Preparation method and application of iron-cobalt composite carbon-based electrode material
The iron-cobalt composite carbon-based electrode material prepared by pyrolysis reaction solves the problem that the prior art is difficult to efficiently degrade bisphenol A, and achieves efficient degradation effect. The method is simple, low-cost and environmentally friendly.
Patent Information
- Application Number
- CN202510202769.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-05-27
AI Technical Summary
Existing water treatment technologies are difficult to efficiently degrade bisphenol A in industrial wastewater, which is a threat to the ecological environment and human health.
The iron-cobalt composite carbon-based electrode material is prepared by a simple pyrolysis reaction, which consists of iron-cobalt inorganic salts and citrate as precursors, and forms a multi-stage pore structure electrode material through chelation reactions and pyrolysis processes, which is used to degrade bisphenol A in electrofenton technology.
This method realizes the efficient preparation of iron-cobalt composite carbon-based electrode material. The material has a high specific surface area and rich microporous and mesoporous structure, which significantly improves the efficiency of the electrofenton reaction and can efficiently degrade bisphenol A. The method is simple, low-cost and environmentally friendly.
Smart Images
Figure CN120037918A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of preparation of composite carbon-based electrode materials, and specifically relates to a preparation method of an iron-cobalt composite carbon-based electrode material and application thereof. Background Art
[0002] Environmental pollution is a major problem facing mankind today, which seriously hinders the development of society and the progress of industry. At present, it is urgent to develop economical, environmentally friendly and efficient water pollution treatment technologies to meet the current growing demand. With the rapid development of industry, bisphenol A (BPA), an organic compound widely used in the production of plastic products and other fields, has entered the water environment in large quantities, posing a serious threat to the ecological environment and human health. Bisphenol A has endocrine disrupting properties and may cause a variety of health problems. The more mature water treatment technologies currently include physical adsorption, membrane separation and electro-Fenton (EF) technology. Among them, researchers have widely used EF technology with fast response speed, low toxicity and reduced sludge generation to treat industrial wastewater. Therefore, EF method for treating wastewater has become a hot topic for scientists. As an advanced oxidation technology, electro-Fenton technology has great potential in degrading organic pollutants because it can produce strongly oxidizing hydroxyl radicals (·OH). Iron-cobalt composite carbon-based electrode materials have unique advantages in the electro-Fenton system, which can effectively improve the efficiency of the electro-Fenton reaction, thereby achieving efficient degradation of bisphenol A. In recent years, they have received extensive attention and research. Therefore, researchers are committed to designing and synthesizing multifunctional carbon materials in the hope of alleviating the energy crisis and completely solving the problem of water pollution.
[0003] At present, iron-cobalt composite carbon-based electrode materials combine the catalytic activity of cobalt and iron elements with the advantages of high conductivity and large specific surface area of carbon materials. As transition metal elements, cobalt and iron have multiple oxidation states, which can promote the cycle of Fe²⁺ / Fe³⁺ in the electro-Fenton reaction and improve the efficiency of OH generation. Carbon materials provide a good electron transmission channel for the reaction, which is conducive to the transfer of electrons. At the same time, their porous structure can increase the exposure of active sites and increase the contact area between electrode materials and pollutants. Iron-cobalt composite carbon-based electrode materials have an adjustable electronic structure and rich electrochemical active sites, which can help improve the ORR electrocatalytic activity of materials and have attracted great attention from researchers. At present, research on the use of iron-cobalt composite carbon-based electrode materials for electro-Fenton degradation of bisphenol A has made certain progress. Many scholars are committed to developing new preparation methods to improve the performance of electrode materials, while in-depth research on the reaction mechanism to provide theoretical support for optimizing reaction conditions. Some studies have achieved efficient degradation of bisphenol A on a laboratory scale, demonstrating the application potential of this technology. The Co and Fe dual-active site catalyst designed and synthesized by Professor Quan Xie's team at Dalian University of Technology synergistically catalyzes the generation of OH, where the Co site is mainly used to promote the generation of O2 Reduction to H 2 O 2 , while the Fe site is responsible for converting the generated H 2 O 2 Activated to ·OH, the diatomic sites synergistically promote the continuous and efficient degradation of pollutants. In summary, the iron-cobalt composite carbon-based electrode material has multiple synergistic effects, especially the Fe and Co elements can synergistically produce a unique electronic structure and further improve the electrocatalytic activity of the material. Therefore, the iron-cobalt composite carbon-based electrode material prepared by a simple hydrothermal reaction using iron-cobalt inorganic salts and citrate as precursors is an effective way to achieve the catalytic properties of the electrode material. Based on the previous research foundation of the research group on electrochemistry and the structure-activity relationship of energy storage and catalytic materials, the present invention is committed to preparing an iron-cobalt composite carbon-based electrode material through a simple pyrolysis reaction in one step, and the iron-cobalt composite carbon-based electrode material has outstanding electrocatalytic properties. Summary of the invention
[0004] The technical problems solved by the present invention are as follows: First, based on the previous research work of this research group, the electrochemical properties of electrode materials are tested by rotating disk electrodes to provide theoretical guidance for the application of screening electrode materials. By calculating, electrode materials with two electron transfers are used for electro-Fenton; and materials with four electron transfers are used for oxygen reduction fuel cells, which will be blindly tried and raised to theoretical guidance, greatly simplifying the attempts to screen electrode materials. Second, through the development of this work, a method for preparing iron-cobalt composite carbon-based electrode materials with multi-level pores coexisting by pyrolysis reaction is provided, which is simple in preparation process, low in cost and environmentally friendly. The method uses iron-cobalt inorganic salts and citrate as precursors, and the iron-cobalt composite carbon-based electrode materials prepared by a simple chelating reaction in one step are an effective way to achieve the catalytic properties of electrode materials. In order to explore the effects of chelating agent types and pyrolysis temperature on the metal content and pore structure of cobalt-iron composite carbon-based electrode materials, the present invention attempts to adjust the types of citrate to explore the effects of different citrates on the performance of carbon-based electrode materials. The preparation method is simple and easy to operate, which better promotes the large-scale application of electro-Fenton method for degrading organic pollutants.
[0005] The present invention adopts the following technical solution to solve the above technical problems, a method for preparing an iron-cobalt composite carbon-based electrode material, characterized in that the specific process is: Step S1: dissolving cobalt nitrate hexahydrate and chelating agent citrate in deionized water, adding potassium ferrocyanide and stirring to dissolve, then standing, centrifugally washing, and drying to obtain material A; Step S2: transferring the material A obtained in step S1 into a nickel boat and placing it in a tube furnace, heating it to 600-900° C. at a heating rate of 1-5° C. / min in a non-oxygen atmosphere with a flow rate of 100 mL / min and maintaining it for 80-200 min, and then naturally cooling it to room temperature to obtain material B; Step S3: Wash the material B obtained in step S2 with a hydrochloric acid solution for 2 to 3 times and then dry to obtain a target product, an iron-cobalt composite carbon-based electrode material with controllable pore size, wherein the specific surface area of the iron-cobalt composite carbon-based electrode material is 100-800 m 2 / g, and contains abundant micropores and mesopores, and is used as electro-Fenton cathode material for the degradation of organic wastewater.
[0006] Furthermore, in step S1, the mass ratio of potassium ferrocyanide to cobalt nitrate hexahydrate is 3:1 to 1:3.
[0007] Furthermore, the chelating agent in step S1 is one or more of sodium citrate, potassium citrate, magnesium citrate, ferrous citrate or ferric citrate.
[0008] Furthermore, the non-oxygen atmosphere in step S2 is one or more of nitrogen or argon.
[0009] Furthermore, the organic wastewater in step S3 is one or more of bisphenol A, levofloxacin or norfloxacin.
[0010] The method for preparing the iron-cobalt composite carbon-based electrode material of the present invention is characterized by the following specific steps: Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of citrate dihydrate were dissolved in 50 mL of deionized water and stirred for 30 min, and then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, and the mixture was stirred for 6 h and then allowed to stand for 6 h, centrifuged and washed, and dried in an oven at 100° C. to obtain material A; Step S2: transferring the material A obtained in step S1 into a nickel boat and placing it in a tube furnace, heating it to 600° C. at a heating rate of 2° C. / min in a nitrogen atmosphere with a flow rate of 100 mL / min and maintaining it for 120 min, and then naturally cooling it to room temperature to obtain material B; Step S3: Wash the material B obtained in step S2 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 100°C for 12 hours to obtain the target product, an iron-cobalt composite catalyst. The iron-cobalt composite catalyst is first tested for its acidic oxygen reduction performance, which shows ultra-high two-electron oxygen reduction performance.
[0011] The iron-cobalt composite carbon-based electrode material of the present invention is used as an electro-Fenton cathode catalyst for treating organic wastewater.
[0012] The iron-cobalt composite carbon-based electrode material of the present invention is used as an electro-Fenton cathode catalyst under acidic conditions for treating organic wastewater.
[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses citrate as a chelating agent to effectively chelate iron and cobalt ions, which not only enables the material to be evenly distributed during the synthesis process but also adjusts the pH of the reaction system, thereby increasing the specific surface area and pore volume of the carbon material, exposing more active sites, and enhancing the catalytic degradation activity of the material. In addition, the method is simple and has strong universality; 2. The present invention uses iron salt and cobalt salt as precursors and citrate as a chelating agent to in-situ introduce metal atoms on the basis of the carbon precursor, which not only improves the hydrophilicity and conductivity of the carbon material, but also exposes more active sites, further enhancing the electrochemical properties of the prepared composite material; 3. The specific surface area of the cobalt-iron composite catalyst prepared by the present invention is 100-800m 2 / g, and the material is regulated under the chelation effect of citrate so that the synthesized cobalt-iron composite catalyst can be evenly distributed on the framework of the material. At the same time, the carbonization process during high-temperature pyrolysis forms a large number of micropores and a multi-level pore structure with smaller pore sizes. It is applied as a cathode material in the electro-Fenton system, which can efficiently degrade organic pollutants, and will not cause secondary pollution during use, which is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 is a field emission scanning electron microscope image of the iron-cobalt composite carbon-based electrode material C1 prepared in Example 1; Figure 2 is the XRD pattern of the iron-cobalt composite carbon-based electrode materials C1-C4 prepared in Examples 1-4; Figure 3 1 is the XPS graph of the iron-cobalt composite carbon-based electrode materials C1 to C4 prepared in Examples 1 to 4; Figure 4 This is a degradation rate diagram of the iron-cobalt composite carbon-based electrode materials C1~C4 prepared in Example 1 for electro-Fenton degradation of bisphenol A. DETAILED DESCRIPTION
[0015] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example 1
[0016] Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of sodium citrate dihydrate were dissolved in 50 mL of deionized water and stirred for 30 min, and then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, and the mixture was stirred for 6 h and then allowed to stand for 6 h, centrifuged and washed, and dried in an oven at 100° C. to obtain material A1; Step S2: transferring material A1 into a nickel boat and placing it in a tube furnace, heating it to 600° C. at a heating rate of 2° C. / min in a nitrogen atmosphere with a flow rate of 100 mL / min and maintaining it for 120 min, and then naturally cooling it to room temperature to obtain material B1; Step S3: Wash material B1 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 100°C for 12 hours to obtain an iron-cobalt composite carbon-based electrode material C1. The iron-cobalt composite carbon-based electrode material is used as a cathode catalyst in an electro-Fenton system to degrade 50 mL of bisphenol A with a concentration of 20 mg / L. The degradation rate is 0.062 after 60 minutes. Example 2
[0017] Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of potassium citrate dihydrate were dissolved in 50 mL of deionized water and stirred for 30 min, and then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, and the mixture was stirred for 6 h and then allowed to stand for 6 h, centrifuged and washed, and dried in an oven at 100° C. to obtain material A2; Step S2: transferring material A2 into a nickel boat and placing it in a tube furnace, heating it to 600° C. at a heating rate of 2° C. / min in a nitrogen atmosphere with a flow rate of 100 mL / min and maintaining it for 120 min, and then naturally cooling it to room temperature to obtain material B2; Step S3: Wash material B2 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 100°C for 12 hours to obtain the target product, iron-cobalt composite carbon-based electrode material C2. The iron-cobalt composite carbon-based electrode material is used as a cathode catalyst in an electro-Fenton system to degrade 50 mL of bisphenol A with a concentration of 20 mg / L. The degradation rate is 0.035 after 60 minutes. Example 3
[0018] Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of ferric citrate dihydrate were dissolved in 50 mL of deionized water and stirred for 30 min, and then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, and the mixture was stirred for 6 h and then allowed to stand for 6 h, centrifuged and washed, and dried in an oven at 100° C. to obtain material A3; Step S2: transferring material A3 into a nickel boat and placing it in a tube furnace, heating it to 600° C. at a heating rate of 2° C. / min in a nitrogen atmosphere with a flow rate of 100 mL / min and maintaining it for 120 min, and then naturally cooling it to room temperature to obtain material B3; Step S3: Wash material B3 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 105°C for 12 hours to obtain the target product, iron-cobalt composite carbon-based electrode material C3. The iron-cobalt composite carbon-based electrode material C3 is used as a cathode catalyst in an electro-Fenton system to degrade 50 mL of bisphenol A with a concentration of 20 mg / L. The degradation rate is 0.053 after 60 minutes. Example 4
[0019] Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of magnesium citrate dihydrate were dissolved in 50 mL of deionized water respectively and stirred for 30 min, then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, the solution was stirred for 6 h and then allowed to stand for 6 h, washed by centrifugation, and dried in an oven at 100° C. to obtain material A4; Step S2: material A1 was transferred to a nickel boat and placed in a tube furnace. In a nitrogen atmosphere with a flow rate of 100 mL / min, the temperature was increased to 600°C at a heating rate of 2°C / min and maintained for 120 min, and then naturally cooled to room temperature to obtain material B4; Step S3: Wash material B4 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 100°C for 12 hours to obtain the target product, iron-cobalt composite carbon-based electrode material C4. The iron-cobalt composite carbon-based electrode material C4 is used as a cathode catalyst in an electro-Fenton system to degrade 50 mL of bisphenol A with a concentration of 20 mg / L. The degradation rate is 0.040 after 60 minutes.
[0020] The above embodiments describe 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 above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.
Claims
1. A method for preparing an iron-cobalt composite carbon-based electrode material, characterized in that The specific process is: Step S1: dissolving cobalt nitrate hexahydrate and chelating agent citrate in deionized water, adding potassium ferrocyanide and stirring to dissolve, then standing, centrifugally washing, and drying to obtain material A; Step S2: transferring the material A obtained in step S1 into a nickel boat and placing it in a tube furnace, heating it to 600-900° C. at a heating rate of 1-5° C. / min in a non-oxygen atmosphere with a flow rate of 100 mL / min and maintaining it for 80-200 min, and then naturally cooling it to room temperature to obtain material B; Step S3: Wash the material B obtained in step S2 with a hydrochloric acid solution for 2 to 3 times and then dry to obtain a target product, an iron-cobalt composite carbon-based electrode material with controllable pore size, wherein the specific surface area of the iron-cobalt composite carbon-based electrode material is 100-800 m 2 / g, and contains abundant micropores and mesopores, and is used as electro-Fenton cathode material for the degradation of organic wastewater.
2. The method for preparing the iron-cobalt composite carbon-based electrode material according to claim 1, characterized in that: The mass ratio of potassium ferrocyanide to cobalt nitrate hexahydrate in step S1 is 3:1 to 1:
3.
3. The method for preparing the iron-cobalt composite carbon-based electrode material according to claim 1, characterized in that: The chelating agent in step S1 is one or more of sodium citrate, potassium citrate, magnesium citrate, ferrous citrate or ferric citrate.
4. The method for preparing the iron-cobalt composite carbon-based electrode material according to claim 1, characterized in that: The non-oxygen atmosphere in step S2 is one or more of nitrogen or argon.
5. The method for preparing the iron-cobalt composite carbon-based electrode material according to claim 1, characterized in that: The organic wastewater in step S3 is one or more of bisphenol A, levofloxacin or norfloxacin.
6. The method for preparing the iron-cobalt composite carbon-based electrode material according to claim 1, characterized in that The specific steps are: Step S1: 3 mmol of cobalt nitrate hexahydrate and 4.5 mmol of citrate dihydrate were dissolved in 50 mL of deionized water and stirred for 30 min, and then 3 mmol of potassium ferrocyanide was dissolved in the obtained uniform solution, and the mixture was stirred for 6 h and then allowed to stand for 6 h, centrifuged and washed, and dried in an oven at 100° C. to obtain material A; Step S2: transferring the material A obtained in step S1 into a nickel boat and placing it in a tube furnace, heating it to 600° C. at a heating rate of 2° C. / min in a nitrogen atmosphere with a flow rate of 100 mL / min and maintaining it for 120 min, and then naturally cooling it to room temperature to obtain material B; Step S3: Wash the material B obtained in step S2 with 2M hydrochloric acid solution for 2 to 3 times and then dry it at 100°C for 12 hours to obtain the target product, an iron-cobalt composite catalyst. The iron-cobalt composite catalyst is first tested for its acidic oxygen reduction performance, which shows ultra-high two-electron oxygen reduction performance.
7. The iron-cobalt composite carbon-based electrode material prepared according to the method described in any one of claims 1 to 6 is used as an electro-Fenton cathode catalyst for treating organic wastewater.
8. The iron-cobalt composite carbon-based electrode material prepared according to the method described in any one of claims 1 to 6 is used as an electro-Fenton cathode catalyst under acidic conditions to treat organic wastewater.