Method for etching carbon carrier by using metal photothermal effect and application thereof
The method of etching carbon carriers through metal photothermal effect solves the problem of high equipment and chemical reagent costs in the etching process of porous carbon media, achieves energy-saving and environmentally friendly uniform pore formation and efficient carbon nanotube grafting, and improves electrode performance.
Patent Information
- Application Number
- CN202510697356.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-28
- Publication Date
- 2025-09-19
AI Technical Summary
In the prior art, the etching process of porous carbon media has high equipment, chemical reagent and energy consumption costs, is prone to pollution, and is complex.
The method of etching carbon carriers using metal photothermal effect is adopted. By loading metal precursors on the surface of porous carbon media, photooxidation and etching are cyclically treated under an inert atmosphere to achieve local rapid heating and control the depth and size of the holes.
It reduces equipment costs, simplifies the etching process, avoids high temperature and high pressure environments, achieves uniform pore formation and efficient carbon nanotube grafting, and improves the hydrophilicity and active sites of the electrode.
Smart Images
Figure CN120664520A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of electrode processing, and in particular relates to a method for etching a carbon carrier by utilizing the metal photothermal effect and an application thereof. Background Art
[0002] Porous carbon media, such as graphite felt, are typical electrode materials for all-vanadium redox flow batteries. They possess excellent corrosion resistance, good catalytic activity, high conductivity, outstanding mass transfer characteristics, and moderate mechanical strength. However, these materials suffer from low surface area, few active sites, and poor hydrophilicity. Etching is often used to create micropores, mesopores, and oxygen-containing groups with high surface areas in the electrode fibers to improve the electrode's mass transfer and electrochemical properties. Compared to pristine graphite felt, etched graphite felt exhibits improved hydrophilicity and a higher surface area.
[0003] In existing technology, pores created in graphite felt fibers are typically created at high temperatures. High-temperature experiments require additional electricity and place specific demands on the reaction vessels, such as excellent heat resistance, corrosion resistance, and strict airtightness. This significantly increases the cost of electrode preparation. Carbon etching at room temperature, such as using Fenton's reagent to treat graphite felt electrodes, consumes large amounts of costly chemical reagents. Furthermore, to ensure accuracy and avoid corrosion and contamination, even higher requirements are placed on the instrumentation. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for etching a carbon carrier using the metal photothermal effect, which is used to solve the technical problems in the prior art that the equipment, chemical reagents or energy consumption involved in the etching process of porous carbon media are high in cost, the process is complicated, and it is easy to cause pollution.
[0005] The method for etching a carbon support using the metal photothermal effect comprises:
[0006] The first step is to load the metal precursor on the surface of the porous carbon medium and obtain a sample after drying;
[0007] The second step is to photo-oxidize the surface of the sample loaded with metal nanoparticles in an oxidizing atmosphere;
[0008] Step 3: Photoetching the surface of the sample loaded with the metal precursor obtained in the previous step under an inert atmosphere;
[0009] The second and third steps are repeated several times until the carbon material is etched to a required depth, thus completing the etching of the porous carbon medium.
[0010] Preferably, in the first step, the metal precursor is loaded onto the surface of the porous carbon medium by spraying or dipping, and the metal element loading per unit area on the porous carbon medium is in the range of 0.01 to 0.5 g / cm2.
[0011] Preferably, the porous carbon medium is graphite felt, the metal precursor is a nitrate or acetate of a metal element, and the metal element is any one or more of nickel, iron, and cobalt.
[0012] Preferably, the light source is a xenon lamp with adjustable current. During illumination, the current range of the xenon lamp is controlled to be 15 to 21 A, and the illumination time range is 1 to 30 minutes.
[0013] Preferably, the second and third steps are repeated 3 to 10 times in a cycle.
[0014] Preferably, the etched sample is pickled and washed with water to remove metal impurities.
[0015] The present invention also provides a method for loading N-doped carbon nanotubes on the surface of graphite felt, wherein the graphite felt is etched using the above-mentioned method for etching a carbon carrier using the metal photothermal effect, and further comprising:
[0016] The fourth step is to place the etched sample in a mixed gas atmosphere consisting of hydrogen, carbon monoxide and ammonia, and generate carbon nanotubes on the sample surface by continuous light exposure;
[0017] Step 5: The sample of generated carbon nanotubes is acid-washed and water-washed to remove metal impurities.
[0018] Preferably, in the fourth step, a mixed gas atmosphere is formed by introducing a mixed gas of H2 / CO / NH3 into the environment of the etched sample, and the volume ratio of H2, CO and NH3 ranges from 5:1:1 to 5:4:1. When the mixed gas is introduced, the flow rate of hydrogen is fixed at 10 ml / min.
[0019] Preferably, in the fourth step, the sample surface is continuously illuminated for 1 to 5 hours in a mixed gas atmosphere consisting of hydrogen, carbon monoxide and ammonia, and the length of the carbon nanotubes is adjusted to be in the range of 20 to 100 μm by adjusting the illumination time.
[0020] An application of the above-mentioned method of etching a carbon carrier using the metal photothermal effect in the field of electrode processing technology.
[0021] The advantages of the present invention are that the etching method provided herein utilizes the photothermal effect between metal nanoparticles and carbon on the graphite surface under illumination to achieve etching, eliminating the need for complex steps, costly chemical reagents, or a high-temperature, high-pressure environment. Consequently, the etching process is simple, energy-efficient, and environmentally friendly. During the etching process, the photothermal effect occurs at the metal nanoparticles, causing rapid localized heating, resulting in high efficiency and time savings. Because the overall temperature rise is limited, the high-temperature resistance requirements for the equipment are low, reducing manufacturing costs.
[0022] Because this method uses localized heating through the photothermal effect rather than global heating, it effectively avoids the sintering of metal nanoparticles during the long electrical heating and insulation process used in conventional preparation methods. Furthermore, due to the small size of the metal nanoparticles, the loading method allows for uniform particle distribution, resulting in uniform etched holes of uniform size and depth. By controlling the reaction atmosphere, the etching method can control the reaction type and thus the depth of the etched holes.
[0023] The present invention provides a method for loading N-doped carbon nanotubes on the surface of graphite felt. The photothermal effect only forms a high-temperature zone around the metal nanoparticles. The carbon nanotubes grow in the defect-rich area etched around the metal nanoparticles and easily form bonds with the carbon atoms of the substrate. In this way, the carbon nanotubes can be grafted onto the substrate, firmly fixed, and not easily fall off. In the photothermal reaction, by regulating the reaction atmosphere, the progress of the reaction can be controlled, the concentration of impurity atoms can be regulated, and the temperature at the active site of the catalyst can be increased and decreased rapidly. By controlling the time of the photothermal reaction, the length of the carbon nanotube growth can be effectively controlled. The electrode with heteroatom-doped carbon nanotubes loaded on the surface of the obtained product has strong hydrophilicity and can provide more defects and active sites. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Schematic diagram of a process for etching a carbon carrier using the metal photothermal effect in the present invention.
[0025] Figure 2 for Figure 1 Schematic diagram of the steps and principles of the method shown.
[0026] Figure 3 The figure is a schematic flow chart of a method for loading N-doped carbon nanotubes on the surface of graphite felt in the present invention.
[0027] Figure 4 for Figure 3 Schematic diagram of the steps and principles of the method shown. DETAILED DESCRIPTION
[0028] The specific implementation methods of the present invention will be further explained in detail below through the description of embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.
[0029] like Figure 1-2 As shown, the present invention provides a method for etching a carbon support using a metal photothermal effect, comprising:
[0030] The first step is to load the metal precursor on the surface of the porous carbon medium and obtain a sample after drying.
[0031] The porous carbon medium in this scheme can be graphite felt, a commercial product with a cross-sectional thickness of approximately 3 mm. The metal precursor can be a nitrate or acetate of a metal element such as nickel, iron, or cobalt. The metal precursor is applied to the surface of the porous carbon medium by spraying or impregnation. The metal element loading per unit area of the porous carbon medium ranges from 0.01 to 0.5 g / cm². After loading, the sample obtained by spraying or impregnation is dried by heating in a vacuum environment, for example, at 100°C.
[0032] The second step is to photo-oxidize the surface of the sample loaded with metal nanoparticles in an oxidizing atmosphere.
[0033] In this step, the dried sample is placed in an oxidizing atmosphere. A light source is used to illuminate the surface of the sample, loaded with the metal precursor, to oxidize the metal nanoparticles. The oxidizing atmosphere can be air or another oxygen-containing gas environment. The duration of illumination is controlled according to conditions and needs, generally ranging from 1 to 30 minutes. The light source can be a 300W xenon lamp with adjustable current, and the current range of the xenon lamp is controlled during illumination.
[0034] In this step, light irradiation causes a carbon thermal reaction between the metal nanoparticles and the carbon on the surface of the graphite fiber, forming a micro-oxidation process in the micro-region and oxidizing the metal nanoparticles.
[0035] The third step is to photo-etch the surface of the sample loaded with the metal precursor obtained in the previous step under an inert atmosphere.
[0036] In this step, the sample, after oxidizing the metal nanoparticles, is placed in an inert environment, such as one filled with an inert gas like argon. A light source is then used to illuminate the surface of the sample loaded with the metal precursor, completing a photoetching step. The light source can be the same as that used in the second step, and the duration of the illumination is controlled based on conditions and needs, typically ranging from 1 to 30 minutes.
[0037] In this step, under light conditions, a carbothermal reaction occurs between the metal oxide and the carbon on the graphite fiber surface. Due to the inert atmosphere, a micro-oxidation process occurs in the microregion, where oxygen from the metal oxide enters the carbon fiber surface. This changes the bonding state of the carbon-carbon bonds and the microscopic appearance of the carbon fiber surface. More oxygen enters the fiber surface, forming oxygen-rich functional groups, while the metal nanoparticles are reduced. This process causes some carbon to oxidize into gas, producing an etching effect, while the reduced metal nanoparticles enter the etched holes.
[0038] Thereafter, the second and third steps are repeated several times, that is, the oxidation and reduction etching processes of the metal nanoparticles are repeated until the carbon material is etched to a depth that meets the requirements, thereby completing the etching of the porous carbon medium.
[0039] Based on the above-mentioned method of etching a carbon carrier using the metal photothermal effect, the present invention also provides two applications of this method, one for the purpose of obtaining a porous carbon medium (such as graphite felt) after etching, and the other for applying this method to load N-doped carbon nanotubes on the surface of graphite felt.
[0040] The present invention provides a method for etching a carbon carrier using the metal photothermal effect. After repeating the second and third steps based on the aforementioned cycle until the etching of the sample is completed, the etched sample is further pickled and washed with water to remove metal impurities.
[0041] This step involves soaking the sample in a solution of hydrochloric acid, sulfuric acid, acetic acid, or nitric acid at a certain concentration. Once all the metal nanoparticles on the sample's surface have dissolved, the sample is rinsed with water and then dried. This results in a graphite felt with a high specific surface area and micropores, mesopores, and oxygen-containing groups.
[0042] like Figure 3-4 As shown, the present invention also provides a method for loading N-doped carbon nanotubes on the surface of graphite felt, comprising: a first step of loading a metal precursor on the surface of the graphite felt, and obtaining a sample after drying.
[0043] The porous carbon medium in this solution can be graphite felt, and the metal precursor can be a nitrate or acetate of a metal element such as nickel, iron, or cobalt. The metal precursor is loaded onto the surface of the porous carbon medium by spraying or impregnation. The metal element loading per unit area of the porous carbon medium ranges from 0.01 to 0.5 g / cm². After loading, the sample obtained by spraying or impregnation is dried by heating in a vacuum environment, for example, at 100°C.
[0044] The second step is to photo-oxidize the surface of the sample loaded with metal nanoparticles in an oxidizing atmosphere.
[0045] In this step, the dried sample is placed in an oxidizing atmosphere, and a light source is used to illuminate the surface of the sample loaded with a metal precursor to achieve oxidation of the metal nanoparticles. The oxidizing atmosphere is such as air or other oxygen-containing gas environments, and the illumination duration is controlled according to conditions and needs, generally in the range of 1 to 30 minutes. The light source can be a 300W xenon lamp with adjustable current. During illumination, the current range of the xenon lamp is controlled to be 15 to 21A. In this embodiment, the illumination duration is 5 minutes and the xenon lamp current is 21A.
[0046] The third step is to photo-etch the surface of the sample loaded with the metal precursor obtained in the previous step under an inert atmosphere.
[0047] In this step, the sample after oxidation of metal nanoparticles is placed in an inert environment, such as an environment filled with an inert gas such as argon, and a light source is used to illuminate the surface of the sample loaded with the metal precursor to complete a photoetching. The light source can be the same as that in the second step, and the illumination duration is controlled according to conditions and needs, generally ranging from 1 to 30 minutes. In this embodiment, the same illumination treatment conditions as in the second step are used under an inert atmosphere for 10 minutes.
[0048] The second and third steps are repeated 3 to 10 times until the carbon material is etched to the required depth.
[0049] The fourth step is to place the etched sample in a mixed gas atmosphere consisting of hydrogen, carbon monoxide and ammonia, and generate carbon nanotubes on the sample surface through continuous light irradiation.
[0050] A mixture of H2 / CO / NH3 is introduced into the atmosphere of the etched sample. The volume ratio of H2, CO, and NH3 ranges from 5:1:1 to 5:4:1. The hydrogen flow rate is kept constant at 10 ml / min. Continuously illuminating the sample surface in this atmosphere for 1 to 5 hours allows carbon nanotubes to form around the metal nanoparticles. The length of the carbon nanotubes can be controlled by adjusting the illumination time, ranging from 20 to 100 μm.
[0051] Step 5: The sample of generated carbon nanotubes is acid-washed and water-washed to remove metal impurities.
[0052] In this step, the sample is soaked in a certain concentration of hydrochloric acid, sulfuric acid, acetic acid or nitric acid solution. After all the metal nanoparticles on the surface of the sample are dissolved, it is washed with water and then dried to obtain a graphite felt with N-doped carbon nanotubes grafted on the surface.
[0053] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the inventive concept and technical solution of the present invention, or the inventive concept and technical solution are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.
Claims
1. A method for etching a carbon support using a metal photothermal effect, characterized in that: include: The first step is to load the metal precursor on the surface of the porous carbon medium and obtain a sample after drying; The second step is to photo-oxidize the surface of the sample loaded with metal nanoparticles in an oxidizing atmosphere; Step 3: Photoetching the surface of the sample loaded with the metal precursor obtained in the previous step under an inert atmosphere; The second and third steps are repeated several times until the carbon material is etched to a required depth, thus completing the etching of the porous carbon medium.
2. The method for etching a carbon support using a metal photothermal effect according to claim 1, wherein: In the first step, the metal precursor is loaded onto the surface of the porous carbon medium by spraying or dipping, and the metal element loading per unit area on the porous carbon medium ranges from 0.01 to 0.5 g / cm2.
3. The method for etching a carbon support using a metal photothermal effect according to claim 2, wherein: The porous carbon medium is graphite felt, the metal precursor is nitrate or acetate of a metal element, and the metal element is any one or more of nickel, iron, and cobalt.
4. The method for etching a carbon support using a metal photothermal effect according to claim 1, wherein: The light source adopts a xenon lamp with adjustable current. The current range of the xenon lamp is controlled to be 15 to 21A during illumination, and the illumination time range is 1 to 30 minutes.
5. The method for etching a carbon support using a metal photothermal effect according to claim 1, wherein: Repeat steps 2 and 3 3 to 10 times.
6. A method for etching a carbon support using a metal photothermal effect according to any one of claims 1 to 5, characterized in that: The etched samples are pickled and washed with water to remove metal impurities.
7. A method for loading N-doped carbon nanotubes on the surface of graphite felt, characterized in that: The method for etching a carbon carrier using a metal photothermal effect according to any one of claims 1 to 5 is used to etch the graphite felt, further comprising: The fourth step is to place the etched sample in a mixed gas atmosphere consisting of hydrogen, carbon monoxide and ammonia, and generate carbon nanotubes on the sample surface by continuous light exposure; Step 5: The sample of generated carbon nanotubes is acid-washed and water-washed to remove metal impurities.
8. The method for loading N-doped carbon nanotubes on the surface of graphite felt according to claim 7, characterized in that: In the fourth step, a mixed gas atmosphere is formed by introducing a mixed gas of H2 / CO / NH3 into the environment of the etched sample. The volume ratio of H2, CO and NH3 ranges from 5:1:1 to 5:4:
1. When the mixed gas is introduced, the flow rate of hydrogen is fixed at 10 ml / min.
9. The method for loading N-doped carbon nanotubes on the surface of graphite felt according to claim 8, characterized in that: In the fourth step, the sample surface is continuously illuminated for 1 to 5 hours in a mixed gas atmosphere consisting of hydrogen, carbon monoxide and ammonia, and the length of the carbon nanotubes is adjusted to be in the range of 20 to 100 μm by adjusting the illumination time.
10. Application of the method for etching a carbon carrier using a metal photothermal effect according to any one of claims 1 to 5 in the field of electrode processing technology.