A polyphenol-amine system constructs controllable ordered mesoporous material and a preparation method and application thereof

Abstract

The application discloses a kind of polyphenol-amine system construction controllable ordered mesoporous material and its preparation method and application.The mesoporous material of the application includes nitrogen-doped mesoporous carbon ball, and the nitrogen-doped mesoporous carbon ball is obtained by carbonizing treatment to mesoporous small ball;The nitrogen-doped mesoporous carbon ball includes skeleton structure, and the skeleton structure includes porous structure;The nitrogen-doped mesoporous carbon ball includes the following components: carbon, oxygen, optional nitrogen and / or sulfur.The mesoporous material of the application has similar activity with natural enzyme, and can be applied as biomimetic enzyme.The mesoporous material of the application has simple preparation process, mild condition, controllable cost, and has the potential of industrial production.

Description

Technical Field

[0001] This invention belongs to the field of controllable ordered mesoporous materials technology, specifically relating to a method for constructing controllable ordered porous carbon spheres using a polyphenol-amine system, its preparation method, and its applications. Background Technology

[0002] Mesoporous materials have gradually become a research hotspot in materials science due to their excellent specific surface area, controllable pore structure, and adjustable pore size. Studies have shown that mesoporous materials have been widely applied in various fields such as adsorption, gas separation, sensors, energy conversion, and biomedicine. The rational design and controllable synthesis of mesoporous materials are key to their performance. After nearly 30 years of development, various methods for synthesizing mesoporous materials have emerged, each with its own advantages and disadvantages. Currently, there are generally three synthetic strategies for mesoporous materials: soft template methods, hard template methods, and template-free methods. Hard templates refer to templates that do not undergo significant deformation or structural damage during synthesis. These templates mainly include mesoporous silica, mesoporous carbon, and mesoporous polymers. Using such templates, it is only necessary to fill the pores of the template with an inorganic precursor, and then remove the template to reverse-engineer the mesoporous material. The terms "soft" and "hard" are relative; soft templates typically select molecules with "soft" structures, commonly known as surfactants, mainly including nonionic surfactants, cationic surfactants, and anionic surfactants. Compared to the soft template method, the hard template method has obvious advantages and disadvantages. This method does not require controlling the self-assembly process between inorganic species and surfactants, but only needs to impregnate the inorganic species into the pores of the hard template. However, it also has many unavoidable drawbacks: (1) It requires the synthesis of a hard template first, resulting in high synthesis costs, complicated steps, time and labor consumption, and low yield; (2) The types of hard templates available are limited, and the pore structure of the target product depends on the pore structure of the hard template; (3) Using hydrofluoric acid or strong base to etch the silicon template is harmful to human health and the environment. These limitations make this method limited to theoretical research and difficult to use for industrialization. Mesoporous materials synthesized using the template-free method are generally disordered, and most mesopores originate from the pores between aggregated nanoparticles. Therefore, in addition to the closed filling structure, how to characterize the pore structure of the material is still a difficult problem. Compared with the traditional soft template method and hard template method, although the template-free method can synthesize a variety of mesoporous materials, greatly expanding the synthesis and application of mesoporous materials, this method does not have a unified synthesis mechanism, lacks universality, and is not suitable for large-scale applications. Current research indicates that synthesizing hierarchical porous structures with both mesopores and macropores simultaneously using simple methods, while also controlling the dimensions of the pore structure and the basic framework, remains a challenge. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a porous material with adjustable pore size, framework structure, and dimensions, as well as a method for its preparation. Furthermore, it provides a method for using this porous carbon material to catalyze substrate oxidation in an enzyme-like manner. This porous carbon material exhibits activities similar to natural enzymes, demonstrating excellent peroxidase, catalase, and superoxide dismutase activities.

[0004] This invention provides a mesoporous microsphere, the mesoporous microsphere comprising a basic framework, the basic framework further comprising a pore structure, the pore structure being formed by a pore-forming agent and / or a pore-expanding agent;

[0005] The basic framework is obtained by the self-assembly of organic amine-induced polyphenol compounds; the pore structure includes at least one or more primary channels, which have the same or different inner diameters.

[0006] According to embodiments of the invention, the polyphenol compound may be selected from, but is not limited to, at least one of resorcinol, pyrogallol, and catechol, preferably resorcinol and / or pyrogallol, and more preferably resorcinol.

[0007] According to an embodiment of the invention, the organic amine may be selected from at least one of organic amines.

[0008] Preferably, the organic amine is selected from, but not limited to, at least one of organic amines having 2 or more carbon atoms, for example, at least one of organic amines having 1-6 carbon atoms. More preferably, the organic amine is selected from at least one of octadecylamine, mercaptoethylamine, ethylenediamine, p-phenylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, and more preferably ethylenediamine.

[0009] According to an embodiment of the present invention, the inner diameter of the primary channel is 8nm to 150nm, preferably 10nm to 100nm, for example 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, or 100nm.

[0010] According to an embodiment of the present invention, the pore structure is a multi-level pore structure.

[0011] According to an embodiment of the present invention, the pore-forming agent is selected from triblock copolymers. Further, the triblock copolymer is selected from, but not limited to, at least one of P123, F127, F108, and F68, preferably P123 and / or F127.

[0012] According to an embodiment of the present invention, the pore-expanding agent is selected from mesitylene.

[0013] According to an embodiment of the present invention, the particle size of the mesoporous microspheres is 140 nm to 2 μm, preferably 200 nm to 1.6 μm.

[0014] According to an embodiment of the present invention, the mesoporous microspheres have a substantially as follows Figure 2 The shape shown.

[0015] According to an exemplary embodiment of the present invention, the mesoporous microspheres include a core structure and a basic framework. The core structure includes P123 and F127. The basic framework is obtained by ethylenediamine-induced self-assembly of phloroglucinol. The basic framework has a hierarchical porous structure, which includes at least one or more primary channels. Preferably, the inner diameter of the primary channel is 8 nm to 150 nm, more preferably 10 nm to 100 nm.

[0016] The present invention also provides a method for preparing the above-mentioned mesoporous microspheres, the method comprising the following steps: adding a pore-forming agent to a binary solvent to form a first micelle, the center of the first micelle being hydrophobic; adding a polyphenol compound to bind with the hydrophilic group of the first micelle, and then adding a pore-expanding agent to form a composite micelle; under the induction of organic amine catalysis, the polyphenol compound on the composite micelle forms a basic framework through self-assembly to obtain mesoporous microspheres.

[0017] According to an embodiment of the present invention, the preparation method includes the following steps:

[0018] (1) Under stirring conditions, a pore-forming agent is added to a binary solvent to obtain a first micelle solution, wherein the center of the first micelle is hydrophobic;

[0019] (2) Add the polyphenol compound to the first micelle solution in step (1), stir, and the polyphenol combines with the hydrophilic group of the first micelle. Then add the pore-expanding agent to form a composite micelle solution.

[0020] (3) Add organic amine to the composite micelle solution in step (2), stir, and the polyphenol compound self-assembles to obtain the basic framework, forming the mesoporous microspheres.

[0021] According to embodiments of the present invention, the pore expander, pore-forming agent, polyphenol compound, organic amine, and mesoporous microspheres have the meanings described above.

[0022] According to an embodiment of the present invention, in step (1), the binary solvent comprises a mixed solvent of an organic alcohol and water. Preferably, the volume ratio of the organic alcohol to water is (0-50):(100-50), for example, 0:100, 10:90, 20:80, 30:70, 40:60, or 50:50.

[0023] Preferably, the organic alcohol is selected from at least one of methanol, ethanol, ethylene glycol, and isopropanol, with ethanol being the most preferred.

[0024] According to an embodiment of the present invention, in step (1), the first micelle solution is a clear solution.

[0025] According to an embodiment of the present invention, in step (1), the particle size range of the first micelles in the first micelle solution is selected from 7 nm to 30 nm.

[0026] According to an embodiment of the present invention, in step (1) and / or step (2), the stirring is rapid stirring. Preferably, the speed of the rapid stirring can be 600 rpm to 800 rpm, for example, 800 rpm. Preferably, the stirring time can be 10 min to 120 min, for example, 30 min.

[0027] According to an embodiment of the present invention, in step (1), the concentration of the porogen is 5 to 15 mg / mL, preferably 10 mg / mL.

[0028] According to an embodiment of the present invention, in step (1), the pore-forming agent is preferably F127 and P127, and their mass ratio is 1:0 to 1:3, for example 1:0, 1:1, 1:2, 1:3, preferably 1:3.

[0029] According to an embodiment of the present invention, in step (2), the concentration of the polyphenol compound is 5 to 10 mg / mL, preferably 6 mg / mL.

[0030] According to an embodiment of the present invention, in step (2), the particle size range of the composite micelles is selected from 7 to 50 nm.

[0031] According to an embodiment of the present invention, in step (3), the organic amine is selected from at least one of octadecylamine, mercaptoethylamine, ethylenediamine, p-phenylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, preferably ethylenediamine.

[0032] According to an embodiment of the present invention, in step (3), the concentration of the organic amine is 1 to 40 mmol / L, preferably 1 to 20 mmol / L, for example 20 mmol / L.

[0033] According to an embodiment of the present invention, the molar ratio of the organic amine and the polyphenol compound is 1 to 50, preferably 1 to 40, for example 3, 5, 10, 20, 30, or 40.

[0034] According to an embodiment of the present invention, in step (3), the self-assembly time is 1 to 48 hours, preferably 18 to 24 hours, for example 24 hours.

[0035] According to an embodiment of the present invention, step (3) further includes purifying the mesoporous microspheres, the purification including washing, centrifugation, and drying. Through this purification, unreacted raw materials, intermediate products (such as oligomers), and some or all of the porogens and / or expanders can be removed, further purifying the microspheres to obtain the mesoporous microspheres.

[0036] According to an embodiment of the present invention, the washing, centrifugation, and drying can be performed using methods known in the art, as long as the mesoporous microspheres are obtained. Preferably, the washing can be performed using the aforementioned organic alcohol and / or aqueous solvent. Preferably, the drying conditions include drying at 400–600°C, more preferably at 450°C for 6–12 hours.

[0037] According to an exemplary embodiment of the present invention, the preparation method includes the following steps:

[0038] (1) Add P123 and F127 to a binary solvent and stir rapidly to obtain a clear first micelle solution, wherein the concentration of P123 and F127 is 10 mg / mL, the mass ratio of P123 and F127 is 1:3, and the particle size of the first micelle is 7 nm to 30 nm.

[0039] (2) Under stirring conditions, pyrogallol is added to the first micelle solution and stirring is continued to allow pyrogallol to be adsorbed onto the first micelle. Trimethylbenzene is added and stirring is continued to form a composite micelle solution of P123 / F127 / polyphenol / trimethylbenzene.

[0040] (3) Ethylenediamine is added to the above composite micelle solution to allow phloroglucinol to self-assemble and form a basic framework, thereby obtaining mesoporous microspheres; preferably, the concentration of ethylenediamine is 20 mmol / L.

[0041] (4) The mesoporous microspheres prepared in step (3) are washed, centrifuged and dried to obtain the mesoporous microspheres.

[0042] The present invention also provides a mesoporous material comprising nitrogen-doped mesoporous carbon spheres, wherein the nitrogen-doped mesoporous carbon spheres are obtained by carbonizing the aforementioned mesoporous microspheres.

[0043] According to an embodiment of the present invention, the carbonization temperature is 700–1000°C.

[0044] According to an embodiment of the present invention, the nitrogen-doped mesoporous carbon sphere includes a framework structure, wherein the framework structure includes a porous structure.

[0045] According to an embodiment of the present invention, the particle size of the nitrogen-doped mesoporous carbon spheres is 140 nm to 2 μm, preferably 200 nm to 1.6 μm.

[0046] According to an embodiment of the present invention, the porous structure includes multiple channels, and the inner diameter of the channels of the porous structure is 1nm to 150nm, for example, 2nm to 100nm, preferably 8nm to 100nm.

[0047] According to an embodiment of the present invention, the nitrogen-doped mesoporous carbon spheres comprise the following components: carbon, oxygen, and optionally nitrogen and / or sulfur.

[0048] The present invention also provides a method for preparing the above-mentioned mesoporous material, the method comprising: carbonizing the above-mentioned mesoporous microspheres under nitrogen protection to obtain the mesoporous material.

[0049] According to an embodiment of the present invention, the carbonization process can be carried out using equipment known in the art, such as a tubular furnace.

[0050] According to an embodiment of the present invention, the carbonization treatment conditions include: first heating to 300-400°C and holding for a period of time, then heating to 700-1000°C and holding for a period of time.

[0051] Preferably, the carbonization treatment conditions include: first heating to 300–400°C at a heating rate of 1°C / min and holding for 1–3 hours; then heating to 700–1000°C at a heating rate of 2°C / min and holding for 1–3 hours. Specifically, the carbonization treatment conditions include: first heating to 350°C at a heating rate of 1°C / min and holding for 2 hours; then heating to 800°C at a heating rate of 2°C / min and holding for 2 hours.

[0052] The present invention also provides the application of the above-mentioned mesoporous material as a biomimetic enzyme.

[0053] The present invention also provides a biomimetic enzyme containing the above-described mesoporous material, wherein the mesoporous material has the meaning as described above.

[0054] According to an embodiment of the present invention, the biomimetic enzyme has the enzyme activity of any one of oxidase, peroxidase, catalase, and superoxide dismutase.

[0055] According to an embodiment of the present invention, the enzyme activity of the biomimetic enzyme is pH-dependent. Preferably, the pH stability value of the biomimetic enzyme is 3 to 5, for example 3.5 to 4.5, and more preferably 4.

[0056] The present invention also provides an oxidation method, the oxidation method comprising using the above-mentioned biomimetic enzyme to oxidize aromatic compounds or hydrogen peroxide.

[0057] According to an embodiment of the present invention, the aromatic compound is selected from at least one of 3,3',5,5'-tetramethylbiphenyl, dopamine, and 2,2'-azido-bis-3-ethylbenzothiazoline-6-sulfonic acid, preferably 3,3',5,5'-tetramethylbiphenyl.

[0058] According to an embodiment of the present invention, the biomimetic enzyme is provided by a solution containing the mesoporous material.

[0059] Preferably, in the solution containing the mesoporous material, the concentration of the mesoporous material is 0.01 to 20 mg / mL, more preferably 0.05 mg / mL, 10 mg / mL, 50 mg / mL, or 100 mg / mL.

[0060] Preferably, in the solution containing the mesoporous material, the solvent is an acidic buffer solution with a pH value of 3 to 5, for example, 3.5 to 4.5, preferably 4. Preferably, the acidic buffer solution in this invention can be any buffer solution known in the art, as long as it meets the above pH requirement. Exemplarily, the acidic buffer solution is selected from an acetic acid-sodium acetate buffer solution.

[0061] Beneficial effects

[0062] This invention uses different types of polyphenols to form a basic framework in a binary solvent, adds pore-forming and pore-expanding agents to form a hierarchical porous structure, and induces self-assembly of porous microspheres through polyphenol polymerization catalyzed by organic amines. The mesoporous microspheres of this invention can have their size and hierarchical pore structure controlled simply by changing the volume ratio of alcohol to water in the binary solvent, thus meeting the needs for different pore structure types in the catalytic field.

[0063] This invention uses natural polyphenolic compounds (such as phloroglucinol, pyroglucinol, and catechol), which are widely available and have significant cost advantages. They are also biodegradable, thus giving the mesoporous material multifunctionality and making it suitable for use in the biomimetic enzyme industry.

[0064] The mesoporous material prepared by this invention can be used as a biomimetic enzyme, exhibiting various enzymatic activities and good stability. Compared with biological enzymes, the biomimetic enzyme of this invention has advantages such as high stability and resistance to acids and alkalis. Moreover, the preparation process of the biomimetic enzyme of this invention is simple, mild, and cost-controllable, showing potential for industrial production. Attached Figure Description

[0065] Figure 1 This is a schematic diagram illustrating the formation of mesoporous microspheres and the fabrication process of corresponding nitrogen-doped mesoporous carbon spheres (denoted as NMCN-x, where x is the volume ratio of ethanol to water).

[0066] Figure 2The image shown is a scanning electron microscope (SEM) image of the mesoporous microspheres obtained in Example 1.

[0067] Figure 3 The image shown is a scanning electron microscope (SEM) image of the mesoporous microspheres in Comparative Example 1.

[0068] Figure 4 The images shown are transmission electron microscope (TEM) images and energy dispersive spectroscopy (EDS) images of nitrogen-doped mesoporous carbon spheres obtained in Example 1.

[0069] Figure 5 The image shows the XPS spectrum of the mesoporous carbon spheres in Example 1.

[0070] Figure 6 This is a schematic diagram of the oxidase-like activity of nitrogen-doped mesoporous carbon spheres.

[0071] Figure 7 The oxidase-like activity of nitrogen-doped mesoporous carbon spheres corresponding to phenolamine mesoporous spheres, with 3,3',5,5'-tetramethylbenzidine (TMB) as the catalytic substrate;

[0072] Figure 8 This is a graph showing the peroxidase activity of NMCN-x in Example 1.

[0073] Figure 9 This is a graph showing the catalase activity of NMCN-x in Example 1.

[0074] Figure 10 This is a graph showing the superoxide dismutase activity of NMCN-x in Example 1. Detailed Implementation

[0075] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0076] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0077] Example 1

[0078] I. Preparation of mesoporous microspheres:

[0079] according to Figure 1 The process flow shown is used to prepare mesoporous microspheres and nitrogen-doped mesoporous carbon spheres:

[0080] The first step involves dissolving a block copolymer mixture of P123 / F127 (with a mass ratio of P123 to F127 of 1:3) in a binary solvent (where the volume ratio of ethanol to water is 0:100, 10:90, 20:80, 30:70, or 40:60) to prepare a 1 mg / mL ethanol-water block copolymer solution. This solution is then rapidly stirred for 0.5 hours under magnetic stirring at 800 rpm to form a first micelle solution. The first micelle comprises a micelle structure with a hydrophobic core and a hydrophilic outer layer, specifically consisting of: polyethylene oxide-polypropylene oxide-polyethylene oxide, where the hydrophilic chain is polyethylene oxide and the hydrophobic chain is polypropylene oxide. The particle size of the first micelle is 7–30 nm.

[0081] The second step involves weighing phloroglucinol (PG) and adding it to the first micelle solution, where the concentration of phloroglucinol is 6 mg / mL. Stirring is continued for 0.5 hours to allow it to adsorb onto the hydrophilic ends of the first micelles. Then, the pore-expanding agent mesitylene is added. Due to its hydrophobic nature, mesitylene enters the core of the first micelles during stirring, resulting in a P123 / F127 / polyphenol / mesitylene composite micelle solution with a particle size of 8–50 nm.

[0082] Third, continue stirring for 30 minutes, then add ethylenediamine (EDA) at a concentration of 20 mmol / L to the above composite micelle solution. Under the induction of ethylenediamine, phloroglucinol undergoes self-polymerization and self-assembly to form mesoporous microspheres. The microspheres are then washed, centrifuged, and dried to obtain the dried mesoporous microspheres. The drying conditions include drying at 450℃ for 6 hours. The prepared mesoporous microspheres are designated as NMN-0, NMN-10, NMN-20, NMN-30, and NMN-40, where 0, 10, 20, 30, and 40 represent the volume ratios of ethanol and water in the binary solvent as 0:100, 10:90, 20:80, 30:70, and 40:60, respectively.

[0083] II. Preparation of nitrogen-doped mesoporous carbon spheres:

[0084] The dried mesoporous microspheres were placed in a tube furnace and carbonized under nitrogen protection to obtain nitrogen-doped mesoporous carbon spheres, denoted as NMCN-0, NMCN-10, NMCN-20, NMCN-30, and NMCN-40. The carbonization conditions included: first heating to 350°C at a heating rate of 1°C / min and holding for 2 hours; then heating to 800°C at a heating rate of 2°C / min and holding for 2 hours.

[0085] Example 2

[0086] This embodiment is basically the same as that of embodiment 1, except that phloroglucinol is used instead of resorcinol.

[0087] Example 3

[0088] This embodiment is basically the same as that of embodiment 1, except that catechol is used instead of phloroglucinol.

[0089] Example 4

[0090] This embodiment is basically the same as that of Embodiment 1, except that isopropanol is used instead of ethanol.

[0091] Example 5

[0092] This embodiment is basically the same as Embodiment 1, except that methanol is used instead of ethanol.

[0093] Example 6

[0094] This embodiment is the same as Embodiment 1, except that ethylene glycol is used instead of ethanol.

[0095] Example 7

[0096] This embodiment is the same as Embodiment 1, except that divinyltriamine is used instead of ethylenediamine.

[0097] Example 8

[0098] This embodiment is the same as Embodiment 1, except that trivinyltetramine is used instead of ethylenediamine.

[0099] Example 9

[0100] This embodiment is the same as Embodiment 1, except that tetraenylpentamine is used instead of ethylenediamine.

[0101] The mesoporous microspheres and nitrogen-doped mesoporous carbon spheres prepared in Examples 2-9 above have similar structures to the mesoporous microspheres and nitrogen-doped mesoporous carbon spheres in Example 1.

[0102] Example 10

[0103] This embodiment is the same as Example 1, except that the molar ratio of ethylenediamine in the third step is adjusted to 5, 10, 20, 30 and 40 respectively, so that phenolic amine mesoporous microspheres and nitrogen-doped mesoporous carbon spheres with different pore sizes can also be prepared, which have a structure that is basically similar to that of Example 1.

[0104] Example 11

[0105] This embodiment is the same as that of Embodiment 1, except that the mass ratio of P123 to F127 is adjusted to make the mass ratio values ​​1:1, 2:1, 3:1, and 4:1, respectively. Phenolic amine mesoporous microspheres and nitrogen-doped mesoporous carbon spheres with different pore sizes can also be prepared, which have a structure that is basically similar to the mesoporous microspheres and nitrogen-doped mesoporous carbon spheres of Embodiment 1.

[0106] Comparative Example 1

[0107] This embodiment is the same as Embodiment 1, except that: mesitylene is not added.

[0108] Figure 6 This is a SEM image of the mesoporous microspheres obtained in this comparative example without the addition of mesitylene, where A, B, C, D, and E represent the mesoporous microspheres prepared with volume ratios of ethanol to water of 0:100, 10:90, 20:80, 30:70, and 40:60, respectively. Figure 3 It can be seen that the mesoporous microspheres obtained without the addition of trimethylbenzene have uneven particle size, are easily aggregated into spherical shapes, and their pore structure does not change with the volume ratio of ethanol and water, and therefore cannot be used as biomimetic enzymes.

[0109] Test Example 1

[0110] Characterization of phenolic amine mesoporous microspheres and nitrogen-doped mesoporous carbon spheres prepared in Example 1

[0111] Figure 2 SEM images of the mesoporous microspheres prepared in Example 1 are shown, where A, B, C, D, and E represent the mesoporous microspheres NMN-10, NMN-20, NMN-30, and NMN-40 prepared when the volume ratios of ethanol and water are 0:100, 10:90, 20:80, 30:70, and 40:60, respectively. Figure 2 It can be seen that mesoporous microspheres were successfully synthesized, comprising a hierarchical porous structure with multiple channels. The average inner diameters of the channels in NMN-0, NMN-10, NMN-20, and NMCN-30 are 8 nm, 16 nm, 24 nm, and 55 nm, respectively; the channels in NMCN-40 include both small and large channels, with average inner diameters of 14 nm and 100 nm, respectively; the average particle sizes of NMN-0, NMN-10, NMN-20, NMN-30, and NMN-40 are 190 nm, 290 nm, 380 nm, 480 nm, and 1.8 μm, respectively. Figure 2 It can be seen that the prepared mesoporous microspheres have uniform pore and particle size, and the size of the mesoporous microspheres and pores increases with the increase of the volume fraction of ethanol in the solvent. When the volume fraction of ethanol is 40%, the pores of the mesoporous microspheres include macropores and micropores.

[0112] Figure 4 TEM image and energy spectrum of nitrogen-doped mesoporous carbon spheres prepared in Example 1. Figure 4In the diagram, A and BE represent the TEM image and energy dispersive spectroscopy (EDS) spectrum of NMCN-0, respectively; F and GJ represent the TEM image and EDS spectrum of NMCN-10, respectively; K and LO represent the TEM image and EDS spectrum of NMCN-20, respectively; P and QT represent the TEM image and EDS spectrum of NMCN-30, respectively; and U and VY represent the TEM image and EDS spectrum of NMCN-40, respectively. TEM testing shows that carbonization of mesoporous microspheres yields nitrogen-doped mesoporous carbon spheres, whose pore size and particle size are close to those of mesoporous microspheres.

[0113] Figure 5 The image shows the XPS spectrum of the mesoporous microspheres prepared in Example 1. XPS analysis revealed that the basic framework of the mesoporous microspheres in Example 1 contains at least C, N, and O elements, indicating that the basic framework is an assembly product of polyphenols and organic amines. Figure 4 As can be seen from the energy spectrum, the nitrogen-doped mesoporous carbon spheres of Example 1 contain C, N, and O elements, as determined by elemental analysis.

[0114] Table 1. Parameters of mesoporous microspheres and nitrogen-doped mesoporous carbon spheres in Example 1

[0115]

[0116] Furthermore, as can be seen from Examples 2-11 above, by changing the type and amount of polyphenolic compounds, organic alcohols, and organic amines, mesoporous microspheres and nitrogen-doped mesoporous carbon spheres with different pore sizes and similar structures to those in Example 1 can also be prepared.

[0117] Application Example 1

[0118] By using nitrogen-doped mesoporous carbon spheres (NMCN-0, NMCN-10, NMCN-20, NMCN-30, and NMCN-40) from Example 1 as biomimetic enzymes, they were uniformly dispersed in a 0.1 mol / L acetate-sodium acetate buffer solution at pH 4 to obtain a concentration of 10 mg / mL. -1 The biomimetic enzyme solution was prepared by adding different concentrations (0 μmol / L, 0.1 μmol / L, 0.2 μmol / L, 0.3 μmol / L, 0.4 μmol / L, 0.5 μmol / L, 0.75 μmol / L, and 1 μmol / L) of 3,3',5,5'-tetramethylbiphenyl to the above biomimetic enzyme solution to test the oxidase-like activity of nitrogen-doped mesoporous carbon spheres.

[0119] like Figure 6 As shown, nitrogen-doped mesoporous carbon spheres can oxidize 3,3',5,5'-tetramethylbiphenyl to obtain oxidized 3,3',5,5'-tetramethylbiphenyl. Figure 7 To measure the absorbance of the above solution at 652 nm using ultraviolet spectroscopy, from... Figure 7It can be seen that NMCN-40 has the highest catalytic rate, meaning that the nitrogen-doped multi-level mesoporous carbon spheres NMCN-40 with multi-level channels have the highest oxide-like biomimetic activity.

[0120] Application Example 2

[0121] Nitrogen-doped mesoporous carbon spheres (NMCN-0, NMCN-10, NMCN-20, NMCN-30, and NMCN-40) from Example 1 were used as biomimetic enzymes and uniformly dispersed in a 0.1 mol / L acetate-sodium acetate buffer solution at pH 4 to obtain a concentration of 50 μg / mL. -1 The biomimetic enzyme solution was prepared by adding different concentrations (0 μmol / L, 0.2 mol / L, 0.4 mol / L, 0.6 mol / L, 0.8 mol / L, 1 mol / L, and 1.5 mol / L) of H2O2 to the above biomimetic enzyme solution, and then adding 0.75 μmol / L of 3,3',5,5'-tetramethylbiphenyl to test the peroxidase activity of nitrogen-doped mesoporous carbon spheres.

[0122] like Figure 8 As shown, in the presence of hydrogen peroxide, nitrogen-doped mesoporous carbon spheres can oxidize 3,3',5,5'-tetramethylbiphenyl to obtain oxidized 3,3',5,5'-tetramethylbiphenyl. Figure 8 To measure the absorbance of the above solution at 652 nm using ultraviolet spectroscopy, from... Figure 8 It can be seen that NMCN-40 has the highest catalytic rate, meaning that the peroxidase activity of nitrogen-doped mesoporous carbon spheres NMCN-40 with multi-level channels is the highest.

[0123] Application Example 3

[0124] Nitrogen-doped mesoporous carbon spheres (NMCN-0, NMCN-10, NMCN-20, NMCN-30, and NMCN-40) from Example 1 were used as biomimetic enzymes and uniformly dispersed in a 0.1 mol / L acetate-sodium acetate buffer solution at pH 4 to obtain a concentration of 50 mg / mL. -1 The biomimetic enzyme solution was prepared by adding different concentrations (0 mol / L, 0.2 mol / L, 0.4 mol / L, 0.6 mol / L, 0.8 mol / L, and 1 mol / L) of H2O2 to the above biomimetic enzyme solution, and the catalase activity of nitrogen-doped mesoporous carbon spheres was tested.

[0125] like Figure 9 As shown, nitrogen-doped mesoporous carbon spheres can catalyze the production of oxygen from hydrogen peroxide in the presence of hydrogen peroxide. Figure 9 To measure the amount of oxygen produced by a dissolved oxygen meter, by Figure 9It can be seen that NMCN-40 has the highest oxygen production rate, meaning that the nitrogen-doped multi-level mesoporous carbon spheres NMCN-40 with multi-level channels have the highest catalase activity.

[0126] Application Example 4

[0127] Nitrogen-doped mesoporous carbon spheres (NMCN-0, NMCN-10, NMCN-20, NMCN-30, and NMCN-40) from Example 1 were used as biomimetic enzymes and were uniformly dispersed in a 0.1 mol / L acetate-sodium acetate buffer solution at pH 4. The superoxide dismutase activity of nitrogen-doped mesoporous carbon spheres at different concentrations (25 μg / mL, 50 μg / mL, 75 μg / mL, 100 μg / mL, and 125 μg / mL) was tested.

[0128] like Figure 10 The image shown is a graph of the tested superoxide dismutase activity. Figure 10 It can be seen that NMCN-40 has the highest oxygen production rate, meaning that the superoxide dismutase of nitrogen-doped mesoporous carbon spheres NMCN-40 with multi-level pores has the highest enzyme activity.

[0129] The exemplary embodiments of the present invention have been described above. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a mesoporous material, characterized in that, The preparation method includes: carbonizing mesoporous microspheres under nitrogen protection to obtain the mesoporous material; the carbonization conditions include: first heating to 300~400℃ at a heating rate of 1℃ / min and holding for 1~3h; then heating to 700~1000℃ at a heating rate of 2℃ / min and holding for 1~3h. The method for preparing the mesoporous microspheres includes the following steps: (1) Under stirring conditions, a porogen is added to a binary solvent to obtain a first micelle solution, wherein the center of the first micelle is hydrophobic; the binary solvent is a mixed solvent of organic alcohol and water; the volume ratio of the organic alcohol to water is 40:60; the organic alcohol is selected from at least one of methanol, ethanol, ethylene glycol, and isopropanol; the porogen is F127 and P123, with a mass ratio of 3:1; the concentration of the porogen is 5~15 mg / mL; (2) Add the polyphenol compound to the first micelle solution in step (1) and stir. The polyphenol compound binds to the hydrophilic group of the first micelle. Then add a pore-expanding agent to form a composite micelle solution. The polyphenol compound is selected from at least one of phloroglucinol, pyroglucinol, and catechol. The pore-expanding agent is selected from mesitylene. The concentration of the polyphenol compound is 5~10 mg / mL. (3) Add the organic amine to the composite micelle solution of step (2), stir, and the polyphenol compound self-assembles to obtain the basic framework, forming the mesoporous spheres; the organic amine is selected from at least one of octadecylamine, mercaptoethylamine, ethylenediamine, p-phenylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine; the concentration of the organic amine is 1~40 mmol / L; the molar ratio of the organic amine to the polyphenol compound is 1~50; the self-assembly time is 1~48 h; The mesoporous material includes nitrogen-doped mesoporous carbon spheres, which have a framework structure and a porous structure. The particle size of the nitrogen-doped mesoporous carbon spheres is 200 nm to 2 μm. The pores of the nitrogen-doped mesoporous carbon spheres include macropores and micropores, with the inner diameter of the micropores being 14 nm and the inner diameter of the macropores being 100 nm. The nitrogen-doped mesoporous carbon spheres comprise the following components: carbon, oxygen, nitrogen, and optionally sulfur; The mesoporous microspheres include a basic framework, which also includes a pore structure formed by a pore-forming agent and a pore-expanding agent. The pore structure is a multi-level channel structure.

2. The preparation method according to claim 1, characterized in that, The hole structure includes at least one or more primary channels, which have the same or different inner diameters.

3. The preparation method according to claim 2, characterized in that, The inner diameter of the primary channel is 8nm to 150nm.

4. The preparation method according to claim 1, characterized in that, The mesoporous microspheres have a particle size of 140 nm to 2 μm.

5. The preparation method according to claim 1, characterized in that, In step (1), the first micelle solution is a clear solution; In step (1), the particle size range of the first micelles in the first micelle solution is selected from 7nm to 30nm.

6. The preparation method according to claim 1, characterized in that, In step (2), the particle size range of the composite micelles is selected from 7~50nm.

7. The application of the mesoporous material obtained by the preparation method according to any one of claims 1-6 as a biomimetic enzyme.

8. A biomimetic enzyme, characterized in that, The biomimetic enzyme contains a mesoporous material obtained by the preparation method according to any one of claims 1-6.

9. The biomimetic enzyme according to claim 8, characterized in that, The biomimetic enzyme has the enzyme activity of peroxidase or superoxide dismutase. The biomimetic enzyme has pH-dependent enzyme activity; the pH stability value of the biomimetic enzyme is 3~5.

10. An oxidation method, characterized in that, The oxidation method includes using the biomimetic enzyme of claim 8 or 9 to oxidize aromatic compounds or hydrogen peroxide.

11. The oxidation method according to claim 10, characterized in that, The aromatic compound is selected from at least one of 3,3',5,5'-tetramethylbiphenyl, dopamine, and 2,2'-azido-bis-3-ethylbenzothiazoline-6-sulfonic acid.

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