A method for preparing porous MnCO3 nanospheres
The method of using porous SiO2 nanospheres as templates to produce MnCO3 nanospheres addresses the lack of effective methods for preparing porous MnCO3 nanospheres with a porous structure, achieving low energy consumption, high repeatability, and uniform product morphology, yielding MnCO3 nanospheres with a porous structure. The porous MnCO3 nanospheres are immersed in a manganese salt solution, and the SiO2 template is removed by an alkaline solution to obtain porous MnCO3 nanospheres.
Patent Information
- Application Number
- CN202211671227.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-26
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-12-26
AI Technical Summary
There is a lack of effective methods for preparing porous MnCO3 nanomaterials, which are crucial for enhancing performance in applications due to their unique physical and chemical properties, particularly in terms of specific surface area and pore structure, as existing methods primarily focus on non-porous nanomaterials.
A method involving the use of porous SiO2 nanospheres as templates, where manganese salt solution immersion, carbonate solution reaction, and alkaline treatment are employed to produce porous MnCO3 nanospheres with a porous structure, utilizing porous SiO2 nanospheres as templates, manganese salt solutions, and alkaline treatment are used to remove the SiO2 template, resulting in MnCO3 nanospheres with a porous structure. The porous MnCO3 nanospheres are immersed in a manganese salt solution, and the SiO2 template is removed by an alkaline solution to obtain porous MnCO3 nanospheres.
The method achieves low energy consumption, high repeatability, and uniform product morphology, yielding MnCO3 nanospheres with a larger specific surface area and richer pore structure, enhancing catalytic activity in electrocatalytic oxygen evolution reactions.
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Figure CN116002762B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of inorganic material preparation, and in particular to a method for preparing porous MnCO3 nanospheres. Background Art
[0002] Manganese carbonate (MnCO3) is a functional material that is widely used in many fields such as batteries, biology, environmental protection, and ceramics. For example, MnCO3 can be used as a precursor to prepare lithium manganese oxide, which is inexpensive and highly safe and can be used as a positive electrode material for lithium-ion batteries. In addition, MnCO3 can be used as a raw material to prepare MnO2 and other manganese oxides (for example, Mn2O3 and Mn3O4). Compared with conventional-sized MnCO3 particles, nanoscale MnCO3 materials have more unique physical and chemical properties and can exert better performance in their application fields. At present, the preparation of MnCO3 nanomaterials has attracted much attention from scientific researchers and related industries.
[0003] The structure of nanomaterials determines their physicochemical properties and performance. In particular, porous nanomaterials have larger specific surface area and richer pore structure than non-porous nanomaterials, which can not only provide a large number of active sites, but also increase the chance of active sites contacting with reaction substrates. So far, MnCO3 nanomaterials (for example, MnCO3 nanorods and MnCO3 nanospheres, etc.) of different morphologies can be obtained by using preparation methods such as coprecipitation and hydrothermal method. However, there are few reports on the relevant research of porous MnCO3 nanomaterials. Therefore, it is necessary to develop a preparation method of porous MnCO3 nanomaterials. Summary of the invention
[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a method for preparing porous MnCO3 nanospheres. By using porous SiO2 nanospheres as templates, MnCO3 nanospheres with a porous structure can be prepared. The preparation method has low energy consumption, good repeatability, and uniform product morphology. The prepared porous MnCO3 nanospheres have a large specific surface area and rich pore structure.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is:
[0006] The present invention provides a method for preparing porous MnCO3 nanospheres, comprising the following steps:
[0007] S1. Use porous SiO2 nanospheres as templates, add them into a manganese salt solution for immersion, and then evaporate the solvent to obtain a large amount of Mn adsorbed on the surface. 2+ Porous SiO2 nanosphere precursor;
[0008] S2, adding the porous SiO2 nanosphere precursor obtained in S1 to the carbonate solution and stirring to react, and obtaining the porous MnCO3 nanosphere precursor after the reaction is complete;
[0009] S3, the porous MnCO3 nanosphere precursor obtained in S2 is fully immersed in an alkaline solution to remove the SiO2 template, thereby obtaining porous MnCO3 nanospheres.
[0010] By adopting the above scheme, porous SiO2 nanospheres are used as templates, added into a manganese salt solution, immersed in the manganese salt solution for a period of time, and then evaporated to remove the solvent, thereby obtaining a large amount of Mn adsorbed on the surface. 2+ A porous SiO2 nanosphere precursor is prepared. In step 2, the porous SiO2 nanosphere precursor is added to a carbonate solution with a relatively high concentration. Since the carbonate ions are in excess, a large amount of MnCO3 microcrystals can be rapidly deposited on the surface of the porous SiO2 nanosphere precursor. Under the pore confinement of the porous SiO2 nanosphere, the MnCO3 microcrystals are converted into MnCO3 nanoparticles. In step 3, the porous SiO2 nanosphere template can be removed by the reaction of the alkaline solution with SiO2, and finally a MnCO3 nanosphere with a porous structure is obtained.
[0011] Preferably, in step S1, the molar ratio of the porous SiO2 nanospheres to the manganese salt is 1:(5-10).
[0012] Preferably, in step S1, the manganese salt solution is one of a manganese chloride solution, a manganese sulfate solution or a manganese acetate solution, the solvent of the manganese salt solution is water, and the concentration of the manganese salt solution is 1 to 2 mol / L.
[0013] Preferably, in step S1, the immersion time is 2 to 6 hours, and the evaporation temperature is 50 to 90°C.
[0014] Preferably, in step S2, the molar ratio of the porous SiO2 nanosphere precursor to the carbonate is 1:(2-6).
[0015] Preferably, in step S2, the carbonate solution is one of a sodium carbonate solution, a potassium carbonate solution or an ammonium carbonate solution, the solvent of the carbonate solution is water, and the concentration of the manganese salt solution is 0.2 to 0.6 mol / L.
[0016] Preferably, in step S2, the stirring time is 10 to 30 minutes.
[0017] Preferably, in step S3, the molar ratio of the porous MnCO3 nanosphere precursor to the alkali is (3-5):200, and the concentration of the alkali solution is 2 mol / L.
[0018] Preferably, in step S3, the soaking time is 12 to 24 hours.
[0019] The present invention also provides the use of MnCO3 prepared by the above preparation method as a catalyst in electrocatalysis.
[0020] Preferably, the electrocatalytic reaction is an electrocatalytic oxygen evolution reaction.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] The present invention provides a method for preparing porous MnCO3 nanospheres, which uses porous SiO2 nanospheres as templates, and obtains a porous MnCO3 nanosphere by immersing the porous SiO2 nanospheres in a manganese salt solution to obtain a porous MnCO3 nanosphere. 2+ The porous nanosphere precursor is prepared by adding the porous nanosphere precursor to a high concentration carbonate solution, and then the porous nanosphere precursor is obtained. Finally, the template agent is removed to obtain the MnCO3 nanosphere with a porous structure. The preparation method of the present invention has low energy consumption, good repeatability, and uniform product morphology. Compared with the non-porous MnCO3 nanomaterial, the prepared porous MnCO3 nanosphere has a larger specific surface area and richer pore structure, with a specific surface area of 150 to 250 m 2 / g, and the pore size distribution is 4-10nm, which can not only provide a large number of active sites, but also increase the chance of the active sites contacting the reaction substrate. The porous MnCO3 nanospheres prepared by the present invention, when used as catalysts, show good catalytic activity in the electrocatalytic oxygen evolution reaction. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is the X-ray powder diffraction pattern of the porous SiO2 nanospheres in Example 1;
[0024] Figure 2 This is a field emission scanning electron microscope image of the porous SiO2 nanospheres in Example 1;
[0025] Figure 3 This is a field emission transmission electron microscopy image of the porous SiO2 nanospheres in Example 1;
[0026] Figure 4 is the X-ray powder diffraction pattern of the porous MnCO3 nanospheres in Example 1;
[0027] Figure 5 This is a field emission scanning electron microscope image of the porous MnCO3 nanospheres in Example 1;
[0028] Figure 6 This is a field emission transmission electron microscopy image of the porous MnCO3 nanospheres in Example 1;
[0029] Figure 7is a nitrogen adsorption-desorption curve of the porous MnCO3 nanospheres in Example 1;
[0030] Figure 8 is a pore size distribution curve of the porous MnCO3 nanospheres in Example 1;
[0031] Fig. 9 This is a performance diagram of the electrocatalytic oxygen evolution reaction of the porous MnCO3 nanospheres in Example 1. DETAILED DESCRIPTION
[0032] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0033] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.
[0034] Example 1 Preparation of porous MnCO3 nanospheres
[0035] The porous SiO2 nanospheres used in this example were purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd. The results of X-ray powder diffraction are shown in Figure 1 As shown, the porous SiO2 nanospheres belong to an amorphous SiO2; Figure 2 This is a field emission scanning electron microscope image of porous SiO2 nanospheres. It can be seen from the image that amorphous SiO2 is a nanosphere with a diameter of 400 to 600 nm. Figure 3 This is a field emission transmission electron microscopy image of porous SiO2 nanospheres. It can be seen from the image that the SiO2 nanospheres have an obvious porous structure.
[0036] The preparation steps of porous MnCO3 nanospheres are as follows:
[0037] (1) 10 mmol of porous SiO2 nanospheres were added to a manganese sulfate aqueous solution (50 mL, 1 mol / L), stirred at room temperature and immersed for 2 h, and then the aqueous solvent was evaporated at 50 °C to obtain a large amount of Mn adsorbed on the surface. 2+ Porous SiO2 nanosphere precursor;
[0038] (2) 5 mmol of the porous SiO2 nanosphere precursor was added to a potassium carbonate solution (50 mL, 0.2 mol / L), stirred at room temperature for 10 min for precipitation reaction, and then the reaction product was transferred to a centrifuge tube for centrifugal collection, and then washed with distilled water for 3 times to obtain a porous MnCO3 nanosphere precursor;
[0039] (3) 3 mmol of porous MnCO3 nanosphere precursor was added to a sodium hydroxide solution (100 mL, 2 mol / L). After sufficient stirring for 24 h, the reaction product was transferred to a centrifuge tube for collection by centrifugation, and then washed with distilled water for 3 times to obtain porous MnCO3 nanospheres after removing the SiO2 template.
[0040] X-ray diffraction analysis of porous MnCO3 nanospheres showed Figure 4 As shown, the diffraction peak of the product is consistent with that of MnCO3 (JCPDS 29-0085), indicating that the product is pure phase MnCO3.
[0041] The porous MnCO3 nanospheres were analyzed by field emission scanning electron microscopy. Figure 5 As shown, the product is a nanosphere with a diameter of 400 to 600 nm.
[0042] The porous MnCO3 nanospheres were analyzed by field emission transmission electron microscopy. Figure 6 As shown, the MnCO3 nanospheres have uniform morphology and a clear porous structure.
[0043] The specific surface area and pore structure of the porous MnCO3 nanospheres prepared in Example 1 were analyzed using a N2 adsorption and desorption performance tester. The nitrogen adsorption and desorption curves of the porous MnCO3 nanospheres are shown in FIG. Figure 7 As shown in Figure 2, based on the results of nitrogen adsorption and desorption experiments, the specific surface area of porous MnCO3 nanospheres was calculated by BET theory to be 178.2 m 2 / g; the pore size distribution curve of porous MnCO3 nanospheres is shown in Figure 8 As shown, the average pore size is 4.3 nm.
[0044] The porous MnCO3 nanospheres prepared in this example were tested for electrocatalytic oxygen evolution reaction in an alkaline solution (the electrode preparation and experimental process refer to the literature J. Mater. Chem. A, 2022, 10, 10209-10218), and their performance is as follows Fig. 9 As shown, at 10mA / cm -2 The overpotential at the current density was 370 mV, indicating that the porous MnCO3 nanospheres had good electrocatalytic oxygen evolution activity.
[0045] Example 2 Preparation of porous MnCO3 nanospheres
[0046] The porous SiO2 nanospheres used in this embodiment are the same as those in Example 1, and the preparation steps of the porous MnCO3 nanospheres are as follows:
[0047] (1) 10 mmol of porous SiO2 nanospheres were added to a manganese sulfate aqueous solution (50 mL, 2 mol / L), stirred at room temperature and immersed for 6 h, and then the aqueous solution was evaporated at 90 °C to obtain a large amount of Mn adsorbed on the surface. 2+ Porous SiO2 nanosphere precursor;
[0048] (2) 5 mmol of the porous SiO2 nanosphere precursor was added to a potassium carbonate solution (50 mL, 0.6 mol / L), stirred at room temperature for 30 min for precipitation reaction, the reaction product was transferred to a centrifuge tube for centrifugal collection, and then washed with distilled water for 3 times to obtain a porous MnCO3 nanosphere precursor;
[0049] (3) 4 mmol of porous MnCO3 nanosphere precursor was added to a sodium hydroxide solution (100 mL, 2 mol / L). After sufficient stirring for 12 h, the reaction product was transferred to a centrifuge tube for centrifugal collection and then washed with distilled water three times to obtain porous MnCO3 nanospheres after removing the SiO2 template.
[0050] The characterization results of the porous MnCO3 nanospheres prepared in Example 2 are the same as those in Example 1. The product is also pure phase MnCO3. The MnCO3 nanospheres are also nanospheres with a diameter of 400 to 600 nm, and have a uniform morphology and a clear porous structure. The specific surface area and pore structure analysis of the MnCO3 nanospheres and the characterization results of the electrocatalytic oxygen evolution reaction are the same as those in Example 1.
[0051] Example 3 Preparation of porous MnCO3 nanospheres
[0052] The porous SiO2 nanospheres used in this embodiment are the same as those in Example 1, and the preparation steps of the porous MnCO3 nanospheres are as follows:
[0053] (1) 10 mmol of porous SiO2 nanospheres were added to a manganese sulfate aqueous solution (50 mL, 1.5 mol / L), stirred at room temperature and immersed for 7 h, and then the aqueous solution was evaporated at 70 °C to obtain a large amount of Mn adsorbed on the surface. 2+ Porous SiO2 nanosphere precursor;
[0054] (2) 5 mmol of the porous SiO2 nanosphere precursor was added to a potassium carbonate solution (50 mL, 0.4 mol / L), stirred at room temperature for 20 min for precipitation reaction, the reaction product was transferred to a centrifuge tube for centrifugal collection, and then washed with distilled water for 3 times to obtain a porous MnCO3 nanosphere precursor;
[0055] (3) 5 mmol of porous MnCO3 nanosphere precursor was added to a sodium hydroxide solution (100 mL, 2 mol / L). After sufficient stirring for 18 h, the reaction product was transferred to a centrifuge tube for centrifugal collection and then washed with distilled water three times to obtain porous MnCO3 nanospheres after removing the SiO2 template.
[0056] The characterization results of the porous MnCO3 nanospheres prepared in Example 3 are the same as those in Example 1. The product is also pure phase MnCO3. The MnCO3 nanospheres are also nanospheres with a diameter of 400 to 600 nm, and have a uniform morphology and a clear porous structure. The specific surface area and pore structure analysis of the MnCO3 nanospheres and the characterization results of the electrocatalytic oxygen evolution reaction are the same as those in Example 1.
[0057] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.
Claims
1. A method for preparing porous MnCO3 nanospheres, characterized in that: The following steps are involved: S1, using porous SiO2 nanospheres as templates, adding them into a manganese salt solution for immersion, wherein the molar ratio of the porous SiO2 nanospheres to the manganese salt is 1:(5-10), and then evaporating the solvent to obtain a large amount of Mn adsorbed on the surface 2+ Porous SiO2 nanosphere precursor; S2, adding the porous SiO2 nanosphere precursor obtained in S1 to the carbonate solution and stirring to react, wherein the molar ratio of the porous SiO2 nanosphere precursor to the carbonate is 1:(2-6), and after the reaction is complete, a porous MnCO3 nanosphere precursor is obtained; S3. Soak the porous MnCO3 nanosphere precursor obtained in S2 in an alkaline solution to remove the SiO2 template. The molar ratio of the porous MnCO3 nanosphere precursor to the alkali is (3-5):
200. The concentration of the alkaline solution is 2 mol / L. The soaking time is 12-24 h to obtain porous MnCO3 nanospheres.
2. The method for preparing porous MnCO3 nanospheres according to claim 1, characterized in that: In step S1, the manganese salt solution is one of a manganese chloride solution, a manganese sulfate solution or a manganese acetate solution, the solvent of the manganese salt solution is water, and the concentration of the manganese salt solution is 1 to 2 mol / L.
3. The method for preparing porous MnCO3 nanospheres according to claim 1, characterized in that: In step S1, the immersion time is 2 to 6 hours, and the evaporation temperature is 50 to 90°C.
4. The method for preparing porous MnCO3 nanospheres according to claim 1, characterized in that: In step S2, the carbonate solution is one of a sodium carbonate solution, a potassium carbonate solution or an ammonium carbonate solution, and the solvent of the carbonate solution is water.
5. The method for preparing porous MnCO3 nanospheres according to claim 1, characterized in that: In step S2, the stirring time is 10 to 30 minutes.
6. The method for preparing porous MnCO3 nanospheres according to claim 1, characterized in that: The specific surface area of the porous MnCO3 nanospheres is 150 to 250 m 2 / g, and the pore size distribution is between 4 and 10 nm.