Search

KR-20260064465-A - Method for producing Prussian blue and analogues by non-aqueous solvent and self-assembly method and Prussian blue and analogues

KR20260064465AKR 20260064465 AKR20260064465 AKR 20260064465AKR-20260064465-A

Abstract

The present invention relates to a method for producing Prussian blue and analogs by synthesis with a non-aqueous solvent and self-assembly, and to Prussian blue and analogs produced by this method. A method for manufacturing Prussian blue and analogs according to the present invention is a method of obtaining a solution by dissolving a first precursor containing sodium (Na) in a solvent, and then synthesizing Prussian blue or analog particles through self-assembly by heating the solution, wherein the solvent includes a non-aqueous solvent, the pH of the solution is controlled to 6 or lower, and a second precursor that is different from the first precursor and contains sodium (Na) is added to the solution so that synthesis is carried out in an excess state of sodium (Na).

Inventors

  • 조창신
  • 장승혜

Assignees

  • 포항공과대학교 산학협력단

Dates

Publication Date
20260507
Application Date
20250602
Priority Date
20241031

Claims (14)

  1. A method of synthesizing Prussian blue or its analog particles through self-assembly by dissolving a first precursor containing sodium (Na) in a solvent to obtain a solution, and then heating the solution. The above solvent includes a non-aqueous solvent, and The pH of the above solution is adjusted to 6 or lower, and A method for preparing Prussian blue and analogs, wherein a second precursor, which is different from the first precursor and contains sodium (Na), is added to the above solution so that synthesis is carried out in an excess state of sodium (Na).
  2. A method of synthesizing Prussian blue or its analog particles through self-assembly by dissolving a first precursor containing sodium (Na) in a solvent to obtain a solution, and then heating the solution. The above solvent includes a non-aqueous solvent, and A method for preparing Prussian blue and analogs, wherein the pH of the above solution is adjusted to 6 or lower to allow synthesis to take place.
  3. In Article 1 or Article 2, A method for preparing Prussian blue and analogs, wherein the first precursor is one or more selected from sodium ferrocyanide hydrate, potassium ferrocyanide ( K₄ [Fe(CN)]· 3H₂O ), ammonium ferrocyanide (( NH₄ ) ₄ [Fe(CN)]), calcium ferrocyanide ( Ca₂ [Fe(CN)]), barium ferrocyanide ( Ba₂ [Fe(CN)]), potassium ferrocyanide ( K₃ [Fe(CN)]), and sodium ferrocyanide ( Na₃ [Fe(CN)]).
  4. In Article 1 or Article 2, The above-mentioned non-aqueous solvent is glycerol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, phenylethyl alcohol, triethanolamine, ethylenediamine, benzyl alcohol, sorbitol, tetrahydrofuran (THF), 1,4-dioxane, methoxyethanol, ethylene glycol methyl ether, ethylene glycol ethyl ether, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), N-methylpyrrolidone (NMP), acetone, acetonitrile, tetramethylurea, hexamethylphosphotriamide, ethyl acetate, butyl acetate, methyl lactate, γ-butyrolactone (GBL), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][ PF6 ]), A method for preparing Prussian blue and analogs, comprising one or more selected from 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][ BF4 ]).
  5. In Article 1 or Article 2, A method for preparing Prussian blue and analogs, wherein the pH of the above solution is controlled to 3 or less.
  6. In Article 1, The second precursor above is selected from NaCl, Na₂SO₄ , NaNO₃ , Na₂CO₃ , NaHCO₃ , NaF , NaBr , NaI , Na₃PO₄ , NaH₂PO₄, Na₂HPO₄ , NaBF₄ , NaPF₆ , Na₂S , NaHS , Na₂Se , NaBO₂ , Na₂MoO₄ , NaVO₃ , Na₂WO₄ , Na₂CrO₄ , Na₂Cr₂O₇ , NaMnO₄ , CH₃COONa , C₆H₅COONa , HCOONa, Na₂C₂O₄, C₆H₅Na₃O₇ , NaOH , NaNH₂ , NaN₃ , NaAlO₃ , EDTA - Na₂ , and EDTA - Na₄ . A method for manufacturing Prussian blue and analogs, comprising one or more types.
  7. In Article 1, A method for preparing Prussian blue and analogs, wherein the second precursor is added in a molar ratio of 3 to 10 times that of the first precursor.
  8. In Article 1 or Article 2, A method for preparing Prussian blue and analogs, wherein the heating of the above solution is carried out at 50 to 100 ℃.
  9. In Article 2, A method for preparing Prussian blue and analogs, wherein the above-mentioned non-aqueous solvent consists of glycerol.
  10. In Article 2, A method for preparing Prussian blue and analogs, wherein the above-mentioned non-aqueous solvent contains water in a volume ratio of greater than 0% and less than or equal to 10% of glycerol.
  11. In Article 1 or Article 10, A method for preparing Prussian blue and analogs, wherein the size of the synthesized Prussian blue particles is 500 nm or less.
  12. In Article 9, A method for preparing Prussian blue and analogs, wherein the synthesized Prussian blue particles have an octahedral structure and the crystal planes on their surfaces are (111) planes.
  13. Prussian blue or an analogue thereof produced by the method described in claim 1 or 2.
  14. Prussian blue or an analog thereof prepared by the method described in claim 2 is a Prussian blue or an analog thereof that has an octahedral structure and is in the form of a particle having a crystal plane on its surface (111) plane.

Description

Method for producing Prussian blue and analogues by non-aqueous solvent and self-assembly method and Prussian blue and analogues The present invention relates to a method for producing Prussian blue and analogs by synthesis with a non-aqueous solvent and self-assembly, and to Prussian blue and analogs produced by this method. Prussian blue can be synthesized into various analogs depending on the type of transition metal used. Most transition metals are included, such as manganese (Mn), nickel (Ni), cobalt (Co), copper (Cu), zinc (Zn), magnesium (Mg), calcium (Ca), potassium (K), barium (Ba), aluminum (Al), vanadium (V), chromium (Cr), and titanium (Ti). Prussian blue is a representative and promising candidate as a cathode material for sodium-ion batteries. In addition, due to its excellent adsorption capacity, it is used for the adsorption of specific radioactive elements such as cesium, and it has high utility value in the medical field, such as as a drug delivery vehicle into the human body. Generally, since the reactants used to synthesize Prussian blue are highly soluble in water, the process is carried out using aqueous solutions as the synthesis solvent. Solvents that can be used with water include acetone, ethanol, methanol, dichloromethane, ethyl acetate, toluene, benzene, chloroform, hexane, cyclohexane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and tetrahydrofuran (THF). The Prussian blue synthesized in this way forms rectangular particles ranging in size from several hundred nanometers to 2–3 micrometers. However, the synthesis of Prussian blue in aqueous solution is primarily carried out through the coprecipitation method. Taking basic iron-based Prussian blue as an example, aqueous solution A containing sodium and iron ions is mixed with aqueous solution B containing iron-cyanide ions to form Na x FeFe(CN) 6 . Since Prussian blue is synthesized in an aqueous solution using this method, crystal water is generated within the lattice during the formation process. Furthermore, because the bonding reaction between the two solutions occurs rapidly, crystal formation and growth also take place at a very fast rate. Consequently, when used as a positive electrode active material for sodium-ion batteries, problems arise such as side reactions between the crystal water present in the structure and the organic electrolyte, as well as performance degradation due to structural collapse. Furthermore, the following patent document discloses a method for synthesizing Prussian blue by mixing solutions in which different precursors are dissolved using a non-aqueous solvent to induce co-precipitation. While this method can reduce the problem of water of crystals generated within the lattice, it leads to the problem of vacancy defects within the lattice due to rapid precipitation, and if an aqueous solution is used in conjunction, it can even cause the problem of water of crystals. Figure 1 is a schematic diagram of the synthesis of Prussian blue in water and a high-viscosity organic solvent. Figure 2 is an SEM image of Prussian blue particles synthesized according to Example 1. Figure 3 is a graph of mass loss (TGA) of Prussian blue particles synthesized according to Example 1 and Comparative Example 1. Figure 4 is a graph analyzing the electrochemical behavior of Prussian blue particles synthesized according to Example 1 and Comparative Example 1. Figure 5 schematically shows the particle shape and growth behavior of Prussian blue according to the type of solvent. Figure 6 shows the particle shape and growth behavior over time when Prussian blue particles were synthesized according to Example 2. Figures 7a and 7b are graphs showing the specific surface area of Prussian blue particles synthesized according to Comparative Example 1 and Example 2. Figure 8 schematically illustrates the fabrication process and structure of a symmetric cell fabricated using Prussian blue particles synthesized according to Comparative Example 1 and Example 2. Figure 9 is a graph analyzing the electrochemical behavior of a symmetric cell to which Prussian blue particles synthesized according to Comparative Example 1 and Example 2 were applied. Figure 10 is an SEM image of Prussian blue particles synthesized according to Example 4. Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In addition, to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals. Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include addi