Method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials

Abstract

The present application relates to the technical field of carbon-based material, specifically to a method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based material, which preparation method comprises the following steps: S1. carbon dioxide capture; S2. carbon dioxide resolution; S3. reactor pretreatment; S4. formation of carbon-based material. The present application combines solid amine adsorbent capture of CO2 in air with photocatalytic cracking technology, and constructs a continuous process of "adsorption-resolution-catalytic conversion", realizing direct conversion from low-concentration CO2 to high-value-added carbon material, and breaking through the bottleneck of separation of capture and conversion in traditional technology. At the same time, the raw materials and their preparation process of the present application do not produce toxic substances, the overall process is green and environmentally friendly, and conforms to the concept of sustainable development.

Description

Technical Field

[0001] This invention relates to the field of carbon-based materials technology, specifically to a method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials. Background Technology

[0002] Developing efficient and low-cost carbon dioxide capture and resource utilization technologies has become a research hotspot.

[0003] Currently, common CO2 capture technologies mainly include chemical absorption, physical adsorption, and membrane separation. Among these, solid amine adsorbents have attracted widespread attention due to their high selectivity and renewability, especially porous materials loaded with polyethyleneimine (PEI), such as alumina and nickel foam, which exhibit good adsorption performance for CO2 in the air at room temperature and pressure. However, existing adsorption materials still suffer from problems such as limited adsorption capacity, poor cycle stability, and high regeneration energy consumption.

[0004] On the other hand, the resource utilization of CO2 is key to achieving the "carbon cycle." Traditional CO2 conversion methods, such as thermocatalysis and electrocatalysis, typically require high temperature and high pressure conditions, resulting in high energy consumption and complex equipment. In recent years, photocatalytic CO2 cracking technology has shown great potential due to its ability to directly utilize solar energy to convert CO2 into carbon-based materials under mild conditions. Various elemental metals, due to their unique surface properties and electronic structures, exhibit excellent catalytic activity and stability in the photocatalytic CO2 cracking process.

[0005] However, there is currently no systematic method that organically combines CO2 capture with photocatalytic cracking technology to directly capture CO2 from the air and convert it into high-value-added carbon materials. Existing technologies often separate the capture and conversion stages, resulting in complex processes, low energy efficiency, and high costs.

[0006] Therefore, developing a continuous, efficient, and low-energy-consumption method for preparing carbon-based materials that integrates CO2 capture, desorption, and photocatalytic conversion is of great scientific significance and practical application value. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials includes the following preparation steps:

[0010] S1. Carbon dioxide capture: Heat the quartz tube in the carbon dioxide trap to 38-42℃ and then introduce air at a flow rate of 38-42 ml / min. Adsorb for 3-4 hours until the carbon dioxide peak area no longer changes and then stop introducing air.

[0011] S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device, introduce argon gas at a flow rate of 28-32 ml / min, exhaust for 15-20 min, then heat the heating band to 98-102℃ and keep it at that temperature for 2-3 h, desorb carbon dioxide until the peak area of ​​carbon dioxide no longer changes.

[0012] S3. Reactor pretreatment: Add microencapsulated metal catalyst to the reactor, adjust the rotation speed to 450-500 r / min, and introduce carbon dioxide obtained from step S2 at a flow rate of 48-52 ml / min for 8-10 min.

[0013] S4. Formation of carbon-based materials: Wrap the reactor with tin foil, turn on the xenon lamp, and irradiate the reaction for 22-24 hours. Then add the product to anhydrous ethanol and ultrasonically disperse for 15-20 minutes. After separating the metal catalyst and the upper anhydrous ethanol, place it in a drying oven and dry for 20-30 minutes to obtain carbon-based materials.

[0014] The preparation of microencapsulated metal catalysts includes the following steps:

[0015] S31. Under argon protection, heat the metal mixture until all metals are melted, then stir for 25-30 minutes to obtain a molten alloy;

[0016] S32. By mass, mix 19-21 parts of molten alloy, 90-100 parts of anhydrous ethanol and 0.5-0.8 parts of polyvinylpyrrolidone, and treat with an ultrasonic disruptor for 20-30 minutes to obtain a metal nanoemulsion.

[0017] S33. Mix 450-500 parts of pyrolysis modifier with metal nanoemulsion, stir magnetically at 450-500 r / min for 50-60 min, then add 90-100 parts of anhydrous ethanol and 8-10 parts of ammonia water, and continue stirring for 10-12 min.

[0018] S34. Slowly add 1.9-2.1 parts of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 25-30 minutes, react at room temperature for 22-24 hours to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them 3-4 times with anhydrous ethanol, and dry them in a vacuum drying oven at 60°C for 10-12 hours to obtain the microcapsule metal catalyst.

[0019] Preferably, the preparation of the pyrolysis modifier includes the following steps:

[0020] S331. By mass, add 5-10 parts of ethylenediamine to 450-500 parts of graphene oxide aqueous dispersion, stir at 300-500 r / min for 25-30 min, then heat to 90-95℃, continue stirring under reflux for 3-4 h, and then cool to room temperature to obtain a preliminary mixture.

[0021] S332. Add 3-5 parts of sodium borohydride to the initial mixture, stir at 300-500 r / min for 25-30 min, add 0.2-0.5 parts of polyvinylpyrrolidone, heat to 75-80℃, and continue stirring for 1-2 h to obtain the pyrolysis modifier.

[0022] Preferably, the carbon dioxide trap consists of an air generator, a flow meter, a humidifier bottle, and a quartz tube, and has good airtightness.

[0023] Preferably, the quartz tube contains a nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.5.

[0024] Preferably, the analysis device consists of an air generator, a flow meter, a humidifier bottle, a quartz tube, and a xenon lamp, and has good airtightness.

[0025] Preferably, the metal mixture consists of liquid gallium, indium particles, tin particles, and copper particles in a mass ratio of 13.8:1.2:2:3.3.

[0026] Preferably, the illuminance of the xenon lamp in step S4 is 4 W / cm². 2 .

[0027] Preferably, the frequency of ultrasonic dispersion in step S4 is 40-50 kHz.

[0028] Preferably, the ultrasonic disruptor in step S32 has a frequency of 40kHz and a power of 300W.

[0029] Preferably, the concentration of the graphene oxide aqueous dispersion in step S331 is 2 mg / ml.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. This invention combines solid amine adsorbents to capture CO2 from the air with photocatalytic cracking technology, constructing a continuous "adsorption-desorption-catalytic conversion" process. This achieves the direct conversion from low-concentration CO2 to high-value-added carbon materials, overcoming the bottleneck of separating the capture and conversion stages in traditional technologies. Furthermore, the raw materials and preparation process of this invention produce no toxic substances, making the overall process green and environmentally friendly, in line with the concept of sustainable development.

[0032] 2. The microcapsule metal catalyst of this invention utilizes a shell structure to better combine the molten alloy with the pyrolysis modifier. The synergistic effect of the two greatly promotes the rapid transfer and injection of photogenerated electrons from the catalyst to CO2 molecules, thereby significantly improving the reaction rate of CO2 pyrolysis and the yield of carbon materials. This allows the entire photocatalytic process to be carried out at room temperature and pressure, greatly reducing system energy consumption. Attached Figure Description

[0033] Figure 1 This is a process flow diagram for the preparation of carbon-based materials based on carbon dioxide capture and desorption and metal catalysis according to the present invention.

[0034] Figure 2 This is a schematic diagram of the solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to the present invention;

[0035] Figure 3 This is a linear fitting curve of CO2 peak area versus volume in this invention;

[0036] Figure 4 This is a linear fitting curve of CO2 peak area versus concentration in this invention;

[0037] Figure 5 This is a thermal imaging display of the reaction in step S4 of Embodiment 1 of the present invention;

[0038] Figure 6 The infrared spectrum of the carbon-based material obtained in Example 1 of this invention;

[0039] Figure 7 The image shows a SEM image of the carbon-based material obtained in Example 1 of this invention.

[0040] Figure 8 This is a pore size distribution diagram of the carbon-based material obtained in Example 1 of the present invention. Detailed Implementation

[0041] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] Please see Figure 1-8 The present invention provides a technical solution:

[0043] Appendix Figure 2This diagram illustrates the experimental approach of solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials. The analytical apparatus of this invention mainly consists of an air generator, a flow meter, a humidifier bottle, a quartz tube, and a xenon lamp, and features good airtightness. Special attention should be paid to the airtightness and flowability of the materials. Observe the flow rate of the flow meter, close both rotary switches, and observe whether the gas can pass through the powder to reach the tail end. Plug the two holes with quartz wool to prevent the powder from being blown away.

[0044] In this invention, air flowing from an air generator enters a drying tube through a pipeline. After the drying tube removes moisture from the air, it flows into a flow meter (which is controlled by a computer). The flow meter adjusts the gas flow rate, and the air flows into a humidification bottle. Then, it flows through a suction bottle into a quartz tube reactor. The quartz tube reactor contains adsorbent. After adsorption saturation, a heating belt is wrapped around the quartz tube, and it is heated to 100 degrees Celsius. The adsorbent begins to desorb, and the desorbed carbon dioxide flows out through the pipeline on the right side of the quartz tube. The desorption device is the same as the carbon dioxide trap, except that the desorption device uses a xenon lamp for desorption. The desorbed gas is directly fed into the reactor (large quartz tube).

[0045] Example 1

[0046] A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials:

[0047] Before preparing carbon-based materials, a pyrolysis modifier and a microcapsule metal catalyst are prepared:

[0048] The preparation of the pyrolysis modifier includes the following steps:

[0049] S331. Add 5g of ethylenediamine to 450g of graphene oxide aqueous dispersion with a concentration of 2mg / ml, stir at 300r / min for 25min, then heat to 90℃, continue stirring under reflux for 3h, and then cool to room temperature to obtain a preliminary mixture.

[0050] S332. Add 3g of sodium borohydride to the initial mixture, stir at 300r / min for 25min, add 0.2g of polyvinylpyrrolidone, heat to 75℃, and continue stirring for 1h to obtain the pyrolysis modifier.

[0051] The preparation of microencapsulated metal catalysts includes the following steps:

[0052] S31. Under argon protection, a metal mixture (composed of liquid gallium, indium granules, tin granules and copper granules in a mass ratio of 13.8:1.2:2:3.3) is heated until all metals are melted and then stirred for 25 minutes to obtain a molten alloy;

[0053] S32. Mix 19g of molten alloy, 90ml of anhydrous ethanol and 0.5g of polyvinylpyrrolidone, and treat with an ultrasonic disruptor (40kHz, 300W) for 20min to obtain a metal nanoemulsion.

[0054] S33. Mix 450 ml of pyrolysis modifier with metal nanoemulsion, stir magnetically at 450 r / min for 50 min, then add 90 ml of anhydrous ethanol and 8 ml of ammonia water, and continue stirring for 10 min.

[0055] S34. Slowly add 1.9 g of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 25 min, react at room temperature for 22 h to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them three times with anhydrous ethanol, and dry them in a vacuum drying oven at 60 °C for 10 h to obtain the microcapsule metal catalyst.

[0056] DAC Module - Solar-Powered Direct Air Capture:

[0057] S1. Carbon dioxide capture: The carbon dioxide capture device (composed of an air generator, flow meter, humidification bottle and quartz tube, with good airtightness, the quartz tube is filled with nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.5) is heated to 38°C and then air is introduced at a flow rate of 38 ml / min. The adsorption is stopped after 3 hours when the peak area of ​​carbon dioxide no longer changes.

[0058] S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device (composed of an air generator, flow meter, humidification bottle, quartz tube and xenon lamp, with good airtightness), introduce argon gas at a flow rate of 28 ml / min, exhaust for 15 min, then heat the heating belt to 98℃ and keep it at that temperature for 2 h, desorb carbon dioxide until the peak area of ​​carbon dioxide no longer changes.

[0059] CO2 Concentrating Photovoltaic Decomposition Module - Solar Concentrating Conversion to Carbon Production Materials:

[0060] S3. Reactor pretreatment: Add microcapsule metal catalyst to the reactor, adjust the rotation speed to 450 r / min, and introduce carbon dioxide obtained from desorption in step S2 at a flow rate of 48 ml / min for 8 min.

[0061] S4. Formation of carbon-based materials: The reactor is wrapped with tin foil, the xenon lamp is turned on, and the light intensity is adjusted to 4 W / cm². 2 After 22 hours of light irradiation, the product was added to anhydrous ethanol and ultrasonically dispersed at a frequency of 40 kHz for 15 minutes. After separating the metal catalyst and the upper anhydrous ethanol, the product was placed in a drying oven and dried for 20 minutes to obtain the carbon-based material.

[0062] Example 2

[0063] A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials:

[0064] Before preparing carbon-based materials, a pyrolysis modifier and a microcapsule metal catalyst are prepared:

[0065] The preparation of the pyrolysis modifier includes the following steps:

[0066] S331. Add 10g of ethylenediamine to 500g of graphene oxide aqueous dispersion with a concentration of 2mg / ml, stir at 500r / min for 30min, then heat to 95℃, continue stirring under reflux for 4h, and then cool to room temperature to obtain a preliminary mixture.

[0067] S332. Add 5g of sodium borohydride to the initial mixture, stir at 500r / min for 30min, add 0.5g of polyvinylpyrrolidone, heat to 80℃, and continue stirring for 2h to obtain the pyrolysis modifier.

[0068] The preparation of microencapsulated metal catalysts includes the following steps:

[0069] S31. Under argon protection, a metal mixture (composed of liquid gallium, indium, tin, and copper in a mass ratio of 13.8:1.2:2:3.3) is heated until all metals are melted and then stirred for 30 minutes to obtain a molten alloy;

[0070] S32. Mix 21g of molten alloy, 100ml of anhydrous ethanol and 0.8g of polyvinylpyrrolidone, and treat with an ultrasonic disruptor (40kHz, 300W) for 30min to obtain a metal nanoemulsion.

[0071] S33. Mix 500 ml of pyrolysis modifier with metal nanoemulsion, stir magnetically at 500 r / min for 60 min, then add 100 ml of anhydrous ethanol and 10 ml of ammonia water, and continue stirring for 12 min.

[0072] S34. Slowly add 2.1 g of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 30 min, react at room temperature for 24 h to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them 4 times with anhydrous ethanol, and dry them in a vacuum drying oven at 60 °C for 12 h to obtain the microcapsule metal catalyst.

[0073] DAC Module - Solar-Powered Direct Air Capture:

[0074] S1. Carbon dioxide capture: The carbon dioxide capture device (composed of an air generator, flow meter, humidification bottle and quartz tube, with good airtightness, the quartz tube is filled with nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.5) is heated to 42°C and then air is introduced at a flow rate of 42 ml / min. The adsorption is stopped after 4 hours when the peak area of ​​carbon dioxide no longer changes.

[0075] S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device (composed of an air generator, flow meter, humidification bottle, quartz tube and xenon lamp, with good airtightness), introduce argon gas at a flow rate of 32 ml / min, exhaust for 20 min, then heat the heating belt to 102℃ and keep it at that temperature for 3 h, desorb carbon dioxide until the peak area of ​​carbon dioxide no longer changes.

[0076] CO2 Concentrating Photovoltaic Decomposition Module - Solar Concentrating Conversion to Carbon Production Materials:

[0077] S3. Reactor pretreatment: Add microcapsule metal catalyst to the reactor, adjust the rotation speed to 500 r / min, and introduce carbon dioxide obtained from desorption in step S2 at a flow rate of 52 ml / min for 10 min.

[0078] S4. Formation of carbon-based materials: The reactor is wrapped with tin foil, the xenon lamp is turned on, and the light intensity is adjusted to 4 W / cm². 2 After 24 hours of light irradiation, the product was added to anhydrous ethanol and ultrasonically dispersed at a frequency of 50 kHz for 20 minutes. After separating the metal catalyst and the upper anhydrous ethanol, the product was placed in a drying oven and dried for 30 minutes to obtain the carbon-based material.

[0079] Example 3

[0080] A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials:

[0081] Before preparing carbon-based materials, a pyrolysis modifier and a microcapsule metal catalyst are prepared:

[0082] The preparation of the pyrolysis modifier includes the following steps:

[0083] S331. Add 6g of ethylenediamine to 460g of graphene oxide aqueous dispersion with a concentration of 2mg / ml, stir at 350r / min for 26min, then heat to 91℃, continue stirring under reflux for 3.5h, and then cool to room temperature to obtain a preliminary mixture;

[0084] S332. Add 3.5g sodium borohydride to the initial mixture, stir at 350r / min for 26min, add 0.3g polyvinylpyrrolidone, heat to 76℃, and continue stirring for 1.5h to obtain the pyrolysis modifier.

[0085] The preparation of microencapsulated metal catalysts includes the following steps:

[0086] S31. Under argon protection, a metal mixture (composed of liquid gallium, indium granules, tin granules, and copper granules in a mass ratio of 13.8:1.2:2:3.3) is heated until all metals are melted and then stirred for 26 minutes to obtain a molten alloy;

[0087] S32. Mix 20g of molten alloy, 92ml of anhydrous ethanol and 0.6g of polyvinylpyrrolidone, and treat with an ultrasonic disruptor (40kHz, 300W) for 21min to obtain a metal nanoemulsion;

[0088] S33. Mix 460 ml of pyrolysis modifier with metal nanoemulsion, stir magnetically at 460 r / min for 52 min, then add 92 ml of anhydrous ethanol and 8.5 ml of ammonia water, and continue stirring for 11 min.

[0089] S34. Slowly add 2g of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 26 min, react at room temperature for 23 h to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them three times with anhydrous ethanol, and dry them in a vacuum drying oven at 60℃ for 10.5 h to obtain the microcapsule metal catalyst.

[0090] DAC Module - Solar-Powered Direct Air Capture:

[0091] S1. Carbon dioxide capture: The carbon dioxide capture device (composed of an air generator, flow meter, humidification bottle and quartz tube, with good airtightness, the quartz tube is filled with nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.5) is heated to 39°C and then air is introduced at a flow rate of 39 ml / min. The adsorption is stopped after 3.5 h when the peak area of ​​carbon dioxide no longer changes.

[0092] S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device (composed of an air generator, flow meter, humidification bottle, quartz tube and xenon lamp, with good airtightness), introduce argon gas at a flow rate of 29 ml / min, exhaust for 16 min, then heat the heating belt to 99℃ and keep it at that temperature for 2.5 h, desorb carbon dioxide until the carbon dioxide peak area no longer changes.

[0093] CO2 Concentrating Photovoltaic Decomposition Module - Solar Concentrating Conversion to Carbon Production Materials:

[0094] S3. Reactor pretreatment: Add microcapsule metal catalyst to the reactor, adjust the rotation speed to 460 r / min, and introduce carbon dioxide obtained from desorption in step S2 at a flow rate of 49 ml / min for 9 min.

[0095] S4. Formation of carbon-based materials: The reactor is wrapped with tin foil, the xenon lamp is turned on, and the light intensity is adjusted to 4 W / cm². 2 After 23 hours of light irradiation, the product was added to anhydrous ethanol and ultrasonically dispersed at a frequency of 45 kHz for 16 minutes. After separating the metal catalyst and the upper anhydrous ethanol, the product was placed in a drying oven and dried for 22 minutes to obtain the carbon-based material.

[0096] Example 4

[0097] A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials:

[0098] Before preparing carbon-based materials, a pyrolysis modifier and a microcapsule metal catalyst are prepared:

[0099] The preparation of the pyrolysis modifier includes the following steps:

[0100] S331. Add 8g of ethylenediamine to 480g of graphene oxide aqueous dispersion with a concentration of 2mg / ml, stir at 450r / min for 28min, then heat to 94℃, continue stirring under reflux for 3.5h, and then cool to room temperature to obtain a preliminary mixture;

[0101] S332. Add 4.5g of sodium borohydride to the initial mixture, stir at 450r / min for 28min, add 0.4g of polyvinylpyrrolidone, heat to 78℃, and continue stirring for 1.5h to obtain the pyrolysis modifier.

[0102] The preparation of microencapsulated metal catalysts includes the following steps:

[0103] S31. Under argon protection, a metal mixture (composed of liquid gallium, indium, tin, and copper particles in a mass ratio of 13.8:1.2:2:3.3) is heated until all metals are melted and then stirred for 28 minutes to obtain a molten alloy;

[0104] S32. Mix 20g of molten alloy, 98ml of anhydrous ethanol and 0.7g of polyvinylpyrrolidone, and treat with an ultrasonic disruptor (40kHz, 300W) for 28min to obtain a metal nanoemulsion;

[0105] S33. Mix 480 ml of pyrolysis modifier with metal nanoemulsion, stir magnetically at 480 r / min for 57 min, then add 96 ml of anhydrous ethanol and 9 ml of ammonia water, and continue stirring for 11 min.

[0106] S34. Slowly add 2g of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 28min, react at room temperature for 23h to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them 4 times with anhydrous ethanol, and dry them in a vacuum drying oven at 60℃ for 11h to obtain the microcapsule metal catalyst.

[0107] DAC Module - Solar-Powered Direct Air Capture:

[0108] S1. Carbon dioxide capture: The carbon dioxide capture device (consisting of an air generator, flow meter, humidification bottle and quartz tube, with good airtightness, the quartz tube is filled with nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.5) is heated to 41°C and then air is introduced at a flow rate of 41 ml / min. The adsorption is stopped after 3.5 h when the peak area of ​​carbon dioxide no longer changes.

[0109] S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device (composed of an air generator, flow meter, humidification bottle, quartz tube and xenon lamp, with good airtightness), introduce argon gas at a flow rate of 31 ml / min, exhaust for 17 min, then heat the heating belt to 101℃ and keep it at that temperature for 2.5 h, desorb carbon dioxide until the peak area of ​​carbon dioxide no longer changes.

[0110] CO2 Concentrating Photovoltaic Decomposition Module - Solar Concentrating Conversion to Carbon Production Materials:

[0111] S3. Reactor pretreatment: Add microcapsule metal catalyst to the reactor, adjust the rotation speed to 480 r / min, and introduce carbon dioxide obtained from desorption in step S2 at a flow rate of 51 ml / min for 9 min.

[0112] S4. Formation of carbon-based materials: The reactor is wrapped with tin foil, the xenon lamp is turned on, and the light intensity is adjusted to 4 W / cm². 2 After 23 hours of light irradiation, the product was added to anhydrous ethanol and ultrasonically dispersed at a frequency of 48 kHz for 18 minutes. After separating the metal catalyst and the upper anhydrous ethanol, the product was placed in a drying oven and dried for 28 minutes to obtain the carbon-based material.

[0113] Performance testing:

[0114] 1. Relationship between CO2 peak area and CO2 volume and concentration

[0115] Since gas chromatographs can only detect the peak area of ​​CO2 produced in the experiment, and cannot directly measure the CO2 volume and CO2 concentration, we need to perform CO2 calibration tests and analyses on the mixed reactants in the experiment to obtain the relationship between CO2 peak area and CO2 volume and CO2 concentration.

[0116] Using a 1ml syringe, 0.1ml of pure CO2 gas was injected into a quartz tube and mixed at 45°C for 30 minutes. The gas from a 1m quartz tube was then injected into the chromatograph using a chromatographic needle to begin FID analysis. First, the chromatograph was turned on to obtain the CO2 peak area. Then, the same steps were repeated to obtain three sets of CO2 peak areas corresponding to 0.1ml of CO2, with the average value being 407996 (mv·s). Next, 0.2ml of pure CO2 gas was injected, and the same steps were repeated to obtain a CO2 peak area of ​​698020 (mv·s); 0.4ml of pure CO2 gas was injected, and the same steps were repeated to obtain a CO2 peak area of ​​949932 (mv·s); 0.6ml of pure CO2 gas was injected, and the same steps were repeated to obtain a CO2 peak area of ​​1155726 (mv·s); 0.8ml of pure CO2 gas was injected, and the same steps were repeated to obtain a CO2 peak area of ​​1303205 (mv·s). The CO2 peak area should increase with increasing CO2 volume. Since the CO2 peak area and volume have a linear function relationship, linear fitting can be performed on different corresponding CO2 volumes and peak areas to obtain the following results. Figure 3 The linear fitting curve of CO2 peak area and volume in this invention.

[0117] Connect the decomposition device, open the switch valve, and introduce Ar gas. Use a flow meter to control the flow rate at approximately 40 ml / min. Exhaust for 20 minutes. After exhausting, tighten the screw cap, check the airtightness of the device, close the switch valve, and turn off the flow meter. At this point, only Ar gas exists in the heating belt. Take 1 ml of 0.2% CO2 gas and inject it into the heating belt. Mix at 45 degrees Celsius for 30 minutes. Use a chromatographic needle to take 1 ml of gas and inject it into the chromatograph to start FID analysis and obtain the CO2 peak area. Then repeat the above steps to obtain three sets of CO2 peak areas corresponding to 1 ml of 0.1% CO2. The average value was 76234 (mv·s); then, 1 ml of 0.4% CO2 gas was taken and the above steps were repeated to obtain a CO2 peak area of ​​184023 (mv·s); 1 ml of 0.6% CO2 gas was taken and the above steps were repeated to obtain a CO2 peak area of ​​246723 (mv·s); 1 ml of 0.8% CO2 gas was taken and the above steps were repeated to obtain a CO2 peak area of ​​356254 (mv·s); 1 ml of 1% CO2 gas was taken and the above steps were repeated to obtain a CO2 peak area of ​​442630 (mv·s). The CO2 peak area should increase with the increase of CO2 concentration.

[0118] Similarly, since the CO2 peak area and concentration also exhibit a linear function relationship, and this relationship is a straight line passing through the origin, the following formula can be deduced by performing linear fitting on different corresponding CO2 concentration and peak area data. Figure 4The linear fitting curve of CO2 peak area versus concentration in this invention shows that the square of R is 0.99943 and the sum of squared residuals is 1.34116.

[0119] 2. Characterization of exhaust gas and investigation of the conversion rate of CO2 by photocatalytic cracking

[0120] After completing the airtightness test of the device, CO2 gas was continuously introduced at a flow rate of 50 mL / min. The chromatographic results of the tail gas before and after the xenon lamp reaction are shown in Table 1 below:

[0121] Table 1 Gas Chromatography Data of CO2 Pyrolysis Tail Gas

[0122]

[0123] CO2 conversion rate refers to the ratio of the peak area of ​​the CO2 gas participating in the reaction to the peak area of ​​the initial CO2 gas. It reflects the efficiency of CO2 conversion into C and O2. The calculation method is as follows: ;

[0124] In the formula, X is the CO2 conversion rate, %; A CO2 The reduction in CO2 peak area due to participation in the reaction, mV; A CO2 t0 is the initial peak area of ​​CO2 in the reaction, in mV; A CO2 t is the peak area of ​​CO2 at time t of the reaction, in mV.

[0125] The calculated conversion rate of CO2 by photocatalytic cracking is 0.6%.

[0126] 3. Thermal imaging characterization

[0127] Appendix Figure 5 This is a thermal imaging view of the reaction in step S4 of Embodiment 1 of the present invention. After 1 hour of focusing time, the temperature of the airflow above the reactor is around 55°C, while the temperature of the metal mixture on the reaction surface is only around 90°C. The temperature decreases with increasing distance from the light source. The reaction temperature is significantly lower than the high temperature required for direct carbon dioxide cracking, which helps reduce energy consumption. The requirements for the reaction apparatus are also lower than those for methods utilizing carbon dioxide such as direct carbon dioxide cracking. Furthermore, the energy required for the reaction is solar energy, which is virtually inexhaustible, resulting in low energy consumption. The core reaction temperature is below 100°C. This demonstrates that the metal mixture can effectively reduce energy consumption and simultaneously achieve photocatalysis of carbon dioxide at relatively low temperatures, thus enabling the decomposition of carbon dioxide.

[0128] 4. Infrared spectroscopy analysis

[0129] Appendix Figure 6 This is the infrared spectrum of the carbon-based material obtained in Example 1 of the present invention. At 802 cm⁻¹ -1At this location, the first vibration occurs, primarily involving the vibration of the C-H bonds, at a depth of 1100 cm⁻¹. -1 The vibration at 1261 cm⁻¹ mainly originates from the C–O vibration. -1 A relatively strong vibration was observed at this location, originating from the vibration of the C-C bond, indicating a high carbon content in the sample and the presence of other carbon-containing functional groups, such as at 1724 cm⁻¹. -1 The vibration of the carbon-carbon double bond present at 3324 cm⁻¹ -1 The peak appearing at [location] originates from the stretching vibrations of water absorbed in the sample. The infrared spectrum indicates that the main component of the sample is carbon material, and the products generated by the concentrated photolysis of carbon dioxide in this study are carbon-containing materials.

[0130] 5. Characterization by scanning electron microscopy

[0131] Appendix Figure 7 This is a SEM image of the carbon-based material obtained in Example 1 of this invention. The image was obtained by observing the morphology at 3000x magnification using a scanning electron microscope. The image shows that the sample surface is composed of a large number of particles of varying sizes, exhibiting an irregular shape. There is some aggregation among the particles; some areas are densely packed with particles, while others are relatively sparse. Most particles are less than 3 μm in size, with a small number larger than 3 μm, and the smaller particles are attached to a larger substrate. The image shows that the material has a large surface area, high dispersion, and an uneven surface with various bumps and depressions.

[0132] 6. Specific surface area test

[0133] Appendix Figure 8 This is a pore size distribution diagram of the carbon-based material obtained in Example 1 of the present invention. In the region with smaller pore sizes (near 0 nm), the curve shows multiple sharp peaks, indicating that the sample contains various pore structures of different sizes within this range, and the pore volume change rate is relatively large, possibly corresponding to some microporous structures. As the pore size increases, another obvious peak appears in the 10-20 nm range, indicating that pores in this range also account for a certain proportion. After exceeding 20 nm, the curve gradually decreases and becomes flat, indicating that the pore volume change rate of large pores gradually decreases, and the number of large pores is relatively small. Through testing and calculation, the specific surface area of ​​this sample is found to be 9.626 m². 2 / g.

[0134] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials, characterized in that, The preparation steps include the following: S1. Carbon dioxide capture: Heat the quartz tube in the carbon dioxide trap to 38-42℃ and then introduce air at a flow rate of 38-42mL / min. Adsorb for 3-4 hours until the peak area of ​​carbon dioxide no longer changes, then stop introducing air. S2. Desorption of carbon dioxide: Connect the adsorbed quartz tube to the desorption device, introduce argon gas at a flow rate of 28-32 mL / min, exhaust for 15-20 min, then heat the heating band to 98-102℃ and keep it at that temperature for 2-3 h, desorb carbon dioxide until the peak area of ​​carbon dioxide no longer changes. S3. Reactor pretreatment: Add microencapsulated metal catalyst to the reactor, adjust the rotation speed to 450-500 r / min, and introduce carbon dioxide obtained from step S2 at a flow rate of 48-52 mL / min for 8-10 min. S4. Formation of carbon-based materials: Wrap the reactor with tin foil, turn on the xenon lamp, and irradiate the reaction for 22-24 hours. Then add the product to anhydrous ethanol and ultrasonically disperse for 15-20 minutes. After separating the microcapsule metal catalyst and the upper anhydrous ethanol, place it in a drying oven and dry for 20-30 minutes to obtain carbon-based materials. The preparation of the microcapsule metal catalyst includes the following steps: S31. Under argon protection, heat the metal mixture until all metals are melted, then stir for 25-30 minutes to obtain a molten alloy; S32. By mass, mix 19-21 parts of molten alloy, 90-100 parts of anhydrous ethanol and 0.5-0.8 parts of polyvinylpyrrolidone, and treat with an ultrasonic disruptor for 20-30 minutes to obtain a metal nanoemulsion. S33. Mix 450-500 parts of pyrolysis modifier with metal nanoemulsion, stir magnetically at 450-500 r / min for 50-60 min, then add 90-100 parts of anhydrous ethanol and 8-10 parts of ammonia water, and continue stirring for 10-12 min. S34. Slowly add 1.9-2.1 parts of tetraethyl orthosilicate to the mixture obtained in step S33. After the addition is completed within 25-30 min, react at room temperature for 22-24 h to form a silica shell on the surface of the metal particles. Collect the microcapsules by centrifugation, wash them 3-4 times with anhydrous ethanol, and dry them in a vacuum drying oven at 60℃ for 10-12 h to obtain the microcapsule metal catalyst. The preparation of the pyrolysis modifier includes the following steps: S331. By mass, add 5-10 parts of ethylenediamine to 450-500 parts of graphene oxide aqueous dispersion, stir at 300-500 r / min for 25-30 min, then heat to 90-95℃, continue stirring under reflux for 3-4 h, and then cool to room temperature to obtain a preliminary mixture. S332. Add 3-5 parts of sodium borohydride to the initial mixture, stir at 300-500 r / min for 25-30 min, add 0.2-0.5 parts of polyvinylpyrrolidone, heat to 75-80℃, and continue stirring for 1-2 h to obtain the pyrolysis modifier. The metal mixture consists of liquid gallium, indium particles, tin particles, and copper particles in a mass ratio of 13.8:1.2:2:3.

3.

2. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, The carbon dioxide trap consists of an air generator, a flow meter, a humidifier bottle, and a quartz tube, and has good airtightness.

3. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 2, characterized in that, The quartz tube contains a nickel foam adsorbent loaded with PEI, wherein the mass ratio of nickel foam to PEI is 100:1.

5.

4. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, The analytical device consists of an air generator, a flow meter, a humidifier bottle, a quartz tube, and a xenon lamp, and has good airtightness.

5. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, In step S4, the illuminance of the xenon lamp is 4 W / cm². 2 .

6. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, In step S4, the frequency of ultrasonic dispersion is 40-50 kHz.

7. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, In step S32, the ultrasonic breaker has a frequency of 40kHz and a power of 300W.

8. The method for solar-driven carbon dioxide capture and catalytic preparation of carbon-based materials according to claim 1, characterized in that, In step S331, the concentration of the graphene oxide aqueous dispersion is 2 mg / mL.

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