Porous carbon material as well as preparation method and application thereof

Abstract

The invention discloses a porous carbon material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing and reacting 10-30 parts by mass of wormwood, 20-40 parts by mass of phenol and 20-40 parts by mass of formaldehyde under an acidic condition to prepare resin; (2) under an alkaline condition, mixing 3-10 parts by mass of a zinc precursor and an alcohol solvent for reaction to prepare zinc oxide; and (3) mixing the zinc oxide-containing solution with resin for reaction, drying and calcining. The wormwood and the phenolic resin are compounded, the nitrogen-containing characteristic and the porous structure of the wormwood are utilized, a nitrogen-containing structure beneficial to the performance of the battery negative electrode material is formed, the first discharge specific capacity and the cycle stability are improved, and the phenolic resin is modified under the condition that a nitrogen source is not additionally introduced. By using an in-situ synthesis method of zinc oxide, the zinc oxide synchronously grows in wormwood / phenolic resin, the pore diameter is accurately regulated and controlled, pores are uniformly distributed in a material matrix, the adsorption performance is improved, and a good channel is provided for lithium ion transmission.

Description

Technical Field

[0001] The present invention specifically relates to a porous carbon material, a preparation method thereof, and an application thereof. Background Art

[0002] In the current fields of materials science and energy technology, the research and development of anode materials for batteries has always been a popular and crucial research direction. With the rapid development of various electronic devices and new energy vehicles, etc., the requirements for battery performance are becoming increasingly stringent. There is a need not only for high energy density, good cycle stability and rate performance, but also for battery materials to have multifunctional characteristics to adapt to more complex application scenarios.

[0003] In the related prior art, Chinese Patent CN114520314B discloses an anode material with a porous carbon coating layer, which is obtained through multi-step treatment of phenolic resin and compounding with a carbon-containing anode material. Although it improves the electrochemical performance of the anode material to a certain extent, it has the following two defects: (1) The problem of single functionality: The main focus of this patent is on improving the electrochemical performance of the battery anode material, and the electrochemical processes such as lithium ion transport are optimized by constructing a porous carbon coating layer. However, this material lacks other additional functions, such as antibacterial and adsorption functions. In practical applications, for example, in batteries for some medical devices or in energy storage systems with a complex environment, the battery material may face problems such as microbial growth or the need to adsorb impurities in the surrounding environment, and this material cannot meet these requirements. (2) The defect of raw material limitation: Its preparation process mainly focuses on phenolic resin and carbon-containing anode materials, and the types of raw materials are relatively limited.

[0004] Chinese Patent Application CN118239469A discloses a hard carbon composite material derived from bamboo-based porous carbon doped with lignocellulose phenolic resin. Through specific structural design and by means of the synergistic effect among lignocellulose phenolic resin, doped atoms, and bamboo-based porous carbon, although it improves the electrochemical performance and stability of the material to a certain extent, it also has obvious deficiencies in antibacterial properties. In some special application scenarios, such as when using batteries in the medical field with high hygiene requirements or in an environment where bacteria are likely to grow due to humidity, the lack of antibacterial properties may lead to a decline in battery performance and even pose potential safety hazards. Moreover, its regulation of the pore structure is mainly to meet the storage and transport requirements of lithium ions or sodium ions, and there is insufficient multifunctional synergy with the material.

[0005] In the prior art, Artemisia argyi is mainly applied in the fields of medicine, health care, food, cosmetics, etc. For example, in the medical field, Artemisia argyi has the effects of warming the meridians to stop bleeding, dispelling cold and relieving pain, removing dampness and relieving itching, etc., and can be used to treat various diseases; Artemisia argyi also has antibacterial, antiviral, anti-inflammatory and other effects. In the health care field, Artemisia argyi can be used to make health care products such as moxibustion and moxa floss; Artemisia argyi can also be used for bathing, foot bathing, etc. In the food field, Artemisia argyi can be used to make food such as Artemisia argyi green dumplings and Artemisia argyi cakes. In the cosmetics field, Artemisia argyi contains various active ingredients such as volatile oils and flavonoid compounds, which have antibacterial, antioxidant, moisturizing and other effects, and can be used to make cosmetics such as Artemisia argyi facial cleanser and Artemisia argyi facial mask. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defect that the materials in the prior art have a single function and cannot have both electrochemical performance and other additional functions (such as antibacterial and adsorption functions), and provides a porous carbon material, a preparation method thereof, and an application. In the present invention, Artemisia argyi and phenolic resin are compounded, and the nitrogen-containing structure beneficial to the performance of the battery negative electrode material is formed by utilizing the nitrogen-containing characteristics and porous structure of Artemisia argyi itself, so as to improve the initial discharge specific capacity and cycle stability, and realize the modification of phenolic resin without additionally introducing a nitrogen source. By using the method of in-situ synthesizing zinc oxide, zinc oxide is synchronously grown in Artemisia argyi / phenolic resin, the pore size is precisely regulated, and the pores are evenly distributed in the material matrix, so as to improve the adsorption performance and provide a good channel for lithium ion transmission. The process of the present invention is simple and is conducive to large-scale industrial production.

[0007] The present invention solves the above technical problems through the following technical solutions.

[0008] In the present invention, through creative labor, a specific component and its specific proportion range are obtained, which can enable the components to synergistically act with each other in the subsequent preparation process, ensuring that the final material can not only perform excellently in terms of battery performance, but also have good adsorption and antibacterial characteristics. For example, the cooperation of an appropriate proportion of Artemisia argyi and phenolic resin will neither cause the material structure to be too loose due to excessive Artemisia argyi, which affects the battery performance, nor cause insufficient adsorption and antibacterial performance due to too little Artemisia argyi.

[0009] The present invention provides a preparation method of a porous carbon material, which comprises the following steps:

[0010] S1 Under acidic conditions, 10-30 parts by mass of Artemisia argyi, 20-40 parts by mass of phenol and 20-40 parts by mass of formaldehyde are mixed and reacted to obtain Artemisia argyi / phenolic resin;

[0011] S2 Under alkaline conditions, 3-10 parts by mass of a zinc precursor and an alcohol solvent are mixed and reacted to obtain zinc oxide;

[0012] S3 The solution containing the zinc oxide is mixed and reacted with the Artemisia argyi / phenolic resin, dried, and calcined.

[0013] In S1, the dosage of the wormwood is preferably 12 - 28 parts, such as 15 parts, 20 parts or 25 parts.

[0014] In S1, the variety of the wormwood is not limited and can be conventional in the art. For example, it can be selected from one or more of Artemisia argyi Lévl. et Vant. var. chinensis (Pamp.) Hsiao, Artemisia argyi Lévl. et Vant. var. umbellata (Wulf.) Pamp., and Artemisia argyi Lévl. et Vant. var. qiai (Tamura) Hsiao, and Artemisia argyi Lévl. et Vant. var. qiai (Tamura) Hsiao is preferred.

[0015] In S1, the form of the wormwood is not limited, and it is preferably wormwood powder. The wormwood can be conventional wormwood leaves, stems or roots in the art. Preferably, the wormwood is wormwood powder ground from conventional wormwood leaves, stems or roots in the art.

[0016] In S1, the dosage of the phenol is preferably 22 - 38 parts, such as 25 parts, 30 parts or 35 parts.

[0017] In S1, the mass ratio of the wormwood to the phenol is preferably 1:(0.8 - 3.5), such as 1:1, 1:1.2, 1:1.5, 1:2, 1:2.33 or 1:3.

[0018] In S1, the mass ratio of the wormwood to the formaldehyde is preferably 1:(0.8 - 3.5), such as 1:1, 1:1.2, 1:1.5, 1:2, 1:2.33 or 1:3.

[0019] In S1, the dosage of the formaldehyde is preferably 22 - 38 parts, such as 25 parts, 30 parts or 35 parts.

[0020] In S1, if other aldehydes are used to replace the formaldehyde, the specific surface area, pore volume and antibacterial performance of the obtained porous carbon material will decrease significantly. For example, if acetaldehyde is used to replace formaldehyde, due to the different molecular structures of acetaldehyde and formaldehyde, the structure of the generated phenolic resin will be different, and the pore structure of the finally prepared porous carbon material will become irregular, and the specific surface area and pore volume will both decrease significantly, about 500 - 600 m² / g and 0.2 - 0.3 cm³ / g respectively. In terms of antibacterial performance, due to the change of the material structure, the antibacterial rate against Escherichia coli may be reduced to 70% - 80% (92% - 96% when using formaldehyde).

[0021] In S1, in the mixed reaction, in addition to the phenol and formaldehyde undergoing an acetal reaction to form a phenolic resin, some components in the wormwood can have physical or chemical interactions with the phenolic resin. For example, triterpenoids, flavonoids, phenols, etc. in the wormwood can react with the active groups in the phenolic resin. For example, phenolic components can undergo condensation reactions with hydroxyl groups in the phenolic resin.

[0022] In S1, " / " in "wormwood / phenolic resin" generally refers to a complex formed through a certain chemical connection.

[0023] In S1, the mixing reaction can generally be carried out by mechanical stirring or ultrasonic mixing.

[0024] When mechanical stirring is used, the stirring rate is preferably 300 - 500 r / min, such as 350 r / min, 400 r / min or 450 r / min. Stirring is generally carried out at room temperature. The time of the mechanical stirring is preferably 2 - 4 h, such as 2.5 h or 3.5 h.

[0025] When ultrasonic mixing is used, the power is preferably 200 - 500 W and the time is 30 - 90 min.

[0026] In S1, it is preferred to dry the product after the mixing reaction. The drying conditions can be conventional in the art. The drying temperature can be 60 - 80 °C, such as 65 °C, 70 °C or 75 °C. The drying time can be 2 - 4 h, such as 2.5 h, 3 h or 3.5 h.

[0027] When drying the product after the mixing reaction, vacuum drying can also be used. The temperature of vacuum drying can be 40 - 60 °C and the vacuum degree can be 0.05 - 0.1 MPa.

[0028] In S1, in the mixing reaction, the pH value of the system is preferably 3 - 5, such as 3.5, 4 or 4.5. Within this pH value range, not only can the polycondensation reaction to produce phenolic resin proceed smoothly, but also the components in wormwood can be better mixed and reacted with phenolic resin to form a stable intermediate structure, which is beneficial to subsequent reactions.

[0029] In S1, the pH value of the system can be adjusted by conventional methods. For example, sodium hydroxide or hydrochloric acid can be added. In a preferred embodiment, the addition amount of sodium hydroxide can be 3 - 8 parts, such as 3 parts, 4 parts or 5 parts. The addition amount of hydrochloric acid can be 1 - 5 parts, such as 2, 3 or 4 parts.

[0030] In a preferred embodiment, the mass ratio of wormwood to sodium hydroxide can be 1:(0.12 - 0.5), such as 1:0.13, 1:0.16, 1:0.2, 1:0.27 or 1:0.4.

[0031] In a preferred embodiment, the mass ratio of wormwood to hydrochloric acid can be 1:(0.08 - 0.4), such as 1:0.1, 1:0.12, 1:0.13, 1:0.15, 1:0.16, 1:0.2 or 1:0.3.

[0032] In S2, the dosage of the zinc precursor is preferably 4 - 9 parts, such as 5 parts, 7 parts or 8 parts.

[0033] In S2, the zinc precursor can be of conventional types in the art, preferably selected from one or more of zinc nitrate, zinc acetate, zinc sulfate, zinc citrate, zinc carbonate, zinc oxalate, zinc phosphate, zinc propionate, zinc thiosulfate, and zinc halide, and more preferably zinc nitrate, zinc acetate, zinc propionate, zinc citrate, or zinc oxalate. In the present invention, according to actual needs, the properties and structure of the material can be flexibly adjusted by diversely selecting the type of zinc precursor.

[0034] In S2, the mass ratio of the wormwood and the zinc precursor is preferably (1.5 - 6.5):1, such as 1.875:1, 2:1, 3:1, 3.57:1, 4:1, 5:1, or 6:1.

[0035] In S2, the mass ratio of the zinc precursor and the alcohol solvent is preferably (3 - 10):(10 - 30), such as 5:15, 8:12, or 7:18.

[0036] In S2, the alcohol solvent can be a conventional alcohol solvent in the art that can dissolve the zinc precursor and promote the uniform mixing of each component, such as one or more of methanol, isopropanol, and ethanol, and ethanol is preferred.

[0037] In S2, in the mixing reaction, the pH value of the system is preferably 9 - 11, such as 9.5, 10, or 10.5. Within this pH value range, it can ensure that the zinc precursor reacts fully with the base to form zinc hydroxide precipitate, and then be transformed into a suitable zinc oxide crystal form.

[0038] In S2, the pH value of the system can be adjusted by conventional methods. For example, adding a base. The base can be sodium hydroxide or potassium hydroxide, and sodium hydroxide is preferred. After adding the base to the system, it is generally stirred at room temperature for 2 - 3 h to completely dissolve it.

[0039] In S2, when adjusting the pH value of the system, the mass ratio of the zinc precursor and the base is preferably 1:(0.375 - 0.8), such as 1:0.8, 1:0.375, or 1:0.714.

[0040] In S2, the conditions of the mixing reaction can be conventional in the art. Generally, it is first stirred at room temperature and then dried in a forced-air oven or heated by microwave. During the stirring process, zinc hydroxide is generally formed by reaction, and it is dried in a forced-air oven and zinc hydroxide decomposes to form zinc oxide.

[0041] When using a forced-air oven, the temperature can be 120 - 180 °C, such as 140 °C, 150 °C, or 160 °C. The time can be 6 - 12 h, such as 8 h, 9 h, or 10 h.

[0042] When microwave heating is used, the power can be 300-800 W. The time can be 1-3 hours. When microwave heating is used, the reaction container generally needs to be made of a material that can withstand microwave radiation and does not react with the reaction system, such as a polytetrafluoroethylene container.

[0043] In S2, after the mixed reaction, the upper clear liquid is generally poured off, and the white precipitate at the bottom is zinc oxide.

[0044] In S2, in a preferred embodiment, the zinc oxide can be prepared by the following steps: dissolving 3-10 parts of zinc precursor in 10-30 parts of ethanol, adding 3-8 parts of NaOH, stirring at room temperature for 2-3 hours to completely dissolve the NaOH, then pouring the solution into a 100-200 mL reactor, and heating in a forced air oven at 120-180° C. for 6-12 hours.

[0045] In S3, the solution containing the zinc oxide can be prepared by conventional methods in the art, for example, dissolving the zinc oxide in an alcohol solvent.

[0046] The alcohol solvent may be an alcohol conventionally used in the art that can dissolve and disperse zinc oxide, such as one or more of methanol, isopropanol and ethanol, preferably ethanol.

[0047] In a preferred embodiment, the solution containing the zinc oxide can be prepared by the following steps: using a dropper to add ethanol to the zinc oxide, stirring in a water bath (60° C.) for 10 minutes to dissolve and disperse.

[0048] In S3, preferably, the mass ratio of the zinc oxide to the wormwood / phenolic resin is (0.2-0.5):1, for example, 0.25:1, 0.3:1 or 0.4:1.

[0049] In S3, preferably, the wormwood / phenolic resin is added dropwise to the solution containing the zinc oxide.

[0050] In S3, the temperature of the mixing reaction is preferably 50-70°C, such as 60°C.

[0051] In S3, the mixing reaction time is preferably 1-3 hours, for example 2 hours.

[0052] In S3, during the mixing reaction, a plastic film may be used to seal the opening of the reaction container to prevent excessive volatilization of the solvent.

[0053] In S3, after the mixing reaction is complete, the system may present a light pink color.

[0054] In a preferred embodiment, the mixing reaction can be carried out through the following steps: Dropwise add wormwood / phenolic resin into an ethanol solution containing zinc oxide (zinc oxide: wormwood / phenolic resin = 0.2 - 0.5), seal the mouth of the reaction vessel with a plastic film to prevent excessive evaporation of the solvent, stir at 60 °C for 2 h to uniformly mix and react zinc oxide with wormwood / phenolic resin.

[0055] In S3, the drying operation can be conventional in the art and is generally carried out in a forced-air oven. The drying temperature can be 80 - 120 °C, such as 90 °C, 100 °C or 110 °C. The drying time can be 2 - 4 h, such as 2.5 h, 3 h or 3.5 h. During the drying process, the phenolic resin can be further polycondensed.

[0056] In a preferred embodiment, the drying operation can include the following steps: Pour the reaction product into a glass petri dish, seal the mouth of the petri dish with tinfoil, pierce holes for ventilation, and place it in a forced-air oven and heat at 80 - 120 °C for 2 - 4 h.

[0057] In S3, the dried product can be a pink solid. In a preferred embodiment, the dried product can be scraped off and ground thoroughly.

[0058] Before calcination in S3, the product is generally ground.

[0059] In S3, the calcination is generally carried out in a tube furnace. During the calcination process, a carbonization reaction occurs in the system. For example, the phenolic resin and wormwood are further carbonized to form a carbon skeleton, and at the same time, nitrogen-containing compounds can undergo transformation to form stable nitrogen-containing structures such as pyridine nitrogen and pyrrole nitrogen. Zinc oxide can interact with the surrounding carbon structures. When the porous carbon material of the present invention is applied as an anode material, these structural changes not only enhance the overall conductivity of the material, improve the reaction activity of lithium ions with the material, but also have a positive impact on the initial discharge specific capacity and cycle stability of the battery anode material.

[0060] In S3, the preferred calcination temperature is 600 - 800 °C, such as 650 °C, 700 °C or 750 °C.

[0061] In S3, the preferred calcination time is 1 - 3 h, such as 2 h, 2.5 h or 3 h.

[0062] In S3, the heating rate for raising the temperature to the calcination temperature is preferably 5 - 10 °C / min, such as 6 °C, 8 °C / min or 9 °C / min.

[0063] In S3, during the calcination process, when nitrogen is used as the protective gas, the nitrogen flow rate is preferably 30 - 50 cc / min, such as 35 cc / min, 40 cc / min or 45 cc / min.

[0064] In S3, during the calcination process, when argon is used as the protective gas, the nitrogen gas flow rate is preferably 20 - 40 cc / min.

[0065] In a preferred embodiment, the calcination operation may include the following steps: in a tubular furnace, maintain at 600 - 800 °C for 1 - 3 h, with a heating rate of 5 - 10 °C / min and a nitrogen gas flow rate of 30 - 50 cc / min.

[0066] In S3, after the calcination, conventional post-treatment is generally carried out. The post-treatment may include adding an excessive amount of acid for stirring, filtering, washing with water until neutral, and drying.

[0067] In a preferred embodiment, the post-treatment may include the following steps: add 0.5 - 2 mol / L of excessive hydrochloric acid (such as 0.8 mol / L, 1 mol / L, or 1.5 mol / L) to the reaction product and stir for 5 h, or add 1 - 3 mol / L of acetic acid and stir for 6 - 10 h to remove zinc oxide; filter and wash with water until the filtrate is neutral, and then dry.

[0068] The present invention also provides a porous carbon material prepared by the preparation method as described above.

[0069] In the present invention, the pore diameter of the porous carbon material may be mainly concentrated in the range of 2 - 50 nm.

[0070] In the present invention, the pore volume of the porous carbon material may be 0.42 cm³ / g - 0.61 cm³ / g.

[0071] In the present invention, the specific surface area of the porous carbon material may be 801 m² / g - 1158 m² / g.

[0072] In the present invention, the antibacterial rate of the porous carbon material against Escherichia coli may be 92% - 96%.

[0073] In the present invention, the powder resistivity of the porous carbon material may be 0.4 Ω·cm - 0.6 Ω·cm.

[0074] In a preferred embodiment, the overall shape of the porous carbon material is irregular, and it is a porous structure formed by the aggregation of numerous tiny carbon particles. These carbon particles are intertwined and adhered to each other, presenting a relatively loose but somewhat agglomerated morphology macroscopically.

[0075] The present invention also provides an application of the porous carbon material as described above as an antibacterial material in the fields of medical and health, food packaging with antibacterial efficacy, or household products, as a negative electrode material in the field of battery materials, or as an adsorption material in the fields of environmental purification and environmental governance.

[0076] In terms of medical and health, for example, it can be used as a surface coating of medical devices, antibacterial dressings, etc.

[0077] In the aspect of furniture supplies with antibacterial efficacy, such as antibacterial and deodorant insoles, etc.

[0078] In the aspect of purification field, such as air purifier filters, etc.

[0079] In the field of environmental governance, such as wastewater treatment, etc.

[0080] On the basis of conforming to the common knowledge in this field, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0081] The reagents and raw materials used in the present invention are all commercially available.

[0082] The positive and progressive effects of the present invention are as follows:

[0083] 1) Precise regulation of pore size by in-situ synthesis of zinc oxide:

[0084] The present invention regulates the pore structure by in-situ synthesizing zinc oxide hard template. This pore structure not only facilitates the transport and storage of lithium ions in the anode material of the battery, but also can significantly improve the adsorption performance of the material, realizing a better synergistic effect between the pore structure and multi-functions (adsorption, antibacterial, battery performance).

[0085] Specifically, in-situ synthesis enables zinc oxide to uniformly form crystal nuclei and grow in the wormwood / phenolic resin system. During the whole preparation process, the growth of zinc oxide is synchronized with the carbonization process of wormwood / phenolic resin, etc., influencing and interacting with each other. For example, in the calcination stage, it not only affects the carbonization degree of wormwood / phenolic resin and the transformation of nitrogen-containing structures, but also affects the structure and properties of zinc oxide at the same time. This synergistic effect enables zinc oxide to be precisely distributed inside the material. After the subsequent template removal, the formed pores can be highly uniformly distributed in the entire material matrix.

[0086] The uniform pore size structure provides a good channel for the insertion and extraction of lithium ions in the anode material of the battery, which is beneficial to improving the initial discharge specific capacity and can reduce the structural damage during the cycling process, thereby maintaining a high capacity retention rate.

[0087] The promoting effect of the uniform pore size structure on the adsorption performance: During the adsorption process, the uniform pore size can provide stable adsorption channels and adsorption sites, enabling adsorbate molecules of different sizes to efficiently diffuse into the material interior and be adsorbed. In contrast, some existing adsorption materials are prone to pore blockage when adsorbing macromolecular substances due to uneven pore size distribution, resulting in a rapid decrease in adsorption capacity and a reduction in adsorption efficiency. However, the material of the present invention can maintain stable and efficient adsorption performance, significantly improving the treatment ability for complex pollutant systems.

[0088] 2) Synergistic antibacterial effect of wormwood and residual zinc:

[0089] During the preparation process of the porous carbon material, part of the zinc element remains inside the material in the form of ionic state or combined with other components. When wormwood and residual zinc coexist in the material, a synergistic antibacterial effect is produced by the residual zinc element and various antibacterial components in wormwood, integrating the two functions of adsorption and antibacterial into one, expanding the application scope of the material, and improving the cost performance and practicality.

[0090] 3) Utilization of natural resources: The present invention uses natural plant wormwood as one of the raw materials, which conforms to the current concept of green environmental protection and sustainable development. In the present invention, wormwood and phenolic resin are compounded, and the nitrogen-containing characteristics and porous structure of wormwood itself are utilized to form a nitrogen-containing structure beneficial to the performance of the battery anode material, improving the initial discharge specific capacity and cycle stability, and realizing the modification of phenolic resin without additionally introducing a nitrogen source.

[0091] 4) The preparation process of the porous carbon material of the present invention is relatively simple and easy to be mass-produced industrially. It is not necessary to additionally introduce a nitrogen source, which simplifies the process.

[0092] 5) Having dual advantages of adsorption and antibacterial: The porous carbon material of the present invention can be widely used as an antibacterial material in medical and health (such as the surface coating of medical devices, antibacterial dressings, etc.), food packaging and preservation with antibacterial effects, household products (such as antibacterial and deodorant insoles, air purifier filters, etc.), and as an adsorption material in environmental purification or environmental governance (such as wastewater treatment, air purification, etc.) and other fields.

[0093] In actual application scenarios, such as wastewater treatment, the material can not only efficiently adsorb and remove impurities such as organic pollutants and heavy metal ions in water, but also kill microorganisms such as bacteria and viruses in water at the same time, avoiding the cumbersome steps of adsorption first and then disinfection in the traditional treatment process, reducing the treatment cost and the floor area of equipment, and improving the treatment efficiency and water quality safety. In the field of air purification, the material can adsorb harmful gases and particulate matters in the air, and at the same time inhibit the growth of bacteria and molds, providing clean and healthy air for the indoor environment. The integration of this adsorption and antibacterial performance enables the material to meet the requirements in a variety of complex environments, expands its application scope, and has higher cost performance and practicality compared with the existing materials with single functions.

[0094] 6) Advantages of the initial discharge specific capacity and capacity retention rate after cycling: The porous carbon material of the present invention exhibits good performance when used as the negative electrode material of a battery. Under the condition of a current density of 0.1 - 1C, the initial discharge specific capacity can reach 480 - 750 mAh / g. After 100 - 200 cycles, the capacity retention rate is 72% - 88%. Compared with many existing negative electrode materials of batteries, it has a higher initial discharge specific capacity and relatively excellent cycle stability. At the same time, the unique porous structure of the material and the synergistic effect among wormwood, phenolic resin, and zinc precursor are beneficial to stabilizing the structure of the material during the charge and discharge cycle process, reducing the structural damage during the process of lithium ion insertion and extraction, improving the cycle stability, making the material have potential application value in the battery field, and being able to provide effective support for improving the battery performance. Description of the Drawings

[0095] Figure 1 (a)- Figure 1 (e) are the antibacterial effect diagrams of the porous carbon materials prepared in Examples 1 - 3 and Comparative Examples 1 - 2 against Escherichia coli respectively.

[0096] Figure 2 is the transmission electron microscope image of the porous carbon material prepared in Example 3.

[0097] Figure 3 is the pore size distribution diagram (NLDFT model) of the porous carbon material prepared in Example 2.

[0098] Figure 4 is the most probable pore size diagram (BJH model) of the porous carbon material prepared in Example 1. Detailed Embodiments

[0099] The present invention will be further illustrated below by way of examples, but the present invention is not limited to the scope of the described examples. The experimental methods without specific conditions noted in the following examples are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0100] The raw materials required for the following examples and comparative examples are all conventional commercially available products. Among them, the wormwood is purchased from Nanyang Luying Wormwood Biological Products Co., Ltd., and they are all wormwood leaves, which need to be ground into powder before use, with a particle size of 100 - 200 mesh. The zinc precursors are all purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0101] The types and dosages of the raw materials of the porous carbon materials in Examples 1 - 3 and Comparative Examples 1 - 2 are shown in Table 1. Unless otherwise specified, the dosages in the following tables are all in parts by mass.

[0102] Table 1

[0103]

[0104] In Examples 1-3, the type of wormwood is Artemisia argyi Levl. et Vant. var. chinensis (H. Lév.) Hsiao & K. M. Hu

[0105] Example 1

[0106] The preparation method of the porous carbon material comprises the following steps:

[0107] S1 Preparation of wormwood / phenolic resin: Wormwood, phenol, sodium hydroxide, formaldehyde, and hydrochloric acid are stirred at room temperature for 3 h at a stirring rate of 400 r / min according to the above ratio, and the pH value is 4. It is dried at 70 °C for 3 h to obtain wormwood / phenolic resin. Among them, the mass ratio of wormwood:phenol:sodium hydroxide:formaldehyde:hydrochloric acid is 1:1.5:0.2:1.5:0.15.

[0108] S2 Preparation of zinc oxide: 5 parts of zinc acetate are dissolved in 15 parts of ethanol, 4 parts of NaOH are added, and it is stirred at room temperature for 2.5 h, and the pH value is 10. It is poured into a 150 mL reaction kettle and heated and mixed at 150 °C for 9 h. After the reaction is completed, the supernatant is poured off, and the white precipitate at the bottom is the zinc oxide precipitate. Among them, the weight ratio of zinc acetate:ethanol:sodium hydroxide is 1:3:0.8.

[0109] S3 Preparation of porous carbon: Ethanol is added dropwise to the zinc oxide precipitate with a dropper, and after dispersion, it is transferred to a small beaker and stirred in a water bath at 60 °C for 10 min. Wormwood / phenolic resin is added dropwise (the weight ratio of zinc oxide to wormwood / phenolic resin is 0.3), and it is mixed and reacted and stirred at 60 °C for 2 h. When mixing and reacting, the mouth of the reaction container can be sealed with a plastic film to prevent excessive volatilization of the solvent.

[0110] After the mixing reaction is completed, the product is poured into a glass petri dish for drying, the mouth of the petri dish is sealed with tinfoil, holes are pricked for ventilation, and it is placed in a blast drying oven and heated at 100 °C for 3 h.

[0111] The dried product is scraped off and ground thoroughly. The obtained powder is kept at 700 °C for 2 h in a tube furnace, the heating rate is 8 °C / min, and the nitrogen flow rate is 40 cc / min.

[0112] The black product is collected, stirred with 1 mol / L hydrochloric acid for 5 h, filtered, washed with water until neutral, and dried to obtain the porous carbon material.

[0113] Example 2

[0114] The preparation method of the porous carbon material comprises the following steps:

[0115] S1 Preparation of wormwood / phenolic resin: Wormwood, phenol, sodium hydroxide, formaldehyde, and hydrochloric acid are stirred at room temperature for 2.5 h at a stirring rate of 350 r / min according to the ratio, the pH value is 3.5, and it is dried at 65 °C for 2.5 h to obtain wormwood / phenolic resin. Among them, the weight ratio of wormwood:phenol:sodium hydroxide:formaldehyde:hydrochloric acid is 1:2.33:0.2:2.33:0.13.

[0116] Preparation of ZnO: Dissolve 8 parts of zinc nitrate in 12 parts of ethanol, add 3 parts of NaOH, stir at room temperature for 2 h with a pH value of 9.5, pour into a 120 mL reaction kettle, and heat and mix at 160 °C for 10 h. After the reaction, pour off the supernatant, and the white precipitate at the bottom is the ZnO precipitate. Among them, the weight ratio of zinc nitrate, ethanol, and sodium hydroxide is 1:1.5:0.375.

[0117] Preparation of porous carbon: Use a dropper to add ethanol to the ZnO precipitate, transfer it to a small beaker after dispersion, stir in a water bath at 60 °C for 10 min, add wormwood / phenol formaldehyde resin (the weight ratio of ZnO and wormwood / phenol formaldehyde resin is 0.4) and mix, and stir at 60 °C for 2 h. When mixing and reacting, a plastic film can be used to seal the mouth of the reaction vessel to prevent excessive volatilization of the solvent.

[0118] After the mixing reaction is completed, pour the product onto a glass watch glass for drying, seal the mouth of the watch glass with tin foil, pierce holes for ventilation, and place it in a forced-air oven and heat at 90 °C for 2.5 h.

[0119] Scrape off the dried product and grind it thoroughly. Keep the obtained powder in a tube furnace at 750 °C for 2.5 h, with a heating rate of 9 °C / min and a nitrogen flow rate of 35 cc / min.

[0120] Collect the black product, stir with 1.5 mol / l hydrochloric acid for 5 h, filter and wash with water until neutral, and dry to obtain the porous carbon material.

[0121] Example 3

[0122] The preparation method of the porous carbon material includes the following steps:

[0123] Preparation of wormwood / phenol formaldehyde resin: Mix wormwood, phenol, sodium hydroxide, formaldehyde, and hydrochloric acid in the above proportions and stir at a stirring rate of 450 r / min at room temperature for 3.5 h with a pH value of 4.5, and dry at 75 °C for 3.5 h to obtain wormwood / phenol formaldehyde resin. Among them, the weight ratio of wormwood:phenol:sodium hydroxide:formaldehyde:hydrochloric acid is 1:1:0.2:1:0.16.

[0124] Preparation of ZnO: Dissolve 7 parts of zinc citrate in 18 parts of ethanol, add 5 parts of NaOH, stir at room temperature for 3 h with a pH value of 10.5, pour into an 180 mL reaction kettle, and heat and mix at 140 °C for 8 h. After the reaction, pour off the supernatant, and the white precipitate at the bottom is the ZnO precipitate. Among them, the weight ratio of zinc citrate, ethanol, and sodium hydroxide is 1:2.57:0.71.

[0125] Preparation of S3 porous carbon: Use a dropper to add ethanol to the zinc oxide precipitate. After dispersion, transfer it to a small beaker, stir in a water bath at 60 °C for 10 min, add wormwood / phenolic resin (the weight ratio of zinc oxide to wormwood / phenolic resin is 0.25), and stir for 2 h at 60 °C for the mixing reaction. When mixing and reacting, a plastic film can be used to seal the mouth of the reaction vessel to prevent excessive evaporation of the solvent.

[0126] After the mixing reaction is completed, pour the product onto a glass watch glass for drying, seal the mouth of the watch glass with tinfoil, pierce holes for ventilation, and place it in a forced-air oven and heat at 110 °C for 3.5 h.

[0127] Scrape off the dried product and grind it thoroughly. Keep the obtained powder in a tube furnace at 650 °C for 3 h, with a heating rate of 6 °C / min and a nitrogen flow rate of 45 cc / min.

[0128] Collect the black product, stir it with 0.8 mol / l hydrochloric acid for 5 h, filter and wash with water until neutral, and dry to obtain the porous carbon material.

[0129] Examples 4 - 5

[0130] Compared with Example 1, in this example, only wormwood is replaced with 20 parts of Artemisia vulgaris and 20 parts of Artemisia indica respectively, and other components and dosages remain unchanged. The preparation process and conditions are the same as those in Example 1.

[0131] Examples 6 - 9

[0132] Compared with Example 1, in this example, only the dosages of wormwood are replaced with 10 parts, 15 parts, 25 parts, and 30 parts respectively, and other components and dosages remain unchanged. The preparation process and conditions are the same as those in Example 1.

[0133] Example 10

[0134] Compared with Example 1, the difference in this example is only that zinc acetate in S2 is replaced with an equal amount of zinc propionate. Other components and dosages remain unchanged, and the preparation process and conditions are the same as those in Example 1.

[0135] Comparative Example 1 (without wormwood)

[0136] Compared with Example 2, the difference is only that wormwood is not added, and other operations and conditions are the same as those in Example 2.

[0137] Comparative Example 2 (without zinc precursor)

[0138] Compared with Example 2, the difference is only that the zinc precursor is not added, and other operations and conditions are the same as those in Example 2.

[0139] Effect Example

[0140] 1. Specific surface area

[0141] Testing instrument: Guoyi Quantum UltraSorb X800 high-performance micropore analyzer.

[0142] Testing standard: GB / T 19587-2017 "Determination of Specific Surface Area of Solid Substances by Gas Adsorption BET Method".

[0143] Testing method: Nitrogen adsorption-desorption method (BET method) is adopted. The sample is subjected to vacuum degassing treatment at a certain temperature to remove the adsorbed impurities on the surface. Then, at the liquid nitrogen temperature (77K), nitrogen is adsorbed and desorbed on the surface of the sample. By measuring the nitrogen adsorption amount at different relative pressures, the specific surface area of the sample is calculated using the BET equation.

[0144] 2. Pore volume

[0145] Testing instrument: Guoyi Quantum UltraSorb X800 high-performance micropore analyzer.

[0146] Testing standard: ISO 15901 - 1:2005 "Porosity of solid materials - Determination of pore size distribution and specific surface area by gas adsorption - Part 1: Analysis of physisorption data obtained by nitrogen adsorption".

[0147] Testing method: Based on the nitrogen adsorption-desorption isotherm, the pore volume is calculated by the NLDFT theoretical method.

[0148] 3. Antibacterial rate

[0149] Testing instrument: Conventional microbial culture and detection equipment, such as constant temperature incubator, microscope, etc.

[0150] Testing standard: GB / T 21510-2008 "Testing Method for Antibacterial Properties of Nano-inorganic Materials".

[0151] Testing method: The plate diffusion method is adopted. The test bacteria (such as Escherichia coli, Staphylococcus aureus, etc.) are inoculated on the nutrient agar plate, and then the filter paper containing a certain amount of porous carbon material (100g) is placed on the plate. It is cultured at 37°C for 24h, the size of the inhibition zone is measured, and the antibacterial rate is calculated by comparing with the blank control.

[0152] 4. Powder resistivity

[0153] Testing instrument: Four-probe tester.

[0154] Test standard: Refer to the relevant part of resistivity test in "Fire hazard testing for electric and electronic products - Part 23: Test method for material flammability - Determination of comparative tracking index (CTI) and proof tracking index (PTI) of electrical insulating materials" in GB / T 5169.23 - 2015.

[0155] Test method: Adopt the four - probe method. Press the sample powder into a thin sheet with a certain shape and size, place it on the sample stage of the four - probe tester, apply a certain current to the sample through the four - probe tester, measure the voltage drop between two points on the sample, calculate the resistance of the sample according to Ohm's law, and then calculate the powder resistivity in combination with the size of the sample.

[0156] 5. Electrochemical performance test

[0157] Battery model and preparation method: Use button cells (such as CR2032) as test batteries. Mix porous carbon materials, conductive agents (such as acetylene black) and binders (such as polyvinylidene fluoride, PVDF) in a certain proportion (such as 8:1:1), add an appropriate amount of N - methylpyrrolidone (NMP) to make a uniform slurry, coat it on copper foil, vacuum - dry it at a certain temperature (such as 120 °C) for a certain time (such as 12 h), and then punch it into circular electrode sheets with appropriate sizes. Use lithium sheets as counter electrodes, polypropylene microporous membranes (such as Celgard 2400) as diaphragms, and a mixed solution of ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC) with a concentration of 1 mol / L LiPF 6 in a volume ratio of 1:1:1 as the electrolyte, and assemble it into a button cell in a glove box filled with argon.

[0158] Test method for the first discharge specific capacity at 0.1C and 1C: The assembled battery is subjected to charge - discharge tests on the LAND battery test system. Perform the first charge - discharge cycle at a current density of 0.1C and 1C within a certain voltage range (such as 0.013V), record the voltage and current changes during discharge, calculate the discharge capacity according to the discharge time and current, and then divide it by the mass of the electrode material to obtain the first discharge specific capacity.

[0159] Test method for the capacity retention rate at 100 and 200 cycles: After completing the first charge - discharge, continue to perform cyclic charge - discharge tests at a specific current density (such as 0.5C) within the same voltage range. Record the discharge capacities of the 100th and 200th cycles respectively, and calculate the capacity retention rate compared with the first discharge capacity.

[0160] Figure 1 (a)- Figure 1(e) Antibacterial effect diagrams of the porous carbon materials prepared in Examples 1-3 and Comparative Examples 1-2 against Escherichia coli. This shows that the porous carbon materials containing wormwood and zinc precursors (Examples 1-3) have a significant antibacterial effect against Escherichia coli and a high antibacterial rate; while the antibacterial effect of the porous carbon materials without wormwood (Comparative Example 1) or without zinc precursors (Comparative Example 2) is significantly reduced, indicating that wormwood and zinc precursors play an important role in synergistic antibacterial action.

[0161] Figure 2 TEM image of the porous carbon material prepared in Example 3. Figure 2 The layered structure of the carbon skeleton and the pores distributed therein can be clearly seen. The edges of the pores are relatively smooth and are tightly combined with the surrounding carbon matrix. This shows that the porous carbon material has a rich pore structure, and these pores are interconnected to form a three-dimensional network-like channel, which is beneficial to the transport and adsorption of substances.

[0162] Figure 3 Pore size distribution diagram (NLDFT model) of the porous carbon material prepared in Example 2. The pore size distribution of the porous carbon material is relatively uniform, mainly concentrated in the mesopore range, and the average pore size is about 3-5 nm. The pore size distribution curve shows a narrow single-peak distribution. This uniform pore size distribution is beneficial to the diffusion and adsorption of adsorbate molecules inside the material, and also provides a stable and suitable channel for the transport of lithium ions in battery applications.

[0163] Figure 4 Most probable pore size diagram (BJH model) of the porous carbon material prepared in Example 1. This shows that the porous carbon material prepared in Example 1 has a relatively concentrated most probable pore size, and this pore size is beneficial to the adsorption of specific-sized molecules and the transport of lithium ions, further reflecting the advantages of the pore structure of this material.

[0164] The porous carbon material of the present invention is mainly composed of carbon elements, and at the same time contains a certain amount of nitrogen element, and the nitrogen doping content is 0.8%-1.2%, and nitrogen atoms are evenly distributed in the carbon skeleton structure. It can be known through X-ray photoelectron spectroscopy (XPS) analysis that nitrogen elements exist in the carbon structure in the forms of pyridine nitrogen, pyrrole nitrogen, etc.

[0165] Table 2

[0166]

[0167] In Examples 1-10, the porous carbon material of the present invention not only has a special carbon structure formed by the composite of wormwood / phenolic resin, but also has a unique and uniform porous structure, which provides channels and active sites for the insertion and extraction of lithium ions. At the same time, the conductivity of the material itself is also beneficial to the transmission of electrons. The change in the electronic structure and the increase in active sites brought about by nitrogen doping enhance the interaction between lithium ions and the material, further improving the overall performance of the battery anode material.

[0168] Judging from the tabular data, the performance of the examples is generally better than that of the comparative examples. Comparative Example 1 (without wormwood) and Comparative Example 2 (without zinc precursor) lag far behind in various indicators, such as low specific surface area, pore volume, antibacterial rate, high powder resistivity, and poor charge-discharge capacity and cycle retention rate. Comparative Example 1 shows that the addition of wormwood plays a key role in improving the comprehensive performance of the material, especially having a significant impact on the specific surface area, antibacterial property, and electrical properties. Comparative Example 2 shows that the lack of zinc precursor affects the material in terms of specific surface area, pore volume, and battery performance, further proving the importance of zinc precursor in the process of constructing high-performance and multifunctional materials.

[0169] Examples 1-3: Example 1 performs best in most indicators, such as specific surface area, antibacterial rate, charge-discharge capacity, and cycle retention rate, etc.; Examples 2 and 3 are second, indicating that different preparation parameters (such as the type of zinc precursor, reaction conditions, etc.) have a certain impact on the performance.

[0170] Comparison of wormwood types (Examples 1, 4, 5): Qiai is used in Example 1 with better performance; Beiai in Example 4 and Haiai in Example 5 have slightly inferior performance, indicating that the type of wormwood will affect the material performance.

[0171] Comparison of wormwood dosage (Examples 1, 6-9): Within a certain range, as the wormwood dosage increases, the performance fluctuates but remains generally high. When the dosage is too much (such as 30 parts), some performances show a downward trend.

[0172] Comparison of zinc precursor types (Examples 1, 10): Zinc acetate is used in Example 1 and zinc propionate is used in Example 10. Their performances are close, but Example 1 is slightly better, indicating that the type of zinc precursor has an impact on the performance.

Claims

1. A method for preparing a porous carbon material, characterized in that: It includes the following steps: S1. Under acidic conditions, 10-30 parts by weight of wormwood, 20-40 parts by weight of phenol and 20-40 parts by weight of formaldehyde are mixed and reacted to prepare a wormwood / phenolic resin; S2 Under alkaline conditions, 3-10 parts by weight of a zinc precursor and an alcohol solvent are mixed and reacted to obtain zinc oxide; S3: mixing the solution containing the zinc oxide with the wormwood / phenolic resin, reacting, drying, and calcining.

2. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S1, the amount of wormwood is 12-28 parts, for example, 15 parts, 20 parts or 25 parts; (2) In S1, the amount of phenol is 22-38 parts, for example, 25 parts, 30 parts or 35 parts; (3) In S1, the amount of formaldehyde is 22-38 parts, for example, 25 parts, 30 parts or 35 parts; (4) In S2, the amount of the zinc precursor is 4-9 parts, for example, 5 parts, 7 parts or 8 parts; (5) In S1, during the mixing reaction, the pH value of the system is preferably 3-5, such as 3.5, 4 or 4.5; and, (6) In S2, during the mixed reaction, the pH value of the system is 9-11, for example, 9.5, 10 or 10.

5.

3. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S1, the mass ratio of the wormwood to the formaldehyde is 1:(0.8-3.5); (2) In S1, the mass ratio of the wormwood to the phenol is 1:(0.8-3.5); (3) In S2, the mass ratio of the mugwort to the zinc precursor is (1.5-6.5):1; (4) In S2, the mass ratio of the zinc precursor to the alcohol solvent is (3-10): (10-30); And, (5) in S3, the mass ratio of the zinc oxide to the mugwort / phenolic resin is (0.2-0.5):

1.

4. The method for preparing a porous carbon material according to claim 3, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S1, the mass ratio of the wormwood to the formaldehyde is 1:1, 1:1.2, 1:1.5, 1:2, 1:2.33 or 1:3; (2) In S1, the mass ratio of the wormwood to the phenol is 1:1, 1:1.2, 1:1.5, 1:2, 1:2.33 or 1:3; (3) In S2, the mass ratio of the mugwort to the zinc precursor is 1.875:1, 2:1, 3:1, 3.57:1, 4:1, 5:1 or 6:1; (4) In S2, the mass ratio of the zinc precursor to the alcohol solvent is 5:15, 8:12 or 7:18; and, (5) In S3, the mass ratio of the zinc oxide to the mugwort / phenolic resin is 0.25:1, 0.3:1 or 0.4:

1.

5. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S1, the mugwort is selected from one or more of Artemisia argyi, Artemisia argyi and Artemisia argyi; (2) In S1, the wormwood is in the form of wormwood powder; the particle size of the wormwood powder is preferably 100-200 mesh; (3) In S2, the zinc precursor is selected from one or more of zinc nitrate, zinc acetate, zinc sulfate, zinc citrate, zinc carbonate, zinc oxalate, zinc phosphate, zinc propionate, zinc thiosulfate and zinc halide, preferably zinc nitrate, zinc acetate, zinc propionate, zinc citrate or zinc oxalate; and, (4) In S2, the alcohol solvent is one or more of methanol, isopropanol and ethanol.

6. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S1, the mixing reaction is carried out by mechanical stirring or ultrasonic mixing; When mechanical stirring is used, the stirring rate is preferably 300-500 r / min, such as 350 r / min, 400 r / min or 450 r / min; the mechanical stirring time is preferably 2-4 h, such as 2.5 h or 3.5 h; (2) In S1, the mixed reaction product is dried, and the drying temperature is preferably 60-80° C. and the drying time is preferably 2-4 hours; and, (3) In S1, sodium hydroxide or hydrochloric acid is added to adjust the pH value of the system; the amount of sodium hydroxide added is preferably 3-8 parts, such as 3 parts, 4 parts or 5 parts; the amount of hydrochloric acid added is preferably 1-5 parts, such as 2, 3 or 4 parts; The mass ratio of wormwood to sodium hydroxide is preferably 1:(0.12-0.5), such as 1:0.13, 1:0.16, 1:0.2, 1:0.27 or 1:0.4; The mass ratio of mugwort to hydrochloric acid is preferably 1:(0.08-0.4), for example 1:0.1, 1:0.12, 1:0.13, 1:0.15, 1:0.16, 1:0.2 or 1:0.

3.

7. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies the following conditions (1) and / or (2): (1) In S2, the pH value of the system is adjusted by adding a base; the base is sodium hydroxide or potassium hydroxide; In S2, when adjusting the pH value of the system, the mass ratio of the zinc precursor to the base is preferably 1:(0.375-0.8), for example, 1:0.8, 1:0.375 or 1:0.714; (2) In S2, the mixing reaction includes: stirring at room temperature and then drying in a forced air oven; When a forced air oven is used, the temperature is preferably 120-180°C; the time is preferably 6-12h; Preferably, in S2, the zinc oxide is prepared by the following steps: dissolving 3-10 parts of zinc precursor in 10-30 parts of ethanol, adding 3-8 parts of NaOH, stirring at room temperature for 2-3 hours to completely dissolve the NaOH, then pouring the solution into a 100-200 mL reactor, and heating in a forced air oven at 120-180° C. for 6-12 hours.

8. The method for preparing a porous carbon material according to claim 1, characterized in that: The method for preparing the porous carbon material satisfies one or more of the following conditions: (1) In S3, the method for preparing the solution containing the zinc oxide comprises: dissolving the zinc oxide in an alcohol solvent; the alcohol solvent is preferably one or more of methanol, isopropanol and ethanol; (2) In S3, the wormwood / phenolic resin is added dropwise to the solution containing the zinc oxide; (3) In S3, the temperature of the mixed reaction is 50-70°C, for example, 60°C; (4) In S3, the mixing reaction time is 1-3 hours, for example, 2 hours; (5) In S3, the drying is carried out in a blast oven; the drying temperature is preferably 80-120° C.; and the drying time is preferably 2-4 hours; (6) In S3, the calcination is carried out in a tubular furnace; (7) In S3, the calcination temperature is 600-800°C, for example, 650°C, 700°C or 750°C; (8) In S3, the calcination time is 1-3 h, for example, 2 h, 2.5 h or 3 h; (9) In S3, the heating rate to the calcination temperature is 5-10°C / min, for example, 6°C / min, 8°C / min or 9°C / min; and, (10) In S3, during the calcination process, when nitrogen is used as the protective gas, the nitrogen flow rate is 30-50 cc / min, for example, 35 cc / min, 40 cc / min or 45 cc / min; Preferably, the calcination operation comprises the following steps: in a tube furnace, maintaining 600-800°C for 1-3h, a heating rate of 5-10°C / min, and a nitrogen flow rate of 30-50cc / min.

9. A porous carbon material obtained by the method for preparing a porous carbon material according to any one of claims 1 to 8; The pore size of the porous carbon material is preferably 2-50 nm; The pore volume of the porous carbon material is preferably 0.42 cm³ / g-0.61 cm³ / g; The specific surface area of ​​the porous carbon material is preferably 801m² / g-1158m² / g; The antibacterial rate of the porous carbon material against Escherichia coli is preferably 92%-96%; The powder resistivity of the porous carbon material is preferably 0.4Ω•cm-0.6Ω•cm.

10. An application of the porous carbon material as claimed in claim 9 as an antibacterial material in medical and health care, food packaging or household products with antibacterial efficacy, as a negative electrode material in the field of battery materials, or as an adsorption material in the field of environmental purification and environmental management.

Images