Method for preparing florisil-type manganese dioxide, obtained manganese dioxide and applications

Abstract

The application provides a preparation method of a manganese dioxide with a corolla layer type, the obtained manganese dioxide and application, in the preparation method, the following steps are included: manganese precursor, oxidizing agent and water are mixed, and pH value is adjusted to 2-5, high-temperature hydrothermal treatment is carried out, and the manganese dioxide with a corolla layer type is obtained; wherein, the mixing temperature is 10-30 DEG C, and the mixing time is 0-1 h; the hydrothermal temperature is 140-180 DEG C, the hydrothermal time is 18-30 h, and the preset heating rate of the hydrothermal reaction is 5-10 DEG C / min. The manganese dioxide prepared by the preparation method has good interlayer gap, is not easy to aggregate, is not easy to inactivate and is stable in performance, can effectively adsorb cobalt ions and nickel ions in waste liquid, realizes resource recycling, reduces heavy metal ion pollution to the environment, and meets the development goal of green energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of metal oxide preparation technology, and in particular to a method for preparing manganese dioxide of the stamen layer type, the obtained manganese dioxide and its applications. Background Technology

[0002] Manganese dioxide (MDC) is an important metallic material widely used in batteries, catalysts, and electronic devices. MDC exhibits diverse morphologies, each with unique physicochemical properties suitable for different applications. Layered, flower-like MDC is a novel functional material with broad application potential, particularly demonstrating unique advantages in metal ion adsorption and recovery. Its highly controllable interlayer spacing provides more reactive sites and ion diffusion channels, thereby improving the material's ion transport performance and making it widely applicable in energy and environmental fields.

[0003] Co and Ni are important metals in the energy and alloy industries. Currently, wastewater and waste liquid pollution containing Co and Ni ions has become a significant environmental and resource issue. Manganese dioxide, as a material with adsorption properties, has the potential to recover and remove Co and Ni under environmentally friendly conditions. Different morphologies of manganese dioxide have different specific surface areas, pore structures, and crystal structures, thus affecting its adsorption capacity and selectivity. Layered manganese dioxide generally exhibits good recovery performance due to its highly controllable interlayer gaps and specific surface area. Furthermore, by controlling the morphology and structure of manganese dioxide, its surface charge distribution and ion diffusion channels can be optimized, further improving the recovery efficiency and selectivity of cobalt and nickel ions.

[0004] Although some progress has been made in the preparation and application of manganese dioxide, some limitations still exist. Some preparation methods may require expensive reagents or complex process conditions, which limits the feasibility of large-scale production. Furthermore, the morphology and structure of the prepared manganese dioxide cannot be well controlled, and it suffers from problems such as easy aggregation, deactivation, or unstable performance, requiring further improvement and optimization.

[0005] In summary, there is an urgent need for a method for preparing manganese dioxide of the stamen layer type, the resulting manganese dioxide, and its applications to solve the problems existing in the related technologies. Summary of the Invention

[0006] The main objective of this invention is to provide a method for preparing manganese dioxide of the stamen layer type, the resulting manganese dioxide, and its applications, in order to solve the technical problems in related technologies such as high preparation cost, complex process, and easy aggregation, deactivation, or unstable performance of the obtained manganese dioxide.

[0007] To achieve the above objectives, the present invention provides a method for preparing manganese dioxide of the stamen layer type, comprising the following steps:

[0008] Manganese precursor, oxidant and water are mixed and the pH is adjusted to 2-5. The mixture is then subjected to high-temperature hydrothermal treatment to obtain manganese dioxide with a flower-like structure. The mixing temperature is 10-30℃ and the mixing time is 0.5-1h. The hydrothermal temperature is 140-180℃ and the hydrothermal time is 18-30h. The preset heating rate of the hydrothermal reaction is 5-10℃ / min.

[0009] Preferably, the manganese precursor includes manganese sulfate or manganese chloride.

[0010] Preferably, the oxidant is potassium permanganate.

[0011] Preferably, the ratio of the manganese precursor, oxidant and water is (5-15) mmol: (40-80) mmol: (50-70) ml.

[0012] Preferably, after the high-temperature hydrothermal step, the high-temperature hydrothermal product is further washed and dried. The washing step includes rinsing with deionized water and anhydrous ethanol in sequence, repeated 2-4 times, with each rinse lasting 25-35 seconds.

[0013] Preferably, the drying method is low-vacuum drying; the drying temperature is 60-80℃, and the drying vacuum degree is 1000-5000Pa.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention provides a method for preparing manganese dioxide with low cost and simple process. Manganese dioxide can be obtained by calcining a mixture of manganese precursor, oxidant and water. In the preparation process, only appropriate mixing temperature, mixing time, hydrothermal temperature and hydrothermal time need to be controlled to obtain manganese dioxide with a flower-like structure. Furthermore, by adjusting the pH value to 2-5, a good acidic atmosphere is created, which reduces the formation of manganese hydroxide precipitate by manganese ion hydrolysis during the mixing and hydrothermal processes, and reduces the occurrence of other manganese impurities in the subsequent calcination process.

[0016] The present invention also provides manganese dioxide prepared by the above preparation method.

[0017] The beneficial effects of this invention are as follows:

[0018] The manganese dioxide obtained by this invention has a flower-like layered structure with good interlayer spacing, making it less prone to aggregation and deactivation, and exhibiting stable performance.

[0019] The present invention also provides a method for preparing manganese dioxide by the above-mentioned method or for the application of the above-mentioned manganese dioxide in the recovery of heavy metal ions in waste liquid.

[0020] Preferably, the heavy metal ions include at least one of cobalt ions and nickel ions.

[0021] Preferably, the recovery step includes: adjusting the pH of the waste liquid to 3-6; adding manganese dioxide with a morphological structure of flower-like layer; the concentration of the added manganese dioxide is ≤0.5g / L; separating manganese dioxide from the waste liquid; and calculating the amount of cobalt ions and nickel ions recovered.

[0022] The beneficial effects of this invention are as follows:

[0023] The manganese dioxide prepared by this invention has good interlayer spacing, is not easy to aggregate or deactivate, and has stable performance. It can effectively adsorb cobalt ions and nickel ions in the solution, realize resource recycling, and reduce heavy metal ion pollution to the environment, which is in line with the development goal of green energy conservation and environmental protection. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a schematic flowchart of a method for preparing manganese dioxide according to an embodiment of this application, wherein MnSO4·2H2O represents manganese sulfate dihydrate, KMnO4 represents potassium permanganate, and δ-MnO2 represents manganese dioxide with a stamen-layer morphology.

[0026] Figure 2 This is an XRD pattern (X-ray diffraction pattern) of manganese dioxide according to an embodiment of this application, where Intensity (au) represents intensity, 2Theta (degree) represents twice the diffraction angle, and JCPDS files represent the PDF "Powder Diffraction Card Set" issued by the Powder Diffraction Standards Association.

[0027] Figure 3 These are SEM (scanning electron microscope) and TEM (transmission electron microscope) images of manganese dioxide according to an embodiment of this application, wherein (a) is an SEM image and (b) is a TEM image.

[0028] Figure 4This is an XPS (X-ray photoelectron spectroscopy) image of manganese dioxide according to an embodiment of this application, wherein (a) is the Mn 3s spectrum of manganese dioxide; (b) is the O 1s spectrum of manganese dioxide, δ indicates that δ-MnO2 was used for testing, AOS indicates the average oxidation state of manganese, Intensity (au) indicates intensity, Binding energy indicates binding energy, eV indicates electron volts, and O vacancy Indicates an oxygen defect peak, O lattice Indicates the lattice oxygen peak;

[0029] Figure 5 This is a BET plot (nitrogen adsorption / desorption plot) of manganese dioxide according to one embodiment of this application. Relative Pressure (P / P0) represents the relative partial pressure, and Quantity Adsorbed (cm³) represents the quantity adsorbed. 3 / g STP) represents the nitrogen adsorption / desorption capacity, and Average pore size represents the average pore size. BET Represents specific surface area;

[0030] Figure 6 This is a graph showing the recovery efficiency of manganese dioxide for cobalt and nickel ions according to an embodiment of this application, where Recovery performance represents the recovery efficiency of cobalt and nickel ions, Initial concentration represents the initial concentration, Dosage represents the amount of manganese dioxide added, pH represents the acidity or alkalinity, μg represents micrograms, g represents grams, t represents time, Co represents cobalt, and Ni represents nickel.

[0031] Figure 7 These are XRD patterns (X-ray diffraction patterns), SEM images (scanning electron microscope images), and TEM images (transmission electron microscope images) of α-manganese dioxide in a comparative manner according to this application. Element indicates an element, and mass indicates the mass.

[0032] Figure 8 This application presents a comparative method for the SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-ray Dioxide) image of commercially available manganese dioxide and a graph showing its efficiency in recovering cobalt and nickel ions.

[0033] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0036] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0037] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0038] This invention provides a method for preparing manganese dioxide of the stamen layer type, comprising the following steps:

[0039] Manganese precursor, oxidant and water are mixed and the pH is adjusted to 2-5. The mixture is then subjected to high-temperature hydrothermal treatment to obtain manganese dioxide with a flower-like structure. The mixing temperature is 10-30℃ and the mixing time is 0.5-1h. The hydrothermal temperature is 140-180℃ and the hydrothermal time is 18-30h. The preset heating rate of the hydrothermal reaction is 5-10℃ / min.

[0040] This invention provides a method for preparing manganese dioxide with low cost and simple process. Manganese dioxide can be obtained by calcining a mixture of manganese precursor, complexing agent and alkaline ion template. In the preparation process, only appropriate mixing temperature, mixing time, hydrothermal temperature and hydrothermal time need to be controlled to obtain manganese dioxide with a flower-like structure. Furthermore, by adjusting the pH value to 2-5 to create an acidic atmosphere, the hydrolysis of manganese ions is reduced, thus reducing the appearance of manganese impurities in other valence states in the final product.

[0041] It is particularly noteworthy that the hydrothermal temperature set in this invention is 140-180℃, and the hydrothermal time is 18-30h. Within this temperature range, the diffusion of reactants and crystal growth can be effectively promoted, while avoiding excessive temperature that could cause a phase transition. The appropriate time ensures sufficient crystal growth and formation, and the reaction time designed provides conditions for the reaction to reach equilibrium, resulting in a more complete product structure, a more obvious interlayer structure, and a better effect on cobalt and nickel removal.

[0042] By controlling the preset heating rate of the hydrothermal reaction, boiling over or violent reactions can be avoided, and the rate of gas generation in the reaction system can be reduced. This increases the size of the obtained manganese dioxide and prevents it from breaking due to excessive airflow impact. It also avoids the risk of explosion due to a huge increase in gas pressure, thus improving the safety of the preparation process.

[0043] In some embodiments, the manganese precursor includes manganese sulfate or manganese chloride.

[0044] Choosing manganese salts with good water solubility as raw materials for manganese dioxide preparation allows them to be fully mixed with complexing agents and alkali ion templates in subsequent preparation processes, resulting in manganese dioxide products with uniform texture and stable performance.

[0045] In some embodiments, the oxidant is potassium permanganate.

[0046] The manganese ions in the manganese precursor are oxidized to manganese dioxide by reacting with an oxidant. During this process, oxygen and / or ammonia are also generated. Due to the non-directional nature of the gases, the escape of oxygen and / or ammonia leads to the formation of a uniformly porous mesoporous and macroporous structure on the surface of the obtained manganese dioxide, which can effectively increase the specific surface area of ​​the manganese dioxide prepared by the method of this application and improve its adsorption capacity.

[0047] In some embodiments, the ratio of the manganese precursor, oxidant, and water is (5-15) mmol : (40-80) mmol : (50-70) ml. By controlling the ratio of the precursor and oxidant, the conversion rate of manganese is improved.

[0048] In some embodiments, following the high-temperature hydrothermal step, the high-temperature hydrothermal product is further washed and dried. The washing step includes rinsing sequentially with deionized water and anhydrous ethanol, repeated three times, with each rinse lasting 25–35 seconds. During the preparation process, some impurities and unreacted organic and inorganic salt reactants may remain. These impurities and residues may negatively affect the material's performance and application. Repeated washing with deionized water and anhydrous ethanol effectively removes these impurities and residues, improving the product's purity.

[0049] In some embodiments, the drying method is low-vacuum drying; the drying temperature is 60-80℃, and the drying vacuum degree is 1000-5000Pa.

[0050] It is worth noting that the final washing step is an anhydrous ethanol rinse. After the washing step, anhydrous ethanol remains in the interlayer gaps of the manganese dioxide obtained in this invention. By drying under low vacuum, the anhydrous ethanol escapes from the surface of manganese dioxide in gaseous form, thereby clearing the mesoporous and macroporous structures on the surface of manganese dioxide and improving the adsorption capacity of manganese dioxide.

[0051] The present invention also provides manganese dioxide prepared by the above preparation method.

[0052] The manganese dioxide obtained by this invention has a flower-like layered structure with good interlayer spacing, making it less prone to aggregation and deactivation, and exhibiting stable performance. This is because the flower-like layered manganese dioxide prepared in this application has a layer of water molecules between its layers, corresponding to an interlayer spacing of approximately 7 angstroms. If the interlayer spacing is too large, corresponding to two layers of water molecules, i.e., Busselite, the nanoconfining effect is weakened. Conversely, if the interlayer spacing is too small, the mineral phase is very easy to transform from a layered structure. Through the support of water molecules and potassium ions doped in the manganese dioxide, it can have good interlayer spacing, making it less prone to aggregation and deactivation, and exhibiting stable performance.

[0053] The present invention also provides a method for preparing manganese dioxide by the above-mentioned method or for the application of the above-mentioned manganese dioxide in the recovery of heavy metal ions in waste liquid.

[0054] In some embodiments, the heavy metal ions include at least one of cobalt ions and nickel ions.

[0055] In some embodiments, the recovery step includes: adjusting the pH of the waste liquid to 3-6; adding manganese dioxide with a morphological structure of flower-like layer; the concentration of the added manganese dioxide is ≤0.5 g / L; separating the manganese dioxide from the waste liquid; and calculating the amount of cobalt ions recovered and the amount of nickel ions recovered.

[0056] The manganese dioxide prepared by this invention has good interlayer spacing, is not easy to aggregate or deactivate, and has stable performance. It can effectively adsorb cobalt ions and nickel ions in the solution, realize resource recycling, and reduce heavy metal ion pollution to the environment, which is in line with the development goal of green energy conservation and environmental protection.

[0057] Example 1

[0058] See Figure 1 A method for preparing manganese dioxide of the stamen layer type includes the following steps:

[0059] Manganese precursor (manganese sulfate), oxidant (potassium permanganate) and water were mixed, and nitric acid was added to adjust the pH to 3. The mixing temperature was 30℃ and the mixing time was 1h. The mixed solution was placed in a polytetrafluoroethylene-lined reactor and placed in a constant temperature oven for high temperature and high pressure hydrothermal reaction. The hydrothermal temperature was set at 160℃, the hydrothermal time was 12h, and the heating rate was 5℃ / min.

[0060] After cooling, manganese dioxide with a flower-like layer morphology was obtained by centrifugation.

[0061] The manganese dioxide with a flower-like structure (δ-MnO2) was obtained by rinsing with deionized water and anhydrous ethanol in sequence, repeating 4 times, each rinse lasting 30 seconds.

[0062] In this embodiment, the ratio of the manganese precursor, oxidant, and water is 10 mmol: 60 mmol: 60 ml.

[0063] In this embodiment, the drying method is low vacuum drying; the drying temperature is 60°C, and the drying vacuum degree is 3000Pa.

[0064] When manganese sulfate and potassium permanganate undergo a hydrothermal reaction under high-temperature hydrothermal conditions to generate δ-MnO2, the reaction equation is as follows:

[0065] 2KMnO4+MnSO4+2H2O→δ-MnO2+K2SO4+2H2SO4.

[0066] The morphological and structural determination of a flower-like layer-type manganese dioxide prepared in this application includes the following steps:

[0067] 1. Characterization of the crystal structure of manganese dioxide

[0068] See Figure 2 It can be seen that the peak positions and intensities of the manganese dioxide crystals synthesized in this application are very close to those in the standard PDF card, and the

[001] crystal plane of δ-MnO2 is its dominant crystal plane, with an interlayer spacing of [missing information]. It has a single-layer water-potassium manganese ore structure with good interlayer spacing, making it less prone to aggregation and deactivation, and its performance is stable.

[0069] 2. Characterization of manganese dioxide morphology

[0070] See Figure 3 It is known that the morphology of the manganese dioxide synthesized and prepared in this application is a flower-like layer type, and the particle size is mainly distributed between 1-2 μm.

[0071] 3. Determination of valence state and bonding structure of manganese dioxide

[0072] according to Figure 4The average oxidation state (AOS) of Mn was calculated using Mn 3s, revealing that δ-MnO2 had an AOS of 3.54. Furthermore, O1s analysis showed that δ-MnO2 had an oxygen defect content as high as 31.13%. The lower redox valence state and greater oxygen defects provide more active sites for cobalt and nickel ion recovery, thereby improving recovery performance. The δ-MnO2 prepared in this example has an AOS much less than 4 and exhibits a high number of oxygen defects, indicating its significant potential for cobalt and nickel ion recovery.

[0073] 4. Determination of specific surface area and pore structure of manganese dioxide

[0074] See Figure 5 It is known that the specific surface area of ​​the manganese dioxide synthesized and prepared in this application is 12.05 m². 2 The manganese dioxide prepared in this application has an average pore size of 24.52 nm, with most pores ranging from 10 to 100 nm, exhibiting a typical mesoporous-macroporous structure. The mesoporous and macroporous structure of the manganese dioxide facilitates the diffusion of cobalt and nickel ions, thereby enhancing its recovery performance.

[0075] Example 2

[0076] The stamen-layer type of manganese dioxide exhibits good performance in recovering cobalt and nickel ions.

[0077] Prepare a sample solution (with cobalt ion concentration of 10 mg / L and nickel ion concentration of 10 mg / L). Mix 5 mg of manganese dioxide prepared in Example 1 with 10 mL of the sample solution. Keep the adsorption temperature at 30 °C, adjust the pH to 3 with HNO3 and NaOH solutions, and shake in a shaker at 150 r / min for 4 h. Measure the residual cobalt ion concentration and nickel ion concentration in the sample solution, and calculate the cobalt ion recovery and nickel ion recovery.

[0078] The pH test instrument was a pH meter (pHS-3G, Shanghai Leici); the concentrations of cobalt and nickel ions were analyzed and determined by an ICP-OES instrument, and the minimum RSDs value was selected as the data reference for three different adsorption bands.

[0079] Example 3: The difference from Example 2 is that the pH value is adjusted to 4 using HNO3 and NaOH solutions.

[0080] Example 4: The difference from Example 2 is that the pH value is adjusted to 5 using HNO3 and NaOH solutions.

[0081] Example 5: The difference from Example 2 is that the pH value is adjusted to 6 using HNO3 and NaOH solutions.

[0082] Comparative Example 1: Manganese precursor (manganese sulfate), oxidant (potassium permanganate) and water were mixed, and nitric acid was added to adjust the pH to 3. The mixing temperature was 30℃ and the mixing time was 1h. The mixed solution was placed in a polytetrafluoroethylene-lined reactor and placed in a constant temperature oven for high-temperature and high-pressure hydrothermal reaction. The hydrothermal temperature was set at 100℃, the hydrothermal time was 24h, and the heating rate was 5℃ / min.

[0083] See Figure 7 After cooling, manganese dioxide was obtained by centrifugation; XRD analysis showed that it was manganese dioxide with a typical α-type crystal form.

[0084] The manganese dioxide (α-MnO2) with a needle-like morphology was obtained by rinsing with deionized water and anhydrous ethanol in sequence, repeated 4 times, with each rinse lasting 30 seconds.

[0085] Comparative Example 2: The performance of commercially available manganese dioxide in recovering cobalt and nickel ions.

[0086] Commercially available manganese dioxide was purchased for comparison. For example... Figure 8 As shown, commercially available manganese dioxide does not exhibit obvious crystal morphology characteristics; it is generally composed of coarse-grained (~5μm) powder particles with a manganese content of 67.93% by mass. The particles contain no obvious impurities other than manganese and oxygen.

[0087] Prepare a sample solution (with cobalt ion concentrations of 10 mg / L and nickel ion concentrations of 10 mg / L). Mix 5 mg of commercial manganese dioxide with 10 mL of the sample solution. Set the adsorption temperature to 30 °C, adjust the pH to 3 with HNO3 and NaOH solutions, and shake in a shaker at 150 rpm for 4 h. Measure the residual cobalt ion and nickel ion concentrations in the sample solution, and calculate the cobalt ion recovery and nickel ion recovery amounts.

[0088] The pH test instrument was a pH meter (pHS-3G, Shanghai Leici); the concentrations of cobalt and nickel ions were analyzed and determined by an ICP-OES instrument, and the minimum RSDs value was selected as the data reference for three different adsorption bands.

[0089] Comparative Example 3: The difference from Comparative Example 2 is that the pH value was adjusted to 4 using HNO3 and NaOH solutions.

[0090] Comparative Example 4: The difference from Comparative Example 2 is that the pH value was adjusted to 5 using HNO3 and NaOH solutions.

[0091] Comparative Example 5: The difference from Comparative Example 2 is that the pH value was adjusted to 6 using HNO3 and NaOH solutions.

[0092] The absorption results of cobalt and nickel ions by manganese dioxide prepared in Examples 2-5 and Comparative Examples 2-5 are shown in Table 1. Figure 6 and Figure 8 .

[0093] Table 1. Recovery results of cobalt and nickel ions in Examples 2-5 and Comparative Examples 2-5

[0094] Example 2 7606 4012 Example 3 9856 5128 Example 4 9308 5698 Example 5 9794 5384 Comparative Example 2 2531 1578 Comparative Example 3 2846 1691 Comparative Example 4 2828 1694 Comparative Example 5 2901 2231

[0095] From Table 1, Figure 6 and Figure 8 The data shows that the manganese dioxide of the flower-like layer type prepared by the present invention has very good recovery performance for cobalt and nickel ions. At pH=3-6, the manganese dioxide of the flower-like layer type prepared by the present invention has a cobalt ion recovery of 7606-9856 μg / g and a nickel ion recovery of 4012-5698 μg / g.

[0096] In comparison, commercially available manganese dioxide exhibits poor recovery performance for cobalt and nickel ions. At pH 3-6, the recovery rate for cobalt ions is 2531-2901 μg / g, and for nickel ions it is 1578-2231 μg / g, significantly lower than the stamen-layer type manganese dioxide prepared in this invention. This is because the specific surface area of ​​the manganese dioxide synthesized in this application is 12.05 m². 2 The manganese dioxide prepared in this application has an average pore size of 24.52 nm, with most pores ranging from 10 to 100 nm, exhibiting a typical mesoporous-macroporous structure. The mesoporous and macroporous structure of the manganese dioxide facilitates the diffusion of cobalt and nickel ions, thereby enhancing its recovery performance.

[0097] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing manganese dioxide of the stamen-layer type, characterized in that, Includes the following steps: Manganese precursor, oxidant and water were mixed and the pH was adjusted to 3. The mixture was subjected to high-temperature hydrothermal treatment to obtain manganese dioxide with a flower-like structure. The mixing temperature was 30℃ and the mixing time was 1h. The hydrothermal temperature was 160℃ and the hydrothermal time was 12h. The preset heating rate of the hydrothermal reaction was 5℃ / min. The ratio of manganese precursor, oxidant and water added is 10 mmol: 60 mmol: 60 ml; The manganese dioxide in the flower-like layer has a mixed mesoporous and macroporous structure; The prepared manganese dioxide layer of the stamen-layer type has a layer of water molecules between its layers; The manganese precursor is manganese sulfate; The oxidant is potassium permanganate.

2. The preparation method according to claim 1, characterized in that, Following the high-temperature hydrothermal step, the high-temperature hydrothermal product is further washed and dried. The washing step includes rinsing with deionized water and anhydrous ethanol sequentially, repeating 2-4 times, with each rinse lasting 25-35 seconds.

3. The preparation method according to claim 2, characterized in that, The drying method is low vacuum drying; the drying temperature is 60-80℃, and the drying vacuum degree is 1000-5000Pa.

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