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CN-121972195-A - Preparation method of bimetallic nitrogen-doped carbon catalyst and application of bimetallic nitrogen-doped carbon catalyst in degradation of organic pollutants in water body

CN121972195ACN 121972195 ACN121972195 ACN 121972195ACN-121972195-A

Abstract

The invention discloses a preparation method of a bimetallic nitrogen-doped carbon catalyst and application thereof in degrading organic pollutants in water, wherein the preparation method comprises the following steps of (1) adding potassium ferricyanide into deionized water to obtain a solution A, adding cobalt nitrate hexahydrate and sodium citrate into the deionized water to obtain a solution B, (2) slowly dropwise adding the solution A into the solution B under continuous stirring to obtain a mixed solution, (3) standing the mixed solution in darkness, filtering, cleaning and drying to obtain a Co-Fe Prussian blue analogue, and (4) mixing the Co-Fe Prussian blue analogue with melamine, placing the mixture in a tubular furnace, carrying out heat treatment under continuous nitrogen flow, grinding, pickling, filtering and drying after pickling to obtain the bimetallic nitrogen-doped carbon catalyst.

Inventors

  • TANG SHENG
  • JIN YIFAN
  • TONG ZHENGYANG
  • ZHANG LIANG

Assignees

  • 江苏科技大学

Dates

Publication Date
20260505
Application Date
20251210

Claims (10)

  1. 1. The preparation method of the bimetallic nitrogen-doped carbon catalyst is characterized by comprising the following steps of: (1) Adding potassium ferricyanide into deionized water to obtain solution A, adding cobalt nitrate hexahydrate and sodium citrate into deionized water to obtain solution B; (2) Slowly dripping the solution A into the solution B under continuous stirring to obtain a mixed solution; (3) Standing the mixed solution in the dark, filtering, cleaning and drying after standing to obtain a Co-Fe Prussian blue analogue; (4) Mixing the Co-Fe Prussian blue analogue with melamine, placing the mixture in a tube furnace, performing heat treatment under continuous nitrogen flow, grinding and acid washing after the heat treatment, filtering and drying after the acid washing to obtain the bimetallic nitrogen-doped carbon catalyst.
  2. 2. The method for preparing a bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (1), the adding mass ratio of potassium ferricyanide, cobalt nitrate hexahydrate and sodium citrate is 0.66-0.68:0.876-0.88:1.14-1.15.
  3. 3. The preparation method of the bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (3), the bimetallic nitrogen-doped carbon catalyst is placed in the dark for 24-36 hours.
  4. 4. The method for preparing a bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (3), the drying temperature is 60-80 ℃ and the drying time is 24-48 h.
  5. 5. The preparation method of the bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (4), the mass ratio of the Co-Fe Prussian blue analogues to the melamine is 1:1-7.
  6. 6. The method for preparing a bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (4), the heat treatment temperature is 600-650 ℃, the speed is 3-5 ℃ per minute, and the heat treatment time is 2-4 hours.
  7. 7. The method for preparing the bimetallic nitrogen-doped carbon catalyst according to claim 1, wherein in the step (4), the specific process of acid washing is that the ground material is soaked in 100-150 mL of sulfuric acid solution with the concentration of 1-1.2M, and stirred for 6-8 hours at 80-100 ℃.
  8. 8. The use of the catalyst prepared by the preparation method of claim 1 for degrading organic pollutants in a water body.
  9. 9. The method according to claim 8, wherein the catalyst is added to an aqueous solution having an initial concentration of organic pollutants of 25-200. Mu.M at a concentration of not higher than 0.2g/L and PMS at a mass concentration of 0.15-0.6 g/L, and the reaction is carried out at a temperature of 25-30 ℃ and a pH of 3-11.
  10. 10. The method according to claim 9, wherein the organic contaminant comprises at least one of an antibiotic, a dye, or a phenolic compound, and the oxidizing agent is potassium hydrogen persulfate.

Description

Preparation method of bimetallic nitrogen-doped carbon catalyst and application of bimetallic nitrogen-doped carbon catalyst in degradation of organic pollutants in water body Technical Field The invention relates to a preparation method of a bimetallic nitrogen-doped carbon catalyst, and also relates to application of the catalyst prepared by the method in degrading organic pollutants in water. Background In recent years, water safety problems are receiving more and more attention from the society, especially in the background of increasingly serious water source pollution and water quality safety. Tetracyclines are used in large amounts because of their broad-spectrum antimicrobial properties, but most are not completely absorbed by organisms and ultimately enter the aqueous environment in the form of their precursors or metabolites. These residual antibiotics not only induce microbial resistance, but also can potentially pose a threat to the ecosystem and human health through food chain enrichment. For removal of pollutants in water, traditional water treatment technologies such as biodegradation, physical adsorption and the like are often limited in efficiency when dealing with such persistent organic pollutants, and thorough mineralization is difficult to achieve. Advanced Oxidation Processes (AOPs) are receiving a great deal of attention for their ability to efficiently remove organic contaminants, wherein persulfate (PMS and PDS) -based AOPs exhibit extremely high redox potentials (2.5-3.1V), long half-lives (30-40 μs) and wide pH application ranges (3-11), and thus have great application potential in water treatment. Among the persulfate activation methods, the transition metal heterogeneous catalysis is considered as one of the most effective modes due to its high efficiency and stability. Transition metals such as cobalt, iron, manganese, by virtue of their variable valence properties, are capable of highly efficient catalysis of PMS to produce Reactive Oxygen Species (ROS), thereby increasing their oxidizing ability. Co has a high oxidation-reduction potential (2.5-3.1 eV), which enables PMS to be activated to generate acid radical (SO 4-) and hydroxyl radical (OH) for oxidative degradation of organic pollutants in water. The currently prepared transition metal heterogeneous catalyst comprises a core-shell structure of a non-metallic material coated with a metallic material, and then the structure can lead to a reduction of the surface active sites of the material, and a reduction of the generation amount of Reactive Oxygen Species (ROS), thereby affecting the pollutant removal capability of the catalyst. However, the existing heterogeneous persulfate catalytic systems with transition metals or alloys thereof as cores still have obvious disadvantages, especially in core-shell structures with carbon materials coating the metal active components. The conventional carbon layer is generally thicker, although the structural stability can be improved, metal active sites such as Co or Fe can be obviously shielded, interface electronic coupling is weakened, the adsorption, bond breaking and activation efficiency of PMS are limited, and generation of Reactive Oxygen Species (ROS) is further inhibited. In addition, the single metal catalyst lacks an electron cooperative regulation space, the fixed electronic structure is difficult to further optimize the reaction path and mineralization capability, the structure and doping strategy of the existing carbon layer are also often lack of pertinence, and the metal protection and electron transmission are difficult to be simultaneously considered, so that the metal can still be dissolved out under a strong oxidation environment, and activity attenuation and secondary pollution are caused. Disclosure of Invention The invention aims to provide a preparation method of the bimetallic nitrogen-doped carbon catalyst, which has high structural stability and high catalytic activity, and the invention also aims to provide the application of the catalyst prepared by the method in degrading organic pollutants in water. The preparation method of the bimetallic nitrogen-doped carbon catalyst comprises the following steps: (1) Adding potassium ferricyanide into deionized water to obtain solution A, adding cobalt nitrate hexahydrate and sodium citrate into deionized water to obtain solution B; (2) Slowly dripping the solution A into the solution B under continuous stirring to obtain a mixed solution; (3) Standing the mixed solution in the dark, filtering, cleaning and drying after standing to obtain a Co-Fe Prussian blue analogue; (4) Mixing Co-Fe Prussian blue analogues with melamine, placing the mixture in a tube furnace, carrying out heat treatment under continuous nitrogen flow, grinding and acid washing after the heat treatment (the acid washing step is used for removing CoFe metal alloy of which the surface of the catalyst is not coated by nitrogen-doped carbon so as to e