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CN-122010105-A - Intercalation agent for graphene preparation and preparation method and application thereof

CN122010105ACN 122010105 ACN122010105 ACN 122010105ACN-122010105-A

Abstract

The invention belongs to the technical field of graphene preparation, and particularly relates to an intercalation agent for graphene preparation, and a preparation method and application thereof. The preparation method of the intercalation agent for preparing the graphene comprises the following steps of (1) providing a sodium cholate aqueous solution as a base solution, (2) adding a micro-environment regulator into the base solution, regulating and stabilizing the pH value and/or the ionic strength I of a system to a preset target value, (3) dropwise adding a calcium ion-containing aqueous solution into the solution obtained in the step (2) under the conditions of continuous stirring and temperature control, and controlling the final molar concentration ratio R of the calcium ions and the sodium cholate to the preset value, and (4) curing the mixed solution obtained in the step (3) at a set temperature to obtain the intercalation agent for preparing the graphene. The intercalation agent system has definite environmental response and self-adaption characteristics, and the application of the intercalation agent system in the preparation of graphene is beneficial to obtaining graphene with narrow layer number distribution and high quality.

Inventors

  • JIN ZUQUAN
  • WANG HONG
  • ZHAO LINGLING
  • PANG BO
  • SHEN AO
  • XU MINGFEI
  • LI SHICAI

Assignees

  • 青岛理工大学

Dates

Publication Date
20260512
Application Date
20260121

Claims (10)

  1. 1. The preparation method of the intercalation agent for preparing the graphene is characterized by comprising the following steps of: (1) Providing sodium cholate aqueous solution as a base solution; (2) Adding a micro-environment regulator into the base liquid, and regulating and stabilizing the pH value and/or the ionic strength I of the system to a preset target value; (3) Dropwise adding an aqueous solution containing calcium ions into the solution obtained in the step (2) under the conditions of continuous stirring and temperature control, and controlling the final molar concentration ratio R of the calcium ions and sodium cholate to a preset value; (4) Curing the mixed solution obtained in the step (3) at a set temperature to obtain an intercalation agent for preparing graphene; In the step (2), the preset target value is pH=5.5-8.5 and/or ionic strength I=0.01-0.2M; In the step (3), 0<R is less than or equal to 1.0.
  2. 2. The method for preparing an intercalating agent for graphene preparation according to claim 1, wherein in step (2), the preset target value is ph=7.0±0.5 and/or ionic strength i=0.05-0.15M; In the step (3), R is more than or equal to 0.25 and less than or equal to 0.75.
  3. 3. The method for preparing an intercalating agent for graphene preparation according to claim 1, wherein in the step (3), the dropping rate is 0.5-2.0mL/min, the stirring rotation speed is 300-600rpm, and the temperature is 25+ -2 ℃; In the step (4), the curing treatment is carried out at a temperature of 25-35 ℃ for 1-3 hours.
  4. 4. The method for producing an intercalating agent for graphene production according to claim 1, wherein the concentration of sodium cholate in the base liquid is 10-100mM; In the aqueous solution containing calcium ions, the concentration of the calcium ions is 2.5-75mM.
  5. 5. The method for preparing an intercalating agent for graphene preparation according to claim 1, wherein the components of the micro-environmental control agent include a pH buffer and/or an inert electrolyte; The pH buffer is at least one of a phosphate buffer pair, a Tris-HCl buffer pair and a carbonate buffer pair; The inert electrolyte is sodium chloride and/or potassium chloride; the calcium salt in the aqueous solution containing calcium ions is at least one of calcium chloride, calcium nitrate and calcium acetate.
  6. 6. An intercalating agent, characterized in that it is prepared by the method according to any of claims 1-5.
  7. 7. A method for preparing graphene, which is characterized by comprising the step of intercalation of a graphite raw material by using the intercalator according to claim 6.
  8. 8. The method for preparing graphene according to claim 7, comprising the steps of: s1, adding a graphite raw material into the intercalation agent, and performing intercalation treatment to obtain a first mixture; S2, carrying out ultrasonic treatment on the mixture obtained by the treatment in the step (1) to obtain a second mixture; s3, separating the second mixture obtained through the treatment in the step S2.
  9. 9. The method for preparing graphene according to claim 8, comprising the steps of step S1, wherein the intercalation treatment is performed under stirring conditions at room temperature for 6-24 hours; In the step S2, the ultrasonic treatment is carried out under the ice water bath condition, the ultrasonic power is 400-600W, the frequency is 40kHz, and the ultrasonic treatment time is 2-8h; In the step S3, the separation mode is step centrifugal separation, namely, firstly, the non-exfoliated graphite raw material is removed by centrifugation at 800-1200rpm for 10-20min, and then, the supernatant is collected by centrifugation at 3000-5000rpm for 20-40min, wherein the graphene is positioned in the supernatant.
  10. 10. A graphene prepared by the method of any one of claims 7-9.

Description

Intercalation agent for graphene preparation and preparation method and application thereof Technical Field The invention belongs to the technical field of graphene preparation, and particularly relates to an intercalation agent for graphene preparation, and a preparation method and application thereof. Background With the rapid development of high and new technologies such as electronic information, new energy sources and composite materials, the demand for two-dimensional materials such as graphene is increasing, and particularly, the accurate requirement is provided for few-layer graphene with a specific layer number (such as single/double layers or 3-5 layers). However, precise control of the number of graphene layers is a core technical bottleneck faced by its scaled and customized applications. Currently, the main methods for preparing few-layer graphene include a mechanical stripping method, a chemical vapor deposition method and a liquid phase stripping method. Among them, the liquid phase stripping method is considered as one of the most potential preparation routes because of relatively simple operation, low cost and easy scale. The method generally reduces van der Waals force between graphite layers by means of a surfactant or a solvent, and achieves exfoliation by physical effects such as ultrasound. The liquid phase stripping method is mainly used for breaking Van der Waals force between graphite layers by physical methods such as ultrasonic and shearing, so that the graphite layers are stripped into graphene. In order to improve the peeling efficiency, it is generally necessary to first intercalate graphite to enlarge the interlayer spacing of graphite and reduce the interlayer acting force. The preparation method of the few-layer graphene is disclosed in CN102583351B, and comprises the steps of combining a liquid phase intercalation technology and a microwave irradiation technology, firstly placing graphite into a solution containing tetraalkyl substituted quaternary amine cations and OH - for ultrasonic treatment, enabling the tetraalkyl substituted quaternary amine cations to be intercalated between graphite layers to form intercalation, then carrying out microwave irradiation on the treated graphite to enable the graphite intercalation to be decomposed to generate a large amount of gas, further increasing the interlayer distance of the graphite, and finally dispersing the treated graphite in a low-polarity organic solvent for ultrasonic treatment to enable the graphite to be exfoliated to generate graphene. CN114735686B discloses a preparation method of graphene aqueous solution and graphene nano-sheets, the method selects graphite particles with particle size less than or equal to 20 μm, the dispersing agent and the graphite particles are added into deionized water, and graphene slurry containing few layers of graphene, multi-layer graphene and graphene nano-sheets is obtained through stirring and shearing treatment, ultrasonic vibration and high-pressure emulsification. CN103910354B provides a method for preparing graphene in a large-scale aqueous phase, which takes graphite as a raw material, firstly intercalates the graphite by using an intercalating agent, enlarges interlayer distance between graphene sheets, weakens interlayer interaction force, further directly treats intercalated graphite by ultrasonic waves, and peels and uniformly disperses the intercalated graphite in an alkaline aqueous solution with ph=10-14. In order to control the number of layers of graphene, CN111017916A discloses a preparation method of graphene with controllable number of layers, which comprises the steps of uniformly dispersing large-size graphite in methyl pyrrolidone, regulating the pH value of a solution to 11, performing ultrasonic dispersion to obtain multi-layer graphene, performing microwave heating and ultrasonic stripping for a certain time, performing high-speed centrifugation, cleaning for three times, and performing freeze drying to obtain a few-layer and single-layer graphene material. CN110980707a discloses a method for preparing few-layer graphene by mechanical stripping, which uses graphite paper as an anode and a graphite plate as a cathode, electrochemical stripping is carried out on the anode in electrolyte, then electrochemical treatment graphite is uniformly dispersed in a mixed solution of a dispersing agent and water, and the few-layer graphene aqueous dispersion is obtained by mechanical stirring and mechanical stripping. However, the method of using the surfactant only in the prior art mainly solves the problems of dispersion and preliminary stripping of graphene, but the stripping process has randomness, and lacks effective control means for the layer number (thickness) of the final product. This results in products that are typically mixtures of single-, double-and multi-layer graphene (more than 10 layers of graphene), with a broad layer number distribution and non-uniform pr