Method for electrocatalytically degrading perfluorooctanoic acid by using metal modified graphite felt
Through the electrocatalytic degradation method of copper and cobalt metal modified graphite felt electrode materials, the problems of low PFOA degradation efficiency and high energy consumption in traditional methods are solved, and efficient and stable PFOA removal effect is achieved at low voltage.
Patent Information
- Application Number
- CN202510350249.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-12-16
- Filing Date
- 2025-03-24
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art is difficult to efficiently and continuously remove perfluorooctanoic acid (PFOA) in water, and the traditional methods are low in efficiency, high in energy consumption and poor in stability.
The copper and cobalt metal modified graphite felt electrode materials are used to load copper and cobalt single atoms through plasma sputtering technology to form copper and cobalt metal modified graphite felt electrodes for electrocatalytic degradation of PFOA.
The degradation efficiency of PFOA is significantly improved at lower voltages, reduced energy consumption, and has good stability and regeneration capabilities.
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Figure CN120459975A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of degradation of perfluorooctanoic acid, and in particular to a method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt. Background Art
[0002] Due to the high chemical stability and bioaccumulation of perfluorooctanoic acid (PFOA), it is difficult to degrade in the environment, and long-term accumulation will pose a potential threat to the ecological environment and human health. Traditional sewage treatment methods (such as adsorption, biodegradation, etc.) are not ideal for removing PFOA from water, especially when the concentration of PFOA is high, the degradation efficiency of existing methods is significantly reduced. To this end, the present invention proposes an electrocatalytic degradation technology based on copper and cobalt metal modified graphite felt, which aims to achieve efficient degradation of PFOA at a lower voltage by improving the efficiency of the electrocatalytic reaction, thereby effectively reducing the concentration of PFOA in water and reducing its harm to the ecological environment and human health.
[0003] Currently, existing PFOA removal technologies mainly include adsorption, biodegradation, photocatalysis, and electrochemical methods. The adsorption method uses activated carbon and other adsorption materials to adsorb PFOA. Although it is easy to operate, its adsorption capacity is limited and it cannot be used continuously, resulting in poor treatment effect. The biodegradation method relies on microorganisms to degrade PFOA into harmless substances. However, due to the strong chemical stability of PFOA, it is difficult for microorganisms to decompose it, and the degradation process is slow and inefficient. The photocatalytic method uses catalysts such as titanium dioxide to degrade PFOA under light, but the recovery and stability of the catalyst have limited its practical application. The electrochemical method uses electrode materials to catalyze the degradation of PFOA and has strong oxidation ability. However, traditional electrocatalytic materials have low catalytic activity and there are problems with electrode surface contamination and reduced catalytic efficiency, which limits its widespread use in practical applications.
[0004] Existing technologies have many deficiencies in the PFOA degradation process. The efficiency of the adsorption method is limited by the capacity of the adsorbent, and the adsorption material needs to be frequently replaced; the degradation cycle of the biodegradation method is long and is less effective for certain highly stable pollutants; the photocatalytic method requires strong light source support, and the regeneration and stability of the catalyst are poor, limiting its application in low-light environments; and in the electrochemical method, the catalytic activity of traditional electrode materials is low and is easily affected by electrode surface contamination, resulting in unstable degradation efficiency. Therefore, it is difficult for existing technologies to remove PFOA from water efficiently and continuously, and there is an urgent need to develop a new, efficient and stable catalytic material. Summary of the Invention
[0005] The present invention aims to solve the problem of difficult degradation of perfluorooctanoic acid (PFOA) in water environment.
[0006] This invention proposes a method for the electrocatalytic degradation of perfluorooctanoic acid using copper- and cobalt-modified graphite felt. This method utilizes plasma sputtering technology to load single metal atoms of copper and cobalt onto the graphite felt surface, forming a copper- and cobalt-modified graphite felt electrode material. This metal catalyst exhibits high catalytic activity and can generate more active free radicals at a lower voltage, significantly improving the degradation efficiency of PFOA. During implementation, the purchased graphite felt material is first cut and cleaned to remove surface impurities. Then, plasma sputtering technology is used to load single atoms of copper and cobalt onto the graphite felt surface, forming copper- and cobalt-loaded materials, respectively. Finally, the modified graphite felt is placed in an electrocatalytic reaction device, and an electrochemical workstation is used to electrocatalyze the degradation of a PFOA solution. In experiments, the copper- and cobalt-modified graphite felt demonstrated significantly greater PFOA degradation at a voltage of 3V than unmodified graphite felt, demonstrating excellent catalytic activity.
[0007] The technical solution adopted in this disclosure is:
[0008] A method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt, comprising the following steps:
[0009] Selecting a first graphite felt material and a second graphite felt material;
[0010] cleaning the first graphite felt material and the second graphite felt material;
[0011] loading first metal atoms onto the surface of the first graphite felt material to form a first metal-modified electrode material;
[0012] loading second metal atoms onto the surface of the second graphite felt material to form a second metal-modified electrode material;
[0013] The first metal-modified electrode material is selected as the anode and the second metal-modified electrode material is selected as the cathode to carry out an electrocatalytic reaction of degrading perfluorooctanoic acid.
[0014] Optionally, the first metal atom and the second metal atom are different.
[0015] Optionally, the first metal atom and the second metal atom include copper, cobalt, platinum or palladium.
[0016] Optionally, the first metal atom is copper and the second metal atom is cobalt.
[0017] Optionally, the first metal atoms and the second metal atoms are loaded onto the surfaces of the first graphite felt material and the second graphite felt material by using plasma sputtering technology.
[0018] Optionally, the supported first metal atomic layer and the second metal atomic layer have a thickness of 2-10 nm.
[0019] Optionally, the first metal atoms and the second metal atoms are uniformly distributed on the surfaces of the first graphite felt material and the second graphite felt material, respectively.
[0020] Optionally, Na2SO4 is selected as the electrolyte for the electrocatalytic reaction.
[0021] Optionally, the electrocatalytic reaction uses a CHI650E electrochemical workstation and sets the reaction voltage to 1V-3V.
[0022] Optionally, the reaction voltage is 3V.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] By precisely controlling the loading and distribution of copper and cobalt, and fully leveraging the advantages of single-atom catalysis, the efficiency of the electrocatalytic reaction is significantly improved. In existing electrochemical degradation methods, most electrocatalytic materials have low catalytic efficiency and require high voltages to degrade PFOA. However, the method of the present invention can achieve efficient degradation at lower voltages, reducing energy consumption and exhibiting good stability and regeneration capabilities. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The present invention is a schematic flow chart of a method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to one embodiment of the present invention.
[0026] Figure 2 The following are scanning electron microscope (SEM) images and EDS images of the modified graphite felt prepared according to one embodiment of the present disclosure;
[0027] Figure 3 This is a comparison of the degradation kinetic curves of PFOA by the modified graphite felt prepared in one embodiment of the present disclosure and the unmodified graphite felt;
[0028] Figure 4 This is a graph showing the degradation kinetics of PFOA by modified graphite felts of different thicknesses prepared according to one embodiment of the present disclosure;
[0029] Figure 5 This is a graph showing the degradation kinetics of PFOA by modified graphite felt at different voltages prepared in one embodiment of the present disclosure;
[0030] Figure 6 This is a graph showing the degradation kinetics of PFOA using different electrode materials according to one embodiment of the present disclosure. DETAILED DESCRIPTION
[0031] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0032] In order to make the objectives, technical solutions, and advantages of the present disclosure more clearly understood, the present disclosure is described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present disclosure and are not intended to limit the present disclosure. In addition, the technical features involved in the various embodiments of the present disclosure described below may be combined with each other as long as they do not conflict with each other.
[0033] like Figure 1 As shown: A method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt, the method comprising the following steps:
[0034] Selecting a first graphite felt material and a second graphite felt material;
[0035] cleaning the first graphite felt material and the second graphite felt material;
[0036] loading first metal atoms onto the surface of the first graphite felt material to form a first metal-modified electrode material;
[0037] loading second metal atoms onto the surface of the second graphite felt material to form a second metal-modified electrode material;
[0038] The first metal-modified electrode material is selected as the anode and the second metal-modified electrode material is selected as the cathode to carry out an electrocatalytic reaction of degrading perfluorooctanoic acid.
[0039] The first and second graphite felt materials are selected, for example, by selecting commercially available graphite felt materials and cutting them into a size suitable for the experimental needs, typically 5-7 cm squares. This step is intended to prepare the graphite felt materials to a size suitable for subsequent processing, ensuring ease of handling and use in subsequent steps.
[0040] The cut graphite felt material needs to be cleaned to remove any impurities, oil, or other contaminants that may be present on the surface, ensuring uniform metal loading and enhancing electrocatalytic performance. During this process, the cut graphite felt material is soaked in a cleaning agent, such as 50%–100% ethanol, for 30–60 minutes. The material is then rinsed with clean water 3–5 times until the surface is clean. This cleaning step ensures that the surface of the graphite felt material is in good condition, allowing for uniform metal loading and optimal catalytic performance.
[0041] Among them, the graphite felt material after cleaning and drying enters the plasma sputtering modification stage. In this stage, plasma sputtering technology is used to load metal atoms onto the surface of the graphite felt to form a metal-modified electrode material. The specific operation is: the treated graphite felt is placed on the sample table, and the high-purity metal target is placed in the vacuum chamber of the ion sputtering instrument. By adjusting the pulse current (usually 40-60mA), the plasma sputtering technology is used to sputter the metal atoms onto the surface of the graphite felt. The thickness of the loaded metal layer is generally between 2-10nm. The core of this step is to ensure the uniform distribution of metal atoms on the surface of the graphite felt by precisely controlling the sputtering conditions to form a metal catalyst with high catalytic activity.
[0042] Among them, the metal atoms include, for example, a first metal atom and a second metal atom, and specific metal atoms include copper, cobalt, platinum or palladium. The first metal atom and the second metal atom can be the same or different. For example, the first metal atom is copper and the second metal atom is cobalt. The first metal atom is loaded onto the surface of the first graphite felt material to form a first metal-modified electrode material; the second metal atom is loaded onto the surface of the second graphite felt material to form a second metal-modified electrode material.
[0043] After metal loading, the graphite felt material is used as an electrode for electrocatalytic reactions. For example, copper and cobalt metal-modified graphite felt electrodes are placed in an electrocatalytic degradation device to conduct PFOA degradation experiments. In the experiment, a 20–50 mg / L PFOA solution is placed in a PP beaker, and 20–30 mM Na2SO4 is added as an electrolyte to ensure the smooth progress of the electrocatalytic reaction. In the electrocatalytic reaction device, the cobalt-loaded graphite felt serves as the cathode, and the copper-loaded graphite felt serves as the anode. A CHI650E electrochemical workstation is used, and the reaction voltage is set to 3 V. Samples are taken every 5 minutes and filtered using a 0.45 μm aqueous disposable syringe filter (PES). The filtered liquid is placed in a PP liquid phase bottle for subsequent analysis. The PFOA removal effect is tested by high-performance liquid chromatography (HPLC) to evaluate the performance of the modified graphite felt electrode in PFOA degradation.
[0044] The key to this step is that the copper and cobalt metal-loaded graphite felt electrodes can efficiently generate active free radicals at a relatively low voltage. These free radicals can quickly oxidize and degrade PFOA molecules. Compared to traditional electrocatalytic electrodes, the copper and cobalt metal catalysts have stronger catalytic activity, significantly increasing the degradation rate of PFOA.
[0045] Alternatively, the first and second metal atoms can be the same, such as copper or cobalt. Although the catalytic activity may be lower, it can still achieve a certain PFOA degradation effect. Alternatively, other metal materials (such as platinum, palladium, and other precious metals) can be used for loading, which can achieve similar catalytic effects but at a higher cost. Furthermore, carbon-based materials (such as graphene or porous carbon) can also be used for modification.
[0046] Example 1
[0047] 1. Cutting of graphite felt materials
[0048] Purchase the graphite felt material used and cut it into 5×5 cm size for subsequent use.
[0049] 2. Cleaning of graphite felt materials
[0050] The cut graphite felt material is cleaned by immersing the cut graphite felt material in 75% ethanol at room temperature for 30 minutes, and then rinsing with clean water for 3-5 times to obtain a clean graphite felt material.
[0051] 3. Plasma sputtering modification of graphite felt materials
[0052] Place the clean graphite felt material on the sample table and the high-purity metal target material in the vacuum chamber of the ion sputtering instrument, evacuate the chamber, adjust the pulse current to 60mA, select the configured operating method, run the instrument, and sputter the high-purity metal target material atoms onto the graphite felt material to obtain copper and cobalt metal modified graphite felt.
[0053] 4. Electrocatalytic degradation of PFOA in water by modified graphite felt materials
[0054] 20mgL -1 The PFOA solution was placed in a PP beaker, and 20 mM Na2SO4 was added as an electrolyte. The copper and cobalt metal-modified graphite felt obtained in step (4) was placed in an electrocatalytic reaction device, the cobalt-loaded graphite felt was the cathode, and the copper-loaded graphite felt was the anode. The electrocatalytic degradation experiment was carried out using a CHI650E electrochemical workstation at a voltage of 3 V. Samples were taken every 5 minutes, filtered using a 0.45 μm water-based disposable needle filter (PES), and placed in a PP liquid phase bottle.
[0055] Figure 2 The scanning electron microscope and EDS images of the modified graphite felt in Example 1 show that metal atoms are successfully loaded on the graphite felt.
[0056] Using unmodified graphite felt as a control, an electrocatalytic degradation experiment of PFOA was conducted. The water concentration was detected by high performance liquid chromatography and the removal rate was calculated. The removal rate of PFOA in water was 41.7% after 30 minutes of electrocatalysis. The results are shown in the figure below. Figure 3 As shown in the figure, it was found that the degradation effect of modified graphite felt on PFOA was significantly higher than that of unmodified graphite felt.
[0057] Example 2
[0058] 1. Cutting of graphite felt materials
[0059] Purchase the graphite felt material used and cut it into 5×5 cm size for subsequent use.
[0060] 2. Cleaning of dirty graphite felt materials
[0061] The cut graphite felt material is cleaned by immersing the cut graphite felt material in 75% ethanol at room temperature for 30 minutes, and then rinsing with clean water for 3-5 times to obtain a clean graphite felt material.
[0062] 3. Plasma sputtering modification of graphite felt materials
[0063] Place the clean graphite felt material on the sample table and the high-purity metal target material in the vacuum chamber of the ion sputtering instrument, evacuate the chamber, adjust the pulse current to 60mA, select the configured operating method, run the instrument, and sputter the high-purity metal target atoms onto the graphite felt material to obtain copper and cobalt metal modified graphite felts with sputtered metal thicknesses of 2nm, 4nm, and 10nm, respectively.
[0064] 4. Electrocatalytic degradation of PFOA in water by modified graphite felt materials
[0065] 20mgL -1 The PFOA solution was placed in a PP beaker, and 20 mM Na2SO4 was added as an electrolyte. Modified graphite felts with sputtered metal thicknesses of 2 nm, 4 nm, and 10 nm were placed in an electrocatalytic reaction device. The cobalt-loaded graphite felt was used as the cathode, and the copper-loaded graphite felt was used as the anode. The electrocatalytic degradation experiment was carried out using a CHI650E electrochemical workstation at a voltage of 3 V. The electrocatalytic degradation experiment was carried out at a voltage of 3 V. Samples were taken every 5 minutes, filtered using a 0.45 μm aqueous disposable needle filter (PES), and placed in a brown liquid phase bottle made of PP.
[0066] The water concentration was determined using high performance liquid chromatography. Figure 4 The PFOA degradation kinetic curve in Example 2 shows that the degradation efficiency of PFOA does not increase with the increase of sputtered metal thickness. Therefore, selecting a suitable sputtering thickness is the key to achieving a high PFOA degradation rate.
[0067] Example 3
[0068] 1. Cutting of graphite felt materials
[0069] Purchase the graphite felt material used and cut it into 5×5 cm size for subsequent use.
[0070] 2. Cleaning of dirty graphite felt materials
[0071] The cut graphite felt material is cleaned by immersing the cut graphite felt material in 75% ethanol at room temperature for 30 minutes, and then rinsing with clean water for 3-5 times to obtain a clean graphite felt material.
[0072] 3. Plasma sputtering modification of graphite felt materials
[0073] Place the clean graphite felt material on the sample table and the high-purity metal target material in the vacuum chamber of the ion sputtering instrument, evacuate the chamber, adjust the pulse current to 60mA, select the configured operating method, run the instrument, and sputter the high-purity metal target material atoms onto the graphite felt material to obtain copper and cobalt metal modified graphite felt.
[0074] 4. Solvent cleaning membrane cleaning
[0075] 20mgL -1 The PFOA solution was placed in a PP beaker, and 20 mM Na2SO4 was added as an electrolyte. The 4 nm copper and cobalt metal-modified graphite felt obtained in step (4) was placed in an electrocatalytic reaction device, with the cobalt-loaded graphite felt as the cathode and the copper-loaded graphite felt as the anode. The electrocatalytic degradation experiment was carried out using a CHI650E electrochemical workstation at voltages of 1 V, 2 V, and 3 V, respectively. Samples were taken every 5 minutes, filtered using a 0.45 μm water-based disposable needle filter (PES), and placed in a PP liquid phase bottle.
[0076] The water concentration was detected by high performance liquid chromatography, and the results were as follows: Figure 5 As shown in the figure, it was found that the degradation effect of modified graphite felt on PFOA was in the voltage range of 1–3 V, and increased with the increase of voltage. Therefore, choosing a suitable applied voltage is crucial to improving the degradation efficiency of modified graphite felt on PFOA in water.
[0077] Example 4
[0078] 1. Cutting of graphite felt materials
[0079] Purchase the graphite felt material used and cut it into 5×5 cm size for subsequent use.
[0080] 2. Cleaning of dirty graphite felt materials
[0081] The cut graphite felt material is cleaned by immersing the cut graphite felt material in 75% ethanol at room temperature for 30 minutes, and then rinsing with clean water for 3-5 times to obtain a clean graphite felt material.
[0082] 3. Plasma sputtering modification of graphite felt materials
[0083] Place the clean graphite felt material on the sample table and the high-purity metal target material in the vacuum chamber of the ion sputtering instrument, evacuate the chamber, adjust the pulse current to 60 mA, select the configured operating method, run the instrument, and sputter the high-purity metal target material atoms onto the graphite felt material to obtain copper and cobalt metal modified graphite felt.
[0084] 4. Solvent cleaning membrane cleaning
[0085] 20mgL -1 The PFOA solution was placed in a PP beaker, and 20 mM Na2SO4 was added as an electrolyte. The copper and cobalt bimetallic modified graphite felt obtained in step (4) was placed in an electrocatalytic reaction device, with ① cobalt-loaded graphite felt as the cathode and copper-loaded graphite felt as the anode; ② cobalt-loaded graphite felt as the cathode and unmodified graphite felt as the anode; ③ unmodified graphite felt as the cathode and copper-loaded graphite felt as the anode. The electrocatalytic degradation experiment was carried out using a CHI650E electrochemical workstation at a voltage of 3 V. Samples were taken every 5 minutes, filtered using a 0.45 μm water-based disposable needle filter (PES), and placed in a PP liquid phase bottle.
[0086] The water concentration was detected by high performance liquid chromatography, and the results were as follows: Figure 6 As shown in the figure, the degradation effect of PFOA using cobalt-loaded graphite felt as cathode and copper-loaded graphite felt as anode is significantly higher than that of the other two groups of experiments.
[0087] Compared with the prior art, the present invention has the following beneficial effects:
[0088] By precisely controlling the loading and distribution of copper and cobalt, and fully leveraging the advantages of single-atom catalysis, the efficiency of the electrocatalytic reaction is significantly improved. In existing electrochemical degradation methods, most electrocatalytic materials have low catalytic efficiency and require high voltages to degrade PFOA. However, the method of the present invention can achieve efficient degradation at lower voltages, reducing energy consumption and maintaining good stability.
[0089] The embodiments described above are merely descriptions of preferred embodiments of the present disclosure. The preferred embodiments do not exhaust all details, nor do they limit the present invention to the specific embodiments described. Any modifications and improvements to the technical solutions of the present disclosure made by persons of ordinary skill in the art without departing from the spirit of the present disclosure shall fall within the scope of protection defined by the claims of the present disclosure.
Claims
1. A method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt, characterized in that: The method comprises the following steps: Selecting a first graphite felt material and a second graphite felt material; cleaning the first graphite felt material and the second graphite felt material; loading first metal atoms onto the surface of the first graphite felt material to form a first metal-modified electrode material; loading second metal atoms onto the surface of the second graphite felt material to form a second metal-modified electrode material; The first metal-modified electrode material is selected as the anode and the second metal-modified electrode material is selected as the cathode to carry out an electrocatalytic reaction of degrading perfluorooctanoic acid.
2. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: The first metal atom and the second metal atom are different.
3. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1 or 2, characterized in that: The first metal atom and the second metal atom include copper, cobalt, platinum or palladium.
4. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 3, characterized in that: The first metal atom is copper, and the second metal atom is cobalt.
5. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: The first metal atoms and the second metal atoms are loaded onto the surfaces of the first graphite felt material and the second graphite felt material by using plasma sputtering technology.
6. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: The supported first metal atomic layer and the second metal atomic layer have a thickness of 2-10 nm.
7. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1 or 6, characterized in that: The first metal atoms and the second metal atoms are uniformly distributed on the surfaces of the first graphite felt material and the second graphite felt material, respectively.
8. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: Na2SO4 is selected as the electrolyte for the electrocatalytic reaction.
9. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: The electrocatalytic reaction was carried out using a CHI650E electrochemical workstation, and the reaction voltage was set at 1V-3V.
10. The method for electrocatalytic degradation of perfluorooctanoic acid using metal-modified graphite felt according to claim 1, characterized in that: The reaction voltage is 3V.