182 results about "Iron nanoparticle" patented technology

The invention discloses a synthesis method and application of an iron-aluminum co-doped catalyst, and the synthesis method is characterized by comprising the following steps: S1, dissolving an aluminum metal salt and an iron metal salt in a beaker containing deionized water to obtain a solution A; s2, adding a phosphorus source into the solution A, and adjusting the pH to form a turbid liquid B; s3, biomass is added into the turbid liquid B to be stirred for 30 min, and a solution C is obtained; s4, adding a nitrogen source into the solution C, and drying the beaker in a water bath kettle; mixing the obtained dried product with an activating agent, and calcining under inert gas to obtain a catalyst crude product; and S5, grinding the catalyst crude product, washing with ethanol and deionized water, and carrying out vacuum drying to obtain the iron-aluminum co-doped catalyst. The preparation method is simple and low in equipment requirement. The invention discloses a novel nitrogen-doped carbon-coated zero-valent iron nanoparticle catalyst which can degrade pollutants by utilizing electron transfer of the pollutants and the catalyst under the condition of adding any oxidizing agent. Under the neutral room temperature condition, the catalyst has a very good removal effect on degradation of organic pollutants which are difficult to biodegrade, has very good stability, and is low in iron ion dissolution rate.

The invention relates to the technical field of composite material preparation, in particular to high-mechanical-property granular hydrogel and a preparation method and application thereof.The high-mechanical-property granular hydrogel is prepared by mixing gelatin nano-particles, calcium carbonate nano-particles, ferric oxide nano-particles and a sodium alginate solution under the alkaline condition, then adding gluconic acid-delta-lactone, and conducting stirring, standing and drying to obtain the high-mechanical-property granular hydrogel. Particle hydrogel with high mechanical property is prepared and is simply recorded as Ca-Alg / MCG, and the gel system is endowed with the catheter injectable property, the blood vessel deliverable property and the intravascular hardenability property. The hydrogel can be delivered to small blood vessels of tumors, the mechanical property can be gradually enhanced along with the change of time, and the embolism effect of the granular hydrogel in the blood vessels is further improved. Meanwhile, the magnetic nanoparticles endow the hydrogel with the magnetic-thermal response capability, the temperature can be rapidly increased under an alternating magnetic field, tumor cells are further killed, and the hydrogel shows an excellent embolism effect in a rabbit kidney embolism model and a liver cancer rabbit embolism model.

The invention provides a self-supporting carbon-based material loaded with iron nanoparticles as well as a preparation method and application of the self-supporting carbon-based material, and belongs to the technical field of preparation and application of an electrocatalyst for removing nitrate in sewage. The preparation method of the self-supporting carbon-based material loaded with the iron nanoparticles comprises the following steps: providing a carbon felt subjected to acid pickling and water bath heating; the method comprises the following steps: mixing an iron precursor and urea in a solvent to obtain a mixed solution containing iron salt; and mixing the carbon felt with the mixed solution containing the iron salt, and carrying out a hydrothermal reaction to obtain the self-supporting carbon-based material loaded with the iron nanoparticles. When the iron nanoparticle-loaded self-supporting carbon-based material provided by the invention is used as a cathode for electro-catalysis of nitrate-containing wastewater, a good removal rate and ammonia nitrogen selectivity are achieved, and the catalyst can keep relatively high nitrate nitrogen removal and ammonia nitrogen production effects under the conditions of acidity, neutrality, alkalinity and different initial nitrate concentrations; the method has the advantages of high removal efficiency, good ammonia nitrogen selectivity, strong stability and the like.

The invention discloses an ultra-stable anti-bioadhesion coating as well as a preparation method and application thereof, and belongs to the technical field of functional materials. The coating provided by the invention comprises a component A and a component B, the component A comprises nanoparticles, carboxyl silicone oil, a silane coupling agent and a solvent; the component B comprises a base material and a solvent; the nano-particles comprise at least one of silicon nano-particles, iron nano-particles or zinc nano-particles; the base material comprises epoxy resin. Through cooperation of the component A and the component B, the carboxyl silicone oil and the functionalized nanoparticles are combined and embedded into a matrix material, the formed coating can be used for preparing an ultra-stable anti-bioadhesion coating, the stability is good, the durability is good, adhesion of blood components, protein, bacteria, cells and the like can be effectively reduced, and the anti-bioadhesion performance of the coating is improved. The coating and the coating prepared from the coating have good application prospects in implantable medical equipment.

The invention provides a chitosan-iron nanoparticle leaf surface resistance and control agent as well as a preparation method and application thereof, and belongs to the technical field of reduction of heavy metal pollution of crops. The preparation method comprises the following steps: dissolving chitosan in an organic solvent to obtain a chitosan solution, mixing the chitosan solution with ferrous sulfate, adding a sodium tripolyphosphate solution for crosslinking and stirring to obtain a solution containing precipitates, centrifuging, and collecting the precipitates to obtain the chitosan / ferrous sulfate composite material. The TPP and amino groups of the chitosan form ionic crosslinking through triphosphate groups, and Fe < 2 + > is successfully loaded on the surfaces of the chitosan nanoparticles. By complexing chitosan and Fe < 2 + >, the crystallinity of the material is reduced, and the adsorption activity of the amorphous structure is enhanced. Pot experiments show that by spraying the chitosan-iron nanoparticle leaf surface resistance and control agent on leaf surfaces, heavy metals of crops can be remarkably reduced, the antioxidant enzyme activity of plant tissues is improved, active oxygen is effectively removed, oxidative damage is relieved, and therefore plant growth is promoted, and the toxic effect of heavy metal stress on the crops is relieved.

A method of applying a pesticide composition to a target surface, including contacting the pesticide composition with the target surface; and leaving the pesticide composition on the target surface for a period of time. The pesticide composition includes a pesticide; and superparamagnetic iron oxide nanoparticles (SPIONs). An outer surface of the SPIONs have at least one coating selected from the group consisting of a polyethylene glycol, a compound with a carbon chain having up to 30 carbon atoms, a silane, and an aminosilane with a primary amine group to form coated SPIONs, where the pesticide interacts with the at least one coating on the coated SPIONs, and where the SPIONs are substantially spherical and have an average diameter of 10-30 nm.

The invention belongs to the technical field of new energy materials, and particularly relates to a preparation method of a biomass-based iron-nitrogen-doped carbon catalyst with a full pH range and application of the biomass-based iron-nitrogen-doped carbon catalyst in the field of zinc-air batteries. According to the preparation method, bacterial cellulose, zinc nitrate, ferric chloride and dimethylimidazole are taken as precursors, a clean, efficient and stable soft template method is selected, and Zn < 2 + > gasification and evaporation etching in a pyrolysis process are utilized, so that the derived carbon catalyst generates a large number of defects and a large number of micropores and mesopores, and overgrowth of iron nanoparticles is limited; and the oxygen reduction catalyst with high specific surface area and high catalytic activity and stability in a whole pH range is prepared through drying and high-temperature carbonization process optimization, so that an electrode active material with excellent electrochemical performance is provided.

A nanocomposite material including iron sulfide (FeS2) nanoparticles, iron oxide (α-Fe2O3) nanoparticles, titanium dioxide (TiO2) nanoparticles, and graphitic carbon nitride (C3N4) nanosheets and a method of its preparation. The nanocomposite is used in a method of forming oxygen gas from water using an applied voltage and photoirradiation, a method of forming hydrogen gas from water using an applied voltage and photoirradiation, and a method of photodegrading organic pollutants using visible light photoirradiation.

The invention discloses iron oxide nanoparticles capable of responding to particle size change in a tumor microenvironment and a preparation method of the iron oxide nanoparticles, and belongs to the technical field of biomedical nano materials. The nano-particle comprises an iron oxide nano-crystal core with the particle size of 3-5nm and a tumor microenvironment response layer coating the surface of the iron oxide nano-crystal core. The response layer contains groups, such as disulfide bonds, enzyme digestion peptide fragments and the like, which can respond to acidic pH, high-concentration reduced glutathione or matrix metalloproteinase and other tumor characteristic stimuli to generate structural changes. In a tumor microenvironment, the hydration particle size of the nanoparticles can be directionally and controllably converted from 3-20 nm to 20-100 nm (or reversely). The preparation method mainly comprises two steps of preparing the core by a thermal decomposition method and modifying the surface response layer. The technical problems of insufficient tumor targeted enrichment capacity, limited imaging contrast and difficulty in balancing permeation and retention caused by fixed particle size of the existing iron oxide nanoparticles are solved, and the accuracy and efficiency of tumor diagnosis and treatment can be remarkably improved.

Provided is an efficient combined nano iron suspension fertilizer. The suspension fertilizer efficient combined nano iron is prepared from ingredients including, in mass percentage: 10.0% to 20.0% of FeSO4; 0.5% to 2.0% of zero-valent iron nanoparticles (nZVI); 5.0% to 10.0% of magnetic iron oxide nanoparticles (Fe3O4-NPs); 30.0% to 50.0% of citric acid; 1.0% to 5.0% of a dispersant 5040; 0.2% to 1.0% of xanthan gum; 1.0% to 5.0% of magnesium aluminum silicate; and water as a balance.

The invention discloses a preparation method and application of an iron carbide nanoparticle modified carbon-based Fe monatomic catalyst, in the preparation process, Fe < 3 + > is complexed with oxalic acid in advance to realize coordination self-assembly and effectively inhibit hydrolysis of Fe < 3 + >, and glucose is used as a carbon-based carrier precursor and a reducing agent to prepare a carbon-based Fe monatomic catalyst. According to the preparation method, the self-assembled iron species are converted into Fe3C nanoparticles at a high temperature, melamine and cyanuric acid are used as N sources to realize N-doped carbon and anchor part of the iron species to form Fe monatomic atoms, and in addition, oxalic acid, melamine and cyanuric acid are easy to decompose at the high temperature to generate small-molecule gas, so that glucose forms a porous carbon structure during high-temperature carbonization, and the porous carbon structure is formed. Finally, Fe3C and Fe monatomic synergistic coexistence hierarchical porous N-doped composite carbon-based catalyst is achieved, the obtained catalyst can efficiently activate peracetic acid and degrade phenol organic pollutants, and the catalyst is simple in preparation process, good in catalytic effect and high in stability and has wide application potential.

The invention discloses a tree-shaped heavy oil demulsifier with magnetic response as well as a preparation method and application thereof. The demulsifying agent comprises composite magnetic nano particles, the composite magnetic nano particles are provided with magnetic particle inner cores and polymers coated on the outer surfaces of the magnetic particle inner cores, the magnetic particle inner cores are modified superparamagnetic ferroferric oxide nano particles, and the polymers are alkyl phenolic resin polyoxyethylene polyoxypropylene ether. Rapid demulsification of the emulsion with the magnetic response effect at the low temperature is successfully achieved, the using amount of magnetic particles is small during demulsification, and the demulsification process is environmentally friendly, efficient and low in cost.

The invention discloses an ultra-small iron carbide nano-particle and a preparation method and application thereof, the particle size of the ultra-small iron carbide nano-particle is smaller than 10 nm, and the phase composition of the ultra-small iron carbide nano-particle comprises Fe3C, Fe5C2, Fe2C and the like; according to the preparation method, mesoporous silica is taken as a template, organic and inorganic double iron sources are adopted, and the iron carbide nanoparticles which are small in size and uniform in particle size distribution and can be stably dispersed in water for more than 2 months are prepared through the steps of hydrothermal reaction, high-temperature calcination, etching and the like; the ultra-small iron carbide nano-particles obtained by the invention have good activity of various nano-enzymes due to the brand-new image structure and ultra-small size of the nano-particles, and have good T1-magnetic resonance imaging performance.

The invention relates to a preparation method of a multifunctional nano growth-promoting bacterium for overcoming successive cropping obstacles, which comprises the following steps: converting bacillus subtilis into bacillus subtilis spores under the condition of heating or inoculating bacillus subtilis into a sporulation culture medium containing manganese sulfate, preparing iron nanoparticles by using a chemical reducing agent and a coprecipitation method under the protection of inert gas, and carrying out vacuum drying on the iron nanoparticles to obtain the multifunctional nano growth-promoting bacterium for overcoming successive cropping obstacles. The preparation method is simple, the cost is low, the production process is green and environment-friendly and suitable for large-scale production, the prepared nano growth-promoting bacteria can integrate the biological functions of the iron nanoparticles and the bacillus subtilis, the soil fertility is improved, trace elements are supplemented, and meanwhile the biological functions of the iron nanoparticles and the bacillus subtilis are improved. The fertilizer promotes proliferation of beneficial bacteria, inhibits proliferation of harmful bacteria, improves the utilization rate of nutrients, degrades harmful substances, improves stress resistance of crops, realizes dual promotion of soil improvement and crop growth, and has remarkable social and economic benefits.

The invention provides hypoxia regulation exosome hydrogel and a preparation method and application thereof in bone defect repair, and compared with the prior art, the hypoxia regulation exosome hydrogel provided by the invention has the advantages that the exosome cultured by 3D stem cells modified by superparamagnetic ferroferric oxide nanoparticles is loaded on the GelMA hydrogel modified by bone targeting polypeptide, and the preparation method is simple. The intelligent oxygen-producing gel is innovatively constructed by skillfully utilizing the relationship between hypoxia and ROS generation according to the challenge that the hypoxia microenvironment of a bone defect part is closely followed. According to the hydrogel disclosed by the invention, osteogenesis regeneration is promoted by regulating and controlling a Wnt / beta-catenin pathway in osteoblasts, so that hypoxia and oxidative stress microenvironments are safely, efficiently and intelligently improved at injured parts. And the adhesion to the defect part is improved, and the problem that the superparamagnetic ferroferric oxide nanoparticles are difficult to effectively retain at the defect part is solved.

The invention discloses a composite nano sound-sensitive agent as well as a preparation method and application thereof. According to the composite nano sound-sensitive agent provided by the invention, a conjugated system of the narrow-gap semiconductor nano sound-sensitive agent core / the ferric oxide nano functional layer / the surface targeting antibody is constructed, so that multi-mode synergy integrating sonodynamic therapy, ferroptosis induction and immunoregulation is realized. The composite nano sonosensitizer further has precise targeting, efficient sonodynamic effect, ferroptosis enhancement effect and good biocompatibility, a targeting antibody on the surface of the composite nano sonosensitizer can specifically recognize high-expression antigens on the surfaces of tumor cells, and dual-targeting enrichment of a treatment system is achieved in combination with magnetic responsiveness guidance; the coating of the iron oxide nanoparticles obviously enhances the sound-sensitive performance of the inner core of the sound-sensitive agent, improves the ROS generation efficiency, and overcomes the hypoxia limitation of the tumor microenvironment; iron oxide is used as an iron source to continuously release Fe < 2 + >, and cooperates with ROS generated by sonodynamic therapy to induce ferroptosis, so that a ferroptosis enhancing effect is generated.

The invention discloses an auxiliary protein composition, iron oxide nanoparticles, a preparation method and application, the composition comprises an SC protein with an amino acid sequence as shown in SEQ ID NO: 1 and an ST protein with an amino acid sequence as shown in SEQ ID NO: 2, and the composition can be used for modifying the iron oxide nanoparticles. The auxiliary protein composition can effectively promote endocytosis of the iron oxide nanoparticles, and assists the iron oxide nanoparticles to realize lysosome escape; moreover, the iron oxide nanoparticles modified by the auxiliary protein composition are good in biocompatibility and long in retention and storage time in cells, can be used for long-time labeling of the cells, and have wide clinical transformation and application prospects as a cell tracer agent.

The invention discloses an iron MOF (Metal Organic Framework) nanoparticle and a preparation method thereof. Specifically, the preparation method comprises the following steps: by taking iron MOF, GOX, egg yolk lecithin, cholesterol, distearoyl phosphatidyl ethanolamine (DSPE), Ce6 and HCPT as reaction raw materials, preparing the Ce6-coated HGMOF nano-particles through a thin lipid membrane hydration and sequential extrusion method. The iron MOF nanoparticles can relieve hypoxia and have photodynamic and ferroptosis treatment effects at the same time.

The invention relates to a hydroxyapatite-ferric oxide nanoparticle composite material and a preparation method thereof. The composite material adopts iron oxide nanoparticles as a core, the surface layer is coated with a gelatin film, and a hydroxyapatite layer is taken as a shell, so that a core-shell structure is formed. The preparation process comprises the following six steps: firstly, preparing a gelatin buffer solution, and then respectively preparing a dipotassium hydrogen phosphate solution and a calcium chloride salt solution; uniformly dispersing the iron oxide nanoparticles in a gelatin buffer solution, and stirring in an ice-water bath to form gelatin-modified iron oxide nanoparticles I; stirring in a calcium chloride salt solution, and converting into ferric oxide nanoparticles II; and finally, adjusting the pH value in a dipotassium hydrogen phosphate solution, heating and stirring to form the hydroxyapatite-coated iron oxide nanoparticles. According to the method, hydroxyapatite particles can be effectively clustered through modification of gelatin, and the defect of particle dispersion in a traditional method is overcome, so that the osteogenesis effect is improved, and bone regeneration is promoted.

The invention discloses application of iron oxide nanoparticles in target treatment of schistosome eggs, and relates to the cross technical field of nano material target delivery and disease prevention and control. On the basis of paramagnetism, a microtubule structure and surface electrical characteristics of schistosoma japonicum egg shells, electrically neutral Fe3O4 magnetic nanoparticles with the particle size of 8-15 nm or electropositive Fe3O4-NH2 magnetic nanoparticles with the surface modified by amino groups are innovatively adopted, efficient egg penetration is achieved through magnetic targeted enrichment and physical-static synergistic effect, and in-vivo and in-vitro experiments prove that the effect of effectively penetrating through the eggs is achieved. The Fe3O4 and Fe3O4-NH2 nanoparticles have obvious worm egg targeting capability, and the penetrating efficiency of the Fe3O4 and Fe3O4-NH2 nanoparticles on worm eggs exceeds 38%, so that an important experimental basis is provided for subsequent development of a nano-drug delivery system for preventing and treating schistosomiasis.

Mechano-chemical wastewater treatment equipment to treat wastewater containing heavy metals to form drainage. An intermediate sewage tank has a sewage inlet and a sewage outlet, and stores wastewater to be treated and sewage formed during the treatment process. At least one mechano-chemical reactor conducts the mechano-chemical reaction between the wastewater and zero-valent iron nanoparticles through a ball milling treatment. A separator to separate a slurry produced by the reactor into solids and liquids. The separator has a slurry inlet, a liquid outlet, and a sludge outlet. The reactor is a ball milling device having a reactor shell with a reaction chamber internally formed, a feeding inlet for the slurry to enter the reaction chamber and a discharge outlet for the slurry to flow out of the reaction chamber. A rotor is set inside the reaction chamber and a driving mechanism rotates the rotor.

A method of adsorbing chloride ions from an aqueous solution with a nanocomposite. The nanocomposite including iron nanoparticles, aluminum nanoparticles and guar gum. The nanocomposite is in the form of extruded cylindrical particles in which the iron nanoparticles and the aluminum nanoparticles are dispersed in a matrix of the guar gum.

The invention discloses a binder-free silicon / carbon nanotube composite carbon fiber negative electrode material, a preparation method thereof and an application of the binder-free silicon / carbon nanotube composite carbon fiber negative electrode material in a lithium ion structure energy storage composite material. Carbon fibers are used as a substrate, catalyst nanowires are grown through a hydrothermal method, then dicyandiamide is used as a carbon source and a nitrogen source through a chemical vapor deposition method, and the binder-free silicon / carbon nanotube composite carbon fiber negative electrode material is prepared. Uniform and compact carbon nanotubes doped with nitrogen and embedded with ferrocobalt nanoparticles and arranged in a three-dimensional disordered structure grow on the surface of the carbon fiber, and then ultra-thin nano silicon is uniformly sputtered on a carbon nanotube substrate supported by the carbon fiber through a radio frequency plasma magnetron sputtering technology. The carbon nano tube and the silicon material are effectively compounded together, the advantages of carbon and silicon are combined, and a synergistic effect is achieved. When the obtained silicon-carbon composite material is used as a negative electrode material of a lithium ion structure energy storage composite material, excellent electrochemical performance and cycling stability are shown, and the flexible structure and excellent mechanical performance ensure efficient use of the material in different fields and different application scenes.

This invention relates to magnetic iron oxide nanoparticle-based sensors and biosensors. This invention also relates to sensing methods utilizing magnetic iron oxide nanoparticle-based sensors. This invention also relates to biosensing methods utilizing magnetic iron oxide nanoparticle-based biosensors. A key approach is to utilize magnetic iron oxide nanoparticles (spherical shape) with appropriate particle size and magnetic properties (superparamagnetic and ferrimagnetic properties) to enhance the efficiency, sensitivity, and selectivity of magnetic nanoparticle-based sensors and biosensors by selecting nanoparticles with suitable particle size and crystallite size. Another key approach is to utilize magnetic iron oxide nanoparticles (cuboid shape) with appropriate particle size and ferrimagnetic properties to enhance the efficiency, sensitivity, and selectivity of magnetic nanoparticle-based sensors and biosensors by selecting nanoparticles with suitable particle size.

The invention belongs to the technical field of nano-enzyme materials, and discloses a cucurbituril nano-enzyme for dispelling effects of alcohol and protecting liver and a preparation method thereof. The antialcoholism and liver-protecting cucurbituril nano-enzyme comprises cucurbituril, heme iron and hydrated iron nano-particles. The cucurbituril nano-enzyme capable of dispelling effects of alcohol and protecting liver keeps constant catalytic efficiency in a pH range of 4.0-8.8, is resistant to high and low temperatures, does not inactivate, can complete ethanol decomposition in the stomach, and has the effect of protecting liver.

The application discloses a kind of by mesoporous Fe 0 Nanometer material enhances the method for activity of gallic acid and application thereof.The present application fixes gallic acid (GA) with redox activity in mesoporous zero-valent iron nanoparticles (Fe 0 NPs), and then encapsulated by SiO2 outer layer containing disulfide bond (denoted as Fe 0 @GA-ss-SiO2NPs). With the help of intracellular glutathione, oxygen molecules are activated by electron transfer, and a large amount of O2 ·‑ And H2O2 are spontaneously generated, and the sustained high concentration of Fe 0 Fe 2+ Further catalyzes the decomposition of H2O2, and generates highly oxidized ·OH free radicals. At the same time, GA quinone derivatives produce 1 O2 by Russel mechanism. In vitro cell experiments confirm that the nanometer material can cause cancer cell ferroptosis, and exhibits high-efficiency cancer cell killing effect at ultra-low dose.

The present invention relates to a catalytically active material comprising non-graphitizing carbon grains with iron nanoparticles dispersed therein, wherein dp, the average diameter of the iron nanoparticles in the non-graphitizing carbon grains, is in the range of 1 nm to 20 nm, D, the average distance between iron nanoparticles in the non-graphitizing carbon grains, is in the range of 2 nm to 150 nm, and Δ, the combined total mass fraction of metal in the non-graphitizing carbon grains, is in the range of 30 wt% to 70 wt% of the total mass of the non-graphitizing carbon grains, and wherein dp, D, and Δ conform to the following relationship: 4.5 dp / Δ > D = 0.25 dp / Δ. Furthermore, the present invention relates to a process for manufacturing the material according to the invention, as well as its use as a catalyst.

The invention discloses a carbon nano composite conductive material and application thereof in a cable shielding layer, and belongs to the technical field of conductive shielding materials, the carbon nano composite conductive material comprises 20-35 parts of magnetic iron / PEDOT: PSS nanoparticles and 40-65 parts of a carbon nano material; the magnetic iron / PEDOT: PSS nanoparticles are obtained by modifying the surfaces of magnetic iron nanoparticles with 3, 4-ethylenedioxythiophene: poly (styrene sulfonic acid); the carbon nanomaterial is one or more of carbon black, graphene oxide, reduced graphene oxide and a carbon nanotube. The carbon material is used as the conductive material, and the magnetic iron / PEDOT: PSS nanoparticles are added to replace part of the conductive filler, so that the cable has the advantages of strong anti-interference capability, light weight, high strength and good flexibility.

The invention relates to an iron-loaded graphene fiber rod catalyst as well as a preparation method and application thereof, and belongs to the technical field of water treatment. The preparation method comprises the following steps: calcining biomass to form a graphene-like structure carbon skeleton, carrying out surface modification on the graphene carbon skeleton to load iron nanoparticles on the surface, forming Fe-O-C or / and Fe-N-C bond bridge connection, taking metal iron as an active center, forming an electron-rich center by a Fe site, and forming an electron-deficient center around a graphene-like C site. The catalyst prepared by the method disclosed by the invention can effectively remove organic pollutants in water without adding extra energy and under natural conditions.

This invention relates to a mesoporous single-atom iron nanoparticle self-catalyzing material, its preparation method, and its application. The mesoporous single-atom iron nanoparticle self-catalyzing material comprises: a mesoporous polydopamine framework, and Fe metal catalytic centers chelated in the mesoporous polydopamine framework in the form of single atoms; the mesoporous polydopamine framework has catechol functional groups.