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CN-119524899-B - Mono-atom catalyst for activating peroxymonosulfate, and preparation method and application thereof

CN119524899BCN 119524899 BCN119524899 BCN 119524899BCN-119524899-B

Abstract

The invention discloses a monoatomic catalyst for activating peroxymonosulfate, a preparation method and application thereof, wherein the catalyst comprises a nitrogen-sulfur co-doped Ti 3 C 2 T x nano-sheet and an iron monoatom or a cobalt monoatom which is aimed at the catalyst in an asymmetric coordination structure. The preparation method comprises mixing Ti 3 C 2 T x nanometer sheet, precursor containing nitrogen source and sulfur source, and soluble metal salt, self-assembling, freeze drying, and pyrolyzing. The monoatomic catalyst has excellent conductivity and electronic structure, can form a large amount of active oxygen substances in a catalytic degradation system on the premise of low addition amount of the persulfates, has the advantages of high activation efficiency of the persulfates, effectively reduced use amount of the persulfates and the like, can activate the persulfates to realize efficient purification of organic wastewater, can effectively reduce the operation cost of a persulfates activation technology, and can also remarkably reduce the new environmental pollution risk caused by using the persulfates in a large amount.

Inventors

  • YUAN XINGZHONG
  • LI MIAO
  • WANG HOU
  • Shu Aoqiang
  • SHU ZIHAN
  • CHEN XIANGYAN

Assignees

  • 湖南大学

Dates

Publication Date
20260508
Application Date
20241018

Claims (6)

  1. 1. The application of the monoatomic catalyst as the catalyst of the peroxymonosulfate in the treatment of the organic wastewater is characterized by comprising the following steps of mixing the monoatomic catalyst, the peroxymonosulfate and the organic wastewater for catalytic reaction to remove organic pollutants in the wastewater, wherein the concentration of the peroxymonosulfate in a catalytic reaction system is 0.05 mM-0.9 mM, and the concentration of the organic wastewater is less than or equal to 20 mu M; The preparation method of the monoatomic catalyst comprises the following steps: s1, mixing Ti 3 C 2 T x nano-sheets, a precursor containing a nitrogen source and a sulfur source and a soluble metal salt solution to perform self-assembly reaction to obtain the precursor, wherein the soluble metal salt solution is a soluble ferric salt solution or a soluble cobalt salt solution; s2, freeze-drying the precursor obtained in the step S1; s3, pyrolyzing the solid obtained after freeze drying in the step S2 to obtain a single-atom catalyst, wherein the pyrolysis is performed in a mixed atmosphere of nitrogen and hydrogen, the volume ratio of the nitrogen to the hydrogen in the mixed atmosphere of the nitrogen and the hydrogen is 9:1, and the pyrolysis temperature is 350-450 ℃; The monoatomic catalyst comprises a nitrogen-sulfur co-doped Ti 3 C 2 T x nano-sheet and a metal monoatom, wherein the metal monoatom is anchored on the nitrogen-sulfur co-doped Ti 3 C 2 T x nano-sheet in an asymmetric coordination structure, and the metal monoatom is an iron monoatom or a cobalt monoatom.
  2. 2. The application of the catalyst according to claim 1, wherein the addition amount of the monoatomic catalyst is 0.01 g-0.02 g of the monoatomic catalyst per liter of the organic wastewater, the concentration of the persulfates in the catalytic reaction system is 0.05 mM-0.6 mM, the organic pollutants in the organic wastewater are acetaminophen, the catalytic reaction is carried out under stirring conditions, the stirring rotation speed is 200 r/min-500 r/min, the temperature of the system is controlled to be 10 ℃ to 35 ℃ in the catalytic reaction process, and the catalytic reaction time is 3 min-8 min.
  3. 3. The use according to claim 1, wherein in step S1, the mass ratio of the Ti 3 C 2 T x nano-sheets, the precursor of the nitrogen source and the precursor of the sulfur source, and the soluble metal salt in the soluble metal salt solution is 100:100-600:1.1-6.4, and the precursor of the nitrogen source and the precursor of the sulfur source are thiourea.
  4. 4. The use according to claim 3, wherein in step S2, the freeze-drying is performed in a freeze-dryer for 24-48 hours; in the step S3, the heating rate in the pyrolysis process is 3-8 ℃ per minute, the pyrolysis time is 1-4 hours, and the treatment after the pyrolysis is finished comprises the steps of washing pyrolysis products by adopting water and ethanol in sequence and drying the washed pyrolysis products under a vacuum condition.
  5. 5. The use according to any one of claims 1,3, 4, wherein the mass of the metal monoatoms is 0.1% -0.5% of the mass of the monoatomic catalyst.
  6. 6. The use according to claim 5, wherein the mass of the metal monoatoms is 0.15% -0.3% of the mass of the monoatomic catalyst.

Description

Mono-atom catalyst for activating peroxymonosulfate, and preparation method and application thereof Technical Field The invention belongs to the field of new environmental materials, and relates to a monoatomic catalyst for activating peroxymonosulfate, and a preparation method and application thereof. Background The Peroxymonosulfate (PMS) activation technology can efficiently generate active oxygen substances such as hydroxyl free radicals, sulfate radical, superoxide free radicals, singlet oxygen and the like, can efficiently remove organic pollutants such as medicines, dyes, industrial chemicals and the like, and becomes a research hot spot in the current water treatment technology. However, complete degradation of contaminants typically requires high concentrations of PMS, which not only increases operating costs but also entails environmental disadvantages associated with high loads of sulfate. Therefore, optimizing process conditions to minimize PMS addition while maximizing contaminant removal efficiency remains a critical area of research. At present, the monoatomic catalyst has the advantage of high atom utilization rate, so that the addition amount of PMS is effectively reduced to a certain extent when the monoatomic catalyst is used for activating PMS, but when the conventional monoatomic catalyst is used for activating PMS, more PMS still needs to be added in order to improve the removal rate of pollutants to the greatest extent, wherein the minimum addition amount of PMS still reaches 1 mM-2 mM, which is unfavorable for effectively reducing the operation cost of the persulfates activation technology, and simultaneously, a large amount of sulfate radicals are introduced into a large amount of PMS so as to bring secondary pollution, so that the persulfates activation technology is difficult to widely develop practical application. Therefore, the monoatomic catalyst which has high PMS activation efficiency and can effectively reduce the PMS usage amount is obtained, and has great significance for realizing low-cost application of the peroxymonosulfate activation technology and promoting wide application thereof in treating organic wastewater. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art and providing a monoatomic catalyst of activated peroxymonosulfate, which has high activating efficiency on PMS and can effectively reduce the using amount of PMS, and a preparation method and application thereof. In order to solve the technical problems, the invention adopts the following technical scheme: A monoatomic catalyst for activating persulfates comprises nitrogen-sulfur co-doped Ti 3C2Tx nanometer sheets and metal monoatoms, wherein the metal monoatoms are aimed on the nitrogen-sulfur co-doped Ti 3C2Tx nanometer sheets in an asymmetric coordination structure, and the metal monoatoms are iron monoatoms or cobalt monoatoms. According to the monoatomic catalyst, the mass of the metal monoatomic catalyst is further improved to be 0.1% -0.5% of that of the monoatomic catalyst. According to the monoatomic catalyst, the mass of the metal monoatomic catalyst is further improved to be 0.15% -0.3% of that of the monoatomic catalyst. As a general technical idea, the present invention also provides a method for preparing a monoatomic catalyst for activating peroxymonosulfate, comprising the steps of: s1, mixing Ti 3C2Tx nano-sheets, a precursor containing a nitrogen source and a sulfur source and a soluble metal salt solution to perform self-assembly reaction to obtain the precursor, wherein the soluble metal salt solution is a soluble ferric salt solution or a soluble cobalt salt solution; s2, freeze-drying the precursor obtained in the step S1; and S3, pyrolyzing the solid obtained after freeze drying in the step S1 to obtain the monoatomic catalyst of the activated peroxymonosulfate. In the preparation method, in the step S1, the mass ratio of the Ti 3C2Tx nano-sheets, the precursor of the nitrogen source and the precursor of the sulfur source, and the soluble metal salt in the soluble metal salt solution is 100:100-600:1.1-6.4, and the precursor of the nitrogen source and the precursor of the sulfur source are thiourea. In the preparation method, in the step S2, the freeze drying is performed in a freeze dryer, and the time of the freeze drying is 24-48 hours. In the step S3, the pyrolysis is carried out in a mixed atmosphere of nitrogen and hydrogen, the volume ratio of the nitrogen to the hydrogen in the mixed atmosphere of the nitrogen and the hydrogen is 9:1, the heating rate in the pyrolysis process is 3-8 ℃ per minute, the pyrolysis temperature is 350-450 ℃, the pyrolysis time is 1-4 hours, and the method further comprises the steps of washing pyrolysis products by adopting water and ethanol in sequence, and drying the washed pyrolysis products under a vacuum condition. According to the preparation method, the monoatomic catalyst comp