide, manganese oxide, and carbon; and heating the mixture to a temperature of 600 to 800°C in a reducing atmosphere. In S2, the volume ratio of solution B to solution A is 1:(1-3).

3. The method of claim 1, wherein the molybdenum-manganese-carbon composite material is prepared by the steps of: preparing a mixture of molybdenum oxide, manganese oxide, and carbon; and heating the mixture to a temperature of 600-1,000°C in a reducing atmosphere. In S2, the stirring is carried out at normal temperature and pressure for 6-8 h.

4. The method of claim 1, wherein the molybdenum-manganese-carbon composite material is prepared by the steps of: preparing a mixture of molybdenum oxide, manganese oxide, and carbon; and heating the mixture to a temperature of 600-1,000°C in a reducing atmosphere. In S3, the water washing is performed for 3-4 times; the drying temperature is 60-80 ℃, and the drying time is 7-10 h.

5. The method of claim 1, wherein the molybdenum-manganese-carbon composite material is prepared by the steps of: preparing a mixture of molybdenum oxide, manganese oxide, and carbon; and heating the mixture to a temperature of 600-1,000°C in a reducing atmosphere. In S4, the calcination treatment is carried out in an argon or nitrogen atmosphere; the calcination temperature is 600-700 ℃, and the time is 1-2 h.

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

7. The use of a molybdenum-manganese-carbon composite according to claim 6, characterized in that The molybdenum-manganese-carbon composite material is used as a photoelectrocatalytic material, a sensing material, a semiconductor material or an electrode material of a secondary battery.

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