Manganese antimonate nanomaterial and preparation method thereof
By combining the sol-gel method with multi-stage heat treatment, the problems of metal ratio control and purity in the preparation of manganese antimonate nanomaterials were solved, and high-purity, high-performance nanomaterials were prepared, which are suitable for magnetic materials and catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN UNIV OF TECH
- Filing Date
- 2024-05-28
- Publication Date
- 2026-05-01
AI Technical Summary
Existing methods for preparing manganese antimonate nanomaterials suffer from problems such as difficulty in controlling the metal ratio, complex processes, harsh reaction conditions, low purity, and unstable performance. The sol-gel method faces challenges in precursor selection and gelation control during the preparation process.
The sol-gel method was adopted, in which manganese salt, antimony salt and complexing agent solution were mixed, pH value was adjusted and then mixed with soft template agent to form sol. After standing and drying, first-stage and second-stage heat treatment were carried out. By controlling the heat treatment parameters, high-purity and high-performance manganese antimony nanomaterials were prepared.
We have achieved the preparation of high-purity, high-performance manganese antimonate nanomaterials. The products are applicable to fields such as magnetic materials, catalysts, and battery materials, and have good operability and reproducibility.
Smart Images
Figure CN118387931B_ABST
Abstract
Description
A manganese antimonate nanomaterial and its preparation method Technical Field
[0001] This invention relates to the field of nanomaterial preparation technology, and in particular to a manganese antimonate nanomaterial and its preparation method. Background Technology
[0002] Manganese antimonate is a novel inorganic functional material developed in recent years. As an inorganic compound with unique physical and chemical properties, it shows significant application potential in fields such as magnetism, catalysis, batteries, piezoelectricity, and optoelectronic materials. The crystal structure and composition of manganese antimonate make it an excellent magnetic material and catalyst. However, traditional preparation methods, such as solid-state reaction, hydrothermal methods, and magnetron sputtering, suffer from problems such as difficulty in controlling particle size, poor uniformity, and harsh reaction conditions, limiting its widespread application.
[0003] The sol-gel method, as a chemical approach for preparing nanomaterials, has attracted widespread attention in recent years. This method offers the following advantages:
[0004] 1. Low-temperature synthesis: The sol-gel method can achieve uniform mixing and reaction of precursors at a lower temperature, effectively avoiding grain growth and inhomogeneity that may occur in high-temperature solid-phase reactions.
[0005] 2. Excellent composition control: The sol-gel method allows for precise control of the stoichiometry of materials, thereby optimizing the composition and performance of the final product.
[0006] 3. Nanoscale control: This method can prepare nanoparticles with uniform size and good dispersion, which is beneficial to improving the specific surface area and activity of the material.
[0007] Despite the numerous advantages of the sol-gel method, some challenges remain in the preparation of manganese antimonate nanomaterials, such as:
[0008] 1. Precursor selection: Manganese and antimony compounds have different solubilities and stability in solution, which can easily lead to precipitation during solution preparation. It is necessary to select appropriate precursors and complexing agents to stabilize the solution.
[0009] 2. Gelization process control: During the transformation of sol into gel, it is necessary to precisely control the pH value, temperature and time to ensure the formation of a uniform gel.
[0010] 3. Optimization of heat treatment conditions: The temperature and time during the heat treatment process directly affect the crystal phase and morphology of the final product and need to be systematically optimized.
[0011] Currently, there is a lack of research on the preparation of manganese antimonate nanomaterials using the sol-gel method. Existing methods may have shortcomings such as low purity, complex processes, and unstable performance. Summary of the Invention
[0012] The purpose of this invention is to provide a manganese antimonate nanomaterial and its preparation method, so as to overcome the problems of existing preparation methods, such as difficulty in controlling the metal ratio, complex process, harsh reaction conditions, high preparation cost, poor product uniformity, low purity, and unstable performance.
[0013] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0014] This invention provides a method for preparing manganese antimonate nanomaterials, comprising the following steps:
[0015] Step 1) Mix the manganese salt solution, antimony salt solution, and complexing agent solution, and adjust the pH to obtain the precursor solution;
[0016] Step 2) Mix the precursor solution and the soft film agent, stir and heat to form a sol, and then let it stand and dry to obtain a dry gel;
[0017] Step 3) In an air or oxygen atmosphere, the dry gel is subjected to a first heat treatment, followed by cooling and grinding, and then subjected to a second heat treatment to obtain manganese antimonate nanomaterials.
[0018] Optionally, the manganese salt solution is prepared by dispersing manganese salt in water, and the concentration of the manganese salt solution is 0.1–0.5 mmol / mL;
[0019] The antimony salt solution is prepared by dispersing antimony salt in anhydrous ethanol, and the concentration of the antimony salt solution is 0.2–0.8 mmol / mL.
[0020] The complexing agent solution is prepared by dispersing the complexing agent in water, and the concentration of the complexing agent solution is 1-2 mmol / mL.
[0021] Optionally, the antimony salt comprises antimony chloride or antimony acetate; the manganese salt comprises manganese nitrate or manganese acetate; and the complexing agent comprises citric acid, oxalic acid, or oxalic acid.
[0022] Optionally, the molar ratio of the manganese salt, antimony salt, and complexing agent is 1:2:5 to 8.
[0023] Optionally, the pH value is 5 to 7.
[0024] Optionally, the flexographic film agent comprises a surfactant, a block copolymer, or polymer micelles;
[0025] The ratio of manganese salt to PVC film agent is 1 mmol: 0.1-0.3 g.
[0026] Optionally, the heating temperature is 60-80°C and the heating time is 2-12 hours.
[0027] Optionally, the temperature of the first stage heat treatment is 200-300℃ and the time is 1-3 hours, and the temperature of the second stage heat treatment is 850-950℃ and the time is 1-5 hours.
[0028] The present invention also provides manganese antimony nanomaterials prepared by the above-mentioned method.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] This invention provides a novel sol-gel process for producing manganese antimonate nanomaterials. By controlling solution chemistry, gelation conditions, and heat treatment parameters, high-purity, high-performance manganese antimonate nanomaterials are prepared. The product exhibits high purity and good crystal structure, and the preparation method is simple, easy to operate, and highly reproducible. The product is suitable for applications in magnetic materials, catalysts, battery materials, and other fields, and has broad industrial application prospects. Attached Figure Description
[0031] Figure 1 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Example 1;
[0032] Figure 2 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Example 2;
[0033] Figure 3 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Example 3;
[0034] Figure 4 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 5;
[0035] Figure 5 shows the X-ray diffraction patterns of manganese antimonate nanomaterials prepared in Example 1 and Comparative Examples 1-4;
[0036] Figure 6 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 1;
[0037] Figure 7 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 2;
[0038] Figure 8 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 3;
[0039] Figure 9 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 4;
[0040] Figure 10 is a scanning electron microscope schematic diagram of the manganese antimonate nanomaterials prepared in Comparative Example 6;
[0041] Figure 11 is a flowchart of the preparation process of Example 1. Detailed Implementation
[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0043] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0044] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0045] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.
[0046] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0047] Unless otherwise specified, "room temperature" and "normal temperature" in this invention refer to 25±2℃.
[0048] All raw materials used in the following embodiments of the present invention are commercially available.
[0049] This invention provides a method for preparing manganese antimonate nanomaterials, comprising the following steps:
[0050] Step 1) Mix the manganese salt solution, antimony salt solution, and complexing agent solution, and adjust the pH to obtain the precursor solution;
[0051] Step 2) Mix the precursor solution and the soft film agent, stir and heat to form a sol, and then let it stand and dry to obtain a dry gel;
[0052] Step 3) In an air or oxygen atmosphere, the dry gel is subjected to a first heat treatment, followed by cooling and grinding, and then subjected to a second heat treatment to obtain manganese antimonate nanomaterials.
[0053] In this invention, step 1) involves adding manganese salt solution and antimony salt solution dropwise to an appropriate amount of complexing agent solution under stirring conditions.
[0054] In this invention, step 2) involves placing the sol at room temperature for several hours to several days to allow it to gradually gel and form a wet gel.
[0055] Drying involves placing the obtained wet gel in a vacuum drying oven for drying at a temperature of 60–100°C, preferably 70–90°C, more preferably 75–80°C; and for a time of 6–24 h, preferably 8–20 h, more preferably 10–16 h, and even more preferably 12–14 h.
[0056] In this invention, the manganese salt solution is made by dispersing manganese salt in water, and the concentration of the manganese salt solution is 0.1-0.5 mmol / mL, preferably 0.15-0.45 mmol / mL, more preferably 0.2-0.4 mmol / mL, and even more preferably 0.3-0.35 mmol / mL;
[0057] The antimony salt solution is prepared by dispersing antimony salt in anhydrous ethanol, and the concentration of the antimony salt solution is 0.2-0.8 mmol / mL, preferably 0.3-0.7 mmol / mL, more preferably 0.4-0.6 mmol / mL, and even more preferably 0.45-0.5 mmol / mL.
[0058] The complexing agent solution is prepared by dispersing the complexing agent in water, and the concentration of the complexing agent solution is 1-2 mmol / mL, preferably 1.2-1.8 mmol / mL, and more preferably 1.5-1.6 mmol / mL.
[0059] In this invention, the antimony salt comprises antimony chloride or antimony acetate, preferably antimony chloride; the manganese salt comprises manganese nitrate or manganese acetate, preferably manganese acetate; and the complexing agent comprises citric acid, oxalic acid, or oxalic acid, preferably citric acid.
[0060] In this invention, the molar ratio of the manganese salt, antimony salt, and complexing agent is 1:2:5 to 8, preferably 1:2:5.5 to 7, and more preferably 1:2:6; weighing the manganese salt and antimony salt according to the stoichiometric ratio can precisely control the proportion of metals.
[0061] In this invention, the pH value is 5 to 7, preferably 6. Adjusting the pH value can prevent metal ions from precipitating prematurely.
[0062] In this invention, the flexible film agent comprises a surfactant, a block copolymer, or polymer micelles, preferably a block copolymer;
[0063] The surfactants include hexadecyltrimethylammonium bromide or sodium dodecyl sulfate;
[0064] Block copolymers include the Pluronic series or polystyrene-polyethylene oxide. The Pluronic series is Pluronic F108 (PEO129-PPO56-PPO129, with a molecular weight of approximately 14,600 Da).
[0065] Polymer micelles contain polyvinylpyrrolidone and polyvinyl alcohol;
[0066] The ratio of manganese salt to PVC film agent is 1 mmol: 0.1-0.3 g, preferably 1 mmol: 0.15-0.25 g.
[0067] In this invention, the addition of a soft film agent can control the morphology of the material, avoid disordered growth and aggregation of nanoparticles, and obtain nanoparticles with uniform morphology.
[0068] In this invention, the heating temperature is 60-80°C, preferably 65-75°C, more preferably 70°C, and the heating time is 2-12 hours, preferably 5-10 hours, more preferably 6-8 hours.
[0069] In this invention, the temperature of the first stage heat treatment is 200-300℃, preferably 220-280℃, more preferably 250-260℃, and the time is 1-3h, preferably 1.5-2.5h, more preferably 2h. The temperature of the second stage heat treatment is 850-950℃, preferably 900℃, and the time is 1-5h, preferably 2-4h, more preferably 3h.
[0070] In this invention, the temperature of the second heat treatment needs to be strictly controlled. The most suitable heat treatment temperature is 900°C.
[0071] In this invention, multi-stage heat treatment can regulate the growth rate and crystallinity of nanoparticles, avoid excessive particle growth and agglomeration, and obtain uniformly dispersed nanoparticles.
[0072] The present invention also provides manganese antimony nanomaterials prepared by the above-mentioned method.
[0073] In this invention, after the two-stage heat treatment, the obtained manganese antimonate nanomaterials are alternately centrifuged and washed multiple times in deionized water and anhydrous ethanol; and can be further processed by ball milling or ultrasonic dispersion to obtain uniformly dispersed nanoparticles.
[0074] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0075] Example 1
[0076] Weigh 1 mmol of manganese acetate tetrahydrate and dissolve it in 5 mL of deionized water to prepare solution one; weigh 2 mmol of antimony chloride and dissolve it in 5 mL of anhydrous ethanol to prepare solution two; weigh 6 mmol of citric acid and dissolve it in 5 mL of deionized water to prepare solution three. Add solutions one and two dropwise to solution three under stirring to form a stable mixed solution; adjust the pH of the solution to 6.
[0077] Add 0.15g of soft template agent Pluronic F108 (PEO129-PPO56-PPO129) to the solution obtained above, heat the solution under stirring at 80℃, and continue stirring for 2h until the solution forms a uniform sol.
[0078] The sol was left to stand at room temperature for 12 hours to form a wet gel.
[0079] The wet gel was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain the dry gel.
[0080] The dried gel was placed in a muffle furnace and calcined in air at an initial temperature of 200°C for 2 hours. After natural cooling, it was ground and then annealed again at 900°C for 3 hours.
[0081] The manganese antimonate nanomaterials obtained in this embodiment have a size between 100 and 150 nm and are characterized by high purity and high uniformity.
[0082] Figure 11 is a flowchart of the preparation process in this embodiment.
[0083] Figure 1 is a schematic diagram of the scanning electron microscope of the product of Example 1; it can be seen that the manganese antimonate nanomaterial has a uniform morphology and high uniformity and ordered structural characteristics.
[0084] Example 2
[0085] The only difference from Example 1 is that hexadecyltrimethylammonium bromide is used as the soft film agent.
[0086] The manganese antimonate nanomaterials obtained in this embodiment have a size between 150 and 250 nm and are characterized by high purity and high uniformity.
[0087] Figure 2 is a schematic diagram of the scanning electron microscope of the product of this embodiment. It can be seen that the manganese antimonate nanomaterial has a uniform morphology and high uniformity and ordered structural characteristics.
[0088] Example 3
[0089] The only difference from Example 1 is that 1 mmol of manganese nitrate was dissolved in 5 mL of deionized water to prepare solution one; 2 mmol of antimony acetate was dissolved in 5 mL of anhydrous ethanol to prepare solution two; and 6 mmol of tetraacetic acid oxalate was dissolved in 5 mL of deionized water to prepare solution three.
[0090] The manganese antimonate nanomaterials obtained in this embodiment have a size between 100 and 150 nm and are characterized by high purity and high uniformity.
[0091] Figure 3 is a scanning electron microscope schematic diagram of the product of this embodiment. It can be seen that the manganese antimonate nanomaterial has a uniform morphology and high uniformity and ordered structural characteristics.
[0092] Comparative Example 1
[0093] The only difference from Example 1 is that the temperature during the second annealing is 600°C.
[0094] The size of the manganese antimonate nanomaterials obtained in this comparative example is between 300 and 400 nm.
[0095] Figure 6 is a scanning electron microscope image of the comparative product. It can be seen that the crystal phase and nanoparticle morphology of the product are irregular and the aggregation is obvious.
[0096] Comparative Example 2
[0097] The only difference from Example 1 is that the temperature during the second annealing is 700°C.
[0098] The size of the manganese antimonate nanomaterials obtained in this comparative example is between 400 and 500 nm.
[0099] Figure 7 is a scanning electron microscope image of the comparative product, which shows that the crystal phase and nanoparticle morphology of the product are irregular.
[0100] Comparative Example 3
[0101] The only difference from Example 1 is that the temperature during the second annealing is 800°C.
[0102] The size of the manganese antimonate nanomaterials obtained in this comparative example is between 200 and 300 nm.
[0103] Figure 8 is a scanning electron microscope image of the comparative product, which shows that the crystal phase and nanoparticle morphology of the product are irregular.
[0104] Comparative Example 4
[0105] The only difference from Example 1 is that the temperature during the second annealing is 1000°C.
[0106] The size of the manganese antimonate nanomaterials obtained in this comparative example is between 100 and 200 nm.
[0107] Figure 9 is a scanning electron microscope image of the comparative product, which shows that the crystal phase and nanoparticle morphology of the product are irregular.
[0108] Figure 5 shows the X-ray diffraction patterns of the materials annealed at different temperatures in the second stage of Examples 1 and Comparative Examples 1-4; when the annealing temperature is below 800℃, no product MnSb2O6 is formed, and the substance that matches the XRD card well is Sb. 1.33 Mn 0.67 O 4.00 When the temperature is raised to 900℃, MnSb2O6 crystals with characteristic crystal planes ((001), (110) and (101)) are generated; when the annealing temperature is raised to 1000℃, the characteristic peaks of Mn3O4, which is more thermodynamically stable, will be more obvious.
[0109] Comparative Example 5
[0110] The only difference from Example 1 is that no soft film agent is added.
[0111] Figure 4 is a scanning electron microscope schematic diagram of the product in Comparative Example 5 without the addition of a soft template agent; it can be seen that the morphology of manganese antimonate nanomaterials is relatively irregular, with high surface area and agglomerated structural characteristics.
[0112] Comparative Example 6
[0113] The only difference from Example 1 is that multi-stage annealing is not performed. Instead, the dry gel is placed directly in a muffle furnace and annealed at 900°C for 3 hours in an air atmosphere.
[0114] The size of the manganese antimonate nanomaterials obtained in this comparative example is between 100 and 200 nm. Figure 10 is a scanning electron microscope image of the product obtained in Comparative Example 6. It can be seen that the product obtained without multi-stage annealing has more obvious agglomeration compared with multi-stage annealing.
[0115] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing manganese antimonate nanomaterials, characterized in that, Includes the following steps: Step 1) Mix manganese salt solution, antimony salt solution, and complexing agent solution, and adjust the pH to obtain a precursor solution; Step 2) Mix the precursor solution and softening agent, stir and heat to form a sol, and then let it stand and dry to obtain a dry gel; Step 3) In an air or oxygen atmosphere, perform a first-stage heat treatment on the dry gel, followed by cooling and grinding, and then perform a second-stage heat treatment to obtain manganese antimonate nanomaterials; The pH value is 5-7; The temperature of the first-stage heat treatment is 200-300℃, and the time is 1-3h; the temperature of the second-stage heat treatment is 850-950℃, and the time is 1-5h.
2. The method for preparing manganese antimonate nanomaterials according to claim 1, characterized in that, The manganese salt solution is prepared by dispersing manganese salt in water, with a concentration of 0.1–0.5 mmol / mL; the antimony salt solution is prepared by dispersing antimony salt in anhydrous ethanol, with a concentration of 0.2–0.8 mmol / mL; and the complexing agent solution is prepared by dispersing a complexing agent in water, with a concentration of 1–2 mmol / mL.
3. The method for preparing manganese antimonate nanomaterials according to claim 2, characterized in that, The antimony salt comprises antimony chloride or antimony acetate; the manganese salt comprises manganese nitrate or manganese acetate; and the complexing agent comprises citric acid, oxalic acid, or oxalic acid.
4. The method for preparing manganese antimonate nanomaterials according to claim 3, characterized in that, The molar ratio of the manganese salt, antimony salt, and complexing agent is 1:2:5 to 8.
5. The method for preparing manganese antimonate nanomaterials according to claim 4, characterized in that, The flexographic film agent comprises a surfactant, a block copolymer, or polymer micelles; the ratio of manganese salt to flexographic film agent is 1 mmol: 0.1–0.3 g.
6. The method for preparing manganese antimonate nanomaterials according to claim 1, characterized in that, The heating temperature is 60-80℃, and the time is 2-12 hours.
7. Manganese antimony nanomaterials prepared by the method of any one of claims 1 to 6.