342results about "Iron cyanides" patented technology

The invention discloses a double-metal cyanide catalyst as well as a preparation method and application thereof, and belongs to the technical field of double-metal cyanide catalysts. The preparation method of the double-metal cyanide catalyst comprises the following steps: S1, mixing a metal salt aqueous solution and a metal cyanide aqueous solution, and reacting to obtain double-metal cyanide slurry; and S2, adding acid into the double-metal cyanide slurry, aging, centrifuging and drying to obtain the double-metal cyanide catalyst, the weight ratio of the double metal cyanide slurry to the acid in the step S2 is 1: (0.001-0.004); the metal cyanide in the metal cyanide aqueous solution comprises cobalt element. When the double metal cyanide catalyst is used for preparing polyether, the chromaticity of the polyether can be reduced.

Disclosed in the present invention are a doped manganese-based Prussian white positive electrode material, and a preparation method therefor and the use thereof. The chemical general formula of the doped manganese-based Prussian white positive electrode material of the present invention is Nan-dAdMn1-xMx[Fe(CN)6]y·zH2O, wherein A is one or more of Li+, K+, Rb+, Cs+, NH4 +, Cu+ or Ag+; M is one or more of Ni2+, Fe2+, Co2+, Zn2+ or Cu2+; and 1.7≤n≤2, 0.02≤d≤0.2, 0.2≤x≤0.4, 0.9≤y<1 and 0＜z<0.8. The doped manganese-based Prussian white positive electrode material in the present invention is co-doped at the Mn site and the Na site, and using the synergistic effect of M and A doping ions can not only effectively inhibit the Jahn-Teller effect of Mn3+, but can also greatly reduce the content of crystal water in the positive electrode material, and can also have the effects of reducing lattice defects and improving lattice stability and sodium ion transmission kinetics, such that the doped manganese-based Prussian white positive electrode material has a high capacity, good rate capability and good cycling stability.

The invention provides a preparation method of a manganese-based Prussian blue sodium ion battery positive electrode material, which comprises the following steps: firstly, adding a mixed solution of a part of manganese salt and a chelating agent into a sodium ferrocyanide solution at a first flow rate in a protective atmosphere for reaction; and continuously adding the residual mixed solution of the manganese salt and the chelating agent into the reaction system in the previous step at a first flow rate, adding the mixed solution of the transition metal salt and the chelating agent at a second flow rate, reacting again, and aging to obtain the manganese-based Prussian blue sodium-ion battery positive electrode material. The chelating agent is used for assisting coprecipitation to synthesize the Prussian blue analogue coated manganese-based Prussian blue sodium ion battery positive electrode material with stable heterogeneous lattices, so that the volume change and particle cracking of the positive electrode material in the charging and discharging process can be effectively inhibited in the circulating process, and the structure collapse is prevented; the cycle stability of the positive electrode material in the charge-discharge process is effectively improved, and the cycle life of the battery is prolonged.

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 present invention discloses a preparation method and production system for sodium nitroprusside. The preparation process comprises the following steps: first, reacting ferrocyanide with nitric acid to obtain a hydrogen nitroprusside aqueous solution; adding alcohol to the concentrated hydrogen nitroprusside aqueous solution to remove inorganic salts generated by the reaction, thereby obtaining a hydrogen nitroprusside alcohol solution; then, adding trisodium citrate to the hydrogen nitroprusside alcohol solution to react to obtain sodium nitroprusside and disodium citrate; separating and removing the citrate to obtain a sodium nitroprusside alcohol solution; and finally, concentrating, crystallizing, separating, and drying the sodium nitroprusside alcohol solution to obtain a sodium nitroprusside product. The present invention also provides a production system based on the preparation method. The production method of the present invention is simple to operate, operates under mild conditions, has a short production cycle, effectively prevents product oxidation, and has high purity. The obtained product is suitable for industrial production, and the production system requires less equipment and has low equipment requirements.

The invention discloses a preparation method of a Prussian blue analogue (CoFe-PBA) and copper metal organic framework (HKUST-1) composite core-shell material and application of the composite core-shell material in oxygen evolution reaction (OER). The material is prepared through a step-by-step synthesis and composite process: firstly, synthesizing copper-based MOF (HKUST-1) and a ferrocobalt Prussian blue analogue (CoFe-PBA), then compounding the copper-based MOF (HKUST-1) and the ferrocobalt Prussian blue analogue (CoFe-PBA) through a solvothermal method to form a core-shell structure (HKUST-1-atCoFe-PBA), and further performing high-temperature oxidation and vulcanization treatment to obtain HKUST-1-atCoFe-O and HKUST-1-atCoFe-S materials. According to the composite material, the electron transmission efficiency and the catalytic activity are remarkably improved by utilizing the synergistic effect of multi-metal active sites of Cu, Co and Fe. No precious metal or strong corrosive reagent is used in the preparation process, the cost is low, and the green synthesis requirement is met. An electrochemical test shows that the OER overpotential of the optimized catalyst at the current density of 10mAcm is only 268mV, and the catalyst shows excellent catalytic performance. The material can be widely applied to the fields of water electrolysis hydrogen production and the like, and has important industrial application prospects.

The invention discloses a method for preparing a sodium-rich boundary-rich iron-based prussian blue analogue (FePBA) through one-step hydrothermal synthesis assisted by sodium thiosulfate. The method specifically comprises the following steps: preparing a solution A and a Na4Fe (I I) (CN) 6 solution; the molar ratio of ferrocyanide to Fe ions in the solution B is 3: 4. And preparing a solution B to react with ferrocyanide to form FePBA. Adding sodium citrate to form a sodium and citrate-rich environment, then adding ferric iron salt, and fully stirring to chelate the added Fe < 3 + > with the citrate; and adding sodium thiosulfate after the step. Preparing a PVP (Polyvinyl Pyrrolidone) solution to play roles in dispersing FePBA and reducing agglomeration, and taking the PVP solution as a solution C; slowly dropwise adding the solution A and the solution B into the solution C at a constant speed by using a rubber head dropper to finally obtain a precursor solution, carrying out hydrothermal reaction for 6 hours at 110 DEG C, carrying out suction filtration on the obtained precipitate, and drying to obtain a FePBA sample. According to the invention, the time required for synthesis is greatly shortened, and the traditional coprecipitation of more than 24 hours is improved into rapid hydrothermal reaction of 6 hours.

The present application discloses a method for treating and resourcefully recycling electroplating cyanide copper wastewater, belonging to the technical field of electroplating wastewater treatment. In this application, the cyanide copper wastewater is adjusted with strong base, and a ferrous sulfate solution is added to the cyanide copper wastewater after strong base adjustment for a combination reaction; the cyanide copper wastewater after the combination reaction is adjusted with acid and subjected to a Prussian blue reaction; a coagulant aid is added to the solution after the Prussian blue reaction, and solid-liquid filtration separation is carried out on it to obtain iron cyanide sludge and preliminarily precipitated cyanide-removing wastewater; the preliminarily precipitated cyanide-removing wastewater is adjusted with weak base, hydrogen peroxide is added to the preliminarily precipitated cyanide-removing wastewater after weak base adjustment, and the copper in the preliminarily precipitated cyanide-removing wastewater after weak base adjustment is used as a catalyst for an oxidation reaction to remove the remaining cyanide-containing pollutants; after the oxidation reaction is completed, lime is added for flocculation precipitation to obtain copper sludge, thus realizing a one-step process flow, converting copper cyanide compounds into resources that can be recycled, and improving the resource utilization rate.

The invention provides an upgrading and purifying method for waste tire pyrolysis carbon black, and belongs to the technical field of upgrading, purifying and high-value utilization of waste tires and waste rubber pyrolysis carbon black. The upgrading and purifying method comprises the following steps: carrying out wet magnetic separation on waste tire pyrolysis carbon black to obtain pyrolysis carbon black subjected to magnetic separation; mixing the cracked carbon black subjected to magnetic separation with hydrobromic acid for acid leaching to obtain first acid leaching filtrate and a first carbon black product; adding zinc particles into the first acid leaching filtrate to obtain second filtrate; evaporating and crystallizing the zinc bromide solution to obtain zinc bromide; zinc bromide is prepared into heavy liquid, the first carbon black product is subjected to reselection, and a pure carbon black product and silicon dioxide tailings are obtained; introducing hydrogen sulfide gas into the ferric ion solution for purification and absorption to obtain sulfur and a third filtrate; and the third filtrate is subjected to electrolytic regeneration, and a regenerated ferric ion solution and hydrogen are obtained after electrolytic regeneration is finished. According to the method, the acid leaching byproduct zinc bromide is used as a reselection medium, and resource recycling is achieved while efficient separation and impurity removal are achieved.

The invention provides a positive electrode material and a preparation method thereof, a positive electrode plate and a secondary battery, and belongs to the field of battery materials, the positive electrode material comprises an inner core and a composite coating layer coating the surface of the inner core; the inner core comprises lithium iron phosphate, and the composite coating layer comprises a carbon material and a metal oxide; wherein the metal oxide comprises at least one of lithium titanate, lithium manganate and lithium cobalt oxide. The carbon material and the metal oxide containing titanium, cobalt and manganese are compounded to serve as the composite coating layer to coat the lithium iron phosphate core, on one hand, the microstructure characteristics of the metal oxide containing titanium, cobalt and manganese are utilized, richer channels are provided for lithium ion diffusion, on the other hand, the high electron conductivity of the carbon material is utilized, and the lithium ion diffusion efficiency is improved. The prepared positive electrode material can simultaneously have relatively high electronic conductivity and lithium ion diffusion rate, and when the positive electrode material is used as a lithium ion battery, the charge-discharge performance and the cycle life of the lithium ion battery are remarkably improved.

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 discloses a preparation method of a hollow nano square Mn1Fe3PBA (at) NiFe LDH composite catalyst. The composite catalyst adopts a substrate material, a Mn1Fe3PBA nano cube is prepared through a solution precipitation method, a NiFe LDH hydrangea is prepared through a hydrothermal method, and the Mn1Fe3PBA nano cube and the NiFe LDH hydrangea are combined to form the Mn1Fe3PBA (at) NiFe LDH composite catalyst with a three-dimensional hollow nano square structure. The invention also discloses an application of the hollow nano square Mn1Fe3PBA-coated NiFe LDH composite catalyst prepared by the preparation method in an alkaline anode oxygen evolution reaction. The NiFe LDH provides good conductivity and a skeleton channel, the Mn1Fe3PBA provides an additional site, and the combination of the NiFe LDH and the Mn1Fe3PBA improves the electronic conductivity of the catalyst and accelerates the catalytic reaction kinetics; the structural stability is enhanced; the service life of the catalyst is prolonged; the overpotential required in the reaction process is reduced, and the overall catalytic efficiency is improved.

The invention discloses a preparation method and application of an aqueous iron ion battery positive electrode material. The preparation method comprises the following steps: (1) respectively mixing a single type of ferric salt and potassium ferricyanide with water to obtain a solution A and a solution B; (2) mixing the solution A and the solution B, stirring in a water bath kettle, and carrying out a co-precipitation reaction to obtain a solid precipitate; and (3) centrifuging, washing and drying the solid precipitate to obtain the nano-particles with the particle size of 150-200nm. The obtained nanoparticles can be used as an aqueous iron ion battery positive electrode material, the positive electrode can realize Fe < 2 + > and NH4 < + > ion co-de-intercalation electrochemical reaction in the charging and discharging process, and the reversible specific capacity of the battery is remarkably improved; the embedded NH < 4 + > and N in the positive electrode material can form a stable hydrogen bond structure, so that the cycling stability of the battery is effectively improved. The preparation process is easy to operate, the product yield is high, the consistency is excellent, and the method is suitable for large-scale preparation and application.

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 present invention belongs to the technical field of sodium ion batteries, and discloses an iron-based Prussian blue positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: mixing ferrous salt, acid and water to obtain a first solution; mixing a cyanide source, a sodium supplement and water to obtain a second solution; mixing a water scavenger and water to obtain a third solution; mixing the first solution, the second solution and the third solution, and aging to obtain an iron-based Prussian blue positive electrode material. The iron-based Prussian blue positive electrode material prepared by the method of the present invention has a high specific capacity, a high coulomb efficiency and a high capacity retention rate at a high rate, and exhibits good rate performance and cycle performance when used as a positive electrode material for a sodium ion battery, providing a broad application prospect for low-cost, high-performance sodium ion batteries in the field of large-scale energy storage.

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.

The invention discloses a method for preparing a potassium-rich type potassium battery positive electrode material by using a chelating agent. The positive electrode material of the potassium-rich type potassium battery is a potassium-rich manganese-based Prussian blue analogue KxTmyMn1-yFe (CN) 6, 0lt, x is less than or equal to 2, 0lt; yt; Yt; 1, the material is prepared through a normal-temperature coprecipitation method; comprising the following steps: mixing concentrated hydrochloric acid, potassium chloride and CMC in deionized water to obtain a first solution, dividing the first solution into two parts, respectively adding potassium ferrocyanide and transition metal salt, mixing and stirring the two solutions, aging, centrifugally collecting, cleaning and drying to obtain the potassium-rich type potassium battery positive electrode material. According to the invention, CMC is used as a chelating agent and combined with the synergistic effect of doped transition metal elements, so that ion and electron transport is promoted together, and the problems of Mn < 2 + > dissolution and water-related side reactions are effectively alleviated, thereby reducing charge transfer resistance, enhancing electrochemical kinetics, and realizing high capacity and long cycle performance.

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 provides a preparation method and application of oversized metal ferrocyanide, and relates to the technical field of nonferrous metallurgy. Comprising the following steps: preparing a DMF aqueous solution, and dividing the DMF aqueous solution into two equal parts which are respectively marked as a solution A and a solution B; soluble metal salt is added into the solution A, and the pH value is controlled to be 3-8; ferrocyanide is added into the solution B, and the pH value is controlled to be 3-8; dropwise adding the solution B into the solution A, and reacting to obtain a solution C; and filtering and drying the solution C obtained in the step 4 to obtain the metal ferrocyanide adsorbent. According to the method, N, N-dimethylformamide (DMF) is added as a surfactant in the process of preparing a metal ferrocyanide adsorbent by a conventional chemical precipitation method, and ferrocyanide is synthesized in one step. The oversized metal ferrocyanide adsorbent can be obtained by regulating and controlling the adding proportion of the ferrocyanide and water, and has a better adsorption effect.

The present invention provides a Prussian blue cathode material, a method for manufacturing the same, a cathode sheet, and a sodium ion battery. The Prussian blue cathode material contains a Prussian blue compound represented by the chemical general formula Na x Fe[Fe(CN)6] y ·nH2O. The Prussian blue cathode material according to the present invention has a simple synthesis method, low raw material cost, and is advantageous for improving the characteristics of sodium ion batteries in terms of specific capacity, Coulomb efficiency, rate characteristics, and long cycle stability when used in sodium ion batteries.

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.

To provide a PB-supporting carbon-coated silica gel suitable for use in electrochemical applications and easy in a production process, and a method for producing the same.SOLUTION: The method for producing a PB-supporting carbon-coated silica gel according to the present invention comprises the steps of: adding an iron cyano complex-containing solution to a container containing carbon-coated silica gel having a porous silica gel having a plurality of mesopores in which a carbon film is formed so as to cover continuously from the inner wall of the mesopores to the outer surface of the carbon-coated silica gel, such that the iron cyano complex is supported on the outer surface of the carbon-coated silica gel from the inner wall of the mesopores; removing a solvent from the iron cyano complex-containing solution to obtain a dry powder composed of carbon-coated silica gel supporting the iron cyano complex; adding an iron ion-containing solution to the dry powder and reacting the iron cyano complex with iron ions to produce Prussian blue from the inner wall of the mesopores to the outer surface of the carbon-coated silica gel; and removing a solvent from the iron ion-containing solution.SELECTED DRAWING: Figure 1

The application relates to the technical field of positive electrode materials, and particularly discloses a method for improving the crystallinity of Prussian blue, Prussian blue, a positive electrode material and a battery. The method for improving the crystallinity of Prussian blue comprises the following steps: mixing a low-crystallinity Prussian blue and its analogues, an aqueous solution of an alcohol compound, hexacyanoferrate (II) and a reducing substance to obtain a reaction solution; reacting the reaction solution at a temperature of 40-80 DEG C to prepare solid precipitates; and washing and drying the prepared solid precipitates to obtain high-crystallinity Prussian blue. The method utilizes a reducing environment, an aqueous solution of an alcohol compound and high-concentration Fe(CN)6 4‑ to promote the separation of crystal water in the material structure from the crystal coordination, Fe(CN)6 4‑ to enter the structure and combine with M (M=Fe, Mn, etc.) in the Prussian blue and its analogues, thereby reducing the vacancy and crystal water content in the structure. The crystallinity of the Prussian blue and its analogues is improved.