174results about "Iron cyanides" patented technology

The invention discloses a preparation method of a CoMnFe-PBA hollow superstructure material, which combines seed induced self-assembly with an in-situ ligand / metal ion exchange growth method, and comprises the following steps: dissolving MOF-74 and potassium ferricyanide in deionized water, and carrying out ultrasonic treatment to form a solution A; dissolving polyvinylpyrrolidone, ferric chloride and manganese chloride tetrahydrate in a mixed solvent of ethanol and deionized water, and stirring for a certain time to obtain a solution B; dropwise adding the solution B into the solution A, stirring, carrying out centrifugal collection, ethanol washing and freeze drying on a reaction product, and collecting a sample to obtain the CoMnFe-PBA hollow superstructure material. According to the CoMnFe-PBA hollow superstructure material prepared through the method, a construction unit of a self-assembly superstructure is expanded to PBA nanoparticles, and the synthesis strategy, the construction unit, the structural level and the application range of the self-assembly superstructure can be further expanded.

The invention discloses a spherical Prussian blue material as well as a preparation method and application thereof. The preparation method comprises the following steps: enabling a mixed reaction system containing soluble transition metal hexacyanoid salt, soluble transition metal salt, a complexing agent, soluble sodium salt, a surfactant and a carbon sphere precursor to react, and then selectively performing or not performing aging treatment to prepare the spherical Prussian blue material. According to the preparation method provided by the invention, the spherical Prussian blue material is obtained by regulating and controlling the reaction raw materials and the reaction steps, so that the rate capability and the cycle stability of the Prussian blue material are improved, and the problem that the compaction density and the compaction density are reduced due to the fact that the rate capability of a Prussian blue cube is improved due to carbon coating is solved.

The invention relates to an iron-based Prussian blue positive electrode material and a preparation method and application thereof, the molecular formula of the iron-based Prussian blue positive electrode material is as follows: 0 < x < = 2, 0 < y < = 1, 0 < z < = 1, the iron-based Prussian blue positive electrode material is a hollow porous sphere structure formed by stacking cubic nanoparticles, the average particle size of the hollow porous sphere structure is 0.3-8 [mu] m, and the average particle size of the hollow porous sphere structure is 0.5-8 [mu] m. And the wall thickness of the hollow porous ball structure is 0.08 mu m-2 mu m. When the iron-based Prussian blue positive electrode material is used as a sodium ion battery positive electrode material, the iron-based Prussian blue positive electrode material has excellent rate capability and cycle performance.

The invention provides a process for removing cyanide from a cyanide-bearing aqueous fluid, the process comprising: (i) adding a solid composition comprising a first mixed-metal cyanide complex comprising copper and iron to a cyanide-bearing aqueous fluid comprising free cyanide and metal-complexed cyanide, wherein at least a portion of the first mixed-metal cyanide complex dissolves, with complexation of the copper by the free cyanide, to produce an aqueous solution comprising cyanometallates, the cyanometallates comprising copper cyanide and iron cyanide complexes derived from the first mixed-metal cyanide complex; (ii) contacting the aqueous solution with an anion-exchange absorbent to absorb the cyanometallates, thereby producing a cyanide-lean aqueous fluid; (iii) extracting the anion-exchange absorbent comprising the absorbed cyanometallates with at least one non-acidic aqueous extractant to produce an aqueous extract comprising the copper cyanide and iron cyanide complexes; and (iv) acidifying the aqueous extract to produce a precipitate comprising a second mixed-metal cyanide complex comprising copper and iron.

The invention provides a high-entropy Prussian blue material and a preparation method and application thereof, and relates to the technical field of electrochemical material preparation and energy. The preparation method of the high-entropy Prussian blue material comprises the following steps: mixing a cobalt source, a nickel source, a copper source, a manganese source, a zinc source, an organic reducing compound and a first dispersing agent to obtain a first mixture; the molar ratio of the cobalt source to the nickel source to the copper source to the manganese source to the zinc source is 1: 1: 1: 1: 1; mixing the ferricyanide compound with a second dispersing agent to obtain a second mixture; and sequentially stirring and standing the first mixture and the second mixture to obtain the high-entropy Prussian blue material. The high-entropy Prussian blue material prepared by the method is stable in morphology, high in crystallinity and high in chemical stability, and can be applied to the field of electrochemical energy storage.

The disclosure relates to an aqueous electrochemical device comprising a negative electrode, a positive electrode, a separator and an aqueous electrolyte having an alkaline pH, wherein onto the positive electrode is disposed at least one layer of nanoparticles capable of being used to form a local hydronium ion rich environment at the positive electrode during operation of the device, and / or the capacity ratio between the negative electrode and the positive electrode is less than 1 so as to substantially avoid production of oxygen at the positive electrode. The electrochemical device may find particular use in large-scale energy storage.

This invention belongs to the field of biochemical detection and discloses a portable hepatitis biomarker detection kit. The kit contains a hydrogel; the hydrogel is obtained by dispersing hollow manganese dioxide in water to obtain an H-MnO2 dispersion, mixing the H-MnO2 dispersion with sodium alginate solution to obtain a mixed solution, and then adding a calcium salt solution to obtain the hydrogel. The hollow manganese dioxide is obtained by etching manganese Prussian blue analog nanoparticles with sodium hydroxide. The manganese Prussian blue analog nanoparticles are prepared from potassium ferricyanide, polyvinylpyrrolidone, and manganese salts. This invention utilizes the color change of hollow manganese dioxide in relation to TMB to construct a method for detecting hepatitis biomarkers using a smartphone to capture signals. This kit reduces the detection cost of hepatitis biomarkers, does not require large instruments, and is highly portable and widely applicable, possessing great potential as a novel point-of-care testing device.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a Prussian blue sodium battery positive electrode material and a preparation method thereof.The preparation method comprises the steps that anhydrous sodium ferrocyanide, anhydrous manganese sulfate and a NaA molecular sieve are mixed and preliminarily ground, and a precursor mixture is obtained; placing the precursor mixture in a planetary ball mill for ball milling to obtain a primary reaction product; and washing the preliminary reaction product, and carrying out vacuum drying to obtain the Prussian blue sodium battery positive electrode material. The method is low in material loss and short in generation period, and the prepared Prussian blue sodium battery positive electrode material is low in crystal water content and has good cycle stability.

The invention provides a colorful Prussian blue film as well as a preparation method and application thereof. The preparation method comprises the following steps: placing a conductive material coated with a metal layer on the surface in a Prussian blue precursor solution, and growing a Prussian blue film layer on the surface of the metal layer in situ to obtain a Prussian blue film layer-metal layer-conductive material layer complex, namely the colorful Prussian blue film. The invention provides a colorful Prussian blue film which is characterized in that a metal layer is sputtered on the surface of conductive glass, on one hand, the problem of poor adhesion between Prussian blue and the conductive glass is solved, and on the other hand, Prussian blue grows on the surface of the metal layer in situ, so that a potential difference is formed between metal and iron ions, and the Prussian blue film is obtained. Further, prussian blue grows on the surface of the metal layer layer by layer, the multi-color film can be constructed by utilizing different thicknesses of the prussian blue layer, and the color of the multi-color film can be changed under the driving of voltage, so that the color gamut of the multi-color film is further enriched; the technical scheme provided by the invention has universality, and the preparation method is simple, low in cost and wide in application prospect.

The invention belongs to the technical field of medicine synthesis, and discloses a preparation method of a sodium nitroprusside raw material medicine. According to the method, weak acid is adopted for catalysis, the effect of remarkably reducing generation of toxic substances such as cyanide and nitrogen dioxide is achieved by controlling the material dripping speed and the dripping pH, the reaction is mild, the technological operation is safe and controllable, and industrial production of the sodium nitroprusside raw material medicine is facilitated. According to the preparation method of some examples, silica gel filtration is used for post-treatment, the residual risk of impurities such as sodium ferricyanide, ferric ferrocyanide and ferric ferricyanide is reduced, and the purity of the raw material medicine is larger than or equal to 99.9% and is far superior to the requirements of pharmacopoeia of various countries.

The present disclosure provides Prussian blue cathode material and preparation method therefor, cathode sheet and sodium-ion battery. The Prussian blue cathode material includes a Prussian blue compound, and the Prussian blue compound has a general chemical formula of NaxFe[Fe(CN)6]y·nH2O. The Prussian blue cathode material provided by the present disclosure has a simple synthesis method and a low raw material cost, and when applied to a sodium-ion battery, is conducive to improving the performance of the sodium-ion battery in terms of specific capacity, coulomb efficiency, rate performance and long cycle stability, etc.

The invention discloses a lanthanide-doped Prussian blue positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing and dissolving sodium ferrocyanide and lanthanide metal salt to obtain a mixed solution; and under a protective atmosphere, dropwise adding the mixed solution into a mixed chelating agent salt solution through a peristaltic pump, and reacting to obtain the lanthanide-doped Prussian blue positive electrode material. The lanthanide metal in the lanthanide-doped Prussian blue positive electrode material occupies the Na site, the single iron source coprecipitation method is adopted for synthesis, the process concentration is uniform, the synthesized positive electrode material has fewer defects, the material structure is stable, the rate capability is excellent, the specific capacity is high, and the application prospect is very good.

The invention belongs to the technical field of adsorption material preparation, and relates to an anion defect type prussian blue analogue and a preparation method and application thereof in cesium adsorption.The preparation method comprises the steps that imidazole and halogenated alkane are subjected to an alkylation reaction and anion exchange to prepare ionic liquid, and after water is added, an ionic liquid-water mixed solvent is obtained; the method comprises the following steps: respectively dissolving transition metal nitrate and potassium ferrocyanide into an ionic liquid-water mixed solvent, dropwise adding a potassium ferrocyanide solution into a transition metal nitrate solution, and stirring to obtain a mixed solution; and carrying out hydrothermal reaction on the mixed solution, cooling to room temperature, washing the material, and drying to obtain the anion defect type prussian blue analogue. The cesium ion adsorption capacity and the cesium ion cycling stability are improved by precisely regulating and controlling anion defects in the Prussian blue analogue, and the cesium ion adsorption material has good ion interference resistance in a complex water environment and shows excellent adsorption selectivity and a wide application range.

The present disclosure generally relates to a Prussian White particle having an inner core and an outer surface, wherein the Prussian White particle is defined by AaX1[X2(CN)6] 1-y⋅mH2O, wherein the Prussian White particle comprises a coating arranged on at least a portion of the outer surface, wherein the coating is defined by Naa'X3[X2(CN)6] 1-y'⋅mH2O, wherein A is Na or K, 1.8 < (a, a') ≤ 2, preferably 1.9 < (a, a') ≤ 2, more preferably 1.98 < (a, a') ≤ 2, 0 < (m, m') ≤ 3, 0 ≤ (y, y') ≤ 0.025, wherein X1 and X2 are selected from Fe and Mn, and wherein X3 is Mn, Ti, Ag, Co, and / or Al. The present disclosure also relates to a method for manufacturing the Prussian White particles, to a cathode comprising a plurality of Prussian White particles, and to an electrochemical energy storage device, preferably a battery cell comprising the cathode. Furthermore, the present disclosure relates to a method for manufacturing a cathode comprising the Prussian White particles.

This invention discloses a cathode material, its preparation method, and its application, belonging to the technical field of cathode materials for sodium-ion batteries. The cathode material has a core-shell structure, with a core of sodium manganese ferrocyanide and a shell of potassium manganese ferrocyanide; a manganese ferrocyanide intermediate layer is also present between the core and the shell. The intermediate layer contains Mn... 2+ The ionic radius is greater than that of the Na core. + Larger K atoms, with higher valence states, can reduce lattice spacing, thus supporting the structure and improving the material's cycling stability while inhibiting the absorption of water molecules; the K atoms in the outer shell... + Not only can it provide capacity, but also K + The ionic radius is also larger than that of Na. + Larger and wider ion transport channels result in a more stable structure, which also helps reduce the material's water absorption. The presence of the aforementioned intermediate layer and outer shell significantly improves the structural stability of the cathode material during charge and discharge, reduces side reactions between the cathode and electrolyte, and enhances interfacial stability, cycle performance, and rate performance.

The invention relates to a preparation method and antibacterial application of an adjustable manganese-based Prussian blue analogue. Through metal ion doping and lattice engineering regulation and control, a manganese element is introduced into a Prussian blue frame structure, and controllable regulation of the doping amount and optimization of a crystal structure are realized. The prepared material has excellent photothermal conversion capability and multienzyme simulation activity, and shows a photothermal-enzyme synergistic enhancement effect under the irradiation of near-infrared light. In-vitro studies show that the material can efficiently inhibit the growth of gram-negative bacteria; animal experiments further verify that the composition has a remarkable curative effect in infected wound repair. The invention not only provides a preparation method of a nano material with controllable metal doping, but also provides a novel photo-enzyme synergistic treatment method for drug-resistant bacterium infection treatment.

The application discloses a novel Na2MnFe(CN)6 material and application thereof as a lithium ion battery, a sodium ion battery, a potassium ion battery, a magnesium ion battery, a zinc ion battery and a zinc-sodium dual-ion battery positive electrode material, wherein the Na2MnFe(CN)6 material is an inorganic material. The excellent electrochemical performance of the novel Na2MnFe(CN)6 material in the application indicates that the novel Na2MnFe(CN)6 material has a very large application prospect as the lithium ion battery, the sodium ion battery, the magnesium ion battery, the zinc ion battery and the zinc-sodium dual-ion battery positive electrode material. Meanwhile, the novel Na2MnFe(CN)6 material has a simple and controllable preparation process, and a simple device, and is a method easy to mass produce.

Provided is a porous metal cyanide-based framework material (MCFs) with cation gating effect, along with its preparation method and application in carbon dioxide capture. The general structural formula of the framework material is Mx[M′(CN)6]y·Az·nH2O, where 0≤n≤10. When n≥1, the crystal structure belongs to the R3c space group. When 0≤n<1, the structure transforms to the P2 / c space group. The framework material has a cage structure, and each cage has six hexagonal windows and six quadrilateral windows. The monovalent cations at the hexagonal windows exhibit a gating effect, which can selectively allow carbon dioxide molecules to pass through. The framework material has the highest CO2 adsorption capacity and selectivity in carbon dioxide capture, especially in the application of carbon dioxide adsorption under low pressure (≤0.15 bar) and high humidity environment (≥40% RH)

The application discloses a nickel-based Prussian blue battery positive electrode material and a preparation method and battery thereof, and belongs to the technical field of batteries, wherein the preparation method of the nickel-based Prussian blue battery positive electrode material comprises the following steps: dissolving sodium citrate into a nickel chloride solution to obtain reagent A; dissolving sodium ferrocyanide in water to prepare a solution to obtain reagent B; dissolving polyvinylpyrrolidone in a sodium chloride solution to obtain reagent C; simultaneously and slowly adding the reagent A and the reagent B into the reagent C to obtain a suspension liquid and aging the suspension liquid; centrifugally separating the suspension liquid after aging, washing, drying and grinding to obtain the nickel-based Prussian blue battery positive electrode material; and the nickel-based Prussian blue battery positive electrode material prepared by the application has the characteristics of high capacity, low alternating current impedance and high long cycle stability, and has excellent electrochemical performance.

The invention belongs to the technical field of energy materials, and particularly relates to preparation and application of a high-crystallinity long-life Prussian blue and analogue positive electrode material thereof. Aiming at the defects in the prior art, the invention provides the preparation method of the high-crystallinity long-life Prussian blue and the analogue thereof, which comprises the following steps: 1) mixing soluble transition metal M salt and a solvent to obtain a solution A; 2) mixing sodium ferrocyanide salt, sodium salt and a solvent to obtain a solution B; adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution A, adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution B, and controlling the total molar ratio of the complexing agent to the acid for regulating and controlling the chelating ability in the solution A and the solution B to be (20-1): 1; and 3) dropwise adding the solution A into the solution B, reacting, aging, centrifuging, washing and drying to obtain the Prussian blue and the analogue thereof. The method disclosed by the invention greatly widens the selection range of the chelating agent in the production process of the Prussian blue analogue positive electrode.

This invention discloses a method for preparing Prussian blue-based cathode materials without saline wastewater. The method employs a combined controlled crystallization and vacuum distillation process to synthesize Prussian blue-based materials. The entire preparation process is free of saline wastewater discharge, and the mother liquor generated from each batch can be recycled after filtration. Therefore, except for the first batch which requires the addition of sodium sulfate and a complexing agent to the base liquid, subsequent processes can directly utilize the same concentration of sodium sulfate and complexing agent in the mother liquor, avoiding fluctuations in salt concentration and saving raw material costs. The cathode materials synthesized using this method maintain consistent physicochemical properties such as particle size, tap density, and material composition between batches, as well as the electrochemical performance of the assembled batteries, indicating that the reused mother liquor as a base liquid does not affect the performance of the cathode material. This invention significantly simplifies the wastewater treatment facilities and process flow, eliminating the need for large-scale equipment such as MVR (Mechanical Vacuum Resiner) systems and effectively reducing material production costs.

The application discloses a kind of low-defect manganese-based prussian blue under solid-liquid dynamic balance fast preparation method, comprising the following steps: S1, sodium citrate is dissolved in deionized water, then add manganese acetate and ascorbic acid, form the solution A containing manganese complex;Wherein, the molar ratio of sodium citrate, manganese acetate and ascorbic acid is (4.5-5.5): 1:(0.3-0.4);S2, sodium ferrocyanide is added to deionized water, stirring is formed at a set temperature containing unsolved sodium ferrocyanide solid supersaturated suspension B;Wherein, the addition amount of sodium ferrocyanide is far more than its saturated solubility at the temperature, so that the system maintains solid-liquid two-phase equilibrium state;Crystalline integrity is higher: thanks to "whole process dynamic saturation" environment, the manganese-based prussian blue prepared by the application has more obvious monoclinic phase characteristics (corresponding XRD double peak is obvious, intensity is obvious, signal-to-noise ratio is good) compared with comparative document, lattice vacancy and coordination water content are significantly lower than comparative document scheme, and electronic conductivity is increased by nearly 50%.

This invention belongs to the field of high-entropy transition metal coordination polymer technology, specifically relating to a high-entropy Prussian blue material, its preparation method, and its applications. The invention involves dissolving various hydrated inorganic metal salts and sodium citrate complexing agent in water, slowly adding potassium ferricyanide solution dropwise to this solution, and then stirring for 30 min. The resulting solution is allowed to settle at room temperature for 24 h, washed three times by centrifugation with deionized water, and then washed three times by centrifugation with ethanol to obtain the high-entropy Prussian blue material Cu. 0.2 Ni 0.2 Co 0.2 Mn 0.2 Zn 0.2 (Fe(CN)6) 0.667 This invention yields a high-entropy Prussian blue electrocatalyst that is simple to synthesize, structurally stable, and uses readily available raw materials. This electrocatalyst can be applied to the electrocatalytic reduction of nitrate, laying the foundation for developing other high-entropy transition metal coordination compounds with framework structures as electrocatalysts for the electrocatalytic synthesis of value-added chemicals from nitrate.

The present application relates to the technical field of biomedical materials, and particularly relates to biological application of prussian blue biomagnetic beads in protein enrichment. The present application provides prussian blue magnetic beads, a preparation method and application thereof, and through doping different metals in the prussian blue material, the magnetic property of the prussian blue material is enhanced, and effective enrichment of low-abundance proteins in blood plasma can be realized.

The invention discloses a copper-iron prussian blue / graphene oxide composite electro-catalysis cathode and a preparation method thereof. The method comprises the following steps: dissolving copper chloride, single-layer graphene oxide powder, citric acid and sodium citrate in water by adopting a one-step coprecipitation method, heating in a water bath, carrying out a heat preservation reaction to form a copper source precursor solution, mixing the copper source precursor solution with a potassium ferricyanide solution, carrying out heat preservation aging, taking the precipitate, carrying out centrifugal washing, drying and grinding to obtain catalyst powder, and drying the catalyst powder to obtain the single-layer graphene oxide / potassium ferricyanide composite catalyst. Finally, the powder and PVDF are mixed and dissolved in NMP, hydrophilic carbon cloth is coated with the mixture, and the copper-iron prussian blue / graphene oxide composite electro-catalysis cathode is prepared. The preparation process is simple, mass production can be achieved, the prepared composite electro-catalysis cathode has efficient hydrogen peroxide production capacity and in-situ Fenton catalysis capacity, active oxygen species can be effectively generated for organic pollutant degradation, and the application potential of a Prussian blue analogue material in the field of water treatment is greatly improved.

The invention relates to the field of compound preparation, and discloses a method for preparing alkali metal ferrocyanide by using iron powder as an iron source through a mechanochemical method, and the method comprises the following steps: mixing the iron powder with a solution containing alkali metal cyanide to obtain a mixture, and enabling the water content of the mixture to be not more than 50wt%, the alkali metal cyanide comprises sodium cyanide or potassium cyanide, the reaction time is short, the reaction temperature is low, the process of treating the raw materials in advance is omitted, hydrolysis of the sodium cyanide is reduced, side reactions are reduced, a small amount of NH3 is released in the complexing reaction process, and the method is suitable for industrial production. The yield is high, sulfate containing ferrocyanide is not produced as a byproduct, and unreacted metal residues are recycled. Compared with a traditional method, the method disclosed by the invention is low in production cost and high in added value of products, and has a relatively good industrial prospect.

The present application relates to the technical field of nanomaterial application, and provides a ruthenium-doped Prussian blue nanoscale enzyme and a preparation method thereof, wherein the ruthenium-doped Prussian blue nanoscale enzyme is obtained by reacting metal ruthenium with Prussian blue nanoparticles under normal temperature conditions. The present application also provides a nanoscale enzyme library containing the ruthenium-doped Prussian blue nanoscale enzyme and a construction method thereof. The present application also provides SNP-PB nanoscale enzyme obtained by loading sodium nitroprusside into the ruthenium-doped Prussian blue nanoscale enzyme. The ruthenium-doped Prussian blue nanoscale enzyme and the SNP-PB nanoscale enzyme both have good antibacterial and anti-inflammatory properties, and can better solve the problem of biofilm resistance after being endowed with the ability to release NO gas, thereby better exerting antioxidant stress and fighting periodontal bacterial infection, and providing a new treatment method for periodontal disease.

The application provides a prussian-type sodium-ion positive electrode material and a recycling method thereof. The application provides a prussian-type sodium-ion positive electrode material recycling method, which comprises the following steps: obtaining a positive electrode material; cleaning or soaking the positive electrode material with an acidic solution, adjusting the concentrations of transition metal ions, ferrocyanide ions and sodium ions in the solution A to a preset concentration, adding a complexing agent solution to the solution B and mixing for a reaction; filtering the solution C to obtain a filter residue; and drying the filter residue to obtain the prussian-type sodium-ion positive electrode material. The prussian-type sodium-ion positive electrode material recycling method can recycle low-toxicity [Fe(CN)6] 4‑ from discarded prussian-type sodium batteries, avoids the great pressure on the environment caused by directly discarding the prussian-type sodium-ion positive electrode material, thereby protecting the ecological balance, and the regenerated prussian-type sodium-ion positive electrode material produced has good regeneration performance and meets the requirements of the market.

The invention belongs to the technical field of secondary batteries, and particularly discloses a strontium-doped nickel-based Prussian blue positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: dissolving a sodium salt of a polydentate carboxylic acid ligand, a reduction protective agent, a strontium salt and a nickel salt in deionized water to obtain a metal ion source solution; dissolving ferrous cyanide and a sodium supplementing agent in deionized water to obtain a cyano iron source solution; the method comprises the following steps: mixing a metal ion source solution and a cyano iron source solution, stirring to form a precipitate, standing and aging, and then carrying out solid-liquid separation to obtain a precipitate; and washing and drying the obtained precipitate to obtain the strontium-doped nickel-based Prussian blue positive electrode material. Strontium doping is introduced, so that the cycling stability of the nickel-based Prussian blue positive electrode material is remarkably improved; the preparation method is low in cost, high in efficiency, excellent in cycle performance and wide in application prospect when being used for a secondary battery.

The invention discloses a vacancy content controllable Prussian blue crystal as well as a preparation method and application thereof, and belongs to the technical field of material synthesis. In order to solve the technical problems that the vacancy content of a prussian blue material is difficult to accurately control and a vacancy-free material is difficult to prepare, the invention provides a series of prussian blue crystals with controllable vacancy content, and the preparation method comprises the following steps: mixing sodium ferrocyanide, a complexing agent, a sodium salt and water to obtain a solution A; mixing soluble manganese salt, soluble ferrous salt, a complexing agent, sodium salt and water to obtain a solution B; and controlling the sodium ion concentration and the reaction atmosphere and temperature, adding the solution A into the solution B, reacting, and aging to obtain the Prussian blue crystal. According to the method, the sodium ion concentration, the reaction atmosphere and the temperature are regulated and controlled by changing the addition amount of the sodium salt and the like, and the crystal growth speed and the ion transmission speed in the coprecipitation reaction are controlled, so that the purpose of accurately controlling the vacancy content is achieved, and a material without vacancy and first-stage crystal water can be prepared.