171results about How to "Many catalytically active sites" patented technology

The invention discloses application of a nitrogen-doped porous carbon fixed Co@Pt nano-particle composite material, prepared by taking ZIF-67 as a template, as an efficient catalyst for oxygen reduction catalytic reaction of a cathode of a fuel cell. The application has the superiorities that (1) a synthetic method of the catalyst is simple and feasible, the shape of the catalyst is controllable, batch preparation can be realized, and the catalytic performance is very stable; (2) the oxygen reduction catalytic reaction of nitrogen-doped porous carbon fixed cobalt-platinum core-shell nano-particles in the cathode of the fuel cell shows that the nano-particles have good catalytic activity and excellent methanol poisoning resistance stability, and compared with traditional commercial Pt/C, the nano-particles have relatively high take-off potentials and half-wave-peak potentials (nano-particles: 0.99V and 0.87V, and Pt/C: 0.98V and 0.83V); and (3) metal organic frameworks (MOFs) for preparing the catalyst have sequential microcellular structures and relatively large specific surface areas and can be widely applied to the storage and conversion of energy sources. Therefore, a method for simply and directly preparing cheap and efficient cathode oxygen reduction electro-catalyst is provided for the fuel cell and has a wide application prospect.

The invention belongs to the technical field of a nanomaterial, and specifically relates to an iron-nitrogen-doped graphene porous material with dual-site catalytic oxygen reduction activity, and a preparation method and an application therefor. The porous material is formed by embedding graphite-carbon-coated iron carbide into a nitrogen-doped porous graphene band network structure; the preparation method for the iron-nitrogen-doped graphene porous material comprises the steps of preparing a graphene oxide solution; adding a proper amount of conductive macromolecular pyrrole to the graphene oxide solution; obtaining uniform hydrogel through a hydrothermal process; performing oxidative polymerization on the hydrogel by ferric iron; then dispersing the hydrogel into a fresh ferric iron solution to complete adsorption; then performing drying and high-temperature carbonization thermal processing; and finally removing non-active and free iron phase from the reaction system by dilute acid so as to obtain the iron-nitrogen-doped graphene porous material. The porous material can be used as the negative electrode catalyst for a fuel cell, and shows quite high catalytic oxygen reduction activity, so that the porous material has quite important research meaning and bright application prospects.

The invention discloses a CdS/metallic organic frame composite photocatalysis material as well as a preparation method and application thereof. The composite photocatalysis material is prepared by modifying a metallic organic frame on the surfaces of CdS nanoparticles. The preparation method of the composite photocatalysis material comprises the following steps: firstly, synthesizing the CdS nanoparticles by using a solvent thermal method, and modifying the metallic organic frame on the surfaces of the CdS nanoparticles by using an in-situ heterogeneous deposition method, thereby obtaining theCdS/metallic organic frame composite photocatalysis material. Compared with conventional CdS, the CdS/metallic organic frame composite photocatalysis material has improved photoelectric stability, and conversion efficiency, circulation stability and catalysis selectivity of photocatalytic reduction of carbon dioxide.

The invention discloses a preparation method of a Ni3Fe-loaded nitrogen-doped carbon nanometer composite material, and a product and applications thereof. The preparation method comprises following steps: 1, a Ni<2+>/Fe<3+>/PVP mixed sol is prepared; 2, the Ni<2+>/Fe<3+>/PVP mixed sol is subjected to electrostatic spinning so as to obtain solid carbon fiber film; 3, the solid carbon fiber film issubjected to pre-oxidation at air atmosphere at 200 to 300 DEG C, programmed heating is adopted for heat processing at 400 to 1000 DEG C at an inert atmosphere so as to obtain the Ni3Fe-loaded nitrogen-doped carbon nanometer composite material. The preparation method is low in cost, is easy, and is universal; the obtained Ni3Fe-loaded nitrogen-doped carbon nanometer composite material is of a one-dimensional composite structure (carbon nanometer fiber and carbon nanotube); Ni3Fe alloy particles can be embedded into the carbon nanometer fiber and carbon nanotube uniformly; the Ni3Fe-loaded nitrogen-doped carbon nanometer composite material can be taken as a water electrolysis hydrogen evolution electrocatalytic material, and possesses relatively high activity and excellent stability.

The invention provides a tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material and a preparation method and application thereof. Compared with the prior art, a hydrothermal method for preparing the tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material has the advantages of mature and stable synthesizing process, easiness in operation, low influence by the environment, easiness in controlling and high yield. The synthesized tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material is of a one-dimensional hollow tubular structure and has a large surface-specific area, and a Co4S3 nanotube directly grows on a foam nickel substrate with high conductivity, so that a product has high electrocatalytic activity in a hydrogen evolution reaction. Compared with other electro-catalysts loaded with noble metal elements, the tetracobalt trisulfide nanometer hollow pipe@foam nickel composite array material has the advantages that a transition metal is effectively combined with foam nickel to serve as an electro-catalyst of the hydrogen evolution reaction, and raw materials are rich in sources and cheap, so that the cost of the electro-catalyst of the hydrogen evolution reaction is lowered greatly.

The invention provides a preparation method of a sawtooth-like nickel-cobalt-iron PBA (prussian blue analogue) sintered oxide nanomaterial, and belongs to the technical field of materials. The preparation method comprises the following steps: a cubic-structured nanometer nickel-cobalt-iron PBA precursor is synthesized from nickel nitrate hexahydrate, trisodium citrate trihydrate, potassium ferricyanide and potassium hexacyanocobaltate(III); an ammonia water solution is used for corrosion, centrifugal separation is performed, a sample is washed and dried, a sawtooth-like nickel-cobalt-iron PBAnanomaterial is obtained and sintered, and a 'Z'-Ox nanomaterial is obtained. The 'Z'-Ox nanomaterial can effectively catalyze peroxymonosulfate to generate hydroxyl radicals and sulfate radicals, andaccordingly, bisphenol A is degraded. The position of corrosion is determined by uneven distribution of metal coordination bonds in the precursor, anisotropic corrosion is formed, and a new way is opened up for fine adjustment of the structure and properties of an MOF material; the method has the characteristics of being simple to operate, short in preparation period, high in economic benefit andsuitable for large-scale production.

The invention discloses a preparation method of a cuprous oxide and tritanium dicarbide heterojunction composite material and application thereof for photocatalytic reduction of carbon dioxide. The preparation method comprises the following steps: etching Ti3AlC2 with HF (Hydrofluoric Acid) to prepare tritanium dicarbide; preparing tritanium dicarbide nanosheets in a DMSO (Dimethylsulfoxide) stirring and ultrasonic mode; and carrying out in-situ growth on Cu2O on the tritanium dicarbide nanosheets under a hydrothermal condition, thereby obtaining the cuprous oxide and tritanium dicarbide heterojunction composite material. By adopting the preparation method, a Cu2O/MXene heterojunction composite material is prepared for a first time, the composite material is used as a photocatalyst for simulating CO2 reduction under radiation of an xenon lamp, and due to dense contact of hexagram-shaped Cu2O with two-dimensional MXene nanosheets, not only is the conductivity of the catalyst improved, but also the separation efficiency of electron holes is improved, and the optical absorption and the photocatalytic activity of Cu2O are improved.

The invention provides a preparation method for similarly coralloid NiSe@NC. The preparation method comprises the following steps that S1, 4,4'-dipyridyl, trimesinic acid and nickel nitrate are dissolved in N,N-dimethylformamide sequentially, after stirring is conducted for 35 minutes at room temperature, the temperature is increased to 120-130 DEG C at the rate of 5-10 DEG C, thermal reaction isconducted for 60-70 h, and Ni-MOFs are obtained; and S2, selenium powder and the Ni-MOFs are heated to 500-800 DEG C at the rate of 1-5 DEG C/min at the argon atmosphere, and after 1-3 h of heat preservation, the similarly coralloid NiSe@NC is obtained. Compared with the prior art, the preparation method has the following beneficial effects that the metal organic frameworks with nickel as the center serve as the precursor, through a one-step in-situ selenylation strategy, the coralloid NiSe@NC is obtained, then the structure can provide abundant catalytic active sites, good electrocatalysis hydrogen production and oxygen production performance is shown, 60 and 320 mV overpotential and 53 and 101 mV dec<-1> Tafel slope are achieved, and the similarly coralloid NiSe@NC can serve as a bifunctional electrocatalyst for electrolysis hydrogen evolution and oxygen evolution.

The invention discloses a metal oxide-sulfide composite oxygen evolution electrocatalyst, a preparation method and applications thereof, wherein the electrocatalyst is a composite material obtained bycoating zinc cobaltate nano-wires with nickel cobalt sulfide nano-sheets. According to the preparation method, zinc cobaltate nano-wires are synthesized by using a hydrothermal reaction, electrochemical deposition of sulfide nano-sheet is combined, and the zinc cobaltate nano-wires are coated with nickel cobalt sulfide nano-sheets so as to prepare the metal oxide-sulfide composite oxygen evolution electrocatalyst having a core-shell coating structure. According to the present invention, the prepared electrocatalyst has the specially designed chemical composition and the microstructure, such that the active sites and the surface area of the composite catalyst are improved, and the catalyst has high oxygen evolution activity and high stability are achieved compared with other oxide and sulfide electrocatalysts; the preparation method is simple and convenient; by using the low-cost non-precious metal raw materials, the large-scale synthesis of anode oxygen evolution catalysts required for water electrolysis reactions can be easily achieved; and the metal oxide-sulfide composite oxygen evolution electrocatalyst has good application prospect.

The invention discloses a preparation method and application of a titanium dioxide nano-sheet photocatalyst. The preparation method of the titanium dioxide nano-sheet photocatalyst comprises the following steps: under an anhydrous condition, uniformly mixing copper salt, a titanium source and absolute ethyl alcohol to obtain a solution A; uniformly mixing the solution A and acid to obtain a solution B; crystallizing, washing and drying the solution B to obtain the titanium dioxide nano-sheet photocatalyst. The invention further provides the titanium dioxide nano-sheet photocatalyst prepared bythe preparation method and the application of the titanium dioxide nano-sheet photocatalyst to photocatalytic ammonia synthesis. According to the preparation method, copper ions are introduced into aprecursor solution and the copper ions enter titanium dioxide structure cells, so that the titanium dioxide nano-sheet photocatalyst has more catalytic activity sites. The titanium dioxide nano-sheetphotocatalyst prepared by the preparation method has excellent performance in reaction of photocatalytically synthesizing ammonia; the high-yield ammonia is prepared by adopting the titanium dioxidenano-sheet photocatalyst for the first time.

The invention discloses a ternary metal organic framework sterilizing material and a preparation method and application thereof. The method comprises the following steps: taking a solvent as a reaction medium, uniformly mixing nickel acetate, cobalt acetate, ferrous acetate and 2-aminoterephthalic acid, and reacting for 1-3 hours at room temperature to obtain the nano flower-shaped ternary metal organic framework sterilizing material. The ternary metal organic framework sterilizing material disclosed by the invention is in a nano flower shape, has a good sterilizing effect, and has dual effects of direct sterilization of nickel, cobalt and iron and decomposition catalytic sterilization of H2O2. Compared with the prior art, the ternary metal organic framework sterilizing material disclosedby the invention combines a metal organic framework and heterogeneous Fenton-like reaction to achieve the aim of efficient synergistic sterilization, and the dosage of the sterilizing material and H2O2 is effectively reduced, so that the toxic and side effects are reduced, and the utilization rate of the sterilizing material and H2O2 is improved.

The invention relates to a triazinyl covalent network loaded metal single atom composite material, a preparation method and application thereof. The composite material comprises a triazinyl covalent network and transition metal single atoms loaded on the triazinyl covalent network, the triazinyl covalent network is composed of a structural unit shown in a formula (I), and the structural unit is formed by crosslinking a pyridine unit and a triazinyl ring. The composite material has a multilayer hierarchical porous structure, endows the material with extremely high specific surface area and rich catalytic active sites, and has excellent catalytic activity, excellent stability and methanol resistance in electrocatalytic oxygen reduction reaction. The method overcomes the defect that in the prior art, a monatomic catalyst is prone to agglomeration and causes unstable catalysis, single atoms can be evenly loaded in a triazinyl covalent network structure, the utilization rate of the single atoms is increased, side reactions in the electrocatalytic reaction are inhibited, and the selectivity of the electrocatalytic reaction is improved.

The invention discloses a preparation method of a nitrogen and phosphorus co-doped foamed carbon nanosheet loaded NiCo nanoparticle composite material, a product and application thereof. The preparation method comprises the following steps: preparing Ni<2+>/Co<2+>/NaCl/EDTMPA/SA mixed hydrogel; and carrying out freeze drying on the Ni<2+>/Co <2+>/NaCl/EDTMPA/SA mixed hydrogel, and carrying out heat treatment in a high-temperature inert atmosphere to obtain the NiCo alloy nanoparticle-loaded nitrogen and phosphorus co-doped highly porous and flexible foamed carbon nanosheet composite material.According to the invention, the product prepared by the method is regular in morphology, NiCo nanoparticles are uniformly loaded in the two-dimensional composite highly-porous flexible foamed carbon nanosheet in size, and the product has the characteristics of multiple active sites, low overpotential, good stability, a two-dimensional composite structure and the like, is an extremely potential water electrolysis electrocatalyst material, and can be used for preparing the alkaline full-water-splitting reaction electrocatalyst.

The invention discloses a preparation method of a CeO2-graphene aerogel catalyst material. Rare earth oxide CeO2 is compounded with graphene aerogel through a sol-gel process by adopting a hydrothermal reduction method or a chemical reduction method, and finally the CeO2-graphene aerogel composite material with excellent and efficient catalytic performance is prepared. Loading of nano oxide particles improves agglomeration between graphene sheet layers, and the graphene aerogel serves as a carrier, so that more catalytic active sites are provided for active components, the dispersibility of active oxide nano particles is improved, and the active components are in fully contact with reactants. By the catalyst material, the defect of a single-component material can be overcome effectively, so that the catalytic efficiency is greatly improved. The specific surface area of the prepared CeO2-graphene aerogel catalyst material is 138-187 m2/g, and the catalytic conversion rate of NO is 86-95%.

The invention provides a hydrogen evolution electrocatalytic material as well as a preparation method and application thereof. The hydrogen evolution electrocatalytic material contains ultrafine ruthenium nanoparticles with the metal loading capacity of 0.05-5wt% and a nitrogen-doped carbon skeleton with the nitrogen doping capacity of 1.0-10.0 at%, wherein the ultrafine ruthenium nanoparticles are uniformly loaded in the nitrogen-doped carbon skeleton, and the nitrogen-doped carbon skeleton contains a nitrogen element, a carbon element and an oxygen element. The hydrogen evolution electrocatalytic material provided by the invention can catalyze water electrolysis hydrogen evolution reaction, and can ensure the stability of the catalyst material while realizing efficient electrocatalytic hydrogen evolution.

The invention relates to a preparation method of a transition metal-nitrogen-carbon nanotube co-doped activated carbon oxygen reduction catalyst, and belongs to the field of catalyst preparation. Themethod comprises the following steps: pretreating an activated carbon carrier, growing a metal organic framework compound on the activated carbon in situ, and carrying out high-temperature pyrolysis carbonization. The method for in-situ growth of the metal organic framework compound on the activated carbon comprises the following steps: dissolving transition metal salt and zincate in a solvent toform a solution A; dissolving a nitrogen-containing organic ligand in a solvent to form a solution B; adding the pretreated activated carbon into the solution B to form a mixed solution; adding the solution A into the mixed solution for reaction, separating precipitates after reaction, and performing washing and drying. The catalyst has rich pyridine nitrogen, graphite nitrogen and metal nitrogencatalytic active sites, highly dispersed transition metal nanoparticles and carbon nanotubes, a developed three-dimensional pore structure and a high graphitization degree, so that the catalyst has relatively high oxygen reduction catalytic performance and can be widely applied to air electrode oxygen catalytic reduction of various fuel cells.

The invention provides a NiS/NiO heterojunction-loaded nitrogen-doped carbon nano composite material and a preparation method and application thereof. The preparation method comprises the following steps: S1, preparing Ni < 2 + >/PVP mixed sol; S2, performing electrostatic spinning on the Ni < 2 + >/PVP mixed sol to obtain a solid carbon fiber film; and S3, pre-oxidizing the solid carbon fiber film in an air atmosphere, and sequentially carrying out heat treatment in an inert atmosphere, oxidation treatment in the air atmosphere and sulfuration vapor deposition to obtain the NiS/NiO heterojunction-loaded nitrogen-doped carbon nano composite material. PVP selected in the method is cheap and easy to obtain, and compared with a traditional method for preparing the water electrolysis oxygen evolution electrocatalyst material, the method is simple and feasible in process, low in cost and easy to operate, and large-scale production can be achieved.

The invention relates to a method for preparing a low-temperature selective catalytic reduction denitration catalyst with an ultrasonic impregnation method. The method is characterized by comprising the following steps: step 1: sufficiently mixing and uniformly mixing raw attapulgite with concentrated sulfuric acid; transferring a mixed solution into a muffle furnace and roasting at certain temperature to obtain a white solid; step 2: adding soluble salt of manganese into distilled water to prepare a precursor solution of the manganese, and adding the white solid obtained by the step 1 into a mixed solution; stirring to form a suspension solution; step 3: transferring the suspension solution obtained by the step 2 into an ultrasonic apparatus and carrying out ultrasonic impregnation reaction at certain temperature for a period of time; step 4: filtering the suspension solution to obtain a solid, and drying at the certain temperature in a drying box; step 5, transferring the dried solid into the muffle furnace and roasting at the certain temperature; cooling and grinding to obtain the needed catalyst.

The invention relates to three methods for preparing nanometer cerium dioxide having specific crystal faces. The method for preparing nanometer cerium dioxide having a {111} crystal face orientation comprises the following steps: adding a NaOH solution to a cerium nitrate solution under a stirring condition to adjust the pH value to 5-7 in order to form a purple suspension; carrying out a hydrothermal reaction on the suspension in a blast drying oven at 160-200 DEG C; and cleaning and drying the resulting product to obtain a white or light yellow solid, and grinding the solid to obtain nanometer cerium dioxide powder. The method for preparing nanometer cerium dioxide having {110} and {100} crystal face orientations is different from the above method, and is characterized in that the pH value is adjusted to 10 or more, and the hydrothermal reaction is carried out at 90-110 DEG C. The method for preparing nanometer cerium dioxide having a {100} crystal face orientation is different fromthe above first method, and is characterized in that the pH value is adjusted to 10-13.

The invention relates to a preparation method of a Zn0.2Cd0.8S / rGO photocatalytic material, which comprises the following steps of: preparing a mixed solution A from hydrofluoric acid and H2O; adding zinc acetate dihydrate and cadmium nitrate tetrahydrate into the mixed solution A to obtain a solution B; adding thiourea into the solution B to form a solution C; adding the solution C into a polytetrafluoroethylene lining for hydrothermal reaction; after the reaction is completed, centrifugally washing with deionized water and ethanol, drying and grinding to obtain a leaf-like Zn0.2Cd0.8S material; preparing graphene oxide and deionized water into a solution to form a solution D; adding the prepared Zn0.2Cd0.8S powder into the solution D, and magnetically stirring to form a solution E; adding the solution E into the polytetrafluoroethylene lining for hydrothermal reaction; after the reaction is completed, centrifugally washing with deionized water and ethanol respectively, and dryingand grinding to obtain the Zn0.2Cd0.8S / rGO material powder. The method adopts hydrothermal method to prepare Zn0.2Cd0.8S / rGO material, and has simple process operation, good crystallinity, high purity and excellent performance of the product.

The invention belongs to the technical field of nano optoelectronic materials, and discloses a preparation method of a C/CoS2 nanotube with a controllable structure. According to the method, a one-step simple chemical vapor diffusion strategy is adopted, controllable growth from nanorods to nanotubes is achieved by regulating and controlling the reaction atmosphere, namely the Ar/H2 gas ratio, andthe method has the advantages of being simple in preparation process, stable in product structure, high in catalytic activity site and the like and has efficient catalytic activity. The problems of uncontrollable product structure, few catalyst active sites and the like in the traditional preparation method are solved. The method has important engineering practical significance, and has wide application prospects in the fields of military industry, spaceflight, energy, electronics, environment and the like.