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CN-121988293-A - Titanium lithium ion sieve adsorption film and preparation method thereof

CN121988293ACN 121988293 ACN121988293 ACN 121988293ACN-121988293-A

Abstract

The application belongs to the field of environmental science and technology, and discloses a titanium-series lithium ion sieve adsorption film and a preparation method thereof, wherein the preparation method comprises the steps of preparing a lithium ion sieve precursor; preparing a two-dimensional transition metal carbon/nitride (MXene) sheet material, preparing a casting solution by using a solvent, PVC, a lithium ion sieve precursor and the MXene sheet material, standing and defoaming the casting solution, coating the casting solution on a clean plane, immersing the casting solution in water to obtain a precursor film, and immersing the precursor film in an HCl solution to extract Li to obtain the lithium ion sieve adsorption film. According to the application, the precursor of the lithium ion sieve is fixed in the membrane by the membrane forming method, so that the powdery adsorbent can be directly limited in the membrane, the prepared adsorption membrane of the lithium ion sieve has good physical and chemical stability, is convenient to recycle, and can be regenerated by the hydrochloric acid solution, thereby realizing the recycling of materials.

Inventors

  • CHEN ZHENNAN
  • TONG KUN
  • SHAO ZHIGUO
  • DU JINGJING
  • XIE SHUIXIANG
  • WEI NING
  • NIE FAN
  • REN WEN
  • LIU GUANGQUAN
  • ZHANG XIAOFEI

Assignees

  • 中国石油天然气集团有限公司
  • 中国石油集团安全环保技术研究院有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. The preparation method of the titanium lithium ion sieve adsorption film is characterized by comprising the following steps of: preparing a lithium ion sieve precursor; preparing a two-dimensional transition metal carbon/nitride (MXene) sheet material; preparing a casting solution by using a solvent, PVC, the lithium ion sieve precursor and the MXene sheet material; Coating the casting solution on a clean plane after standing and defoaming, and immersing the casting solution in water to obtain a Li 2 TiO 3 /MXene@PVC precursor film; And (3) putting the Li 2 TiO 3 /MXene@PVC precursor film into an HCl solution to soak and extract Li, so as to obtain the HTO/MXene@PVC titanium lithium ion sieve adsorption film.
  2. 2. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 1, wherein the preparation of the lithium ion sieve precursor comprises the following steps: And uniformly mixing Li 2 CO 3 and TiO 2 , and calcining to obtain the lithium ion sieve precursor.
  3. 3. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 2, wherein the molar ratio of Li 2 CO 3 to TiO 2 is 0.9-1.1:1.
  4. 4. The method for preparing the titanium-based lithium ion sieve adsorption film according to claim 1, wherein the preparation of the MXene sheet material comprises the following steps: etching MAX Ti 3 AlC 2 by using LiF to obtain etching material; Washing the etching material for the first time until the neutral pH value is reached; Carrying out ultrasonic treatment and primary centrifugation on the etching material subjected to primary washing in an organic solvent, and then carrying out secondary washing and secondary centrifugation to remove residual organic solvent, thereby obtaining an intermediate; Mixing the intermediate with water, and collecting upper-layer d-MXene nano-sheet slurry after ultrasonic and centrifugal treatment; And freeze-drying the d-MXene nano-sheet slurry to obtain the MXene sheet material.
  5. 5. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 1, wherein the solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, chloroform and tributyl phosphate.
  6. 6. The preparation method of the titanium-series lithium ion sieve adsorption film according to claim 1, wherein the mass ratio of the lithium ion sieve precursor to the MXene flaky material in the casting film liquid is 2-8:1.
  7. 7. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 1 or 6, wherein the ratio of the sum of the mass of PVC, the mass of a lithium ion sieve precursor and the mass of an MXene sheet material to the mass of a solvent in the casting film liquid is 7-9:13.
  8. 8. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 1 or 6, wherein the ratio of the sum of the mass of the lithium ion sieve precursor and the mass of the MXene sheet material to the mass of the PVC in the casting film liquid is 5:3.
  9. 9. The method for preparing a titanium-based lithium ion sieve adsorption film according to claim 1, wherein the casting solution is coated on a clean plane after standing and defoaming and immersed in water for at least 12 hours.
  10. 10. A titanium-based lithium ion sieve adsorption membrane, characterized in that the titanium-based lithium ion sieve adsorption membrane is prepared by the method of any one of claims 1-9.

Description

Titanium lithium ion sieve adsorption film and preparation method thereof Technical Field The application belongs to the field of environmental science and technology, and particularly relates to a titanium lithium ion sieve adsorption film and a preparation method thereof. Background The main existing forms of lithium in nature are solid lithium ore and liquid lithium, wherein the solid lithium ore is mainly a pegmatite type and sedimentary type lithium-containing ore, and the liquid lithium is mainly in salt lake brine, underground brine and sea water. Of these, lithium is most abundant in continental saline (59%) followed by hard rock (25%). With the increasing activities of petroleum exploration and development, a large amount of oilfield water resources are generated. Besides a large amount of Na +、K+ plasma, the oilfield water is enriched with various microelements such as lithium ions and the like. The lithium resources rich in the oilfield water are recycled, so that the environmental pollution caused by direct discharge of the oilfield water can be avoided, and the method has important significance for the maximum utilization and sustainable development of the resources. The existing methods for obtaining liquid lithium resources mainly comprise a precipitation method, an extraction method, an adsorption method and an electrochemical method. Among them, the ion sieve adsorption method has become the most promising method for extracting lithium from salt lake brine because of the advantages of lower toxicity, lower cost, stable chemical property and high selectivity. Ion sieve adsorbents mainly comprise manganese-based lithium ion Sieves (HMOs) and titanium-based lithium ion Sieves (HTOs), and titanium-based lithium ion sieves are receiving more and more attention because of their strong chemical stability and lower dissolution loss rate than manganese-based lithium ion sieves. However, the conventional titanium-based lithium ion sieve has problems that the adsorption capacity is low, the powdery adsorbent is difficult to recycle in actual production, and the adsorption capacity of the formed titanium-based lithium ion sieve is greatly reduced. There is therefore a need for improvements over existing titanium-based lithium ion sieves. Disclosure of Invention In order to overcome the defects in the prior art, the application aims to provide the titanium lithium ion sieve adsorption film which can realize selective adsorption of lithium ions in water and has good adsorption capacity and cycle performance. In order to achieve the above object, in a first aspect, the present application provides a method for preparing a titanium-based lithium ion sieve adsorption membrane, comprising: preparing a lithium ion sieve precursor; preparing a two-dimensional transition metal carbon/nitride (MXene) sheet material; preparing a casting film solution by using a solvent, PVC (polyvinyl chloride), a lithium ion sieve precursor and an MXene sheet material; standing and defoaming the casting solution, coating the casting solution on a clean plane, and immersing the casting solution in water to obtain a Li 2TiO3/MXene@PVC precursor film; And (3) putting the Li 2TiO3/MXene@PVC precursor film into an HCl solution to soak and extract Li, so as to obtain the HTO/MXene@PVC titanium series lithium ion sieve adsorption film. Further, preparing a lithium ion sieve precursor, comprising: And uniformly mixing Li 2CO3 and TiO 2, and calcining to obtain the lithium ion sieve precursor. Further, the molar ratio of Li 2CO3 to TiO 2 is 0.9-1.1:1. Further, an MXene sheet material was prepared comprising: etching MAX Ti 3AlC2 by using LiF to obtain etching material; Washing the etching material for the first time until the neutral pH value is reached; Carrying out ultrasonic treatment and primary centrifugation on the etching material subjected to primary washing in an organic solvent, carrying out secondary washing by deionized water, and removing residual organic solvent through secondary centrifugation to obtain an intermediate; mixing the intermediate with deionized water, and collecting upper-layer d-MXene nano-sheet slurry after ultrasonic treatment and centrifugation; And freeze-drying the d-MXene nano-sheet slurry to obtain the MXene sheet material. Further, the solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, chloroform and tributyl phosphate. Further, the mass ratio of the lithium ion sieve precursor to the MXene flaky material in the casting film liquid is 2-8:1. Further, the ratio of the sum of the mass of PVC, the mass of the precursor of the lithium ion sieve and the mass of the MXene sheet material to the mass of the N-methylpyrrolidone in the casting solution is 7-9:13. Further, the ratio of the sum of the mass of the lithium ion sieve precursor and the mass of the MXene sheet material to the mass of the PVC in the casting film liquid is 5:3. Furt