274 results about "Alloy nanoparticle" patented technology

The invention discloses a preparation process of a modified porous carbon material catalyst. The preparation process comprises the following steps: (1) mixing and calcining a biomass precursor and a template agent to prepare graded porous carbon; (2) low-frequency plasma pretreatment and high-frequency plasma fluorination modification are adopted; (3) introducing the pulse plasma into a nitrogen doping site; (4) spraying ionic liquid and activating H2 plasma to form a B / F co-doped layer; and (5) loading alloy nanoparticles such as PtRu through pulse electrodeposition. According to the obtained catalyst, biomass derived porous carbon serves as a carrier, a fluorine / nitrogen co-doped active layer is constructed on the surface of the carrier through multi-frequency plasma synergistic modification and ionic liquid auxiliary modification, superfine precious metal nanoparticles are loaded, the hydrogen evolution overpotential of the catalyst is smaller than or equal to 28 mV under the current density of 10 mA / cm < 2 >, the activity attenuation is smaller than 5% after 1000 times of circulation, and the catalyst has a good catalytic activity. The water electrolysis hydrogen production device is suitable for a large-scale water electrolysis hydrogen production device.

The invention relates to the technical field of high polymer materials, in particular to a high-entropy alloy modified polyvinyl alcohol / polypyrrole composite hydrogel material as well as a preparation method and application thereof. Firstly, a polypyrrole aqueous solution is prepared through chemical oxidative polymerization, and high-entropy alloy nanoparticles are synthesized through a Joule thermal technology; and then mixing a polypyrrole aqueous solution, the high-entropy alloy nanoparticles and a polyvinyl alcohol aqueous solution, and adding a cross-linking agent and a catalyst to prepare the high-entropy alloy modified polyvinyl alcohol / polypyrrole composite hydrogel material. According to the composite hydrogel, under the synergistic effect of the high-entropy alloy, the light absorption performance is remarkably improved, wide-spectrum efficient absorption of ultraviolet rays, visible light and near-infrared light in a solar spectrum is achieved, and meanwhile the mechanical strength and chemical stability of the material are enhanced. The preparation process is simple, the cost is low, and the prepared composite hydrogel has wide application prospects in the fields of seawater desalination, wastewater treatment and the like as a solar interface evaporator.

The invention belongs to the technical field of catalytic materials, and particularly relates to high-entropy alloy nanoparticles used as a biocatalyst and application of the high-entropy alloy nanoparticles. The PtFeCuCoNi high-entropy alloy nano-particles with pH adaptability are developed through a one-step solvothermal synthesis method, it is found that the PtFeCuCoNi high-entropy alloy nano-particles can serve as potent oxidase, can generate reactive oxygen species (ROS) and effectively kill bacteria such as MRSA under the acidic condition, and can play the functions of superoxide dismutase and catalase under the neutral condition, so that the PtFeCuCoNi high-entropy alloy nano-particles with the pH adaptability can be used for effectively killing bacteria such as MRSA. Active oxygen in cells is efficiently removed, oxidative stress is relieved, and the cell protection effect is achieved.

The invention discloses a hydrogen energy fuel cell catalyst carrier based on a graphene graft polymer, which is characterized in that two-dimensional graphene is used as a substrate, the surface of the two-dimensional graphene is modified with an oxygen-containing functional group, and a functional polymer branch chain containing nitrogen, sulfur or phosphorus heteroatoms is covalently grafted to form a local three-dimensional network winding structure; the carrier is loaded with platinum, palladium, ruthenium and other metal or alloy nanoparticles, the particle size is 2-8 nm, the loading capacity is 10%-40%, and the particles are anchored to polymer functional sites or reduced in situ to a graphene defect area through coordination. A polymer branch chain has pH responsiveness and can adjust the local proton transmission efficiency; the grafting density is 3-15 grafting points per 100 carbon atoms, so that high dispersion and stable anchoring of metal particles are effectively realized; the specific surface area of the carrier is 400-800m < 2 > / g, the electrochemical active area is not less than 80m < 2 > / g, and the activity retention rate is greater than 80% after 5000 circles of accelerated durability tests. The activity, the stability and the proton conduction performance of the catalyst are remarkably improved, and the catalyst is suitable for high-performance fuel cells.

The invention relates to the technical field of energetic materials, in particular to a laser response type high-entropy alloy-based initiating explosive material and a preparation method thereof. The initiating explosive material is mainly formed by uniformly loading a heat-sensitive high-energy compound (such as lead stilbeneate or hexa (4-amino-3, 5-dinitropyrazole) copper) on high-entropy alloy nanoparticles containing five or more metal elements, wherein the heat-sensitive high-energy compound is such as lead stilbeneate or hexa (4-amino-3, 5-dinitropyrazole) copper. The preparation method comprises the following steps: mixing acetylacetone metal salt, a surfactant and a reducing agent in an organic solvent, and stirring and reacting at 180-220 DEG C to prepare high-entropy alloy nanoparticles; the nano particles and a high-energy compound are co-dispersed in a mixed solvent containing a dispersing agent, ultrasonic treatment is carried out to form suspension liquid, and freeze drying is carried out to obtain the nano particles. The method is characterized in that the excellent photo-thermal conversion performance of the high-entropy alloy is utilized, under low laser energy irradiation, a high-energy compound can be effectively excited, and stable detonation of secondary charge CL-20 is successfully achieved. According to the invention, the problems of high response threshold and low output energy of the existing laser initiating explosive material are solved.

The invention relates to a PEM ternary alloy catalyst for water electrolysis hydrogen production and a preparation method thereof, and belongs to the technical field of water electrolysis catalysts. 1-butyl-3-methylimidazolium tetrafluoroborate is introduced in the generation of a carrier manganese dioxide to increase the specific surface area of the carrier, fluorine doping and oxygen vacancy construction are realized on the surface of the carrier through hydrofluoric acid treatment, and then a metal precursor is dispersed through an ethylene glycol / water system; and finally, loading and alloying of the alloy nanoparticles are completed through hydrothermal reduction and heat treatment. The morphology and electronic structure of the carrier are synergistically regulated and controlled through ionic liquid and fluorine doping, the specific surface area and active sites are remarkably increased, strong interaction of metal and the carrier is achieved through ternary alloy component optimization, and the oxygen evolution reaction activity and stability of the catalyst and the precious metal utilization rate are effectively improved.

The invention belongs to the field of hydrogen sensors, and particularly relates to an MEMS hydrogen sensor based on a high-entropy alloy and a preparation method of the MEMS hydrogen sensor. The hydrogen sensor comprises an insulating substrate, an interdigital electrode and a hydrogen sensitive layer, the hydrogen sensitive layer is formed by compounding high-entropy alloy nanoparticles composed of at least five transition metal elements and a semiconductor metal oxide substrate, and the high-entropy alloy nanoparticles are uniformly dispersed on the surface of the semiconductor metal oxide substrate to form a heterojunction; the atomic percent of each transition metal element in the high-entropy alloy nanoparticles is 5%-35%; the semiconductor metal oxide substrate is of a SnO2 or ZnO nano structure, and the specific surface area is larger than or equal to 50 m < 2 > / g. The preparation method is the preparation method of the hydrogen sensor. The hydrogen sensor provided by the invention has an ultralow hydrogen detection limit, the response speed is within a second level, the consumption of noble metal is greatly reduced, and the activity attenuation in a high-temperature environment is small.

The invention discloses a FeNi-C-CNTs-carbon fiber composite material and a preparation method and application thereof, and the preparation method comprises the following steps: (1) cutting carbon fibers into short fibers, dispersing the short fibers into fiber bundles, fixing the fiber bundles, and carrying out electrostatic dispersion; (2) spraying an adhesive on the surface of the dispersed carbon fiber to form an adhesive layer on the surface of the carbon fiber, and then pre-curing the adhesive; and (3) carrying out chemical vapor deposition by adopting a horizontal tube furnace and taking a mixture of ferric acetylacetonate and nickel acetylacetonate as a metal precursor. In the FeNi-C-CNTs-carbon fiber composite material, the FeNi alloy nanoparticles and the carbon nanotubes cooperatively construct a three-dimensional conductive network, wave absorbing mechanisms such as magnetic loss, dielectric loss and multiple scattering are strengthened by means of the unique structure, the wave absorbing performance is remarkably improved, the effective frequency band is widened, and the composite material has excellent microwave absorbing performance and structural stability.

The invention provides a hydrogen fuel cell catalyst as well as a preparation method and application thereof, and relates to the technical field of catalysts, the catalyst comprises an N atom modified carbon carrier and platinum alloy nanoparticles loaded on the surface of the carbon carrier, the platinum alloy nanoparticles are binary or multicomponent alloys formed by Pt and metal M, the molar ratio of platinum to the metal M is (0-10): 1, and the molar ratio of platinum to metal M is (0-10): 1. The weight ratio of the N atom modified carbon carrier to the platinum alloy nanoparticles is (25-80): (75-20). According to the preparation method of the hydrogen fuel cell catalyst, the N-modified carbon-supported PtFe alloy is prepared by a two-step pyrolysis method, so that the use amount of Pt is effectively reduced, the cost is controlled, and the utilization rate of Pt is increased; through the strong coordination capability of the 1, 10-phenanthroline, the formed Fe-N-C layer can restrain the growth and agglomeration of the PtFe alloy nanoparticles, the adsorption to a reaction intermediate is weakened, and the oxygen reduction activity and stability of the alloy catalyst are improved.

The embodiment of the invention discloses a bifunctional catalyst for direct synthesis and catalytic oxidation of hydrogen peroxide and a preparation method of the bifunctional catalyst. The catalyst with the dual functions is provided with Pd-based alloy nanoparticles and high-dispersion monatomic transition metal sites at the same time. The preparation method comprises the following steps: preparing a zeolite-like molecular sieve carrier taking transition metal as link ions through a rolling hydrothermal method; then loading gold and palladium metals on the zeolite-like molecular sieve carrier by adopting a low-temperature liquid phase reduction method to obtain a bifunctional catalyst; the bifunctional catalyst for direct synthesis of hydrogen peroxide and preparation of methanol through methane oxidation has high methane conversion rate, methanol selectivity and yield.

The invention provides a high-entropy intermetallic compound bifunctional catalyst as well as a preparation method and application thereof, and belongs to the technical field of energy materials. A wet chemical synthesis method and a controllable annealing process are combined to prepare the high-entropy intermetallic compound bifunctional catalyst, the catalyst comprises carbon-loaded platinum-cobalt-copper-tungsten-molybdenum five-element high-entropy alloy nanoparticles, the alloy nanoparticles have a high-entropy effect and an ordered structure at the same time, the particle size is 4-7 nm, and the particle size of the alloy nanoparticles is 4-7 nm. The molar ratio of metal atoms, namely platinum to cobalt to copper to tungsten to molybdenum, is 4: (1.75 to 2.5): (1.75 to 2.5): (0.01 to 0.5): (0.01 to 0.5). The platinum loading capacity in the catalyst is 20-70 wt%, the catalyst is used for oxygen reduction reaction catalysis of a cathode in a hydrogen fuel cell and / or methanol oxidation reaction catalysis of an anode in a direct methanol fuel cell, the half-wave potential in an acid medium exceeds a commercial Pt / C catalyst by 30 mV or above, and the methanol oxidation peak current density is 1.4-2.5 times that of the commercial Pt / C catalyst or a commercial PtRu / C catalyst.

The invention discloses a porous carbon catalyst embedded with high-density alloy nanoparticles as well as a preparation method and application of the porous carbon catalyst, and belongs to the technical field of fuel cells or water electrolysis catalytic materials. The porous carbon catalyst embedded with the high-density alloy nanoparticles is a nitrogen and oxygen co-doped carbon carrier which has a porous structure and is partially graphitized, the high-density and high-crystallinity alloy nanoparticles which are uniformly dispersed are embedded in the carbon carrier, and the particle size distribution is below 6nm. According to the porous carbon catalyst embedded with the high-density alloy nanoparticles, the dispersity and the utilization rate of the metal alloy nanoparticles are remarkably improved, and meanwhile, the conductivity and the stability of a carbon carrier are improved, so that the catalytic activity of the carbon carrier in an oxygen reduction reaction and an oxygen evolution reaction in an alkaline medium is effectively enhanced; the catalyst has very excellent bifunctional oxygen catalysis performance, and has a wide application prospect in the field of renewable energy source conversion and storage.

Herein is described a composite material, the composite material comprising composite 5 particles comprising particles of a mesoporous carbon support material having dispersed on their surfaces noble metal nanoparticles and / or noble metal-M alloy nanoparticles and optionally particles of the elemental metal M or metal oxide MOy, wherein y is >0 to a stoichiometric value of the metal oxide, wherein M is a less noble metal than the noble metal, wherein the composite particles have a BJH average pore diameter of from 2 to 0 50 nm and a particle size D90, as measured by laser diffraction and volume distribution, of 10 µm or less.

The invention discloses preparation of superfine PdInBi alloy nano-particles and application of the superfine PdInBi alloy nano-particles in an electrocatalytic oxidation reaction. The superfine alloy nanoparticle catalyst is prepared by adopting a simple solvothermal method, the size of the obtained catalyst is about 4nm, and the catalyst is uniformly dispersed. In addition, due to the nanoscale particle size, the Pd-based catalyst has more proportion of exposed Pd atoms, so that the electro-catalytic performance of the Pd-based catalyst is improved. The precious metal alloying is an effective way for improving the reaction activity and selectivity. According to the multi-metal-based catalyst, the dosage of precious metal can be remarkably reduced, agglomeration of the precious metal is prevented, all the elements regulate and control the electronic structure through the synergistic effect, meanwhile, combination of different metal atoms can form new active sites on the surface of the catalyst, and therefore the activation energy of the reaction is reduced. Compared with a Pd / C catalyst, the catalyst provided by the invention has higher catalytic performance on ethylene glycol oxidation reaction.

The invention discloses a RuNi alloy electrocatalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. Ruthenium acetylacetonate and nickel acetylacetonate are used as precursors, a dispersing agent of polyvinylpyrrolidone is added, the mixture is dissolved in a mixed solvent of benzyl alcohol and aniline, and a mixed solution is obtained; the preparation method comprises the following steps: uniformly stirring, sealing in a reaction kettle, continuously preserving heat at a certain reaction temperature, continuously stirring in the reaction process, and centrifugally drying after the reaction is finished to obtain the RuNi alloy catalyst. The agglomeration of the RuNi alloy nano-particles is effectively prevented, and the nano-particles are ensured to be uniformly dispersed in the synthesis process, so that the catalyst with uniform size and good dispersity is obtained. Through in-situ growth of the Ru element on the surface of the Ni nanostructure, catalytic sites of noble metal are utilized to the maximum extent, excellent conductivity and structural stability of Ni are exerted, the hydrogen evolution effect of the catalyst under the alkaline condition is remarkably improved, and the catalytic activity is improved.

The invention discloses a positive electrode photocatalytic material for a solid-state battery, a preparation method of the positive electrode photocatalytic material, a battery positive electrode and the solid-state battery. The positive electrode photocatalytic material comprises a one-dimensional semiconductor nano array composite structure containing vacancies / defects, the one-dimensional semiconductor nano array composite structure comprises an oxide semiconductor nano array structure containing oxygen vacancies / defects or a sulfide semiconductor nano array structure containing sulfur vacancies / defects; the multi-element alloy nano-particles are binary alloy particles and / or high-entropy alloy particles with more than three elements, and the sizes of the binary alloy particles and / or the high-entropy alloy particles are in sub-nanometer and nanometer scale ranges; and the multi-element alloy nano particles are assembled on the one-dimensional semiconductor nano array composite structure. According to the invention, the photocatalytic characteristic of the low-dimensional semiconductor nano array structure is coupled with the plasmon effect of the multi-component alloy nano particles, so that the wide-spectrum strong absorption of sunlight and the efficient light-heat-electric energy synergistic conversion are realized.

The invention provides an oxide-loaded high-entropy alloy nanoparticle material as well as a preparation method and application thereof. The high-entropy alloy material comprises an oxide matrix and high-entropy alloy nanoparticles loaded on the surface of the oxide matrix, wherein the high-entropy alloy nanoparticles grow on the surface of the oxide matrix in situ. Therefore, strong interaction energy exists between the oxide matrix and the high-entropy alloy nanoparticles in the oxide-loaded high-entropy alloy nanoparticle material, the stability of the high-entropy alloy material can be improved, and meanwhile, the high-entropy alloy material also has excellent ionic conductivity and catalytic activity.

The invention discloses a copper-cobalt alloy / lanthanum hydroxide heterojunction catalyst and a preparation method and application thereof.The preparation method includes the steps that lanthanum-based perovskite oxide LaCu (1-x) CoxO3 is prepared through a sol-gel method, and x is equal to 0.1-0.5; laCu1-xCoxO3 is placed in hydrogen and argon mixed gas for reduction treatment, and the copper-cobalt alloy / lanthanum hydroxide heterojunction catalyst is obtained and used for preparing ammonia through electro-catalysis nitrate radical reduction. According to the preparation method, an in-situ dissolution strategy is adopted, a copper-cobalt alloy / lanthanum hydroxide strong interface coupled heterostructure is constructed, CuCo alloy nanoparticles provide high conductivity and rich active sites and form a heterostructure with La (OH) 3, the d-band center of the active sites is optimized through interaction of strong electrons, NO3 <-> adsorption and reaction intermediate stability are promoted, and the stability of the reaction intermediate is improved. The excellent electro-catalytic performance is realized.

The present invention provides a method for preparing an ultra-low platinum loading fuel cell catalyst. This method first prepares a nitrogen-doped carbon support loaded with single-atom transition non-precious metals, then reduces ultra-small high-entropy alloy nanoparticles by microwave ethylene glycol and loads them on the support, and then anneals in a reducing atmosphere. After natural cooling, the powder is collected to obtain the ultra-low platinum loading fuel cell catalyst. Through the synergistic effect of ultra-small high-entropy alloy nanoparticles and single-atom transition non-precious metals, the present invention greatly reduces the platinum loading while maintaining high-efficiency oxygen reduction performance and stability, and to a certain extent solves the high-cost problem of fuel cell catalysts caused by low platinum utilization rate.

The invention discloses a ruthenium-based rare earth composite catalyst and a preparation method and application thereof, the composite catalyst is formed by loading alloy particles of Ru metal and rare earth metal on carboxyl modified lignin derived mesoporous carbon, the molecular formula of the composite catalyst is RuxREy-CLC, x is equal to 0.5-1, y is equal to 0.01-0.1, and RE is any one of neodymium, cerium, lanthanum, samarium, gadolinium, erbium, dysprosium and praseodymium; the catalyst is obtained by coordinating ruthenium ions, rare earth metal ions and carboxyl modified lignin and then carbonizing. According to the ruthenium-based rare earth composite catalyst, more catalytic active sites can be provided through alloy nanoparticle ultra-fining and high dispersion, OH * strong adsorption poisoning is remarkably weakened through introduction of rare earth metal, the excellent alkaline hydrogen evolution reaction electrocatalytic activity is shown, the catalytic stability is improved, and the catalytic activity of the catalyst is improved. The comprehensive performance is obviously superior to that of similar and commercial catalysts, and the catalyst has considerable energy application potential.

The invention relates to a preparation method and application of a nitrogen-doped carbon nanotube coated with platinum-ruthenium alloy, and is characterized in that the nitrogen-doped carbon nanotube of which the tube wall is coated with PtRu alloy nanoparticles is prepared by using a chemical vapor deposition process assisted by an anodic aluminum oxide template and subsequent ammonia gas annealing; although the contents of Pt and Ru are respectively as low as 0.8 wt% and 4.2 wt%, the combined action of Pt, Ru and N doping enables the platinum-ruthenium-nitrogen doped carbon nanotube composite material to have excellent HER electrocatalytic activity in alkaline, acidic and neutral electrolytes, and the HER activity of the composite material in the alkaline and acidic electrolytes exceeds that of a commercial Pt / C catalyst; besides, after the platinum-ruthenium-nitrogen-doped carbon nanotube composite material is used as a cathode electrocatalyst to assemble an anion exchange membrane electrolytic cell, the electrolytic cell provides low voltage of 1.78 V under the industrial grade current density of 1Acm <-2 >, and the electrolytic cell has good durability; therefore, the invention provides a new opportunity for designing and synthesizing a high-performance pH universal HER electrocatalyst.

The invention discloses a universal synthesis method of medium-entropy / high-entropy alloy nanoparticles and application of the medium-entropy / high-entropy alloy nanoparticles. Comprising the following steps: 1) dissolving three or more metal precursor salts in deionized water according to a required molar ratio, and carrying out ultrasonic treatment until the salts are completely dissolved to obtain a metal precursor solution A; (2) adding polyvinylpyrrolidone into the solution A as a stabilizer, and uniformly stirring; 3) under a stirring condition, slowly dropwise adding 0.3-0.5 M of a sodium borohydride solution as a reducing agent into the solution A to form a reaction solution B; (4) carrying out constant-temperature reaction on the reaction liquid B at 60-80 DEG C for 4-5 hours to form uniform nano-particle colloid; and (5) centrifuging, washing and freeze-drying the nano-particle colloid to obtain black powdery alloy nano-particles. The reaction temperature of the preparation method is 1t; 90 DEG C; the overpotential of the alloy nanoparticles in the HER is lt; 10mA / cm < 2 > at 30mV.

The invention belongs to the technical field of fuel cells, and particularly relates to a high-durability alloy catalyst and a preparation method and application thereof. The prepared high-durability alloy catalyst comprises a metal monatomic carrier Q-N-C and PtM alloy nanoparticles loaded on the metal monatomic carrier Q-N-C, the metal monatomic carrier Q-N-C is composed of a nitrogen-doped carbon carrier N-C and a metal monatomic Q loaded on the nitrogen-doped carbon carrier N-C, and the PtM alloy nanoparticles are composed of Pt salt and M metal salt; the related preparation method can effectively adjust the interaction between the carrier and the alloy, has high durability, and can solve the problem that the second phase metal in the alloy catalyst is easy to dissolve out by using the monatomic catalyst as the carrier of the catalyst and using the carrier as a receiver for receiving the dissolution of the second phase of the alloy catalyst. Meanwhile, excellent electrochemical performance and relatively high stability are realized.

The invention discloses a preparation method of a copper-palladium alloy loaded nano titanium dioxide semiconductor material as a catalyst for a carbon dioxide reduction reaction. Firstly, alloy nanoparticles are generated through a sol-gel method, the morphology of the nanoparticles is controlled and agglomeration is prevented through oleylamine and oleic acid, and borane-tert-butylamine is added at the temperature of 170 DEG C to regulate and control the sizes of the generated alloy nanoparticles. A series of characterizations prove that the catalyst has a very good particle loading condition, uniform particle distribution and increased reaction active sites, and shows excellent activity when being applied to a carbon dioxide reduction reaction, when the loading capacities of copper and palladium are respectively 1%, the activity of the obtained catalyst is the highest, the methane generation rate can reach 20.23 mol / g / h, and the methane generation rate can reach 20.23 mol / g / h. The selectivity of methane reaches 100%.

Low-cost and earth abundant, Ni1-xMox alloy nanocrystals, with sizes ranging from 18-43 nm and varying Mo composition (0.0-11.4%), were produced by a colloidal chemistry method for alkaline HER reactions. For a water splitting current density of −10 mA / cm2, these alloys demonstrate over-potentials of −62 to −177 mV, which are comparable to commercial Pt-based electrocatalysts (−68 to −129 mV). The cubic Ni0.934Mo0.066 alloy nanocrystals exhibit the highest activity as alkaline HER electrocatalysts, outperforming commercial Pt / C (20 wt %) catalyst.

The invention relates to a carbon-supported noble metal ordered alloy electrocatalyst capable of realizing mass production. The electrocatalyst comprises a carbon carrier and small-size noble metal ordered alloy nanoparticles loaded on the carrier, the loading capacity of the alloy is 20 to 90 weight percent; the average particle size of the precious metal ordered alloy nanoparticles is 1-10 nm; the noble metal ordered alloy comprises an alloy consisting of a noble metal and at least one different transition metal M; wherein the noble metal is platinum, palladium, iridium, rhodium or ruthenium. The method is used for solving the problem that the size of catalyst particles becomes large in the high-temperature ordering process, high metal loading capacity is achieved, the feed ratio is increased to 60 times, successful synthesis of the catalyst can be achieved on the gram scale level, and the method can be popularized to actual production to achieve large-scale production.

The invention relates to a preparation method and application of a CoNi alloy nanoparticle doped double-shell hollow carbon material, and belongs to the field of nano material preparation technology and electromagnetic wave absorption application. 3-aminophenol and formaldehyde are subjected to a condensation polymerization reaction to synthesize phenolic resin balls, the phenolic resin balls are placed in 3-aminophenol and formaldehyde again to react, and the double-shell hollow phenolic structure is obtained. And adding the double-shell hollow phenolic aldehyde structure into cobalt nitrate hexahydrate (Co (NO3) 2.6 H2O) and 2-methylimidazole for low-temperature reaction, then adding a solution of (Ni (NO3) 2.6 H2O) for reaction at high temperature and high pressure, and drying to obtain the CoNi alloy nanoparticle doped double-shell hollow carbon material. According to the preparation method disclosed by the invention, the double-shell structure is taken as a main template, and the CoNi alloy nanoparticles are used as active components to be doped in the double-shell hollow structure in situ, so that the cascade synthesis of the microstructure of the nano material is greatly enriched, and the obtained CoNi alloy nanoparticle doped double-shell hollow carbon material has excellent electromagnetic wave absorption performance.

The invention relates to the technical field of catalytic materials, in particular to a monatomic alloy catalyst and a preparation method and application thereof.The preparation method comprises the steps that a first solution obtained by mixing cobalt salt, silver salt and a solvent is mixed with a second solution obtained by mixing 2-methylimidazole and a solvent, stirring treatment is conducted, and a first precursor solution is obtained; and carrying out first heat treatment on the obtained precipitate in an inert atmosphere to obtain the fcc Ag1Co / C monatomic alloy catalyst. A first solution and a second solution are mixed to obtain an Ag / ZIF-67 precipitate which is a Co-based zeolite imidazate framework structure composite material, an organic framework of the Co-based zeolite imidazate framework structure composite material is decomposed and carbonized through high-temperature heat treatment, meanwhile, Ag and Co species are reduced and converted into nanoparticles, and the Ag / ZIF-67 precipitate is obtained. And finally, the composite material catalyst with the Ag1Co monatomic alloy nanoparticles embedded into the nitrogen-doped carbon matrix is formed. The catalyst shows the most excellent activity and selectivity, the removal rate of 4-NP reaches 100% within 6 min, and high catalytic activity can be achieved.

The invention discloses a preparation method of a high-resilience expanded polytetrafluoroethylene sealing material, and belongs to the technical field of high polymer material modification. According to the method, high-molecular-weight or modified polytetrafluoroethylene is used as a matrix, and high-orientation fibers are obtained through ultrasonic premixing, twin-screw melt extrusion, stretching and heat setting; dipping the fiber in a dispersion liquid containing high-entropy alloy nanoparticles, carbon nanotubes and graphene nanosheets, carrying out vacuum drying and gradient heat treatment to form a nano-reinforced precursor fiber, and constructing a porous anisotropic skeleton by adopting conventional or supercritical expansion and a specific weaving process; and interface strengthening and surface functionalization are realized through plasma surface treatment, silane coupling agent chemical grafting and wear-resistant coating coating. The obtained sealing material has low density, high strength, high resilience and low compression set, has excellent chemical medium resistance and anti-static performance, and is suitable for sealing parts of flanges, valves and the like under harsh working conditions of petrochemical engineering, electric power, hydrogen energy, aerospace and the like.

The application belongs to the technical field of carbon material preparation, and particularly relates to a waste fiber-based three-dimensional flexible functional carbon felt and a preparation method thereof. The carbon felt is made of waste textiles through steps of opening, mixing, three-dimensional needling, pre-oxidation, carbonization and surface modification. The application discloses that waste textiles are used as raw materials, a micron-level fiber network is constructed through three-dimensional needling technology, high-entropy alloy nanoparticles are synthesized on the surface of the carbonized fiber, and carbon nanotubes are grown, so that a unique multi-scale micro-nano interpenetrating network structure is formed. The structure not only improves the specific surface area and conductivity of the material, but also endows the material with excellent flexibility and mechanical properties. In addition, the preparation method realizes high-value utilization of the waste textiles, and has significant environmental and economic benefits. The material has wide application prospects in the fields of flexible electrodes, energy storage, electrochemical sensing and the like.