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CN-118142581-B - Preparation method and application of chitosan-coated CoCe-LDH catalyst

CN118142581BCN 118142581 BCN118142581 BCN 118142581BCN-118142581-B

Abstract

The invention discloses a preparation method and application of chitosan-coated CoCe layered double hydroxide CoCe-LDH, which can realize rapid and efficient degradation of roxarsone and removal of inorganic arsenic. The LDH in the material is coated by chitosan, and the obtained material is in a sheet shape. The chitosan can disperse active sites and adsorb PMS to enrich the active sites, the LDH can convert PMS ions into an anion layer through anion exchange, so that the active sites are increased, and after PMS is coupled with materials, the PMS is specifically converted into 1 O 2 through electron transfer, so that the degradation rate is accelerated.

Inventors

  • ZHANG JINLONG
  • ZHOU LIANG
  • LEI JUYING
  • WANG YU
  • ZHENG YIFAN
  • WANG LIANGHUA
  • WANG LIHAN
  • An Qianfeng
  • CHEN HAIXIN

Assignees

  • 华东理工大学

Dates

Publication Date
20260505
Application Date
20240119

Claims (10)

  1. 1. A preparation method of chitosan-coated CoCe layered double hydroxide CoCe-LDH is characterized by comprising the following specific preparation steps: Dissolving cobalt nitrate and cerium nitrate in a molar ratio of 2:1 into deionized water, dripping sodium hydroxide and sodium carbonate solution until the pH value is=10, stirring under the condition of heating by an oil bath, obtaining precipitate after the reaction is complete, and washing and drying to obtain CoCe-layered double hydroxide CoCe-LDH; And 2) weighing a certain amount of the product obtained in the step 1), adding the product into a chitosan solution containing acetic acid, stirring uniformly, then dripping the chitosan solution into a sodium hydroxide solution, filtering to obtain a product, washing to be neutral, adding the product into glutaraldehyde solution for crosslinking, standing, filtering, washing, drying, and grinding to obtain CoCe layered double hydroxide CoCe-LDH coated with chitosan.
  2. 2. The method of claim 1, wherein in the step 2), the mass ratio of the product of the step 1) to chitosan is 0.2-0.8:1.
  3. 3. The method of claim 1, wherein in the step 2), the mass ratio of the product of the step 1) to chitosan is 0.6-0.8:1.
  4. 4. The method according to claim 1, wherein in step 1), the concentration of sodium hydroxide in the solution is 0.3mol/L and the concentration of sodium carbonate is 0.15mol/L.
  5. 5. The method of claim 1, wherein in step 1), the heating temperature is 65℃and the time is 24 hours.
  6. 6. The process according to claim 1, wherein in step 2), the concentration of acetic acid in the solution is 5% by volume and the concentration of chitosan in the solution is 33.3mg/mL.
  7. 7. The process according to claim 1, wherein in step 2), the concentration of the sodium hydroxide solution is 0.5mol/L.
  8. 8. The process according to claim 1, wherein in step 2), the glutaraldehyde concentration is 0.025mol/L.
  9. 9. A chitosan-coated CoCe layered double hydroxide material prepared by the method of any one of claims 1-8.
  10. 10. Use of the chitosan coated CoCe layered double hydroxide material of claim 9 for simultaneous removal of inorganic arsenic during degradation of roxarsone by activated peroxymonosulfate PMS.

Description

Preparation method and application of chitosan-coated CoCe-LDH catalyst Technical Field The invention relates to a preparation method of chitosan-coated CoCe layered double hydroxide CoCe-LDH (CCHG) and application thereof in activating and degrading roxarsone by peroxomonosulfate PMS and removing inorganic arsenic in situ, belonging to the field of functional technical materials. Background In recent years, advanced oxidation processes have been widely used in the field of contaminant remediation to degrade organic contaminants by generating reactive species. The persulfate-activated advanced oxidation process is considered to have a broad prospect due to its high reaction speed and high mineralization rate. Reactive Oxygen Species (ROS), such As OH, SO 4. Cndot. -and 1O2, are generally generated during the activation of PMS, which have high oxidation potentials, not only to degrade ROX, but also to oxidize the As (III) formed to As (V). The Co-based material widely studied at present has good performance in the aspect of activating PMS, but has poor adsorptivity to inorganic arsenic, and is unfavorable for completely removing ROX. In general, iron-based materials are commonly used for adsorbing inorganic arsenic, but the iron-based materials are very easy to leach out in the process of activating PMS, so that secondary pollution of water is caused, and the catalyst is quickly deactivated. Thus, bimetallic composite strategies have attracted attention. The rich metal ions and the valence state change between the metal ions bring faster PMS activation speed, and meanwhile, the reasonable selection of the bimetal can simultaneously meet the activation of PMS and the adsorption of inorganic arsenic. Chitosan is a common naturally degradable cationic biopolymer. the-NH 2 in the chitosan can adsorb metal ions in water, so that ion leaching is reduced, and the adsorption of PMS is promoted, so that the activation of PMS is enhanced, and the chitosan becomes an excellent metal-based catalyst substrate. Thus, chitosan-encapsulated CoCe-LDH appears to be a catalyst that can efficiently activate PMS and has a high stability. Disclosure of Invention The invention provides a preparation method of chitosan-coated CoCe layered double hydroxide CoCe-LDH (CCHG) and application of the chitosan-coated CoCe layered double hydroxide in PMS activation to reduce Jie Luoke sand arsine and remove inorganic arsenic in situ. The LDH in the material is coated by chitosan, and the obtained material is in a sheet shape. The chitosan can disperse active sites and adsorb PMS to enrich the active sites, the LDH can convert PMS ions into an anion layer through anion exchange, so that the active sites are increased, and after PMS is coupled with materials, the PMS is specifically converted into 1O2 through electron transfer, so that the degradation rate is accelerated. A preparation method of chitosan-coated CoCe layered double hydroxide CoCe-LDH is characterized by comprising the following specific preparation steps: Dissolving cobalt nitrate and cerium nitrate in a molar ratio of 2:1 into deionized water, dripping sodium hydroxide and sodium carbonate solution until the pH value is=10, stirring under the condition of heating by an oil bath, obtaining precipitate after the reaction is complete, and washing and drying to obtain CoCe-layered double hydroxide CoCe-LDH; And 2) weighing a certain amount of the product obtained in the step 1), adding the product into a chitosan solution containing acetic acid, stirring uniformly, then dripping the chitosan solution into a sodium hydroxide solution, filtering to obtain a product, washing to neutrality, adding the product into glutaraldehyde solution for crosslinking, standing, filtering, washing, drying, and grinding to obtain CoCe layered double hydroxide CoCe-LDH (CCHG) wrapped by chitosan. Further, in step 2), the mass ratio of the product of step 1 to chitosan is 0.2-0.8:1, preferably 0.6-0.8:1. Further, in the step 1), the concentration of sodium hydroxide was 0.3mol/L. Further, in the step 1), the concentration of sodium carbonate was 0.15mol/L. Further, in step 1), the heating temperature was 65℃and the time was 24 hours. Further, in the step 2), the volume concentration of acetic acid was 5% (v/v), and the chitosan concentration was 33.3 mg/mL. Further, in the step 2), the concentration of the sodium hydroxide solution was 0.5mol/L. Further, in the step 2), the concentration of glutaraldehyde is 0.025mol/L. A chitosan-coated CoCe layered double hydroxide material is prepared by the preparation method. An application of the chitosan-coated CoCe layered double hydroxide material in synchronously removing inorganic arsenic in the process of activating PMS (peroxomonosulfate) to reduce Jie Luoke sand arsine. The beneficial technical effects of the invention 1. The anionic layer in the cobalt-cerium layered double hydroxide CoCe-LDH structure exchanges with PMS ions to increase active sites,