Preparation method of porous carbon
By using shrimp shells as raw material and employing potassium hydroxide sintering and acidification treatment to prepare porous carbon, the application problem of shrimp shell raw material in supercapacitor electrode materials has been solved, and the industrial production of high-performance porous carbon has been realized.
Patent Information
- Application Number
- CN202511960278.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-02-10
AI Technical Summary
There are no reports in the current technology of preparing high-performance porous carbon from shrimp shells, especially in the application of supercapacitor electrode materials.
Shrimp shells were washed with deionized water, crushed, mixed with potassium hydroxide, and sintered in a tube furnace under a carbon dioxide atmosphere. Then, they were treated with hydrochloric acid to prepare porous carbon.
The prepared porous carbon exhibits excellent cycle stability and high specific capacitance as a supercapacitor electrode material, making it suitable for industrial production.
Smart Images
Figure CN121493977A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of porous carbon preparation technology, and specifically to a method for preparing porous carbon. Background Technology
[0002] Faced with the increasing consumption of fossil fuels and environmental pollution, renewable energy has been vigorously developed and utilized in recent years. However, renewable energy is limited in time and space, and must be converted and stored to be effectively utilized. Therefore, energy conversion and storage technologies have become a research hotspot in the field of new energy. Supercapacitors stand out among many energy storage devices due to their long cycle life, high power density, and good safety performance. Among the various electrode materials available for supercapacitors, porous carbon materials, with their high specific surface area and good chemical stability, are widely used as the preferred electrode material. To further improve the electrochemical performance of supercapacitors, the research and development of porous carbon electrode materials that are easy to prepare, have high energy density, and are low in cost is an urgent issue to be addressed.
[0003] Porous carbon refers to carbon materials with different pore structures, the pore size of which can be adjusted according to the selection of raw materials and the preparation process. Studies have shown that porous carbon has advantages such as good thermal stability, acid and alkali resistance, electrical conductivity, and thermal conductivity, and can be used in adsorption separation, catalysis, energy storage, and bioengineering materials. Porous carbon can be prepared from a variety of raw materials, with waste marine biomass being one of the ideal raw materials. Using waste marine biomass as a raw material to prepare porous carbon can effectively reduce the direct discharge of waste into nature and the resulting environmental pollution, while obtaining high-value-added porous carbon products, making it an effective method of waste utilization.
[0004] Shrimp shells are an abundant and inexpensive source of raw materials. However, there are currently no reports on the preparation of porous carbon from shrimp shells, especially high-performance porous carbon. Therefore, developing a method for preparing porous carbon from shrimp shells, particularly a high-performance porous carbon, has significant application value. Summary of the Invention
[0005] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a method for preparing porous carbon.
[0006] The above-mentioned technical problem to be solved by the present invention is achieved through the following technical solution:
[0007] A method for preparing porous carbon, comprising the following steps:
[0008] (1) Wash the shrimp shells with deionized water, dry the shrimp shells, crush the shrimp shells, and pass them through a 150-mesh sieve to obtain shrimp shell powder;
[0009] (2) Mix shrimp shell powder and potassium hydroxide in a mass ratio of 1:4 to 1:1;
[0010] (3) Pour the mixture of shrimp shell powder and potassium hydroxide into a corundum crucible, place the corundum crucible in a tube furnace, raise the temperature to 700-1000 ℃ at a heating rate of 2-5 ℃ under a carbon dioxide atmosphere, and sinter at a constant temperature for 2-4 hours.
[0011] (4) Soak the sintered material in 0.5~1 mol / L hydrochloric acid for 2~5 hours, then wash it with deionized water until neutral, and dry it to obtain porous carbon.
[0012] This invention provides, for the first time, a method for preparing porous carbon using shrimp shells as raw material. Through extensive experimentation, the inventors surprisingly discovered that porous carbon prepared by thoroughly mixing shrimp shell powder with potassium hydroxide, followed by a pore-forming reaction, and then acidification treatment, exhibits high specific capacitance and cycling stability when used as an electrode material for supercapacitors. Specific experimental studies show that when used as a supercapacitor electrode material in organic electrolytes, it exhibits high specific capacitance, and after 30,000 cycles, no significant decrease in specific capacitance was observed, demonstrating excellent cycling performance.
[0013] Furthermore, the inventors emphasize that the three reaction steps described in this invention are crucial and indispensable. The porous carbon prepared without any one of these steps will not possess excellent cycle performance when used as an electrode material for supercapacitors. Using shrimp shells as raw material, the porous carbon prepared through three steps—first, thoroughly mixing the shrimp shell powder with potassium hydroxide, then undergoing a pore-forming reaction, and finally, acidification treatment—is essential for its excellent cycle performance when used as an electrode material for supercapacitors.
[0014] Preferably, the raw material mentioned in step (1) is shrimp shells.
[0015] Preferably, the mixing method of shrimp shell powder and potassium hydroxide in step (2) is: stirring and ball milling.
[0016] Preferably, the pore-forming agent in step (2) is composed of potassium hydroxide and carbon dioxide.
[0017] Preferably, the mass ratio of shrimp shell powder to potassium hydroxide in step (2) is 1:4 to 1:1.
[0018] Preferably, the heating rate of the tubular furnace in step (3) is 2~5 °C.
[0019] Preferably, the sintering temperature of the tubular furnace in step (3) is 700~1000 ℃.
[0020] Preferably, the sintering time of the tubular furnace in step (3) is 2 to 4 hours.
[0021] Preferably, the pickling agent in step (4) is 0.5~1 mol / L hydrochloric acid.
[0022] Preferably, the pickling time in step (4) is 2 to 5 hours.
[0023] Preferably, the drying method in step (4) is: vacuum drying, forced air drying, or spray drying.
[0024] The inventors discovered that the choice of pore-forming agent plays a crucial role in the excellent cycling performance of the prepared porous carbon when used as an electrode material for supercapacitors, during the preparation of porous carbon using the method described in this invention. Surprisingly, the inventors found that when potassium hydroxide and carbon dioxide were used as pore-forming agents, the prepared porous carbon exhibited superior cycling performance when used as an electrode material for supercapacitors. Its cycling performance was significantly higher than that of porous carbon prepared using potassium carbonate and carbon dioxide or zinc chloride and carbon dioxide. When potassium hydroxide and carbon dioxide were used as pore-forming agents, they could combine with calcium carbonate contained in shrimp shells to form a mixed pore-forming agent, which could synergistically create pores and produce porous carbon with excellent performance.
[0025] Beneficial Effects: This invention provides a novel method for preparing porous carbon using shrimp shells as raw material. The method involves three steps: first, thoroughly mixing shrimp shell powder with potassium hydroxide; then, subjecting it to a pore-forming reaction; and finally, acidification treatment. The resulting porous carbon exhibits high specific capacitance and cycle stability when used as an electrode material for supercapacitors. Furthermore, the method described in this invention is simple to operate, operates under mild conditions, has low extraction costs, and produces high-purity products, making it suitable for industrial-scale production. Attached Figure Description
[0026] Figure 1 This is a transmission electron microscope image of the porous carbon prepared in Example 1 of the present invention. Detailed Implementation
[0027] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.
[0028] Example 1
[0029] Shrimp shells were washed clean with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0030] Example 2
[0031] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:1. The mixture was poured into an alumina crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0032] The difference between Example 2 and Example 1 is that in Example 2, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:1; while in Example 1, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:3.
[0033] Example 3
[0034] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:2. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0035] The difference between Example 3 and Example 1 is that in Example 3, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:2, while in Example 1, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:3.
[0036] Example 4
[0037] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:4. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900℃ at a heating rate of 3℃, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0038] The difference between Example 4 and Example 1 is that in Example 4, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:4, while in Example 1, the shrimp shell powder and potassium hydroxide are mixed in a mass ratio of 1:3.
[0039] Example 5
[0040] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 700°C at a heating rate of 3°C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0041] The difference between Example 5 and Example 1 is that the sintering temperature of the tube furnace in Example 5 is 700 ℃, while the sintering temperature of the tube furnace in Example 1 is 900 ℃.
[0042] Example 6
[0043] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 800℃ at a heating rate of 3℃, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0044] The difference between Example 6 and Example 1 is that the sintering temperature of the tube furnace in Example 6 is 800 ℃, while the sintering temperature of the tube furnace in Example 1 is 900 ℃.
[0045] Example 7
[0046] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 1000℃ at a heating rate of 3℃, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0047] The difference between Example 7 and Example 1 is that the sintering temperature of the tube furnace in Example 7 is 1000 ℃, while the sintering temperature of the tube furnace in Example 1 is 900 ℃.
[0048] Example 8
[0049] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C and sintered at this temperature for 2 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0050] The difference between Example 8 and Example 1 is that the sintering time of the tube furnace in Example 8 is 2 hours, while the sintering time of the tube furnace in Example 1 is 3 hours.
[0051] Example 9
[0052] Shrimp shells were washed clean with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C and sintered at this temperature for 4 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0053] The difference between Example 9 and Example 1 is that the sintering time of the tube furnace in Example 9 is 4 hours, while the sintering time of the tube furnace in Example 1 is 3 hours.
[0054] Comparative Example 1
[0055] Shrimp shells were washed clean with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture of shrimp shell powder and potassium carbonate was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0056] The difference between Comparative Example 1 and Example 1 is that potassium carbonate is used as the pore-forming agent in Comparative Example 1, while potassium hydroxide is used as the pore-forming agent in Example 1.
[0057] Comparative Example 2
[0058] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture of shrimp shell powder and zinc chloride was poured into an alumina crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0059] The difference between Comparative Example 2 and Example 1 is that zinc chloride is used as the pore-forming agent in Comparative Example 2, while potassium hydroxide is used as the pore-forming agent in Example 1.
[0060] Comparative Example 3
[0061] Coconut shells were washed with deionized water, dried, crushed, and passed through a 150-mesh sieve to obtain coconut shell powder. The coconut shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900℃ at a heating rate of 3℃, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0062] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses coconut shells as raw materials, while Example 1 uses shrimp shells as raw materials.
[0063] Comparative Example 4
[0064] Bamboo was washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain bamboo powder. The bamboo powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into a corundum crucible, which was placed in a tube furnace. Under a carbon dioxide atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0065] The difference between Comparative Example 4 and Example 1 is that bamboo was used as the raw material in Comparative Example 4, while shrimp shells were used as the raw material in Example 1.
[0066] Comparative Example 5
[0067] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into an alumina crucible, which was placed in a tube furnace. Under a nitrogen atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0068] The difference between Comparative Example 5 and Example 1 is that nitrogen was used as the reaction atmosphere in Comparative Example 5, while carbon dioxide was used as the reaction atmosphere in Example 1.
[0069] Comparative Example 6
[0070] Shrimp shells were washed with deionized water, dried, pulverized, and passed through a 150-mesh sieve to obtain shrimp shell powder. The shrimp shell powder and potassium hydroxide were mixed at a mass ratio of 1:3. The mixture was poured into an alumina crucible, which was placed in a tube furnace. Under an argon atmosphere, the temperature was raised to 900 °C at a heating rate of 3 °C, and sintered at this temperature for 3 hours. The sintered material was then soaked in 1 mol / L hydrochloric acid for 2 hours, washed with deionized water until neutral, and dried to obtain porous carbon.
[0071] The difference between Comparative Example 6 and Example 1 is that argon is used as the reaction atmosphere in Comparative Example 6, while carbon dioxide is used as the reaction atmosphere in Example 1.
[0072] When the porous carbon prepared in Examples 1-9 and Comparative Examples 1-6 were used as electrode materials for supercapacitors, the performance of the organic system was tested. The specific capacitance (F / g) after 30,000 cycles was tested, and the results are shown in Table 1.
[0073] Table 1
[0074] The specific capacitance (F / g) of a supercapacitor electrode after 30,000 cycles. Porous carbon prepared in Example 1 158 Porous carbon prepared in Example 2 102 Porous carbon prepared in Example 3 113 Porous carbon prepared in Example 4 115 Porous carbon prepared in Example 5 98 Porous carbon prepared in Example 6 126 Porous carbon prepared in Example 7 119 Porous carbon prepared in Example 8 116 Porous carbon prepared in Example 9 123 Porous carbon prepared in Comparative Example 1 89 Porous carbon prepared in Comparative Example 2 76 Porous carbon prepared in Comparative Example 3 93 Porous carbon prepared in Comparative Example 4 86 Porous carbon prepared in Comparative Example 5 82 Porous carbon prepared in Comparative Example 6 87
[0075] As shown in Table 1, the specific capacitance of the porous carbon prepared in Example 1 after 30,000 cycles as a supercapacitor electrode material is 158 F / g, which is significantly higher than that of the porous carbon prepared in Examples 2-4. This indicates that the porous carbon prepared using the method described in this invention, with shrimp shells as raw material and shrimp shell powder and potassium hydroxide in a mass ratio of 1:3, exhibits excellent cycling performance and a high specific capacitance as a supercapacitor electrode material. It also indicates that when the mass ratio of shrimp shell powder to potassium hydroxide is 1:1 and 1:2, the amount of potassium hydroxide added is insufficient, resulting in poor pore-forming effect of potassium hydroxide and carbon dioxide with the calcium carbonate contained in the shrimp shell, leading to insufficient pore-forming capacity. When the mass ratio of shrimp shell powder to potassium hydroxide is 1:4, the amount of potassium hydroxide added is excessive, and the synergistic pore-forming effect of potassium hydroxide and carbon dioxide with the calcium carbonate contained in the shrimp shell has a significant destructive effect, resulting in excessive pore-forming and damage to the porous carbon structure. Furthermore, this also illustrates that the three reaction steps in the method described in this invention are crucial and indispensable; the absence of any one step will prevent the preparation of porous carbon. The porous carbon prepared by using shrimp shells as raw material, first thoroughly mixing shrimp shell powder with potassium hydroxide, then undergoing a pore-forming reaction, and finally acidification treatment, exhibits excellent cycle performance when used as an electrode material for supercapacitors.
[0076] The porous carbon prepared in Examples 5-7, when used as a supercapacitor electrode material, exhibited a significantly lower specific capacitance after 30,000 cycles compared to the porous carbon prepared in Example 1. This indicates that the selection of the tubular furnace sintering temperature plays a crucial role in determining the excellent cycling performance of the prepared porous carbon when used as a supercapacitor electrode material during the preparation of porous carbon using the method described in this invention. When the tubular furnace sintering temperature is 900 °C, the prepared porous carbon exhibits excellent cycling performance when used as a supercapacitor electrode material. Sintering temperatures of 700 °C and 800 °C are too low, resulting in insufficient pore formation in the porous carbon. A sintering temperature of 1000 °C is too high, leading to the collapse of the porous carbon structure.
[0077] The specific capacitance of the porous carbon prepared in Examples 8 and 9 after 30,000 cycles as a supercapacitor electrode material is significantly lower than that of the porous carbon prepared in Example 1. This indicates that the selection of the tubular furnace sintering time plays a crucial role in the excellent cycling performance of the prepared porous carbon when used as a supercapacitor electrode material during the preparation of porous carbon using the method described in this invention. When the tubular furnace sintering time is 3 hours, the prepared porous carbon exhibits excellent cycling performance when used as a supercapacitor electrode material. When the tubular furnace sintering time is 2 hours, the sintering activation time is too short, resulting in insufficient pore formation in the porous carbon. When the tubular furnace sintering time is 4 hours, the sintering activation time is too long, leading to severe damage to the porous carbon structure.
[0078] The specific capacitance of the porous carbon prepared in Comparative Examples 1 and 2 after 30,000 cycles as a supercapacitor electrode material was significantly lower than that of the porous carbon prepared in Example 1. This indicates that the choice of pore-forming agent plays a crucial role in the excellent cycling performance of the prepared porous carbon when used as a supercapacitor electrode material during the preparation of porous carbon using the method described in this invention. When potassium hydroxide and carbon dioxide are used as the pore-forming agent, the prepared porous carbon exhibits excellent cycling performance when used as a supercapacitor electrode material. When potassium carbonate and carbon dioxide or zinc chloride and carbon dioxide are used as the pore-forming agent, the performance of the prepared porous carbon is poor.
[0079] The porous carbon prepared in Comparative Examples 3 and 4, when used as electrode materials for supercapacitors, exhibited significantly lower specific capacitance after 30,000 cycles compared to the porous carbon prepared in Example 1. This demonstrates that the selection of raw materials plays a crucial role in the excellent cycling performance of the prepared porous carbon when used as an electrode material for supercapacitors, during the preparation of porous carbon using the method described in this invention. When shrimp shells were used as the raw material, the prepared porous carbon exhibited excellent cycling performance when used as an electrode material for supercapacitors. When coconut shells or bamboo were used as the raw material, the performance of the prepared porous carbon was very poor.
[0080] The porous carbons prepared in Comparative Examples 5 and 6, when used as electrode materials for supercapacitors, exhibited significantly lower specific capacitance after 30,000 cycles compared to the porous carbon prepared in Example 1. This indicates that the choice of reaction atmosphere plays a crucial role in determining the excellent cycling performance of the prepared porous carbon when used as an electrode material for supercapacitors, during the preparation of porous carbon using the method described in this invention. When carbon dioxide is used as the reaction atmosphere, the prepared porous carbon exhibits excellent cycling performance when used as an electrode material for supercapacitors. When nitrogen or argon is used as the reaction atmosphere, the performance of the prepared porous carbon is poor.
Claims
1. A method for preparing porous carbon, characterized in that, It includes the following steps: (1) Wash the shrimp shells with deionized water, dry the shrimp shells, crush the shrimp shells, and pass them through a 150-mesh sieve to obtain shrimp shell powder. (2) Mix shrimp shell powder and potassium hydroxide in a mass ratio of 1:4 to 1:1; (3) Pour the mixture of shrimp shell powder and potassium hydroxide into a corundum crucible, place the corundum crucible in a tube furnace, raise the temperature to 700-1000℃ at a heating rate of 2-5℃ under a carbon dioxide atmosphere, and sinter at a constant temperature for 2-4 hours. (4) Soak the sintered material in 0.5~1 mol / L hydrochloric acid for 2~5 hours, then wash it with deionized water until neutral, and dry it to obtain porous carbon.
2. The method for preparing porous carbon according to claim 1, characterized in that, The raw material mentioned in step (1) is shrimp shells.
3. The method for preparing capacitive graphene according to claim 1, characterized in that, In step (2), the specific mixing method of shrimp shell powder and potassium hydroxide is: stirring and ball milling.
4. The method for preparing porous carbon according to claim 1, characterized in that, The pore-forming agent mentioned in step (2) consists of potassium hydroxide and carbon dioxide.
5. The method for preparing porous carbon according to claim 1, characterized in that, The mass ratio of shrimp shell powder to potassium hydroxide mentioned in step (2) is 1:4 to 1:
1.
6. The method for preparing porous carbon according to claim 1, characterized in that, The heating rate of the tubular furnace described in step (3) is 2~5℃.
7. The method for preparing porous carbon according to claim 1, characterized in that, The sintering temperature of the tubular furnace mentioned in step (3) is 700~1000 ℃.
8. The method for preparing porous carbon according to claim 1, characterized in that, The sintering time for the tubular furnace mentioned in step (3) is 2 to 4 hours.
9. The method for preparing porous carbon according to claim 1, characterized in that, The pickling agent mentioned in step (4) is 0.5~1 mol / L hydrochloric acid.
10. The method for preparing porous carbon according to claim 1, characterized in that, The pickling time in step (4) is 2 to 5 hours.