330 results about "Nitrate" patented technology

The invention belongs to the field of biochar adsorbing materials, and relates to a method for preparing modified biochar with aquatic plant waste and hematite. The method includes the following steps: (1) naturally drying aquatic plants prior to crushing to obtain aquatic plant powder; (2) crushing the hematite to obtain hematite powder; (3) weighing the hematite powder prior to putting the hematite powder into deionized water, and performing ultrasonic treatment to obtain suspension; (4) weighing the aquatic plant powder, soaking the aquatic plant powder in the suspension, and stirring and drying to obtain fully mixed aquatic plant and hematite mixture; (5) weighing the fully mixed aquatic plant and hematite mixture, putting the mixture in a batch-type atmosphere furnace, and feeding nitrogen into the furnace; performing temperature programming to the target temperature, and maintaining final-temperature pyrolysis; after the pyrolysis process is finished, obtaining the target product, namely the modified biochar. The modified biochar has strong adsorbability in nitrate and phosphate, high in stability and reusable.

The invention relates to the technical field of composite catalyst materials, in particular to a ferrocobalt bimetal hydroxide / BCN composite material and a preparation method and application thereof.The preparation method comprises the steps that cobalt nitrate and ferric nitrate are used for preparing a metal salt solution, sodium carbonate and sodium hydroxide are used for preparing a precipitant solution, a B-doped carbon nitride BCN material is added into the metal salt solution to form a uniform suspension, and the suspension is dried to obtain the ferrocobalt bimetal hydroxide / BCN composite material; dropwise adding the precipitant solution into the suspension to obtain a precursor solution, performing hydrothermal reaction on the precursor solution, and performing centrifugal impurity removal and drying to construct a heterostructure between layered double hydroxide and BCN in situ to obtain the Co-Fe LDH-coated BCN composite material. Through boron doping and heterostructure construction, the charge separation capacity of graphite carbon nitride is enhanced, the electron migration efficiency is improved through a heterointerface structure, the metal ion release amount and the cycle stability are controlled, and the catalytic performance is remarkably improved.

The invention discloses a complex microbial inoculant for treating underground water as well as a preparation method and application thereof, relates to the field of sewage treatment, and aims to solve the problem that TBBPA and nitrate in underground water are difficult to remove at the same time in an existing biological treatment method. The composite microbial agent is prepared from pseudomonas koreensis Y5-11, acinetobacter pidermatum LYS-5, Pseudomonas sp. Y39-6 and psychrophilic bacteria F5-6, and the pseudomonas sp. Y5-11, the acinetobacter pidermatum LYS-5, the Pseudomonas sp. Y39-6, the psychrophilic bacteria F5-6 and the psychrophilic bacteria F5-6 are added into the microbial agent. The four strains are respectively subjected to fermentation culture, and the four fermentation liquids are mixed to prepare the complex microbial inoculant. The four bacteria in the complex microbial inoculant have a stronger metabolism complementation effect, and the effect on composite pollution remediation is more remarkable. The complex microbial inoculant is used for removing TBBPA and nitrate in underground water at the same time, the complex microbial inoculant has biodiversity, and the treatment result conforms to the water quality characteristics of the underground water.

The invention relates to a detection method for determining isotope abundance of a 15N or 18O labeled nitrate sample by using an organic mass spectrum. The detection method comprises the following steps: (1) dissolving the 15N or 18O labeled nitrate sample in a methanol aqueous solution; (2) taking the supernatant, filtering with a filter membrane, and diluting with a methanol aqueous solution to obtain a solution to be detected; and (3) detecting the solution to be detected by using a high-resolution liquid chromatograph-mass spectrometer, selecting a mass spectrum in a peak appearance time window, recording relative mass spectrum signal intensities with mass-to-charge ratios of 61.988 and 62.985, and calculating to obtain the 15N isotope abundance. Or recording the relative mass spectrum signal intensities with the mass-to-charge ratios of 61.988, 63.993, 65.997 and 68.001, and calculating to obtain the abundance of the < 18 > O isotope. Compared with the prior art, the method has the advantages that the sample pretreatment time is greatly shortened, the economic cost is low, and the test result is accurate.

The invention provides an efficient environment-friendly petroleum passivator as well as a preparation method and application thereof, and belongs to the technical field of passivators. The preparation method comprises the following steps: reacting bismuth nitrate with tetra (4-carboxyl phenyl) porphyrin and benzoic acid to prepare a carboxyl phenyl porphyrin bismuth-MOF material, reacting antimony nitrate with tetra (4-pyridyl) porphyrin and benzoic acid to prepare a pyridyl porphyrin antimony-MOF material, and performing sol-gel reaction on lanthanum isopropoxide and cerium isopropoxide to prepare lanthanum-cerium sol; the preparation method comprises the following steps: mixing calcium nitrate, magnesium chloride, organic acid, organic amine and hydrogen peroxide for reaction to prepare a calcium / magnesium organic matter, mixing the calcium / magnesium organic matter with other substances, adding the mixture into an acetonitrile / ethanol mixed solvent, and uniformly stirring and mixing to prepare the efficient environment-friendly petroleum passivator. The high-efficiency environment-friendly petroleum passivator prepared by the invention is green, safe, non-toxic and efficient, has better capturing and passivating effects on metal ions such as nickel and vanadium in the catalytic cracking reaction process of heavy oil, improves the activity of a catalyst, prolongs the service life of the catalyst, and thus, has a wide application prospect.

The invention discloses a preparation method of a beaded cobalt-doped Bi25FeO40 / BiFeO3 nanofiber wave-absorbing material, which comprises the following steps: obtaining a precursor by a standing method, and adding the precursor, bismuth nitrate, ferric nitrate and a spinning aid into a mixed solvent compounded by N, N-dimethylformamide and absolute ethyl alcohol to obtain a spinning solution; spinning the spinning solution by adopting an electrostatic spinning technology to obtain a nanofiber membrane; and finally, drying and calcining to obtain the wave-absorbing material. According to the wave-absorbing material, multiple reflection and scattering of electromagnetic waves are increased, the absorption performance of the electromagnetic waves is improved, due to the fact that a heterogeneous interface is generated after two phases are compounded, the interface polarization loss is further increased, when the thickness of the wave-absorbing material is 2.33 mm, the minimum reflection loss reaches-56.01 dB, the effective absorption frequency band width is 6.32 GHz, and the whole Ku wave band is covered.

The invention provides a cobalt modified multistage heterostructure catalyst and a preparation method and application thereof, and belongs to the technical field of ammonia synthesis. The cobalt modified Con-Cu3P / Cu catalyst is prepared by depositing copper and cobalt on a substrate step by step and then carrying out calcination, phosphorization and electrochemical reduction. In the catalyst, the metal Co mainly exists in the catalyst in the form of an elementary substance, Cu exists in the form of elementary substance Cu and monovalent Cu3P, and the problem that protonation of an intermediate is limited is solved by modifying and regulating an electronic structure through Co. The Co-Cu3P / Cu catalyst is used for electro-catalysis nitrate reduction reaction (NO3RR), and sustainable green ammonia (NH3) synthesis and nitrate (NO3 <->) pollutant removal can be achieved.

The invention provides a monatomic cobalt-based composite catalyst, a preparation method of the monatomic cobalt-based composite catalyst and application of the monatomic cobalt-based composite catalyst to degradation of antibiotics by activating peroxymonosulfate, and belongs to the technical field of advanced oxidation. The method comprises the following steps: mixing biomass powder and water to obtain a biochar suspension, adding cobalt nitrate hexahydrate into the biochar suspension, centrifuging the mixed solution, collecting residues, and drying to obtain a sample; and pyrolyzing the sample in a protective gas atmosphere, taking out, cooling, washing, and drying to obtain the monatomic cobalt-based composite catalyst. The cobalt-based catalyst prepared by the invention has high specific surface area, abundant pore structures and a large number of active sites, and is beneficial to activation of PMS and degradation of pollutants; the cobalt-based composite catalyst prepared by the method is used for activating peroxymonosulfate to degrade tetracycline, and the removal rate of tetracycline in a solution is greater than 99% after reaction is carried out for 20 minutes under a dark condition.

The invention relates to the technical field of electrochemical catalysis, and particularly discloses a preparation method of a cobalt-based catalyst for synthesizing ammonia through electrocatalysis of nitrate. The method comprises the following steps: placing melamine on the upstream of ZIF-67 powder, carrying out two-step temperature-programmed pyrolysis treatment in a high-purity nitrogen protective atmosphere, and naturally cooling to obtain the cobalt-based catalyst which takes rhombic carbon as a substrate and on which Co-NC nanoparticles are anchored. In the prepared catalyst, nitrogen atoms are doped on the surfaces of cobalt clusters to form Co-NC sites, the local electronic structure of cobalt can be accurately regulated and controlled, and the Faraday efficiency and yield of electrocatalytic nitrate reduction synthesis of ammonia are effectively improved.

The invention discloses a preparation method of a modified red-mud-based chlorobenzene catalyst, which comprises the following steps: taking solid waste red mud as a main component, adding a certain amount of acid for dissolving, dropwise adding alkali liquor to enable the pH value of red mud suspension to reach 8-9, washing to be neutral, drying, grinding, passing through a molecular sieve, and roasting to obtain red-mud-based catalyst carrier powder; the red-mud-based catalyst carrier powder is mixed with a nitrate solution, it is guaranteed that the active component loading content in the mixed solution is 10-20%, and a filter cake loaded with the active component is roasted and then ground to obtain the red-mud-based catalyst. According to the method, the solid waste red mud is subjected to resource utilization, the red mud is modified into the efficient and low-cost catalyst to be applied to catalytic oxidation of volatile organic compounds, volatile organic compound waste gas is eliminated, the atmospheric environment quality is improved, waste is turned into wealth, and pollution is treated with waste.

The invention discloses an iron-carbon composite material for heavy metal contaminated soil remediation and a preparation method of the iron-carbon composite material, and belongs to the field of heavy metal contaminated soil remediation. The iron-carbon composite material comprises rape straw, hydroxyapatite, zero-valent iron, sulfydryl functionalized magnetic cerium oxide and nitrogen-doped graphene quantum dot-sodium alginate. The sulfydryl-functionalized magnetic cerium oxide is prepared from cerium nitrate and ferric nitrate through precipitation, calcination and sulfhydrylation, and the nitrogen-doped graphene quantum dot-sodium alginate is prepared from citric acid and urea through microwave reaction, dialysis, mixing and freeze drying; the preparation method comprises the following steps: treating straws and hydroxyapatite to obtain ball-milled phosphorus-containing biochar, mixing the ball-milled phosphorus-containing biochar with zero-valent iron and two modifiers, and carrying out molding and high-temperature calcination to obtain the phosphorus-containing biochar-based composite material. The material has a remarkable remediation effect on the heavy metal contaminated soil, can effectively reduce the activity of heavy metals in the soil, has the characteristics of environmental friendliness and high stability, and is suitable for treating the soil compositely contaminated by the heavy metals such as cadmium and lead.

The invention relates to the technical field of chemical synthesis, and discloses a method for preparing 2, 5-furandicarboxylic acid, which comprises the following steps: dispersing cobalt nitrate and nickel sulfate into an aqueous solution of polyvinylpyrrolidone at room temperature; adding a sodium borohydride solution to obtain nano colloid; preparing an aqueous suspension of cerium oxide, and adding the aqueous suspension into the nano colloid; centrifugally filtering, and recovering a solid product; washing the solid product; centrifuging, putting solid powder obtained after centrifuging into a drying oven, and drying; and calcining and grinding the solid powder to finally prepare the Co-Ni / CeO2 catalyst. And dissolving 5-hydroxymethylfurfural in water at normal temperature, adding the prepared Co-Ni / CeO2 catalyst and a sodium hypochlorite solution, reacting, and filtering to remove the catalyst, thereby obtaining the 2, 5-furandicarboxylic acid. The method disclosed by the invention has the advantages of no use of strong base, low reaction temperature, short reaction time, few byproducts, greenness and sustainability.

The invention discloses a high-entropy perovskite hydroxide, a preparation method thereof and application of the high-entropy perovskite hydroxide in electro-catalysis of nitrate to synthesize ammonia, and belongs to the technical field of high-entropy perovskite hydroxides. The high-entropy perovskite hydroxide is ASn (OH) 6, and A is one or more of Zn, Mn, Co, Ni and Cu. The high-entropy perovskite hydroxide electrocatalyst which is simple in synthesis method, stable in structure and easy in raw material obtaining is obtained, the electrocatalyst can be applied to electrocatalysis of nitrate to synthesize ammonia, the highest NH3 Faraday efficiency is 98.16%, and the yield is 5.12 mg h <-1 > mgcat <-1 >. And a foundation is laid for developing other high-entropy perovskite compounds as electrocatalysts for electrocatalytic synthesis of nitrate.

The invention discloses a ferrocobalt-based self-supporting oxygen evolution electrode and a preparation method and application thereof, and belongs to the technical field of electrodes. The electrode is obtained by growing a layer of needle-like ferrocobalt layered double hydroxide catalyst on the surface of foamed nickel through a simple solution immersion-etching method and through preparation of a precursor solution. The preparation method comprises the following steps: mixing an isopropanol solution of cobalt nitrate with a ferrous sulfate aqueous solution, and putting a nickel-based substrate into the solution for immersion etching, so as to obtain the cobalt-iron layered double hydroxide catalyst electrode. The preparation method disclosed by the invention is mature and simple in process route, mild in condition, easy to control and easy to amplify, and the oxygen evolution (OER) catalytic activity of the nickel-based catalyst is also remarkably improved.

The present invention discloses the preparation of a metal-organic framework material and its application in flue gas desulfurization and dehumidification, belonging to the technical field of adsorption separation materials. The material is prepared by mixing an organic ligand 4,4',4",4"',4"",4""'-(9,10-dihydro-9,10-[1,2]benzanthracene-2,3,6,7,14,15-hexayl)hexabenzoic acid, yttrium nitrate, and o-fluorobenzoic acid, and then performing a solvent thermal reaction using N,N-dimethylformamide and water or nitric acid as solvents. The material is filtered, washed, and dried to obtain the product. The desulfurization performance of the material is substantially unaffected by humidity changes and exhibits stable and good performance even under high humidity conditions. The material is also capable of dehumidification, and its performance is substantially unaffected by the presence of sulfur dioxide gas.

This invention discloses a continuous synthesis apparatus and process for nitrobenzene. The synthesis apparatus includes a mixed acid preparation system, a continuous benzene nitration system, an organic phase continuous stratification system, and a continuous water washing-alkali washing-water washing system. The process includes: concentrated sulfuric acid and concentrated nitric acid are pumped into the mixing module of the mixed acid preparation system to obtain a mixed acid solution; benzene and the mixed acid solution are pumped into the microchannel reactor of the continuous benzene nitration system; the nitrated material is cooled and then pumped into the continuous organic phase stratification system; the resulting intermediate organic phase nitrate enters the next processing unit; the organic phase nitrate and water enter the continuous water washing-alkali washing-water washing system for washing to obtain the final product, nitrobenzene. The synthesis apparatus and process of this invention achieve continuous production of nitrobenzene throughout the entire process, realizing continuous and automated operation from raw material benzene to the final product, nitrobenzene.

The invention belongs to the technical field of pyridazine derivative preparation. The invention provides a preparation method of a pyridazine derivative. The preparation method comprises the following steps: adding a compound with a general formula 1, iron nitrate nonahydrate, potassium carbonate and 4CzIPN into tetrahydrofuran for reaction; the reaction equation is shown in the specification; in the formula (I), R is hydrogen, 4-methyl, 4-methoxyl, 3-methoxyl, 2-iodine or 4-chlorine. The method provided by the invention is simple and convenient to operate and does not need high temperature and oxidant. The target product simultaneously contains diaza and pyridazine skeletons.

The invention discloses an SCR catalyst ammonium sulfate poisoning rapid recovery method, and relates to the technical field of industrial flue gas denitration, and the specific method comprises the following steps: S1, when it is detected that the denitration efficiency of an SCR system is lower than a threshold value, the temperature of flue gas entering an SCR reactor is controlled to be T1, and the temperature is maintained for t1; s2, a ferric nitrate solution is sprayed into flue gas at an inlet of the SCR system, and the temperature T2 is maintained for t2; and S3, the ferric nitrate solution is stopped from being added, the flue gas temperature is gradually reduced to the normal operation temperature, and normal operation of the SCR system is recovered. The ferric nitrate sprayed into the flue gas not only can introduce NO2 into the flue gas and quickly recover the valence state of the vanadium active center in the catalyst under a low-temperature condition, so that the efficient regeneration of the catalyst activity is realized, but also the formed metal oxide can achieve a synergistic promotion effect in the quick recovery process of ammonium sulfate poisoning of the SCR catalyst.

This invention discloses a method for preparing sheet-like nano-sized cobalt hydroxide. The method includes the following steps: using cobalt nitrate as the cobalt source and sodium hydroxide solution as the precipitant, a co-precipitation reaction is carried out. The cobalt nitrate solution and sodium hydroxide solution are added together to a reaction vessel. By controlling the synthesis pH and temperature, the synthesized cobalt hydroxide slurry is washed with hot pure water, dried, and crushed using an air jet mill to obtain sheet-like nano-sized pink cobalt hydroxide with low sodium content. Specifically, the key to preparing sheet-like nano-sized cobalt hydroxide is to prevent oxidation and particle agglomeration during the synthesis process. This invention uses a low-temperature (40-60℃), low-pH (8.0-9.0) cobalt hydroxide synthesis process with a small amount of antioxidant added to prepare sheet-like micron-sized cobalt hydroxide that is not easily oxidized or agglomerated. In addition, at the low pH, the sodium content is low, making the subsequent filtration and washing steps easier to operate.

The invention relates to the field of combined application of MOF (Metal Organic Framework) crystal material synthesis and a sonodynamic antibacterial technology, in particular to an Eu-TCPP-SO4 crystal as well as a preparation method and application thereof. The rare earth-porphyrin complex Eu-TCPP-SO4 crystal with a specific crystal structure is constructed by virtue of coordination and self-assembly of europium nitrate pentahydrate, meso-tetra (4-carboxyl phenyl) porphyrin (TCPP) and sulfate ions. The Eu-TCPP-SO4 crystal disclosed by the invention as a sound-sensitive agent has high sound-sensitive activity and good stability, overcomes the limitations of low efficiency and poor stability of the sound-sensitive agent in the prior art, and can provide a safer and more effective solution for actual antibacterial application.

The invention relates to a copper-cobalt bimetallic phosphide heterojunction and a preparation method and application thereof.The preparation method comprises the following steps that 1, pretreated foamy copper is soaked in an ammonium persulfate and sodium hydroxide solution, and the substance serves as a strong oxidant and is used for reacting to form copper hydroxide; (2) mixing cobalt nitrate hexahydrate with methanol, and putting copper hydroxide to react for two days; 3) adding dimethylimidazole for continuous reaction, and then washing, drying and phosphorizing at room temperature; compared with the prior art, the preparation method is simple in process and low in cost; the prepared catalyst has a heterojunction nanowire array structure, more active sites are provided, charge redistribution at a phosphide heterojunction interface is promoted by electron directional movement, the electron structure of the catalyst can be adjusted, and adsorption energy of reactants and intermediates on the active sites can be changed, so that reaction kinetics is promoted. The catalyst product is mainly ammonia gas, is good in stability and can be repeatedly used for multiple times.

An analytical process for detecting compounds in a sample suspected of containing a peroxide-based compound, a nitrate-based compound, a nitrotoluene-based compound, or a nitramine-based compound includes treating the sample with a superbase and then contacting the sample with a composition. The composition includes or consists of a Ni-porphyrin and an acid and optionally an acid stable solvent.

This invention discloses a magnetic Ni x％ This paper describes the preparation method and application of FeNb2O6 composite catalysts, which fall under the technical field of supported bimetallic oxide catalysts. First, magnetic FeNb2O6 nanocatalysts are prepared via a one-pot hydrothermal method using niobium oxalate hydrate as the niobium source and ferric nitrate as the iron source. Then, magnetic Ni is prepared via a modified deposition precipitation method using nickel nitrate as the nickel source and the magnetic FeNb2O6 nanocatalyst as the support. x％ @FeNb2O6 composite catalyst. The beneficial effect of this invention is that Ni... x％ In the FeNb2O6 composite catalyst, iron, niobium, and nickel species are highly dispersed with no obvious agglomeration, exhibiting high activity and high stability. Furthermore, the catalyst's magnetic properties allow for recovery and reuse, overcoming the shortcomings of traditional metal catalysts such as easy loss and difficulty in recovery after reaction. This Ni... x％ The FeNb2O6 composite catalyst is used for the catalytic hydrogenation conversion of Caragana korshinskii and its related model compounds. Due to its high C-O- bond cleavage activity, it can more effectively promote the depolymerization of Caragana korshinskii organic matter, thereby obtaining bio-oil rich in high-value COH functional groups.

The invention relates to a preparation method for in-situ growth of a NiFeS nanosheet array by taking ZIF-67 as a template for integral water decomposition. The preparation method comprises the following steps: (1) treating cobalt nitrate and 2-methylimidazole by using a methanol solution to obtain ZIF-67 dodecahedron nanoparticles; then mixing the ZIF-67 and PDA in methanol, and carrying out water bath reflux to obtain Co (ZIF-67) (at) PDA for later use; and (2) putting the sample into a tubular furnace, and continuously calcining for 1 hour at 800 DEG C in an N2 atmosphere to obtain the Co-coated CN-800. And (3) carrying out hydrothermal reaction on the sample and a certain amount of FeCl3, Ni (NO3) 2, urea and NH4F to obtain NiFe-OH-Co-CN, respectively placing the prepared material and S powder in an upstream quartz boat and a downstream quartz boat of a tubular furnace, and keeping for 1 hour at 500 DEG C in an N2 atmosphere to obtain the NiFeS-Co-CN heterostructure.

The invention discloses a supported catalyst and application thereof in synthesis of difluoroacetyl fluoride, the supported catalyst comprises a carrier and active components, the active components comprise superacid and an active auxiliary agent; in the supported catalyst, the loading capacity of the superacid is 20 wt%-25 wt%, and the loading capacity of the active auxiliary agent is 5 wt%-10 wt%; the superacid is selected from at least one of fluoboric acid, fluorosulfonic acid, fluoroantimonic acid and carborane acid; the active auxiliary agent is selected from at least one of molybdenum nitrate, technetium nitrate, ruthenium nitrate, rhodium nitrate and chromic nitrate; when the supported catalyst is used for synthesizing difluoroacetyl fluoride, 1, 1, 2, 2-tetrafluoroethyl ethyl ether is used as a raw material, hydrogen fluoride is added under the action of the supported catalyst to inhibit generation of ethylene, and difluoroacetyl fluoride and fluoroethane are generated through cracking under relatively mild conditions; compared with an existing preparation method, the conditions are milder, and the one-way yield is larger than 95%.

The invention relates to the technical field of desulfurizing agents, in particular to a reusable iron oxyhydroxide desulfurizing agent and a preparation method thereof. The problem that the activity of a traditional material is reduced due to sulfate accumulation and compact layer formation in a vulcanization-regeneration cycle is solved. The preparation method comprises the following steps: dissolving ferric nitrate and urea, adjusting the pH value to 1.8, and adding cerous nitrate and citric acid; heating, introducing zirconium oxynitrate, controlling the pH value at 3.7-3.9 for 2-3 hours, heating to 7.2, adding samarium nitrate and zirconium acetylacetonate, aging, and mixing with bentonite and ammonium bicarbonate for molding; and finally, carrying out segmented activation in a nitrogen and low-oxygen mixed atmosphere. The desulfurizer has high specific surface area and pore volume, the breakthrough sulfur capacity reaches 148-160mgS / g, the 10-time circulating sulfur capacity retention rate is 88-91%, and the desulfurizer is high in particle compressive strength, low in abrasion rate and suitable for the industrial desulfurization process.

The invention discloses a preparation method of an Eu-Tb-In-MOF material based on a dual fluorescence emission source type, and the preparation method specifically comprises the following steps: under a closed condition, uniformly mixing terbium nitrate hexahydrate, europium nitrate hexahydrate, indium nitrate pentahydrate, an organic ligand, N, N-dimethylformamide and acetonitrile, then adjusting the pH value of a mixed solution, and carrying out solvothermal reaction, washing, filtering and drying to obtain the Eu-Tb-In-MOF material. The invention also discloses an application of the Eu-Tb-In-MOF material in identification of heavy metal ions Cr in a water environment. The Cr (VI) ions in the water environment are detected through fluorescence quenching sensing, excellent high selectivity is shown, and interference of other single and mixed anions and cations in the water environment can be resisted.

The invention relates to the technical field of organic water-soluble fertilizers, in particular to an organic water-soluble fertilizer suitable for crops and a preparation method of the organic water-soluble fertilizer. The preparation method sequentially comprises the following steps: adjusting the pH value of an aqueous solution to 5.3-5.7, adding sodium polyaspartate, carboxyl polyethylene glycol carboxyl and dopamine hydrochloride, carrying out a condensation reaction in the presence of a condensing agent, and obtaining a solution A after the condensation reaction is ended; adding tannic acid, ferric nitrate and citrate, and keeping the pH value to obtain a solution B; adjusting the pH value to 6.6-7.0, adding sodium periodate for oxidation, and introducing taurine, histamine and ascorbic acid to obtain a solution C; and finally, adding carbonate, a large amount of ferric nitrate, zinc-magnesium salt and citrate, adjusting the pH value, and supplementing water to a certain amount to obtain a final product. By constructing a multidentate ligand and dynamic covalent network synergistic system, the long-term stability and anti-interference capability of metal ions are remarkably improved, hydrolytic precipitation is effectively inhibited, the low water-insoluble substance content is maintained, and good storage stability and field yield increasing effect are achieved.

The present invention relates to a method for preparing rare earth co-doped ferrite, belonging to the technical field of magnetic materials. The rare earth co-doped ferrite is prepared from materials such as ferric nitrate nonahydrate, zinc nitrate hexahydrate, cobalt nitrate hexahydrate, cerium nitrate hexahydrate, lithium chloride, and nickel chloride. The rare earth co-doped ferrite prepared using the method has excellent overall magnetic properties, and can improve the coercivity and magnetization strength of the ferrite.

This invention discloses a bimetallic complex with whitening and anti-aging effects, its preparation method, and its application, belonging to the field of biomaterial preparation technology. The preparation method includes S1, dissolving an amino acid in water to obtain solution A; S2, dissolving a metal salt in ethanol to obtain solution B; S3, mixing solutions A and B evenly, and then reacting them through a solvothermal reaction to obtain solution C; S4, washing and drying solution C to obtain the final product. The amino acid in step S1 is at least one of glutamic acid and aspartic acid; the metal salt in step S2 is copper acetate and zinc acetate, copper acetate and manganese chloride, or copper acetate and cobalt nitrate; the solvothermal reaction conditions in step S3 are: temperature 60-110℃, reaction time 2-48h. The prepared bimetallic complex has both whitening and anti-aging effects, providing a new direction for the application of BioMOFs materials.