Preparation method of seawater corrosion resistant chlorine doped five-membered ring defect rich carbon-based electrode material and seawater electrocatalytic application
By synergistically constructing carbon-based electrode materials with porous nanosheet structures through chlorine doping and rich five-membered ring defects, the problems of insufficient corrosion resistance and electrocatalytic performance of carbon-based electrodes in seawater environment were solved, and the stability and electrocatalytic activity of the materials were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HAINAN UNIV
- Filing Date
- 2025-09-24
- Publication Date
- 2026-06-30
AI Technical Summary
Existing carbon-based electrode materials exhibit poor corrosion resistance in seawater environments, are difficult to construct due to the five-membered ring-rich defects, and have complex preparation methods, resulting in insufficient stability and electrocatalytic performance in seawater electrolysis and seawater treatment.
By synergistically constructing chlorine doping and five-membered ring defects, fullerenes and molten salts are mixed in a molten salt system and subjected to segmented pyrolysis activation treatment to form a porous nanosheet structure of chlorine-doped carbon-based electrode material with five-membered ring defects. This simplifies the preparation process and improves the stability and electrocatalytic activity of the material.
The material significantly enhances the stability and electrocatalytic performance of carbon-based electrodes in seawater. It has a good uniform structure and high specific surface area, making it suitable for seawater electrocatalytic reactions and promising for industrial application.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of electrochemical materials technology, and in particular to a method for preparing a seawater corrosion-resistant, chlorine-doped, five-membered ring defect-rich carbon-based electrode material and its application in seawater electrocatalysis. Background Technology
[0002] The world is facing the dual challenges of energy and the environment. Excessive consumption of fossil fuels leads to climate change, while freshwater scarcity limits the application of electrolysis technology. As the Earth's richest water resource, the efficient utilization of ocean water could provide a new approach to addressing resource shortages. Against this backdrop, seawater electrocatalytic reactions, particularly the oxygen reduction reaction (ORR) to synthesize hydrogen peroxide (H₂O₂) and the hydrogen evolution reaction (HER), have become research hotspots in the energy and environmental fields. Carbon materials, due to their high specific surface area and good conductivity, can promote ion transport and catalytic reactions, and possess advantages such as low cost, wide availability, and environmental friendliness, making them ideal materials for seawater electrocatalysis. However, due to chloride (Cl) corrosion and poisoning in seawater, carbon materials suffer from poor activity and stability. Therefore, corrosion-resistant carbon-based electrodes have significant application potential in marine environments, especially in the electrocatalytic reactions of seawater electrolysis and seawater treatment.
[0003] Currently, most carbon-based electrode materials rely on defect technology and nitrogen doping, oxygen doping and other technologies to improve their catalytic performance. However, these materials generally suffer from poor seawater corrosion resistance, difficulty in constructing five-membered ring-rich defects and complex and costly preparation methods.
[0004] Currently, there are several independent solutions in existing technologies. The first is to use carbon-based composite materials to resist seawater corrosion, but existing technologies still face problems such as weak interfacial bonding and uneven composite structure, resulting in poor stability. The second is to use fullerene pyrolysis to construct five-membered ring-rich structures, but due to the lack of effective template guidance, the fullerene pyrolysis method is difficult to form a stable structure, which limits its long-term effectiveness in practical applications. The third is to dope to improve the performance of carbon materials. However, these doping methods are not very effective against chlorine corrosion, especially in seawater environments, where the doped carbon materials are still easily corroded by chloride ions, resulting in poor material stability.
[0005] Although existing technologies have made breakthroughs in improving the seawater corrosion resistance of carbon materials, constructing five-membered ring-rich defects, and doping modification, no technology can achieve all of these simultaneously. Therefore, this invention proposes a method for preparing and applying a seawater corrosion-resistant chlorine-doped carbon-based electrode material rich in five-membered ring defects to solve the problems existing in the prior art. Summary of the Invention
[0006] To address the aforementioned problems, the present invention aims to propose a method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material and its application in seawater electrocatalysis. This method for preparing the seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material significantly improves the stability and electrochemical performance of the carbon-based electrode in a seawater environment through the synergistic construction of chlorine doping and five-membered ring defects, while taking into account structural innovation, superior performance, and process feasibility.
[0007] To achieve the objectives of this invention, the invention is implemented through the following technical solution: a method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material, comprising the following steps:
[0008] Step 1: Mixing of the chlorine-doped system. Fullerene and molten salt are thoroughly mixed and ground for 30 minutes to form a homogeneous mixed system A.
[0009] Step 2: Pyrolysis activation treatment. The mixed system A is transferred to a tube furnace and heated in stages under an inert atmosphere for 2 hours to obtain a mixture with chlorine doping and rich five-membered ring defects.
[0010] Step 3: Salt template removal, cooling and washing. After the mixture obtained in Step 2 is cooled naturally, it is thoroughly washed with deionized water and ethanol to remove residual salt and obtain the washing product.
[0011] Step 4: Washing and drying. The washing product is washed again with deionized water and ethanol until neutral, and then dried to obtain chlorine-doped carbon-based electrode material rich in five-membered ring defects.
[0012] A further improvement is that: in step one, fullerene and molten salt are mixed and ground at a mass ratio of 1:10, and the molten salt is made by mixing lithium chloride and potassium chloride at a mass ratio of 1:1.
[0013] The further improvement lies in the following: In step two, the segmented heating is specifically achieved by first raising the temperature to 400-500℃ and holding it for 2 hours to allow the salt system to completely melt.
[0014] Then, the temperature is raised to 800-1000℃ and held for 2 hours to achieve pyrolytic etching. The heating rate for both stages is 3-10℃ / min. The high-temperature molten salt is used as a template to etch a porous carbon nanosheet structure and is also used as a chlorine source for doping. The inert atmosphere is nitrogen or argon.
[0015] The further improvement is that microwave drying is used in step four, with a microwave power of 800W and a drying time of 5 minutes.
[0016] A further improvement is that the chlorine-doped carbon-based electrode material rich in five-membered ring defects obtained in step four is a porous nanosheet structure with a thickness of 5-20 nm and a pore size of 2-50 nm; wherein the chlorine doping concentration is 0.1-2.0 at%, and the specific surface area is ≥1000 m². 2 / g.
[0017] A method for preparing a seawater-resistant chlorine-doped carbon-based electrode material rich in five-membered ring defects; application of the obtained chlorine-doped carbon-based electrode material rich in five-membered ring defects in seawater electrocatalysis.
[0018] The beneficial effects of this invention are as follows: By effectively doping chlorine elements in the molten salt system, this invention significantly enhances the resistance of carbon-based electrodes to chloride ions in seawater, effectively solving the problems of severe corrosion and short lifespan of traditional carbon materials in high-chlorine environments, and ensuring the long-term stable operation of the material under seawater conditions.
[0019] This invention utilizes the structural deconstruction reaction of fullerenes during pyrolysis to successfully construct a large number of five-membered ring defects, effectively regulating the electron distribution of the carbon skeleton, increasing the number and intensity of active sites, and significantly improving the electrocatalytic activity and reaction selectivity of the material.
[0020] This invention uses the molten salt method as the reaction environment, which not only promotes the synergistic formation of chlorine doping and five-membered ring-rich defects, but also avoids complex template etching or multi-step activation processes. The process is simple to operate and has low cost. The resulting material has a uniform structure and high specific surface area, showing good potential for large-scale preparation.
[0021] In summary, this invention significantly improves the stability and electrochemical performance of carbon-based electrodes in seawater environments through the synergistic construction of chlorine doping and five-membered ring-rich defects. It balances structural innovation, superior performance, and process feasibility, and has broad prospects for industrialization and technological promotion. Attached Figure Description
[0022] Figure 1 This is a schematic diagram illustrating the fabrication of the chlorine-doped carbon-based electrode (PDCN-CL) rich in five-membered ring defects according to the present invention.
[0023] Figure 2 This is a topographic diagram of the PDCN-CL of the present invention.
[0024] Figure 3 This is a comparison chart of the performance of the PDCN-CL of this invention and commercial carbon-simulated seawater in ORR electrosynthesis of hydrogen peroxide.
[0025] Figure 4 This is a HER performance diagram of the PDCN-CL of the present invention.
[0026] Figure 5 This is an OER performance diagram of the PDCN-CL of the present invention.
[0027] Figure 6 This is a simulated seawater stability diagram of the PDCN-CL of this invention. Detailed Implementation
[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.
[0029] In fields such as energy conversion and environmental remediation, carbon-based electrodes are widely used in electrocatalysis, energy storage, and environmental pollution control due to their excellent conductivity, good chemical stability, and high specific surface area. Among them, carbon-based electrodes with strong corrosion resistance have significant application potential in marine environments, especially in electrocatalytic reactions for seawater electrolysis and seawater treatment.
[0030] Currently, most carbon-based electrode materials used in seawater environments rely on nitrogen doping and oxygen doping techniques to improve their stability and catalytic performance. However, these materials generally suffer from the following technical problems:
[0031] 1. Poor resistance to seawater corrosion: Existing carbon-based electrode materials generally have poor resistance to seawater corrosion, which limits their stability and service life in applications such as seawater electrolysis.
[0032] 2. Difficulty in constructing five-membered ring-rich defects: Traditional preparation methods are difficult to accurately construct five-membered ring-rich defects in the carbon framework, which limits the improvement of electrocatalytic performance of carbon-based electrodes;
[0033] 3. Complex and costly preparation methods: Many carbon-based electrode preparation methods, such as chemical vapor deposition (CVD), usually require high-cost precursors and harsh process conditions, which limits their large-scale application.
[0034] To address the problems of poor seawater corrosion resistance, difficulty in constructing five-membered ring-rich defects, and limited electrochemical performance, several solutions exist in the existing technology, including but not limited to the following categories:
[0035] 1. Seawater Corrosion Resistance of Carbon-Based Composites. Carbon-based composites are being combined with other corrosion-resistant materials (such as metal oxides and conductive polymers) to improve their corrosion resistance in seawater environments. However, existing technologies still face problems such as weak interfacial bonding and uneven composite structures, resulting in poor long-term stability of the composites in seawater. Furthermore, the coatings of some composites are prone to peeling or degradation in seawater, thus reducing their chlorine corrosion resistance and durability, limiting their widespread application in marine applications.
[0036] 2. Fullerene pyrolysis is used to construct five-membered ring-rich structures. Some studies have attempted to utilize C... 60Pyrolysis introduces non-six-membered ring (especially five-membered ring-rich) structures, thereby constructing carbon skeletons rich in structural defects, altering the electronic structure of carbon materials, and improving their electrocatalytic performance. However, due to the lack of effective template guidance, fullerene pyrolysis is difficult to form stable structures, and the introduction of five-membered ring defects may lead to weak connections between materials and structural instability, limiting its long-term effectiveness in practical applications.
[0037] 3. Doping improves the properties of carbon materials. Traditional doping techniques (such as nitrogen doping and oxygen doping) can improve the electrical conductivity, catalytic activity, and stability of carbon materials to some extent. However, these doping methods are not very effective against chloride corrosion, especially in seawater environments, where doped carbon materials are still susceptible to chloride ion attack. Furthermore, it is often difficult to precisely control the uniform distribution of dopant elements during the doping process, leading to unstable electrochemical properties and corrosion resistance of the material.
[0038] In summary, although existing technologies have made breakthroughs in improving the seawater corrosion resistance of carbon materials, constructing five-membered ring-rich defects, and doping modification, no technology has yet been able to achieve all of these simultaneously.
[0039] Example
[0040] according to Figure 1 and Figure 2 As shown, this embodiment provides a method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material, comprising the following steps:
[0041] Step 1: Mixing of the chlorine-doped system. Fullerene and molten salt are mixed at a mass ratio of 1:10 and then ground for 30 minutes to form a uniform mixed system A.
[0042] The molten salt is made by mixing lithium chloride and potassium chloride in a 1:1 mass ratio.
[0043] Step 2: Pyrolysis activation treatment. The mixed system A is transferred to a tube furnace and heated in stages under an inert atmosphere for 2 hours to obtain a mixture with chlorine doping and rich five-membered ring defects.
[0044] The segmented heating process involves first raising the temperature to 400-500℃ and holding it for 2 hours, then raising the temperature to 800-1000℃ and holding it for 2 hours. The heating rate for both stages is 3-10℃ / min. The inert atmosphere is nitrogen or argon.
[0045] Step 3: Cooling and washing. After the mixture obtained in step 2 is cooled naturally, it is washed thoroughly with deionized water and ethanol to remove residual salts and obtain the washing product.
[0046] Step 4: Washing and drying. The washing product is washed again with deionized water and ethanol until neutral, and then microwave dried at 800W for 5 minutes to obtain chlorine-doped carbon-based electrode material rich in five-membered ring defects (PDCN-CL).
[0047] The prepared PDCN-CL is a porous nanosheet structure with a thickness of 5-20 nm and a pore size of 2-50 nm; the chlorine doping concentration is 0.1-2.0 at%, and the specific surface area is ≥1000 m². 2 / g. It has a good synergistic effect of rich five-membered ring defects and chlorine doping to improve electrocatalytic activity and selectivity, and chlorine doping has good seawater stability.
[0048] Application examples
[0049] according to Figures 3-6 As shown, this embodiment provides a method for preparing and verifying the performance of a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material. The method includes the following steps:
[0050] Step 1: Mix 0.2g of fullerene with 2g of molten salt thoroughly and grind for 30 minutes to form a homogeneous mixture system A;
[0051] The molten salt is made by mixing lithium chloride and potassium chloride in a 1:1 mass ratio.
[0052] Step 2: Transfer the mixture A to a tube furnace and heat it to 400℃ for 2 hours at a rate of 5℃ / min under a nitrogen atmosphere. Then continue to heat it to 900℃ and hold it for 2 hours to obtain a mixture with chlorine doping and rich five-membered ring defects.
[0053] Step 3: Cooling and washing. After the mixture obtained in step 2 is cooled naturally, it is washed thoroughly with deionized water and ethanol to remove residual salts and obtain the washing product.
[0054] Step 4: Washing and drying. The washing product is washed again with deionized water and ethanol until neutral, and then microwave dried at 800W for 5 minutes to obtain chlorine-doped carbon-based electrode material rich in five-membered ring defects (PDCN-CL).
[0055] The prepared PDCN-CL is a porous nanosheet structure with a thickness of 5-20 nm and a pore size of 2-50 nm; the chlorine doping concentration is 1.6 at%, and the specific surface area is ≥1000 m². 2 / g.
[0056] The prepared electrode material PDCN-CL was used in simulated seawater environments for energy conversion processes such as oxygen reduction reaction (ORR), oxygen evolution reaction (OER) in seawater cracking, and hydrogen evolution reaction (HER) in seawater cracking.
[0057] The specifically prepared PDCN-CL exhibits higher ORR half-wave potential, plateau current, and hydrogen peroxide detection current compared to other commercial carbon materials (graphene nanosheets, carbon nanotubes), indicating that it possesses ORR activity and hydrogen peroxide selectivity surpassing those of commercial carbon materials, as shown in the attached specification. Figure 3 As shown.
[0058] As per the instruction manual Figure 4 As shown, as the potential shifts negatively, the current increases sharply from 0 to over 200 mA cm⁻¹. -2 This indicates that PDCN-CL has HER performance.
[0059] As per the instruction manual Figure 5 As shown, with a positive shift in potential, the current increases sharply from 0 to over 20 mA cm⁻¹. -2 This indicates that PDCN-CL has OER performance.
[0060] As per the instruction manual Figure 6 As shown, the PDCN-CL electrode was subjected to 100 mA cm⁻¹ in simulated seawater. -2 It exhibits excellent stability under industrial current density, with no significant potential decay after 220 hours, and maintains excellent Faraday efficiency.
[0061] In summary, the material prepared by this invention exhibits excellent electrochemical activity and selectivity in various electrocatalytic reactions such as ORR, OER, and HER; and is less susceptible to corrosion and poisoning by seawater Cl ions, with good stability suitable for multiple application scenarios such as energy conversion.
[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material, characterized in that, Includes the following steps: Step 1: Mixing of the chlorine-doped system. Fullerene and molten salt are thoroughly mixed and ground for 30 minutes to form a homogeneous mixed system A. Fullerene and molten salt are mixed and ground at a mass ratio of 1:
10. The molten salt is made by mixing lithium chloride and potassium chloride at a mass ratio of 1:
1. Step 2: Pyrolysis activation treatment. The mixed system A is transferred to a tube furnace and heated in stages under an inert atmosphere for 2 hours to obtain a mixture with chlorine doping and rich five-membered ring defects. The segmented heating process involves first heating to 400-500℃ and holding for 2 hours, then heating to 800-1000℃ and holding for 2 hours. The heating rate for both stages is 3-10℃ / min. The inert atmosphere is nitrogen or argon. Step 3: Cooling and washing. After the mixture obtained in step 2 is cooled naturally, it is thoroughly washed with deionized water and ethanol to remove residual salts and obtain the washing product. Step 4: Washing and drying. The washing product is washed again with deionized water and ethanol until neutral, and then dried to obtain chlorine-doped carbon-based electrode material rich in five-membered ring defects.
2. The method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material according to claim 1, characterized in that: In step four, microwave drying is used with a microwave power of 800W and a drying time of 5 minutes.
3. The method for preparing a seawater-resistant, chlorine-doped, five-membered ring-defect-rich carbon-based electrode material according to claim 1, characterized in that: The chlorine-doped carbon-based electrode material rich in five-membered ring defects obtained in step four is a porous nanosheet structure with a thickness of 5-20 nm and a pore size of 2-50 nm; wherein the chlorine doping concentration is 0.1-2.0 at%, and the specific surface area is ≥1000 m². 2 / g.
4. The application of the chlorine-doped chlorine-doped carbon-based electrode material with rich five-membered ring defects obtained by the preparation method of the seawater corrosion-resistant chlorine-doped carbon-based electrode material according to any one of claims 1-3 in seawater electrocatalysis.