402 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.

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 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.

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 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 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 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 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 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 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.

The invention relates to the field of building materials, and particularly discloses a high-ductility cement-based composition with wave-absorbing performance and a preparation method thereof, the high-ductility cement-based composition comprises the following raw materials: cement, sand, water, copper slag, a ferrite-copper slag compound, fly ash, mineral powder, an additive, modified carbon fiber loaded with mica powder-modified waste rubber powder composite filler, and PE fiber; the ferrite-copper slag compound is prepared by mixing iron-containing electroplating sludge and iron salt, adding water to form slurry, adding copper slag and calcium oxide into the slurry, performing high-temperature oxidation treatment in an air atmosphere, and crushing; the preparation method comprises the following steps: mixing the cement, the sand, the copper slag, the ferrite-copper slag compound, the fly ash and the mineral powder, adding the modified carbon fiber loaded with the mica powder-modified waste rubber powder composite filler and the PE fiber, and stirring to prepare a primary mixture; and mixing the admixture with water, adding the primary mixture, and stirring to obtain the concrete. The preparation method has the characteristic of preparing the cement-based material with high ductility and wave-absorbing property.

The invention discloses an iron-cobalt spinel oxide, which is prepared by the following steps: with ferric salt and cobalt salt as raw materials, dissolving the ferric salt, the cobalt salt and sodium acetate in an ethanol aqueous solution to obtain a precursor solution, carrying out hydrothermal treatment on the precursor solution, and washing and drying a reaction product to obtain the iron-cobalt spinel oxide. The iron-cobalt spinel type oxide is stable in crystal structure, the leaching rate of metal ions is remarkably reduced due to existence of metal-oxygen bonds, the recycling rate is increased, and meanwhile the risk of secondary pollution of water is reduced. In the process of degrading nitrogen-containing organic wastewater by an advanced oxidation technology for generating sulfate free radicals based on peroxymonosulfate, the iron-cobalt spinel type oxide has good catalytic performance, and can basically complete degradation of multi-nitrogen organic pollutants in water; and the method has relatively strong capability of resisting interference of inorganic ions and organic matters, and has relatively great application potential in actual wastewater treatment. The invention also discloses a method for degrading the multi-nitrogen explosive wastewater by using the ferrocobalt spinel type oxide.

The invention provides a step-by-step leaching remediation method for chromium-contaminated soil, which comprises the following steps: mixing the chromium-contaminated soil and a first leacheate, carrying out first oscillation, then adding a second leacheate into the mixture, and carrying out second oscillation to obtain the remediated soil, the first leacheate comprises sodium salt; the second leacheate comprises organic acid and ferric salt; the temperature of the second oscillation is 70 DEG C to 90 DEG C. The method comprises the following steps: desorbing and releasing hexavalent chromium adsorbed on the surfaces of soil particles by using a sodium salt eluting agent, dissolving the soil particles to promote release of insoluble hexavalent chromium, and dissolving the soil particles containing high-concentration insoluble hexavalent chromium by using a composite eluting agent of organic acid and ferric salt under a high-temperature condition. And when the hexavalent chromium is released, the hexavalent chromium is efficiently reduced and stabilized, so that the aim of removing the hexavalent chromium in the polluted soil is fulfilled.

The invention discloses a treatment method of an electrolyte after wet crushing of a waste lithium ion battery. During crushing, an alkaline solution is sprayed out of a spraying opening located above a shearing opening to completely cover the waste lithium ion battery crushed material, a hydrolysis reaction is carried out under the cooperation of ultrasonic waves, and waste water, a pole piece mixture, a shell pile head, a diaphragm and the like are separated out through hydrodynamic force. The method comprises the following steps: adding dilute acid into wastewater to adjust the pH value, adding bivalent iron salt and hydrogen peroxide, performing Fenton oxidation and mineralization on an organic solvent in the wastewater under the synergism of ultrasonic waves, then adding an alkali metal salt solution to adjust the pH value, and filtering and separating to obtain filtrate and ferric hydroxide precipitate; adding alkali into the filtrate twice to adjust the pH value for precipitation, and filtering to separate valuable precipitate and filtrate; and adding dilute acid into the ferric hydroxide precipitate for dissolving, and then adding a reducing agent to obtain a ferrous salt solution which is circularly used for Fenton reaction. According to the method, hydrolysis, Fenton oxygenolysis, mineralization of the organic electrolyte and regeneration and recycling of the ferrous salt are adopted, and the method is suitable for large-scale and low-cost treatment of the electrolyte in the waste lithium ion battery.

The invention relates to a high-entropy metal oxide catalyst and a preparation method and application thereof.The preparation method comprises the following steps that S1, ferric salt, cobalt salt, manganese salt, nickel salt, copper salt and organic alkaline matter are mixed to obtain a mixed solution, hydrothermal reaction is conducted, and a precursor is obtained; and S2, calcining the precursor at the temperature of 500-600 DEG C to obtain the high-entropy metal oxide catalyst. The high-entropy metal oxide catalyst uniformly doped with iron, cobalt, manganese, nickel and copper is prepared by adopting a hydrothermal reaction and calcination method, and the high-entropy metal oxide catalyst not only can efficiently catalyze ozone to remove antibiotics, but also can still keep an excellent antibiotic removal rate constant in a water body containing hetero ions and humic acid; and the anti-interference capability is excellent.

The invention provides a metal hydroxide (LDH) and a preparation method and application thereof in seawater electrolysis, and belongs to the field of new materials and hydrogen energy preparation. Aqueous solutions of ferric salt, cobalt salt and nickel salt are stirred to obtain a mixed solution; under a constant voltage, metal ions of the mixed solution are subjected to a reduction reaction on the surface of the working electrode to generate ternary NiCoFe-LDH, namely, the metal hydroxide is obtained; according to the method, a high-activity and high-stability nano-structure material directly grows on a conductive substrate through an electrochemical deposition method of three metal (Fe, Co and Ni) hydroxides in a specific proportion, and the low-cost seawater electrolysis catalyst can be constructed only through direct in-situ growth of LDH through a potentiostatic method, so that the high-temperature and high-pressure requirements of a traditional hydrothermal method are avoided, and the method is suitable for industrial production. The LDH nanosheet array structure directly grown in the invention avoids the use of a binder, improves the mechanical stability of the electrode and prolongs the cycle life of the electrode. The ternary NiCoFe-LDH is used as an anode material of an electrolytic tank and can be used for directly electrolyzing seawater to produce hydrogen.

The invention discloses preparation and application of a nickel selenide / ferronickel phosphate crystal / amorphous heterogeneous catalyst, and relates to the technical field of electrochemistry. Selenizing the foamed nickel at low temperature in an inert atmosphere to generate a crystalline NiSex layer in situ; and by taking the obtained electrode as a working electrode, carrying out electrodeposition in a deposition solution containing nickel salt, ferric salt, hypophosphite and acetate by adopting a cyclic voltammetry method, so that amorphous NiFePOy is deposited on the surface of NiSex, and a NiSex / NiFePOy crystal / amorphous heterostructure nanosheet layer is constructed and is used for an alkaline medium urea oxidation reaction. The invention has the following beneficial effects: crystalline / amorphous interface coupling and a nanosheet self-supporting structure synergistically improve active sites and charge transfer capability, reduce energy consumption and improve current output; meanwhile, the electrode stability and durability are enhanced; the method has the advantages of low material cost, mild and simple process, suitableness for amplified preparation, and application potential of urea-assisted water electrolysis energy-saving hydrogen production.

The invention discloses a preparation method of particle composite sheet-shaped battery-grade iron phosphate, and particularly relates to the field of lithium ion battery positive electrode materials. The method comprises the steps of purification and oxidation of a ferric salt solution, preparation and synthesis of a phosphorus salt solution, aging and separation. The iron phosphate with the particle composite sheet-shaped morphology is low in impurity content, low in specific surface area and small in particle size, and presents a hierarchical structure morphology formed by combining particles and sheets, and the prepared material shows higher specific capacity, higher rate capability and good cycle performance, and has huge application potential in the aspect of improving the performance of a lithium ion battery.

The invention discloses a preparation method and application of a high-entropy layered double hydroxide oxygen evolution catalyst, and relates to the field of oxygen evolution reaction catalysis, and the preparation method comprises the following steps: S1, washing foamed nickel in absolute ethyl alcohol and deionized water, and then carrying out ultrasonic treatment in a hydrochloric acid solution to obtain pretreated foamed nickel; s2, adding ferric salt, cobalt salt, nickel salt, manganese salt, zinc salt and a proper amount of urea into deionized water, then adding ammonium fluoride, and uniformly stirring to obtain a mixed solution; and S3, transferring the mixed solution and the pretreated foamed nickel into a reaction kettle, carrying out a hydrothermal reaction, and washing and drying the obtained product to obtain the high-entropy layered double hydroxide oxygen evolution catalyst. According to the method, the key regulation and control effect of NH4F on the structure, chemical and electro-catalytic properties of HELDHs in the synthesis process of the HELDHs is analyzed, and the performance enhancement is attributed to NH4F-induced morphology and crystal engineering and catalytic active cation vacancies generated in situ through selective leaching of Zn < 2 + > and adsorption of sulfate under the alkaline condition.

The invention provides a method for removing phosphorus from a cobalt sulfate solution. The method comprises the following steps: providing a cobaltous sulfate solution to be treated; the method comprises the following steps: mixing a to-be-treated cobaltous sulfate solution, a composite polymer soluble ferric salt and a coagulant aid, carrying out precipitation reaction, and separating to obtain phosphorus-containing slag and cobaltous sulfate primary purified liquid; a deep phosphorus removal adsorbent is adopted to adsorb trace phosphorus in the cobalt sulfate primary purification liquid, then trace iron in the cobalt sulfate primary purification liquid generates precipitates in an oxygen-containing atmosphere, and after separation, a cobalt sulfate secondary purification liquid is obtained. According to the method, firstly, the synergistic effect of the composite polymer soluble ferric salt and the coagulant aid is adopted, and primary efficient removal of phosphorus is achieved; then, a deep phosphorus removal adsorbent is used for directionally adsorbing trace phosphorus in the cobalt sulfate primary purification liquid, so that deep removal of phosphorus is further realized; and finally, the residual trace iron is precipitated and separated in the oxygen-containing atmosphere, so that the purity of the secondary purified cobalt sulfate liquid is further guaranteed.

A method of manufacturing a nanocomposite may include combining a magnesium salt, an aluminum salt, and a ferric salt in stoichiometric proportions within 5 mol. % in an aqueous solvent including menthol or dextrose, to obtain a first mixture, heating the first mixture to remove at least 99.5 wt. % of the aqueous solvent to obtain a first solid, grinding the first solid into a first powder, calcining the first powder at a temperature of about 600° C. to 800° C. for a time of about 2 to 4 hours to obtain a second solid, grinding the second solid and urea, in an amount sufficient to form the nanocomposite, into a second powder, heating the second powder at a temperature of about 550° C. to 650° C. for a time of about 15 minutes to 1.5 hours to obtain the nanocomposite.

The invention relates to a preparation method of an alumina-loaded iron-aluminum co-doped graphene-like catalyst and application of the alumina-loaded iron-aluminum co-doped graphene-like catalyst in the field of water treatment. The method comprises the following steps: dispersing biomass (such as silkworm excrement, corncob and the like) in water to form a suspension, sequentially adding ferric salt, aluminum salt and a nitrogen source (such as urea, melamine and the like), adjusting the pH value, impregnating alumina pellets, drying, and roasting at high temperature in an inert atmosphere to prepare the immobilized catalyst. According to the catalyst, iron-aluminum co-complexed nitrogen-doped graphene is loaded on alumina pellets, and the catalyst has high specific surface area and active sites. The catalyst disclosed by the invention is suitable for degrading refractory organic pollutants (such as tetracycline, bisphenol A and ciprofloxacin) in water, can realize rapid degradation within 30 minutes through a synergistic effect with microorganisms, and is excellent in long-term operation stability (for example, the tetracycline removal rate is kept 100% for 106 days). The immobilized design of the catalyst facilitates separation and recovery, avoids secondary pollution, and is suitable for industrial water treatment. The matched curing bed reactor controls contact reaction of pollutants and a catalyst through a peristaltic pump, and continuous and efficient treatment is achieved. The method has the advantages of low raw material cost, simple process, high catalytic activity and cyclic utilization, and provides an efficient and environment-friendly solution for the treatment of organic polluted water.

The invention belongs to the technical field of pyruvic acid biological detection, and relates to a pyruvic acid sensing chip of a Prussian blue nano frame / gold nano composite material. The method comprises the following steps: adding soluble metal salt containing ferricyanide ions into water; the method comprises the following steps: adding soluble ferric salt and a complexing agent into water, mixing, and carrying out hydrothermal synthesis reaction to obtain PB powder; adding PB powder into ethanol, adding ammonia water for reaction, mixing with conductive carbon paste to obtain nano printing paste, and printing the printing paste on a substrate to form a working electrode; the preparation method comprises the following steps: preparing a working electrode, drying the working electrode, placing the working electrode in a chloroauric acid solution for constant potential electrodeposition, mixing a PBS solution of pyruvate oxidase, a polylysine solution and an EDC solution, dropwise adding the mixture on the surface of the working electrode, and drying to obtain the pyruvic acid sensing chip. The obtained pyruvic acid sensor can reach the sensitivity of 50.42 [mu] A.mM <-1 >. Cm <-2 >, and is simple in preparation process and relatively low in cost.

This application relates to the field of chemical production and discloses a metal salt catalyst for desulfurization and denitrification, its preparation method, and its application. The catalyst comprises an active metal component of 30%-35%, a support of 60%-65%, and an additive of 5%-10%. The active metal component is specifically ferrous sulfate. The activity of the ferrous salt at medium and low temperatures, combined with the adjustment of the catalyst surface acidity by alkali metal sodium and rare earth element cerium, broadens the active temperature range. The support is specifically alumina. The additives consist of 3%-6% alkali metal sodium and 2%-4% rare earth element cerium by mass. Simultaneously, alkali metal sodium and rare earth element cerium can reduce impurity adsorption and enhance resistance to poisoning. This invention, through the rational selection of the active metal component, support, and additives, broadens the active temperature range of the catalyst, enabling it to adapt to flue gas temperature changes under different operating conditions, thus providing a wider range of applications for desulfurization and denitrification in industrial production.

The invention provides an iron-based catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, continuously conveying pulverized coal into an absorption reactor, simultaneously continuously conveying an iron salt solution, an alkali liquor and compressed gas into a three-fluid mixing nozzle in the absorption reactor, spraying fog drops containing iron precipitates with the diameter of less than or equal to 1000 microns, and enabling the fog drops containing the iron precipitates to be loaded on the surface of the pulverized coal to obtain a precursor; wherein the three-fluid mixing nozzle comprises a feeding area, an atomization area and a precipitation reaction area from top to bottom, and the feeding area comprises a central channel, an inner annular gap channel and an outer annular gap channel from inside to outside; the ferric salt solution is conveyed to the atomization area through the central channel, and the alkali liquor is conveyed to the atomization area through the outer annular gap channel; or the alkali liquor is conveyed to the atomization area through the central channel, and the ferric salt solution is conveyed to the atomization area through the outer annular gap channel; compressed gas is conveyed to the atomization area through the inner annular gap channel; and S2, carrying out ball milling and drying treatment on the precursor to obtain the iron-based catalyst.

The invention discloses a method for preparing 2, 5-diformyl furan by selectively oxidizing 5-hydroxymethylfurfural, which comprises the following steps of: reacting 5-hydroxymethylfurfural serving as a raw material, air or oxygen serving as an oxidant, nitrate or ferric salt and sodium iodide serving as main active components of a catalyst and DMSO (dimethylsulfoxide) serving as a solvent at the temperature of between 80 and 160 DEG C for a certain time under the condition of normal pressure, and separating a product to obtain the 2, 5-diformyl furan. The ferric salt is ferric nitrate nonahydrate, and the catalyst is 2, 5-diformyl furan. The dosage of the ferric salt is 0 to 0.50 mmol; the use amount of the sodium iodide is 0 to 0.50 mmol. According to the method, DMSO is adopted as a solvent, the used catalyst is cheap and easy to obtain, the yield of 2, 5-diformyl furan can reach 95% at most after the reaction is carried out at 140 DEG C for 20 h, the requirement for equipment is low, and the method is suitable for industrial production.

The application discloses a method for removing organic pollutants by using molybdenum dioxide to promote activated periodate, and comprises the following steps: adding molybdenum dioxide, ferric salt and periodate into wastewater containing organic pollutants, and then performing catalytic degradation reaction to remove the organic pollutants in the wastewater. In the method, molybdenum dioxide is introduced into the homogeneous ferric / periodate system, and serves as an electron donor and mediator of a Fenton-like reaction. The molybdenum dioxide can not only accelerate the Fe 3+ / Fe 2+ cycle rate and promote the activation of the periodate, but also promote the generation of high-valence iron (Fe(IV)) in the system, form a non-radical pathway dominated oxidation mechanism, promote the degradation reaction to be more rapid and intense, and finally realize the efficient degradation of the organic pollutants. The method has the advantages of rapid degradation rate, good reusability, simple process, convenient operation and environmental friendliness, and can be widely used in the treatment of organic pollutant wastewater.