565 results about "Ferric salts" patented technology

The invention discloses a composite electrode material for removing uranium through photoelectrocatalysis and a preparation method and application of the composite electrode material, and belongs to the technical field of catalytic materials and wastewater treatment.The preparation method of the composite electrode material comprises the following steps that a ZIF-8 material, copper salt and ferric salt are mixed, and a first metal composite material is prepared; reacting the first metal composite material with a KOH solution to prepare a second metal composite material; carrying out carbonization treatment on the second metal composite material, and then carrying out acid treatment by using acid to obtain a bimetallic atom catalytic material; the preparation method comprises the following steps: dispersing a bimetallic atom catalytic material and a g-C3N4 material in a mixed solution containing phytic acid and a Nafion solution to obtain catalyst ink; and coating the catalyst ink on a substrate, and carrying out illumination drying to obtain the composite electrode material. According to the composite electrode material, under the synergistic effect of the bimetallic single atomic cluster catalyst and g-C3N4, respective advantages are fully exerted, and efficient deposition removal of uranium is achieved.

The invention discloses a method for recovering lithium, nickel cobalt manganese composite hydroxide and aluminum copper powder from a waste ternary lithium ion battery pole piece. The method comprises the following steps: treating waste pole pieces of a ternary plant or a mixture of positive and negative pole pieces by using a Fenton technology, leaching by using a mixed ferric salt solution, and filtering to obtain lithium-containing leachate and slag; adjusting the pH value of the leachate, oxidizing and filtering to obtain a purified solution and ferric hydroxide precipitate, and adding the purified solution and a lithium hydroxide solution into a reactor for coprecipitation to obtain a deeply purified solution and the nickel-cobalt-manganese composite hydroxide. And dissolving the ferric hydroxide precipitate with dilute acid, adding a reducing agent to generate a ferrous salt solution, and returning the ferrous salt solution for Fenton reaction and leaching reaction. And adding the sodium carbonate saturated solution into the deep purification solution, and crystallizing and precipitating to obtain the battery-grade lithium carbonate. And performing hydrodynamic screening on the leaching residues to obtain an aluminum-copper mixture and graphite residues, and performing grinding and specific gravity separation on the aluminum-copper mixture to obtain high-purity aluminum powder and copper powder. According to the method, the iron salt is directly leached from the pole piece, the used iron salt can be recycled, and the method is suitable for large-scale recovery of the waste ternary lithium ion battery.

This invention discloses a method for leaching lithium iron phosphate mixed powder with iron salts and recovering all components, belonging to the field of battery recycling. The invention uses an iron salt solution to leach the mixed powder, obtaining a lithium-containing leachate and leaching residue. Ferrous ions in the leachate are regenerated into ferric iron through acidification and oxidation, and recycled for leaching the next batch of mixed powder. After reaching a preset number of cycles, the leachate is used for re-leaching multiple batches of leaching residue to improve the lithium leaching rate. Ultimately, a enriched solution containing Li, Fe, Cu, and Al and graphite-containing iron phosphate residue are obtained. Copper is recovered from the enriched solution through iron powder replacement, and a high-purity lithium chloride solution is obtained through extraction and separation, while ferric chloride (recycled) and aluminum chloride crystals are also recovered. The leaching residue is treated with hydrochloric acid to obtain regenerated graphite, and the pH is adjusted with alkali to obtain high-purity iron phosphate. This method achieves full component recovery under mild conditions, reducing separation steps and chemical consumption through a "leaching-regeneration-leaching" cycle mechanism, thus achieving both environmental and economic benefits.

The invention relates to an electrochemical cleaning method for removing organic matters on the surface of a silicon carbide wafer, which comprises the following steps of: immersing the silicon carbide wafer with the polluted surface into electrolyte containing bivalent and / or trivalent ferric salt, applying voltage or current between a cathode material and an anode material, and carrying out electrochemical reaction to remove the organic matters on the surface of the silicon carbide wafer. The surface of the silicon carbide wafer is subjected to organic matter removal. According to the method, an electrochemical oxidation method technology is adopted, the strong oxidation effect of hydroxyl free radicals is utilized, organic residues on the surface of the silicon carbide wafer are oxidized and decomposed into short-chain organic matter, water, carbon dioxide and other products, and the purpose of removing the organic residues is achieved. The method provided by the invention is simple and efficient, can quickly remove organic pollutant residues on the surface of the silicon carbide wafer, does not use high-concentration chemicals and organic component cleaning agents which are difficult to degrade in the cleaning process, is safe and reliable to operate, reduces the consumption of the chemicals, avoids secondary pollution, and is more environment-friendly.

The invention discloses a preparation method of a carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material, which is specifically implemented according to the following steps: step 1, dissolving sodium salt, ferric salt and phosphate in deionized water in proportion, then adding a carbon source into the solution, and uniformly stirring to obtain a mixed solution; step 2, fully drying the mixed solution obtained in the step 1 to obtain precursor powder; and 3, carrying out heat treatment on the precursor powder in a protective atmosphere, and cooling to obtain the carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material. The invention also discloses a coating prepared by the method, a single-crystal structure is combined with uniform carbon coating, grain boundary defects are eliminated, conductivity is improved, high specific capacity and long cycle life are realized, single-crystal growth and carbon layer in-situ coating are synchronously realized by a synthesis process, and structural integrity and efficient conductive network construction can be ensured.

The invention relates to a sunken porous magnetic alloy ball wave-absorbing material and a preparation method and application thereof.The wave-absorbing material is prepared through the following steps that S1, citric acid, soluble ferric salt, soluble cobalt salt and soluble nickel salt are dissolved in a mixed solvent of ethylene glycol and water, and the mixture is fully stirred to form a uniform mixed solution; and S2, the mixed solution obtained in the step S1 is subjected to spray drying, obtained precursor powder is placed in the air atmosphere to be calcined to remove the carbon source, then the precursor powder is placed in the H2 / Ar atmosphere to be subjected to heating reduction, and the porous FeCoNi alloy balls with the surface pits are obtained and are the target product. The surface of the prepared alloy microsphere has an obvious concave structure, magnetic anisotropy and magnetic performance are enhanced, a small number of pores are generated in the reduction process, impedance matching of the material is optimized, and effective high-frequency electromagnetic absorption is achieved; and due to the synergistic effect of the recesses and the pores, the obtained alloy microspheres have obvious lightweight characteristic, and have good application prospects in the field of electromagnetic absorption.

Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. The cobalt ferrite particles are obtained by a method for producing cobalt ferrite particles, including performing a thermal treatment on an aqueous solution containing a divalent iron salt and a divalent cobalt salt stabilized by a complexing agent (ferrite precursor).

The invention discloses a mine water fluorine removal agent and a preparation method and application thereof, and belongs to the technical field of wastewater treatment.The preparation method of the fluorine removal agent comprises the following steps that aluminum salt, calcium salt, magnesium salt and ferric salt are added into water to be stirred, then a chelating agent, a hydroxy carboxylic acid compound and a dispersing agent are added, the mixture is heated to 40-60 DEG C to be stirred and dispersed, and heat preservation is conducted. The preparation method gets rid of the constraint of traditional calcium salt, introduces the chelating agent, the hydroxy carboxylic acid compound and the dispersing agent on the basis of controlling the compatibility of the materials and the synthesis reaction process, and utilizes the excellent fluorine ion adsorption performance and flocculation settling performance of the aluminum-calcium-magnesium-iron-based quaternary metal material to improve the fluorine ion adsorption performance of the aluminum-calcium-magnesium-iron-based quaternary metal material. Quaternary metals are assembled into a long-chain porous structure through chelation, the specific surface area and the pore volume are further increased, the contact area with fluorine ions in mine water is increased, and the porous structure adsorbs complexing groups to achieve the purposes of rapid coordination, strong adsorption, precise chelation, flocculating settling and efficient removal of fluoride in mine water.

The invention belongs to the technical field of new energy and electrochemistry, and particularly relates to a corrosion-resistant structured transition metal alloy electrode suitable for hydrogen production from alkaline water and a preparation method of the corrosion-resistant structured transition metal alloy electrode. The method comprises the following steps: sequentially carrying out sand blasting treatment and electrochemical activation treatment on a nickel net substrate so as to improve the surface roughness and the number of active sites; and then performing constant-current deposition in an electro-deposition solution containing nickel salt and ferric salt and / or cobalt salt, and constructing a nickel-based alloy catalyst layer in a micron array shape to obtain the alloy electrode. Through observation of a scanning electron microscope, the surface of the obtained electrode has a sphere-like microstructure, the arrangement is compact, and the catalytic efficiency and durability can be improved. The prepared structured alloy electrode has the advantages of being high in interface bonding force, high in electro-catalytic performance, high in alkali corrosion resistance and the like, and is suitable for efficient and long-term operation of hydrogen production through alkaline electrolysis of water.

The invention provides a preparation method of a Fe3C catalyst. The preparation method comprises the following steps: preparing a ferric salt solution; transferring the ferric salt solution into a crystallization kettle for hydrothermal aging; centrifugally separating and collecting solids, washing and drying to obtain a catalyst precursor; and carrying out reduction carbonization on the catalyst precursor, and then carrying out decarbonization treatment to obtain the Fe3C catalyst. The catalyst prepared by the invention is high in CO conversion rate and low in CO2 and CH4 selectivity in Fischer-Tropsch synthesis, and has excellent catalytic activity and stability.

The invention discloses ferric salt modified myriophyllum verticillatum biochar and a preparation method and application thereof.The preparation method comprises the steps that S1, myriophyllum verticillatum is washed and soaked with distilled water, then dried, smashed and sieved, and myriophyllum verticillatum powder is obtained; s2, adding the myriophyllum spicatum powder obtained in the step S1 into a ferrous chloride solution, and heating in a water bath until gel is formed; s3, drying the gel obtained in the step S2 at a constant temperature to obtain dry gel; s4, pyrolyzing the xerogel obtained in the step S3 in an inert gas atmosphere to obtain a pyrolysis product; and S5, washing the pyrolysis product obtained in the step S4, drying, grinding and sieving to obtain the ferric salt modified myriophyllum spicatum biochar. Myriophyllum verticillatum is adopted as a raw material, gelatinization and pyrolysis are performed to obtain the biochar, the biochar is chemically modified by using a ferrous chloride solution to improve the adsorption characteristic so as to adsorb phosphate in a polluted water body, and the prepared biochar has magnetism and is beneficial to recycling.

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 invention discloses tannic acid-oleylamine modified nano molybdenum disulfide as well as a preparation method and application thereof. The preparation method of the tannic acid-oleylamine modified nano-molybdenum disulfide comprises the following steps: 1) dispersing nano-molybdenum disulfide and tannic acid in a solvent, then adding ferric salt for reaction, and then carrying out product separation to obtain the tannic acid modified nano-molybdenum disulfide; and 2) dispersing the tannic acid modified nano molybdenum disulfide and oleylamine in a solvent for reaction, and then carrying out product separation to obtain the tannic acid-oleylamine modified nano molybdenum disulfide. The tannic acid-oleylamine modified nano molybdenum disulfide disclosed by the invention has the advantages of excellent friction reduction and wear resistance, good dispersity in ester oil, good compatibility with other additives and the like, the preparation raw materials are safe and non-toxic, the preparation method is simple, and the tannic acid-oleylamine modified nano molybdenum disulfide is suitable for large-scale industrial production and application.

The invention discloses a method for producing mRNA (messenger ribonucleic acid) template plasmids by fermenting escherichia coli. When the recombinant escherichia coli is fermented and cultured, a seed solution of the recombinant escherichia coli is inoculated into a basic culture medium to be fermented and cultured until the OD600 value of fermentation liquor is 18-22, then a fed-batch culture medium is continuously added at the feeding rate of 5-15 mL / L / h to be subjected to continuous fed-batch fermentation culture, the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate, and the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate. The basal culture medium contains 10-15 g / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the basal culture medium contains 0.1-0.3 mmoL / L of a ferric salt compound, 0.1-0.3 mmoL / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the fed-batch culture medium contains 360-480 g / L of glycerol, and the ferric salt compound is one or more of ferrous citrate, ferric ammonium citrate or ferrous sulfate heptahydrate. According to the method, the yield and superhelix content of the mRNA template plasmids are improved by optimizing the culture medium formula and culture conditions, and large-scale production of the high-quality target mRNA template plasmids is facilitated.

The invention provides a multi-characteristic iron-carbon derivative material for adsorbing and repairing PFAS pollution of a water body as well as a preparation method and application of the multi-characteristic iron-carbon derivative material. The preparation method comprises the following steps: 1, dissolving a ferric salt in N, N-dimethylformamide, adding a ligand terephthalic acid under a stirring condition, and synthesizing a precursor through a solvothermal method; and 2, carrying out heat treatment on the precursor in an inert atmosphere to obtain the multi-characteristic iron-carbon derivative material. The application of the multi-characteristic iron-carbon derivative material in the aspect of environmental restoration comprises the following steps: by taking the multi-characteristic iron-carbon derivative material as an adsorbent, carrying out adsorption purification treatment on a PFAS polluted water body under the assistance of a cationic complexing agent. The multi-characteristic iron-carbon derivative material is synthesized through a solvothermal-thermal treatment two-step method, so that the multi-characteristic iron-carbon derivative material has high hydrophobicity, a two-dimensional-three-dimensional tight interface and magnetism, can quickly remove PFAS with various different structures and carbon chain lengths, can realize material separation within 30 seconds after the PFAS is removed through adsorption, and does not generate secondary pollution.

The invention belongs to the field of catalysts, and discloses a catalytic material based on lignin derivation and a preparation method and application thereof. The catalytic material is prepared from lignin derived carbon and NiFe LDH; the lignin derived carbon is inserted into the interlayer of the NiFe LDH and is coated on the surface of the NiFe LDH. The preparation method comprises the following steps: S1, dissolving a lignin derivative in water to obtain a first solution; s2, dissolving metal salt in water to obtain a second solution, wherein the metal salt comprises ferric salt and nickel salt; s3, mixing the first solution and the second solution, and adjusting the pH value to obtain a mixed solution; and S4, immersing the conductive current collector into the mixed solution for hydrothermal reaction, taking out the conductive current collector after the reaction is finished, and treating the conductive current collector to obtain the catalytic material. The obtained catalytic material is used for an anode oxygen evolution reaction in an electrolytic seawater environment, and has high activity, high stability and good chlorine corrosion resistance.

The invention provides a preparation method of an F-doped carbon-coated MOF-derived lithium iron phosphate material. The preparation method comprises the following steps: uniformly mixing and dispersing a trivalent iron salt, a fluorine-containing ligand, a surfactant and a solvent, and carrying out solvothermal reaction to obtain fluorine-containing Fe-MOF; the preparation method comprises the following steps: uniformly mixing fluorine-containing Fe-MOF with a phosphorus source and a lithium source, grinding, and carrying out solid-phase sintering to obtain the F-doped carbon-coated MOF-derived lithium iron phosphate material (LFP (at) FC). The F-doped functional porous carbon has relatively high adsorption capacity, meanwhile, the Li < + > diffusion barrier is reduced, additional active sites are further endowed, the electronic conductivity of the material is improved, and a diffusion channel is accelerated. The LFP (at) FC positive electrode shows excellent rate capability and long cycle stability.

The invention discloses a preparation method and application of a UIO-66 (Fe) / PAN nanofiber membrane, and the preparation method comprises the following steps: (1) adding zircon salt and ferric salt into a solvent, and uniformly mixing to obtain a solution A; (2) adding terephthalic acid into an acid-base regulator, then adding a solvent, and uniformly mixing to obtain a solution B; (3) uniformly mixing the solution A and the solution B, carrying out solvothermal reaction, cooling to room temperature, centrifuging, washing and drying to obtain a UIO-66 (Fe) solid; (4) dissolving polyacrylonitrile in a solvent, and uniformly mixing to obtain a PAN solution; (5) ultrasonically dispersing a UIO-66 (Fe) solid in a solvent to obtain a dispersion liquid, adding the dispersion liquid into the PAN solution, and uniformly stirring and mixing to obtain a spinning solution; and (6) carrying out electrostatic spinning on the spinning solution to obtain the UIO-66 (Fe) / PAN nanofiber membrane. The nanofiber membrane prepared by the method has high adsorption capacity and good selectivity on Se (IV) in a water body.

The invention relates to the technical field of sewage treatment and resource utilization, in particular to a method for recovering phosphorus from sludge, which comprises the following steps: carrying out anaerobic digestion on the sludge to be treated under anaerobic conditions to release phosphorus in the sludge into supernate to obtain sludge anaerobic digestion liquid, adding an iron salt coagulant into the sludge anaerobic digestion liquid, precipitating, filtering, washing and drying to obtain the phosphorus-containing sludge. Removing phosphorus from the supernate, enabling the phosphorus to enter a precipitate, and removing the supernate to obtain a solid-liquid mixture; and adding the solid-liquid mixture into a reactor, adding a mixed bacterial agent of iron reducing bacteria and metal-resistant bacteria into the reactor, reducing ferric iron into ferrous iron under the action of the iron reducing bacteria, dissolving the precipitate, and recrystallizing to obtain the blue iron ore, thereby realizing the recovery of phosphorus in the sludge. According to the invention, ferric salt precipitates are re-induced to precipitate and recrystallize, so that the problems of low phosphorus load, large volume, low economic benefit of direct recovery, low crystallinity of chemical precipitates, more impurities, difficulty in controlling dissolved oxygen and easiness in oxidation at present are solved.

The invention discloses a method for degrading gold cyanidation tailings through photo-Fenton of an aluminum-based bimetallic catalyst, and belongs to the technical field of cyanidation tailings treatment. Iron salt and zinc salt are loaded on activated aluminum oxide through an impregnation method, the aluminum-based bimetallic catalyst is obtained through the treatment processes of roasting, grinding, drying and the like, and iron oxide and zinc ferrite contained in the synthesized aluminum-based bimetallic catalyst are main active substances for degrading cyanide residues through photo-Fenton catalysis; under the participation of hydrogen peroxide and an ultraviolet light source, the concentration of cyanide in the cyanide residues can be remarkably reduced, toxicity detection on the reacted filter residues shows that the concentration of the cyanide is lower than the national standard, and the cyanide residues can be treated as general solid waste; the cyanide removal rate can reach 95% or above, and the method has a very good application prospect.

The invention discloses a system and method for directly preparing battery-grade ferrous oxalate based on dimethyl oxalate, and the system comprises a rectifying tower which is used for carrying out hydrolysis reaction on dimethyl oxalate and discharging a hydrolysis solution through a liquid phase outlet; the decolorizing kettle is used for decolorizing the hydrolysis solution; the precipitation reaction kettle is used for carrying out mixed reaction and aging on the hydrolysis solution and ferric salt; the product recovery unit is connected with the precipitation reaction kettle and is used for separating and recovering reaction products to obtain battery-grade ferrous oxalate. According to the method, the hydrolysis solution of the dimethyl oxalate and the iron salt are directly mixed for precipitation reaction to prepare the battery-grade ferrous oxalate, high-energy-consumption steps such as crystallization and drying in the oxalic acid solid production process are reduced, meanwhile, the step of dissolving the solid oxalic acid is not needed, the heating energy consumption needed in the dissolving process is reduced, and the production efficiency is improved. The production energy consumption is greatly reduced, the production equipment and process are reduced, the cost is reduced, and the product yield is favorably improved.

The invention provides iron phosphate as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. Specifically, the method comprises the following steps: preparing a raw material solution from a ferrous sulfate crude salt of a titanium dioxide production by-product, heating the raw material solution to boil, and cooling to obtain a mixed solution; then carrying out solid-liquid separation to obtain recrystallized ferric salt and preparing into a ferric salt solution; adjusting the pH value of the ferric salt solution to be lower than 1.80, repeatedly boiling, cooling and crystallizing to obtain secondary crystallized ferric salt, and preparing into a second ferric salt solution; preparing a phosphorus salt solution from monoammonium phosphate and ammonia water; mixing the second ferric salt solution, the phosphorus salt solution and hydrogen peroxide, reacting, and separating to obtain an iron phosphate precursor; and preparing the iron phosphate precursor into slurry, adjusting the pH value, and sequentially carrying out heating reaction, solid-liquid separation and calcination after the slurry becomes white to obtain iron phosphate. According to the method, resource utilization of the ferrous sulfate crude salt byproduct is realized, and meanwhile, the defects of high impurity content and low product purity during resource product preparation are overcome.

The invention relates to application and a method of phosphorus adsorption resin for selectively adsorbing phosphorus from phosphorus-containing wastewater. The phosphorus adsorption resin comprises weak acid cation exchange resin and Fe < 3 + > loaded on the surface of the weak acid cation exchange resin; the pH value of the phosphorus-containing wastewater is 0.8-3.0, the phosphorus concentration is 0.1-5 g / L, and the wastewater further contains 0.1-1 g / L of Ca; the phosphorus adsorption resin is prepared by the following steps: i) carrying out contact reaction on weak acid cation exchange resin and a ferric salt solution, wherein the ferric salt is selected from one or more of ferric sulfate, ferric chloride, ferric nitrate, ferric citrate and ferric tartrate; and ii) after the reaction is completed, carrying out solid-liquid separation to obtain the Fe < 3 + >-loaded phosphorus adsorption resin. According to the method, high-selectivity adsorption (larger than or equal to 95%) of phosphorus can be achieved, the phosphorus and calcium separation effect is good, the iron-calcium ratio in the phosphorus-enriched strip liquor is larger than or equal to 800, and the method can be used for preparing battery-grade iron phosphate.

The invention discloses a method for preparing CNTs and hydrogen-rich gas through sludge pyrolysis, sludge is subjected to pyrolysis after being conditioned by ferric salt, pyrolysis gas is collected and reduced under the action of a Ni-Fe / NF catalyst, the Ni-Fe / NF catalyst is prepared and obtained, and the Ni-Fe / NF catalyst is obtained by dipping foamed nickel in a mixed solution containing nickel nitrate and ferric nitrate and reducing the foamed nickel. Under the action of the Ni-Fe / NF catalyst, on the basis of not changing pyrolysis conditions and not influencing preparation of pyrolytic carbon and pyrolytic oil by sludge pyrolysis, the pyrolysis gas is synchronously converted into the Ni-Fe / NF catalyst with higher value, so that the economic values of the sludge and the pyrolysis gas are improved, the influence on the environment is reduced, and the engineering application of the sludge pyrolysis technology is favorably realized.

The invention provides chitosan-based polymer composite aerogel as well as a preparation method and application thereof. The preparation method of the chitosan-based polymer composite aerogel comprises the following steps: homogenizing phosphate functionalized boron nitride nanosheets in water to obtain a suspension; mixing the suspension liquid, chitosan powder and ferric salt to form composite gel; and drying to obtain the chitosan-based polymer composite aerogel. The mass ratio of the chitosan to the phosphate functionalized boron nitride nanosheet to the iron salt is 1: (0.5 to 2.5): (0.08 to 0.3). According to the preparation method disclosed by the invention, a ternary cross-linked hierarchical network structure is constructed by utilizing coordination cross-linking of iron ions and chitosan molecular chains and a chelation effect of phosphate ester groups on the surfaces of boron nitride nanosheets, so that the composite aerogel with low density and high specific strength is prepared; efficient flame retardance can be achieved through a triple synergistic mechanism of a physical barrier, free radical capture of phosphorus elements and catalytic char formation of iron ions.

The invention discloses a preparation method of a ferrocerium / molecular sieve catalyst and an application of the ferrocerium / molecular sieve catalyst in preparation of acetic acid by mild oxidation of methane, and the specific preparation method comprises the following steps: taking metal cerium, ferric salt and a microporous molecular sieve as raw materials, dipping, drying and calcining to prepare the ferrocerium / molecular sieve catalyst. The preparation method is simple in process, easy to implement, simple, convenient and safe to operate, process parameters are easy to control, and active metal cerium and iron in the obtained cerium-iron / molecular sieve catalyst are anchored in micropore channels of a molecular sieve in a monodisperse cation state, so that the cerium-iron / molecular sieve catalyst can selectively oxidize small molecules such as methane and carbon monoxide under mild conditions; and the preparation of high-yield acetic acid chemicals is realized, few byproducts are produced, and large-scale production can be realized.

The invention discloses a preparation method of a size-controllable alpha-iron oxide nanosheet catalyst, the prepared catalyst and application of the catalyst. Comprising the following steps: mixing ferric iron salt, ethanol, water and sodium acetate at room temperature, reacting in a closed container, centrifuging, washing, drying and roasting to obtain the size-controllable alpha-iron oxide nanosheet catalyst. The catalyst provided by the invention is controllable and uniform in size and is used for ortho-parahydrogen reaction, and an effective method is provided for structural design and development of the high-activity ortho-parahydrogen catalyst.

The invention provides a Fe-Fe3C-coated rGO carbon nanoelectrode material as well as a preparation method and application thereof, and belongs to the technical field of electrode materials. Aiming at the problem that an existing electrode material is difficult to be used as a CDI electrode material for removing heavy metals, the CDI electrode material is prepared by utilizing the characteristic that multivalent metal iron ions can be subjected to cross-linking reaction with a sodium alginate solution, and the preparation method comprises the following steps: obtaining a graphene oxide dispersion liquid; under a water bath condition, adding sodium alginate into the graphene oxide dispersion liquid, dropwise adding the obtained gel liquid into a ferric salt solution, stirring, and freeze-drying to obtain aerogel microspheres; and carrying out high-temperature carbonization on the aerogel microspheres to obtain the Fe-Fe3C-coated rGO carbon nanomaterial. When the material is used as a CDI electrode material, aggregation of an iron compound on the surface of graphene can be effectively reduced, the specific capacitance, the conductivity and the cycling stability of the electrode material are improved, and a good Cr (VI) removal effect is achieved.

The invention discloses a method for circularly leaching lithium iron phosphate mixed powder from ferric salt and recovering all components, and belongs to the field of battery recovery. The method comprises the following steps: leaching mixed powder by adopting an iron salt solution to obtain a lithium-containing leaching solution and leaching residues; ferrous ions in the leachate are regenerated into ferric iron through acidification and oxidation, the ferric iron is cyclically used for leaching the next batch of mixed powder, after the preset cycle number is reached, the leachate is used for re-leaching treatment of multiple batches of leaching residues, and the lithium leaching rate is increased. And finally obtaining enriched liquid containing Li, Fe, Cu and Al and iron phosphate slag containing graphite. And replacing the enriched liquid with iron powder to recover copper, extracting and separating to obtain a high-purity lithium chloride solution, and simultaneously recovering ferric chloride (recycling) and aluminum chloride crystals. And treating the leaching residues with hydrochloric acid to obtain regenerated graphite, and adjusting the pH value with alkali to obtain high-purity iron phosphate. According to the method, all-component recovery is achieved under the mild condition, separation steps are reduced through a leaching-regeneration-leaching circulation mechanism, chemical consumption is reduced, and the method has both environmental and economic benefits.

A method for preparing mesoporous iron phosphate by induction of block copolymers is provided. The method comprises preparing a ferric salt solution having a certain concentration and evenly dispersing it into a dispersant, then evenly mixing a structure directing agent solution with a phosphorus source solution, next adding the mixed solution to the ferric salt solution while dropwise adding an oxidant and stirring to react, thus after ending the reaction, washing, drying and calcinating the reaction product to obtain mesoporous iron phosphate. It is achievable to treat the block copolymer acting as a structure directing agent by way of using diverse dispersants and acidifiers different in concentration and induce the disodium hydrogen phosphate dihydrate to react with ferric salt solution to prepare mesoporous iron phosphate, producing mesoporous iron phosphate with controllable different conformations and meeting the requirements of cathode materials for lithium-ion batteries in different application scenarios.