Preparation method and application of molybdenum silver vanadate nanomaterial

Abstract

This invention relates to the field of inorganic materials technology, specifically to a method for preparing and applying silver molybdenum vanadate nanomaterials. The method includes the following preparation steps: S1, dissolving ammonium molybdate tetrahydrate, silver nitrate, and ammonium metavanadate in pure water to obtain a mixed solution; S2, adding acid to the mixed solution to adjust the pH, and then carrying out a hydrothermal reaction at a temperature of 100–200°C for 1–24 hours, followed by cooling, washing, and drying to obtain the silver molybdenum vanadate nanomaterials. This preparation method features mild reaction conditions and is easy to scale up for production. The silver molybdenum vanadate nanomaterials have a single-phase structure composed of four elements: Ag, Mo, V, and O. The complex composition and the introduction of multiple metal elements enhance the structural stability of the silver molybdenum vanadate nanomaterials, which exhibit a one-dimensional nanowire or two-dimensional nanosheet structure.

Description

Technical Field

[0001] This invention relates to the field of inorganic materials technology, specifically to a method for preparing and applying silver molybdenum vanadate nanomaterials. Background Technology

[0002] In recent years, multi-component (or greater than ternary) metal vanadate materials have attracted widespread attention due to their good structural stability and excellent physicochemical properties, and they can be applied in fields such as catalysis and optics. However, because the composition and structure of multi-component metal vanadates are much more complex than those of ternary metal vanadates, their preparation is more difficult.

[0003] In existing technologies, the commonly used synthesis methods for multi-metal vanadates are mainly high-temperature solid-state methods, or obtaining precursors through liquid-phase methods, spray methods, etc., followed by high-temperature heat treatment. However, the high-temperature heat treatment process often requires the use of inert gases to ensure the stability of the product's composition and valence state. All of these synthesis methods for multi-metal vanadates suffer from high temperatures and high energy consumption. Furthermore, the products are prone to agglomeration and aggregation at high temperatures, resulting in large, irregularly shaped, and non-uniformly sized bulk materials. Moreover, the difficulty in controlling the composition and size of the products using these methods limits their production and application. Summary of the Invention

[0004] To address the above-mentioned technical problems, this invention provides a method for preparing silver molybdenum vanadate nanomaterials and their applications. This preparation method employs a one-step hydrothermal synthesis to produce multi-component silver molybdenum vanadate nanomaterials with different morphologies. The reaction conditions of this method are mild, and it is easy to scale up for production.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing silver molybdenum vanadate nanomaterials, comprising the following preparation steps:

[0007] S1. Dissolve ammonium molybdate tetrahydrate, silver nitrate and ammonium metavanadate in pure water to obtain a mixed solution;

[0008] S2. After adjusting the pH by adding acid to the mixed solution, a hydrothermal reaction is carried out at a temperature of 100-200°C for 1-24 hours. Then, the solution is cooled, washed, and dried to obtain silver molybdenum vanadate nanomaterials.

[0009] This invention employs a one-step hydrothermal synthesis method to prepare multi-component silver molybdenum vanadate nanomaterials with different morphologies. This preparation method is simple, and the reaction conditions are easy to control. The aforementioned reaction temperature and time are conducive to sufficient hydrothermal synthesis reactions among the reactants. The hydrothermal synthesis conditions are mild, yielding products with regular shapes, uniform sizes, high purity, and good crystal forms, thus enabling control over the morphology and appearance of the products. This preparation method is easy to scale up for production and solves the problems of high temperature, high energy consumption, and product agglomeration and aggregation caused by high-temperature heat treatment in the synthesis of multi-component metal vanadates in existing technologies.

[0010] Optionally, the molar ratio of ammonium molybdate tetrahydrate, silver nitrate and ammonium metavanadate in S1 is 1:(4-8):(6-10).

[0011] By adjusting the ratio of the above reactants, this invention can control the morphology and microstructure of multi-component silver molybdenum vanadate nanomaterials, thereby obtaining multi-component silver molybdenum vanadate nanomaterials with a microstructure of one-dimensional nanowires or two-dimensional nanosheets.

[0012] Optionally, the molar ratio of ammonium molybdate tetrahydrate, silver nitrate, and ammonium metavanadate is 1:7:7. This ratio is more conducive to obtaining multi-component silver molybdate nanomaterials with a chemical composition of AgMoVO6 and a microstructure of one-dimensional nanowires or two-dimensional nanosheets.

[0013] Optionally, the acid adjustment of pH in S2 includes: adjusting pH to 1-3 with nitric acid. Using nitric acid does not introduce other impurities, and a pH of 1-3 is more conducive to the occurrence of hydrothermal synthesis reaction.

[0014] The cooling refers to cooling to room temperature.

[0015] The washing process includes: first washing with deionized water until neutral, and then washing with anhydrous ethanol at least twice; the above washing method can remove impurities mixed in the product and obtain a product with high purity and good crystallization.

[0016] The drying temperature is 70-80℃, and the drying time is 8-10 hours. The drying process removes moisture from the product, resulting in a pure product.

[0017] Optionally, the hydrothermal reaction temperature is 110–180°C and the reaction time is 1–12 h. The above-mentioned preferred hydrothermal reactant temperature and time result in a lower reaction temperature, which can avoid large product size and side reactions, and a shorter reaction time, which can save energy. The above-mentioned reactant temperature and time are conducive to obtaining products with one-dimensional nanowire structures.

[0018] Secondly, the present invention also provides silver molybdenum vanadate nanomaterials obtained by the above preparation method, wherein the chemical composition of the silver molybdenum vanadate nanomaterials is AgMoVO6.

[0019] The silver molybdenum vanadate nanomaterial (AgMoVO6) of this invention has a single-phase structure composed of four elements: Ag, Mo, V, and O. Its complex composition and the introduction of multiple metal elements enhance its structural stability. Its microstructure consists of one-dimensional nanowires or two-dimensional nanosheets. Due to its different nanostructures, it possesses a large specific surface area, a large electrolyte contact area, and a short zinc ion migration path, making it suitable as an electrode material and effectively improving its cycle life and discharge specific capacity. This silver molybdenum vanadate nanomaterial enriches the field of materials science and provides new options for catalysis, energy storage, and semiconductors. Currently, research on the crystal structure and synthesis of AgMoVO6 is very limited, and there are no reports on its synthesis and applications as a nanomaterial. Furthermore, the XRD data of this AgMoVO6 material are not yet indexed in the ICDD-PDF database.

[0020] The silver molybdenum vanadate nanomaterial is a quaternary compound, and its crystal structure is far more complex than that of binary compounds. The difference in phase structure results in a huge difference in material properties. Therefore, the structure and properties of the silver molybdenum vanadate nanomaterial are significantly different from those of traditional binary compounds.

[0021] Optionally, the silver molybdenum vanadate nanomaterial is in the form of nanowires or nanosheets, wherein the diameter of the nanowires is 30–80 nm and the thickness of the nanosheets is 20–50 nm. Silver molybdenum vanadate nanomaterials within this size range exhibit better stability and conductivity.

[0022] Thirdly, the present invention also provides the application of the silver vanadate nanomaterial obtained by the above preparation method or the silver vanadate nanomaterial as an electrode material in an aqueous zinc-ion battery, comprising: mixing the silver vanadate nanomaterial with acetylene black and polyvinylidene fluoride in a mass ratio of (7-8):(2-3):1 to form a working electrode, and using a zinc sheet as a counter electrode and a reference electrode to form an aqueous zinc-ion battery.

[0023] The molybdenum silver vanadate nanomaterials prepared in this invention exhibit good reversibility when applied to the cathode material of aqueous zinc-ion batteries, expanding the application range of existing aqueous zinc-ion battery cathode materials and providing a theoretical basis and experimental evidence for the design and development of novel high-performance aqueous zinc-ion battery cathode materials. Attached Figure Description

[0024] Figure 1 The image shows the X-ray diffraction (XRD) pattern of the silver molybdenum vanadate nanomaterial prepared according to Example 1.

[0025] Figure 2 This is a scanning electron microscope (SEM) image of the silver molybdenum vanadate nanomaterials prepared according to Example 1;

[0026] Figure 3 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared according to Example 2.

[0027] Figure 4 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared according to Example 3.

[0028] Figure 5 Here is a SEM image of the silver molybdenum vanadate nanomaterials prepared according to Example 3;

[0029] Figure 6 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared according to Example 4.

[0030] Figure 7 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared according to Example 5.

[0031] Figure 8 Here is a SEM image of the silver molybdenum vanadate nanomaterials prepared according to Example 5;

[0032] Figure 9 The charge-discharge curves of the silver molybdenum vanadate nanomaterials prepared in Example 1 are shown to illustrate their application as cathode materials for aqueous zinc-ion batteries. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0034] Example 1

[0035] This invention provides a method for preparing silver molybdenum vanadate nanomaterials, comprising the following preparation steps:

[0036] At room temperature, 0.1 mmol of ammonium molybdate tetrahydrate and 0.4 mmol of silver nitrate were weighed into a beaker and dissolved in 6 mL of distilled water by stirring. 1 mmol of ammonium metavanadate was weighed into another beaker and dissolved in 10 mL of distilled water by heating. After the ammonium metavanadate solution cooled, it was added dropwise to the mixture of ammonium molybdate tetrahydrate and silver nitrate. After stirring for 20 min, HNO3 solution was added to adjust the pH of the reaction system to approximately 2. Stirring continued for 30 min, and the mixture was transferred to a 25 mL hydrothermal reactor. The reaction was carried out at 100 °C for 6 h. After cooling to room temperature, the reactor was opened, and the mixture was washed with deionized water by centrifugation until neutral. It was then washed twice by centrifugation with anhydrous ethanol. The precipitate was dried in an oven at 70 °C for 10 h to obtain silver molybdenum vanadate material.

[0037] Figure 1 This is the X-ray diffraction (XRD) pattern of the silver molybdenum vanadate nanomaterial prepared in this embodiment.

[0038] Figure 2 This is a scanning electron microscope (SEM) image of the silver molybdenum vanadate nanomaterials prepared in this embodiment.

[0039] from Figure 1 The X-ray diffraction (XRD) pattern of the product shows that the diffraction peaks are consistent with those of AgMoVO6. From... Figure 2 It can be seen that the product consists of nanowires aggregated together, with the diameter of a single nanowire being approximately 30–80 nm.

[0040] Example 2

[0041] At room temperature, 0.1 mmol of ammonium molybdate tetrahydrate and 0.6 mmol of silver nitrate were weighed into a beaker and dissolved in 6 mL of distilled water by stirring. 8 mmol of ammonium metavanadate was weighed into a beaker and dissolved in 10 mL of distilled water by heating. After the ammonium metavanadate solution cooled, it was added dropwise to the mixture of ammonium molybdate and silver nitrate. After stirring for 23 min, HNO3 solution was added to adjust the pH of the reaction system to approximately 3. Stirring continued for 33 min, and the mixture was transferred to a 25 mL hydrothermal reactor. The reaction was carried out at 120 °C for 1 h. After cooling to room temperature, the reactor was opened, and the mixture was washed with deionized water by centrifugation until neutral. It was then washed twice by centrifugation with anhydrous ethanol. The precipitate was dried in an oven at 80 °C for 8 h to obtain silver molybdenum vanadate material.

[0042] Figure 3 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared in this embodiment.

[0043] from Figure 3 It can be seen that the position and intensity of the product diffraction peaks are consistent with AgMoVO6.

[0044] Example 3

[0045] At room temperature, 0.1 mmol of ammonium molybdate and 0.4 mmol of silver nitrate were weighed into a beaker and dissolved in 6 mL of distilled water by stirring. 6.0 mmol of ammonium metavanadate was weighed into a beaker and dissolved in 10 mL of distilled water by heating. After the ammonium metavanadate solution cooled, it was added dropwise to the mixture of ammonium molybdate and silver nitrate. After stirring for 25 min, HNO3 solution was added to adjust the pH of the reaction system to approximately 1. Stirring continued for 35 min, and the mixture was transferred to a 25 mL hydrothermal reactor. The reaction was carried out at 120 °C for 24 h. The product was washed with deionized water by centrifugation until neutral, then washed twice with anhydrous ethanol by centrifugation, and finally dried in an oven at 80 °C for 8 h to obtain silver molybdenum vanadate material.

[0046] Figure 4 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared in this embodiment.

[0047] Figure 5 Here is a SEM image of the silver molybdenum vanadate nanomaterials prepared in this embodiment;

[0048] from Figure 4 It can be seen that the position and intensity of the product's diffraction peaks are consistent with those of AgMoVO6. From Figure 5 It can be seen that the product is mainly nanowires, and there is adhesion between the nanowires. The diameter of a single nanowire is about 30-80 nm.

[0049] Example 4

[0050] At room temperature, 0.1 mmol of ammonium molybdate and 0.8 mmol of silver nitrate were weighed into a beaker and dissolved in 6 mL of distilled water by stirring. 1 mmol of ammonium metavanadate was weighed into a beaker and dissolved in 10 mL of distilled water by heating. After the ammonium metavanadate solution cooled, it was added dropwise to the mixture of ammonium molybdate and silver nitrate. After stirring for 20 min, HNO3 solution was added to adjust the pH of the reaction system to approximately 2. Stirring continued for 30 min, and the mixture was transferred to a 25 mL hydrothermal reactor. The reaction was carried out at 140 °C for 6 h. After cooling to room temperature, the reactor was opened, and the mixture was washed with deionized water by centrifugation until neutral. It was then washed twice by centrifugation with anhydrous ethanol. The precipitate was dried in an oven at 70 °C for 10 h to obtain silver molybdenum vanadate material.

[0051] Figure 6 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared in this embodiment.

[0052] from Figure 6 It can be seen that the position and intensity of the product diffraction peaks are consistent with AgMoVO6.

[0053] Example 5

[0054] At room temperature, 0.1 mmol of ammonium molybdate and 0.7 mmol of silver nitrate were weighed into a beaker and dissolved in 6 mL of distilled water by stirring. 0.7 mmol of ammonium metavanadate was weighed into a beaker and dissolved in 10 mL of distilled water by heating. After the ammonium metavanadate solution cooled, it was added dropwise to the mixture of ammonium molybdate and silver nitrate. After stirring for 20 min, HNO3 solution was added to adjust the pH of the reaction system to approximately 2. Stirring continued for 30 min, and the mixture was transferred to a 25 mL hydrothermal reactor. The reaction was carried out at 200 °C for 24 h. After the reaction was completed and cooled to room temperature, the reactor was opened, and the mixture was washed with deionized water by centrifugation until neutral. It was then washed twice by centrifugation with anhydrous ethanol. The precipitate was then dried in an oven at 70 °C for 10 h to obtain silver molybdenum vanadate material.

[0055] Figure 7 The image shows the XRD pattern of the silver molybdenum vanadate nanomaterials prepared in this embodiment.

[0056] Figure 8Here is a SEM image of the silver molybdenum vanadate nanomaterials prepared in this embodiment;

[0057] from Figure 7 It can be seen that the product is AgMoVO6. From Figure 8 It can be seen that the products are mainly nanosheets of different sizes, with a thickness of about 20-50 nm.

[0058] Application Example 1

[0059] The electrochemical performance of the silver molybdenum vanadate nanomaterial of the present invention as a cathode material for aqueous zinc-ion batteries was tested using the product prepared in Example 1 as an example.

[0060] The working electrode was prepared by thoroughly mixing AgMoVO6, acetylene black, and polyvinylidene fluoride in a mass ratio of 7:2:1; a zinc sheet was used as the counter electrode and reference electrode. Charge-discharge tests were conducted at room temperature and a current density of 50 mA / g within the range of 0.4–1.3 V.

[0061] Figure 9 The charge-discharge curves of the silver molybdenum vanadate nanomaterials prepared in Example 1 are shown to illustrate their application as cathode materials for aqueous zinc-ion batteries.

[0062] Figure 9 The first three charge-discharge curves are shown, from Figure 9 As can be seen, the specific capacities of AgMoVO6 nanowires as cathode materials for aqueous zinc-ion batteries in the first three discharge cycles were 211.5 mAh / g, 202.1 mAh / g, and 194.0 mAh / g, respectively, all showing good cycle stability.

[0063] The above results indicate that AgMoVO6 is a promising cathode material for aqueous zinc-ion batteries. Its application in aqueous zinc-ion batteries expands the scope of existing aqueous zinc-ion battery cathode materials and provides a theoretical basis and experimental evidence for the design and development of novel high-performance aqueous zinc-ion battery cathode materials.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing silver molybdenum vanadate nanomaterials, characterized in that, The preparation steps include the following: S1. Add ammonium molybdate tetrahydrate, silver nitrate and ammonium metavanadate to pure water and dissolve to obtain a mixed solution; S2. Add acid to the mixed solution to adjust the pH to 1-3, and carry out a hydrothermal reaction. The temperature of the hydrothermal reaction is 100-200℃, and the reaction time is 1-24 h. Then cool, wash, and dry to obtain silver molybdenum vanadate nanomaterials. The chemical composition of the silver molybdenum vanadate nanomaterial is AgMoVO6, and it is used as an electrode material in aqueous zinc-ion batteries. The silver molybdenum vanadate nanomaterial is a nanowire or a nanosheet, wherein the diameter of the nanowire is 30~80 nm and the thickness of the nanosheet is 20~50 nm.

2. The method for preparing silver molybdenum vanadate nanomaterials according to claim 1, characterized in that, The molar ratio of ammonium molybdate tetrahydrate, silver nitrate, and ammonium metavanadate in S1 is 1:(4~8):(6~10).

3. The method for preparing silver molybdenum vanadate nanomaterials according to claim 2, characterized in that, The molar ratio of ammonium molybdate tetrahydrate, silver nitrate, and ammonium metavanadate is 1:7:

7.

4. The method for preparing silver molybdenum vanadate nanomaterials according to claim 1, characterized in that, The acid-based pH adjustment described in S2 includes: adjusting pH with nitric acid.

5. The method for preparing silver molybdenum vanadate nanomaterials according to claim 1, characterized in that, The cooling described in S2 refers to cooling to room temperature; and / or The washing process includes: first washing with deionized water until neutral, then washing at least twice with anhydrous ethanol; and / or The drying temperature is 70-80℃, and the drying time is 8-10 hours.

6. The method for preparing silver molybdenum vanadate nanomaterials according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 110–180°C for 1–12 hours.

7. The method for preparing silver molybdenum vanadate nanomaterials according to claim 1, characterized in that, The molybdenum vanadate silver nanomaterial is used as an electrode material in an aqueous zinc-ion battery. Specifically, the molybdenum vanadate silver nanomaterial is thoroughly mixed with acetylene black and polyvinylidene fluoride at a mass ratio of (7-8):(1-2):1 to form a working electrode. A zinc sheet is used as the counter electrode and reference electrode to form an aqueous zinc-ion battery.

8. The silver molybdenum vanadate nanomaterials prepared by the method according to any one of claims 1 to 7 are characterized in that, The chemical composition of the silver molybdenum vanadate nanomaterial is AgMoVO6.

9. The silver molybdenum vanadate nanomaterial according to claim 8, characterized in that, The silver molybdenum vanadate nanomaterial is a nanowire or a nanosheet, wherein the diameter of the nanowire is 30-80 nm and the thickness of the nanosheet is 20-50 nm.

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