1523 results about "Doped carbon" patented technology

The invention discloses a modified graphite felt electrode for an all-vanadium redox flow battery and a preparation method of the modified graphite felt electrode, and belongs to the technical field of redox flow battery electrode materials. The preparation method comprises the following steps: graphite felt electrochemical oxidation etching treatment; self-assembling a conductive layer on the oxidized and etched graphite felt to obtain the graphite felt attached with the conductive layer; and loading a metal and nitrogen-doped carbon (M and NC) nano catalyst layer on the graphite felt attached with the conductive layer to obtain the modified graphite felt electrode. Various properties of the graphite felt are comprehensively improved through matrix treatment, structure change and load catalysis, mild electrochemical oxidation etching is adopted, a carbon fiber structure is protected, a self-assembled net-shaped conductive layer forms a stable conductive channel, the specific surface area is remarkably increased, a nitrogen-doped carbon shell is adopted to wrap metal nanodots to form an M-NC catalytic layer, and the specific surface area is remarkably increased. The catalyst layer is not easy to dissolve out, the capacity fading rate is obviously improved, the loading capacity of the catalyst layer on the reticular structure conducting layer with a larger specific surface area is larger, and meanwhile, the process is simple and low in cost.

The invention discloses a modified carbon-coated sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, and relates to the technical field of new energy materials. The preparation method comprises the following steps: preparing MnFe-MOF from a manganese source, a first iron source and a first organic ligand under a hydrothermal reaction; a second iron source, the MnFe-MOF and a second organic ligand are subjected to a hydrothermal reaction, and MnFe-MOF / Fe-MOF is obtained; uniformly mixing with a sodium source and a phosphorus source, and sintering to obtain a positive electrode material; and carrying out high-temperature gas-phase etching treatment to obtain the fluorine-doped carbon-coated modified sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material. The material disclosed by the invention has a coating modified structure, so that an interface side reaction caused by direct contact between sodium ferromanganese phosphate and an electrolyte can be effectively avoided, a manganese dissolution phenomenon is reduced, and the structural stability of the material is improved; and meanwhile, the material has high conductivity, excellent structural stability, excellent long cycle life and excellent rate capability.

The invention discloses a metal-doped carbon quantum dot as well as preparation and application of the metal-doped carbon quantum dot in a nano antibacterial agent, citric acid, urea and tea polyphenol are taken as precursors, metal salt is added, carbon dot synthesis and metal ion doping are synchronously completed in one step through a hydrothermal method, and the metal-doped carbon quantum dot is prepared; the surfaces of the metal-doped carbon quantum dots are negatively charged, and the metal-doped carbon quantum dots have peroxidase-like activity and catalase-like activity at the same time; the metal ions adopt any one of Fe < 3 + >, Cu < 2 + > and Ce < 3 + >; the metal-doped carbon quantum dots are in a sphere-like shape. The metal-doped carbon quantum dots prepared by the preparation method disclosed by the invention have peroxidase-like activity and catalase-like activity at the same time through precise doping of metal ions, and the two activities have a synergistic effect in an oral periodontitis microenvironment, so that a good antibacterial effect is achieved.

The invention discloses a process for synthesizing ammonia by coupling low-temperature plasma with electro-catalysis in the field of clean energy and green chemical industry, which comprises the following specific steps: mixing air and water vapor, feeding the mixture into a dielectric barrier discharge reactor, filling the reactor with a multi-stage heterojunction gradient doped carbon coated catalyst, generating active gas containing NOx under pulse high voltage, and condensing and then entering an electrocatalytic reduction unit. And an electro-catalysis product enters a photo-thermal separation module integrated with a Janus type photo-thermal electrode, the temperature of the electrode is locally increased under visible light irradiation, NH3 desorption is promoted, and finally high-purity ammonia is obtained through polyimide membrane separation. The multistage heterojunction gradient-doped carbon-coated catalyst adopted in the process is prepared through multiple steps and contains gradient-doped boron, sulfur and Au nanoparticles on the surface, NOx adsorption, electron transport and sintering resistance are synergistically improved, and efficient ammonia synthesis under mild conditions is achieved.

The invention relates to a fluorine-nitrogen co-doped carbon-coated positive electrode material and a preparation method thereof, and the cycle performance of the positive electrode material is effectively improved by arranging a fluorine-nitrogen co-doped carbon-coated layer on the surface of a positive electrode active material. When the positive electrode material is applied to a battery system, the cycle life of the battery can be prolonged.

A nanocomposite electrode and a supercapacitor device including said nanocomposite electrode. The nanocomposite electrode includes a mixture of at least one binding compound, at least one conductive additive, and at least one molybdenum doped carbon material coated onto a substrate. The supercapacitor device includes two nanocomposite electrodes disposed facing one another, wherein the substrate of each nanocomposite electrode is coated with the mixture on an inside facing surface and the outer surfaces of the nanocomposite electrodes are not coated with the mixture, and the inside facing surfaces are separated by at least one electrolyte.

The invention discloses a silk protein-MXene composite film and a preparation method thereof. The silk protein-MXene composite film sequentially comprises a conductive surface layer, a porous response layer and a supporting bottom layer from top to bottom, the invention relates to the technical field of composite films. According to the fibroin-MXene composite film and the preparation method thereof, a three-layer gradient structure is formed by the conductive surface layer, the porous response layer and the supporting bottom layer, good conductivity and electromagnetic shielding effectiveness are ensured by utilizing oriented arrangement of MXene of the conductive surface layer, gallic acid and MXene form a hydrogen bond network, and nitrogen-doped carbon quantum dots coat the surface of MXene to form a physical barrier, so that the electromagnetic shielding effect is improved, and the electromagnetic shielding effect is improved. Through double oxidation resistance of gallic acid and nitrogen-doped carbon quantum dots, a sponge body structure formed by the porous response layer is matched to endow the composite film with high-sensitivity response to external stimulation, the supporting bottom layer is crosslinked by hexamethylene diisocyanate and enhanced by nanocellulose, the tensile strength is improved, and the tensile strength of the composite film is improved. And the contradiction between the mechanical property and the conductivity of the traditional composite film is effectively solved.

An electrode structure for a solid-state or semi-solid-state battery is provided in which NCM electrode particles coated with an interphase layer and a nitrogen-containing carbon layer are disposed. [Solution] The NCM electrode particles comprise NCM (nickel-cobalt-manganese oxide) particles (15), primary particles (30) that coat the outer surfaces of the NCM particles, an interphase layer (16) that includes a glass phase layer (241) and a plurality of ceramic particles (242), and a nitrogen-containing carbon layer (35) that coats the exterior of the primary particles. Nitrogen-doped carbon molecules in the nitrogen-containing carbon layer aid in the conduction of electrons and lithium ions, modifying the electrical potential of the NCM particles. The nitrogen-containing carbon layer is formed by coating the surfaces of the primary particles with a nitrogen-containing polymer material and calcining the material in an inert atmosphere. Conjugated bonds are formed between the carbon and nitrogen, modifying the energy band structure, reducing the energy required for electrons to transition to the conduction band, and improving overall electronic conductivity.

The invention relates to the technical field of batteries, in particular to a negative electrode material, a preparation method thereof and a battery. The negative electrode material comprises a silicon nano material; the metal silicide layer at least partially coats the surface of the silicon nano material; the nitrogen and sulfur doped carbon layer at least partially coats the surface of the metal silicide; and the thickness of the metal silicide layer is greater than that of the nitrogen and sulfur doped carbon layer. According to the negative electrode material, the preparation method thereof and the battery provided by the invention, the coating structure of the negative electrode material is optimized, and the metal silicide / heteroatom doped carbon double-layer coated silicon nano material can be prepared by adopting a synthesis method which is low in energy consumption and capable of constructing a functional multi-layer coating structure, so that the long cycle life and the high-rate fast charging performance can be considered at the same time.

The present invention belongs to the technical field of battery materials, and particularly relates to a composite phosphate-based positive electrode material, and a preparation method therefor and the use thereof. The composite phosphate-based positive electrode material comprises a phosphate-based active core, wherein the outer surface of the phosphate-based active core is sequentially coated with a carbon coating layer, a nitrogen-doped carbon coating layer and a nitrogen-phosphorus co-doped carbon coating layer from inside to outside, wherein the carbon coating layer can improve the electronic and ionic conductivity of the composite positive electrode material, and optimize the particle size and morphology of the composite positive electrode material. The nitrogen-doped carbon coating layer improves the consistency and integrity of coating; and nitrogen-atom-doped carbon further enhances the electronic conductivity and lithium-ion diffusion of the carbon coating layer. Electron-rich clouds of P and N atoms in the nitrogen-phosphorus co-doped carbon coating layer can provide a rich conductive network, mutual contact is formed among different particles to form a series network, thus promoting the interfacial electron transport of the composite material during a charging and discharging process, and improving the cycling and rate performance of the composite phosphate-based positive electrode material during the charging and discharging process.

The invention belongs to the field of carbon nanomaterials, and provides a method for preparing a carbon quantum dot material doped with elements such as silicon and aluminum by oxidative depolymerization and stripping of coal gangue. Comprising the steps of screening and matching of coal gangue, oxidative depolymerization stripping, centrifugal dialysis membrane filtration and modification, drying and the like, raw materials and all the steps are specifically set, and the particle size or fluorescence performance of fluorescent carbon dots can be specifically selected and set according to selective oxidative depolymerization stripping conditions. The main particle size of the prepared multi-inorganic-element doped carbon quantum dot material is kept within the range of 1.5-2.0 nm, the structure is stable, the optical performance also meets the requirements, and the material can be further modified and is expected to be applied to the fields of photovoltaic equipment, biological imaging, photocatalytic degradation of organic pollutants or sensing and the like.

The invention discloses a preparation method of a lithium iron phosphate positive electrode material, three iron sources with different forms and different particle sizes participate in preparation of the lithium iron phosphate positive electrode material, and gradation is formed to improve the compaction density and rate capability of the material. The EDTMPA reduces the viscosity of the slurry, is anchored on the surface of FePO4 particles through strong adsorption, inhibits particle aggregation through steric hindrance and electrostatic repulsion effect, and introduces hydrophilic groups to enhance wettability, reduce the viscosity of the system, optimize dispersion stability, accelerate particle crushing and refining, reduce the particle size and shorten the grinding time; in the sintering process, a reducing agent is generated through pyrolysis to inhibit too fast oxalic acid decomposition to cooperate with the generated reducing gas, Fe < 3 + > is completely reduced, the reduction temperature is reduced to inhibit grain growth, and the grading effect between large and small particles is improved; in addition, an N-doped carbon coating layer is formed through high-temperature cracking, pores are filled with residual carbon generated through decomposition of ferrous oxalate, the coating density is improved, the carbon-coated graphitization degree is improved, and then the electronic conductivity and the rate capability of the material are improved.

The invention provides a CoCe-SNC catalyst and a preparation method and application thereof, and belongs to the technical field of hydrogen fuel cell / metal air cell cathode catalysts. The preparation method comprises the following steps: mixing and grinding a metal organic framework ZIF-8 and KSCN, carrying out first pyrolysis, compounding the obtained nitrogen and sulfur-containing co-doped carbon with two metal complexes Co-PM and Ce-PM, and carrying out second pyrolysis to obtain the CoCe-SNC diatomic catalyst. According to the invention, the two-dimensional lamellar structure carbon material and the asymmetric coordination diatomic metal are compounded, so that the catalytic performance of the whole catalyst is improved, and meanwhile, the yield of hydrogen peroxide generated by side reaction is reduced. The catalyst is applied to a hydrogen fuel cell / metal air cell, and the defects that in the prior art, a noble metal catalyst is high in cost, and a non-noble metal catalyst is low in catalytic activity, high in hydrogen peroxide yield, poor in catalyst stability and the like are overcome.

The invention provides a preparation method of an iron and nitrogen co-doped biomass-based carbon material, which can be applied to the technical fields of environmental functional materials and advanced oxidation. The preparation method comprises the following steps: obtaining target charcoal precursor powder; mixing the charcoal precursor powder with soluble ferric salt and urea to form initial mixed powder, adding water into the initial powder, and drying after water bath to obtain mixed powder; and heating and calcining the mixed powder according to preset process parameters to obtain the iron and nitrogen co-doped biomass-based carbon material. The prepared iron and nitrogen co-doped biomass-based carbon material FeOx has a high specific surface area and a rich pore structure, FeOx is uniformly dispersed on a nitrogen-doped carbon substrate, ozone catalytic activity and electron conduction performance are improved, and reactive oxygen species (ROS) can be efficiently generated to degrade sulfamethoxazole.

The invention relates to the technical field of agricultural application of nano materials, and discloses a preparation method and application of a photosynthetic accelerant containing carbon quantum dots. Urea and citric acid are adopted as raw materials, and the nitrogen-carbon molar ratio and hydrothermal reaction parameters are optimized, so that efficient doping of nitrogen and accurate regulation and control of the particle size are achieved, and the photosynthetic accelerant containing the carbon quantum dots is obtained. The nitrogen-doped carbon quantum dot photosynthetic promoter with excellent upconversion performance is successfully synthesized, the promoter has good water solubility and biocompatibility, the photosynthetic efficiency of plants can be greatly improved within the concentration range of 0-100 mg / L, a safe application window is defined, and by establishing foliage spraying and water planting dual-mode application specifications, the application range of the nitrogen-doped carbon quantum dot photosynthetic promoter is widened, and the application range of the nitrogen-doped carbon quantum dot photosynthetic promoter is widened. The problems that current crops are insufficient in solar spectrum utilization and low in light energy conversion efficiency are solved in a targeted manner by utilizing an ultraviolet light-photosynthetically active radiation conversion function mediated by the carbon quantum dots and combining the targeted enrichment permeation characteristic of the carbon quantum dots in chloroplast.

The invention belongs to the technical field of catalysts, and discloses a rare earth platinum alloy catalyst and a preparation method and application thereof. The catalyst comprises a nitrogen-doped carbon carrier, and a PtGd alloy and a Ni elementary substance are loaded on the nitrogen-doped carbon carrier. The preparation method comprises the following steps: (1) preparing a Gd-ZIF material; and (2) uniformly mixing the Gd-ZIF, the platinum source solution and the nickel source solution, carrying out vacuum drying treatment, heating to 700-1000 DEG C in a reducing atmosphere, keeping the temperature for 1-2 hours, and cooling to room temperature to obtain the rare earth platinum alloy catalyst. The invention discloses application of a rare earth platinum alloy catalyst which is used as a cathode oxygen reduction reaction catalyst of a hydrogen fuel cell. The preparation method disclosed by the invention is simple to operate and can be used for large-scale preparation; the Pt content of the rare earth platinum alloy catalyst prepared by the method is reduced to 13%, and the cost of raw materials is directly and greatly reduced; the maximum half-wave potential of the rare earth platinum alloy catalyst can reach 0.93 V vs.RHE which is far higher than that of commercial Pt / C.

The invention relates to the technical field of lithium ion batteries, in particular to a chromium-molybdenum double-doped lithium iron phosphate material as well as a preparation method and application thereof. The preparation method is used for solving the problems of low capacity, low electronic conductivity and poor cycling stability of the existing lithium iron phosphate material. According to the preparation method, chromium-molybdenum is doped into lithium iron phosphate, and the bond energy of a Cr-O bond and a Mo-O bond is stronger than that of a Fe-O bond, so that the dissolution loss of Fe < 2 + > in long-term circulation is reduced, and the battery capacity and the intrinsic electron conductivity of the material are improved; lithium iron phosphate is coated with nitrogen-doped carbon nanotubes, and nitrogen is doped in graphite crystal lattices of the carbon nanotubes, so that additional free electrons are provided, the intrinsic conductivity is improved, the resistance is reduced, the rate capability is improved, and the cycle life is prolonged; the polyaniline coating layer forms a barrier layer on the surface of the lithium iron phosphate particles, so that the cycle performance and the battery capacity are improved; the three components cooperate to improve the capacity, conductivity, rate capability and cycling stability of the material.

This invention relates to a method for synthesizing iron-cobalt alloy-doped carbon nanofibers for electrocatalysis using zinc oxide etching, belonging to the technical field of electrode materials and catalysts. The preparation method includes the following steps: 1) mixing DMF (dimethylformamide), PMDA (pyromellitic dianhydride), and ODA (4,4-diaminodiphenyl ether) in a certain proportion to prepare a PAA (polyamic acid) spinning solution; 2) preparing PAA nanofibers from the PAA spinning solution using an electrostatic melt-blowing device; 3) imidizing the PAA nanofibers using a programmed temperature rise method to obtain PI nanofibers; 4) impregnating the PI nanofibers in a salt solution; 5) carbonizing the impregnated PI nanofibers with a large number of metal ions on their surface in an inert atmosphere using a certain temperature rise program to obtain iron-cobalt alloy-doped carbon nanofibers. The iron-cobalt alloy-doped carbon nanofibers prepared by this method exhibit excellent performance as an ORR / OER bifunctional electrocatalyst and have wide applications.

The invention belongs to the technical field of inclusion type composite catalysts, and particularly relates to a preparation method of a spherical sulfur-doped carbon-based catalyst based on cyclodextrin and application of the spherical sulfur-doped carbon-based catalyst in bisphenol A sewage treatment. Cyclodextrin, elemental sulfur and polyether F127 are subjected to supercritical carbon dioxide reaction and high-temperature roasting to obtain the spherical sulfur-doped carbon-based catalyst, the spherical sulfur-doped carbon-based catalyst has excellent degradation and adsorption functions on bisphenol A (BPA) pollutants in sewage, the adsorption rate of 0.005 g of the catalyst to 50 mL of 0.02 g / L BPA is 46% in 10 min and reaches 90% in 90 min, 0.03 g of PMS is added for catalytic degradation, and the adsorption rate reaches 90% in 90 min. The degradation rate of 50 mL of 0.02 g / L BPA can reach 100% in 20 min, and the adsorption efficiency is remarkably improved. After three times of recycling, the adsorption rate is still kept at 85% or above, and the adsorbent has excellent regeneration cyclicity. The preparation method is simple, environment-friendly and low in cost.

The invention provides a preparation method of nitrogen and phosphorus-doped carbon dots and application of the nitrogen and phosphorus-doped carbon dots in quercetin detection, the nitrogen and phosphorus-doped fluorescent carbon dots (N, P-CDs) are successfully constructed for the first time by adopting a hydrothermal synthesis method, and the carbon dots have emission peaks at 465 nm under the excitation wavelength of 325 nm and show green fluorescence under the irradiation of an ultraviolet lamp; quinine sulfate is used as a standard reference substance, and the quantum yield is 1301%; an N, P-CDs solution is used as a probe molecule, after quercetin is added, fluorescence quenching of N, P-CDs is induced, and the concentration of quercetin and the fluorescence intensity of N, P-CDs are linearly changed, so that the method can be used for quantitative detection of quercetin. The N, P-CDs preparation method provided by the invention is simple and rapid, the product property is stable and non-toxic, the detection sensitivity on the quercetin is high, and the N, P-CDs can be used for detecting the content of the quercetin in serum.

The invention belongs to the technical field of iron ion detection, and particularly relates to a rapid detection method for ferric ions in water, which comprises the following steps: a fluorescent probe preparation step: taking trihydrate of copper nitrate and tryptamine, adding into a centrifuge tube in sequence, adding ultrapure water, performing ultrasonic dissolution, transferring into a high-pressure reaction kettle, and performing hydrothermal reaction to obtain a fluorescent probe; cooling to room temperature, centrifuging the obtained yellow green solution in a centrifugal machine, and filtering the supernate through a microfiltration membrane to obtain a copper-doped carbon quantum dot CuCDs stock solution, namely the fluorescent probe; analyzing and determining Fe < 3 + >: taking the diluent of the prepared CuCDs solution, adding the diluent into a centrifugal tube containing a Fe < 3 + > standard solution, uniformly mixing, carrying out fluorescent quantitative analysis and detection, and exploring the change rule of the fluorescence intensity ratio of CuCDs; according to the rapid detection method for Fe < 3 + > provided by the invention, the synthesized CuCDs have high sensitivity, can realize on-site rapid detection of Fe < 3 + > in a water medium, and shows a wide application prospect in the field of environmental monitoring.

The invention provides an iron-selenium double-monatomic nitrogen-doped carbon-based composite material and a preparation method and application thereof, the composite material comprises an N-doped carbon matrix, and Fe monatomic and Se monatomic distributed on the N-doped carbon matrix, and the Fe monatomic and the Se monatomic are anchored on the N-doped carbon matrix. The method comprises the following steps: preparing a Fe / Se / N-doped carbon-based precursor, and carrying out high-temperature carbonization on the Fe / Se / N-doped carbon-based precursor to obtain the iron-selenium double-monatomic nitrogen-doped carbon-based composite material. The preparation method overcomes the technical bottlenecks of low specific capacity, poor cycling stability, poor rate capability, complex preparation process, no environmental protection and the like of the existing sodium-ion battery negative electrode material. The composite material has high reversible capacity, excellent cycle stability and good rate capability, comprehensively improves the comprehensive electrochemical performance of the sodium-ion battery, provides a competitive high-performance material solution for the field of sodium-ion batteries, and practically meets the urgent demand of the current new energy field on high-performance battery materials.

The invention belongs to the technical field of nano functional materials and intelligent textiles, and particularly discloses a preparation method and application of high-brightness nitrogen-doped carbon quantum dots based on phycocyanin. The method is used for solving the problems of large difference and poor reproducibility when the same biomass in different batches is used for preparing the carbon dots in the prior art. Comprising the following steps: (1) freeze-drying spirulina, and grinding into powder to obtain spirulina powder; (2) extracting phycocyanin by utilizing spirulina powder; (3) phycocyanin is added into the reaction container, then distilled water is added, the adding amount ratio of phycocyanin to distilled water is 1 g: 33.3-50 mL, and full stirring is conducted; and then, carrying out carbonization treatment, cooling to room temperature, collecting the solution, and dialyzing for 24 hours, so that the solution outside a dialysis bag is a purified carbon quantum dot solution. According to the method, the phycocyanin is used as a single nitrogen source for the first time, the reproducibility of preparing the carbon dots from the same biomass in different batches is good, and large-scale production is facilitated.

The invention discloses a nitrogen-doped carbon-based iron monatomic catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts, the nitrogen-doped carbon-based iron monatomic catalyst with a hierarchical porous structure, namely an Fe-N4 monatomic catalyst (ITFeSA-N4), is constructed by adopting a strategy of taking inorganic salt as a template and assisting synergistic pyrolysis of nitrogen-containing ionic liquid and Fe-MOF. Inorganic salt is taken as a template, so that agglomeration of active sites can be effectively inhibited, a hierarchical pore structure is constructed, and the template removal process is simpler and more convenient due to excellent water solubility of the inorganic salt; the nitrogen-containing ionic liquid is used as a nitrogen source, the coordination environment of Fe-pyridine N4 can be accurately regulated and controlled, the structure can remarkably improve the Fe site electron cloud density (d-band center upward shift) and promote O-O bond dissociation (energy barrier reduction) in PMS, and meanwhile, the hierarchical pore channel structure can improve the O2 diffusion rate, so that ORR reaction kinetics is greatly improved.

Described herein is a catalyst comprising a nitrogen-doped carbon matrix, iron atoms, iron carbide particles, and carbon nanotubes, wherein the carbon nanotubes are dispersed and bonded to the nitrogen-doped carbon matrix, the iron atoms, and the iron carbide particles are dispersed and bonded to the nitrogen-doped carbon matrix and / or the carbon nanotubes. The catalyst may be used to coat an electrode for use in an electrochemical cell and electrolysis.

This invention discloses a method for preparing a nitrogen-doped titanium dioxide and carbon hollow sphere heterojunction photocatalyst, comprising the following steps: 1) preparing a carbon hollow sphere core-shell structure sample based on melamine-formaldehyde nanospheres; 2) preparing a TiO2@carbon core-shell structure sample using the carbon hollow sphere core-shell structure and tetrabutyl titanate as the reaction system; 3) using a one-step method to simultaneously dope nitrogen into the TiO2@carbon core-shell structure to form an N-TiO2@N-doped carbon hollow sphere heterojunction. This invention provides a method for preparing a nitrogen-doped titanium dioxide@carbon hollow sphere heterojunction photocatalyst and its application. This method achieves uniform nitrogen doping and effective composite of TiO2 and carbon hollow spheres through specific steps, and the prepared photocatalyst exhibits excellent photocatalytic performance under both visible and ultraviolet light.

The invention relates to a nitrogen-tellurium co-doped carbon-loaded cobalt-lanthanum-gallium triatomic oxygen reduction catalyst as well as a preparation method and application thereof. The catalyst comprises a carbon carrier, doped nitrogen atoms, doped tellurium atoms, supported cobalt atoms, supported lanthanum atoms and supported gallium atoms, wherein the doping proportions of nitrogen atoms and tellurium atoms in the carrier are 3.63 wt%-6.96 wt% and 2.11 wt%-3.83 wt% respectively, the loading capacity of cobalt atoms is 0.86 wt%-1.05 wt%, the loading capacity of lanthanum atoms is 0.38 wt%-0.47 wt%, and the loading capacity of gallium atoms is 0.21 wt%-0.47 wt%; in the preparation method, the nitrogen-tellurium co-doped carbon carrier is fully anchored and coordinated to Co and La atoms through a hydrothermal reaction; and through freeze drying, collapse of a carbon skeleton of the catalyst can be effectively avoided. The obtained catalyst shows good oxygen reduction activity in a solid zinc-air battery, and the peak power density of the catalyst reaches up to 1.68 mW cm <-2 >.

The invention discloses a graphene aerogel modified elastic graphite material and a preparation method thereof, and the graphene aerogel modified elastic graphite material comprises the following components by mass: 50-80 parts of crystalline flake graphite; 8 to 15 parts of graphene aerogel; 3 to 8 parts of aminated modified boron-doped carbon nanotubes; 2 to 6 parts of hydroxyapatite-cerium oxide composite nano particles; 1 to 4 parts of a polyimide-montmorillonite nano composite material; 0.5 to 3 parts of titanate coupling agent modified nano silicon dioxide; 1-3 parts of a dispersant; 2-5 parts of a binder; the amination modified boron-doped carbon nanotubes can enhance the electrical conductivity and interface bonding force of the material, the hydroxyapatite-cerium oxide composite nanoparticles improve the high-temperature stability and mechanical toughness of the material, and the polyimide-montmorillonite nanocomposite improves the corrosion resistance and resilience durability of the material. And the titanate coupling agent modified nano silicon dioxide further optimizes the dispersion uniformity of all the components, and the comprehensive performance of the material is remarkably improved.

The invention relates to the field of lithium ion batteries, and discloses a lithium titanate composite material and a preparation method thereof, a negative pole piece and a preparation method thereof, a lithium battery and a battery pack. The surfaces of lithium titanate particles are sequentially coated with the nitrogen-doped carbon intermediate layer and the two-dimensional MXene material outer layer, and the MXene material outer layer is formed by bridging adjacent particles through hydrogen bonds, so that a'core-shell-bridge 'three-dimensional conductive network structure is constructed, the electronic conductivity of the lithium titanate composite material is remarkably improved, the electron / ion transmission efficiency of the lithium titanate negative electrode is improved, and the lithium titanate negative electrode has a good application prospect. The lithium ion battery has excellent rate capability and cycle performance; and through collaborative optimization of the three-dimensional composite material and the electrolyte, the interface impedance is reduced, and polarization is inhibited, so that the lithium battery still keeps high capacity and long cycle stability under ultrahigh rate, and meanwhile, the problems of discontinuous conductive network and high interface impedance in the prior art are solved. And excellent rate capability and cycle performance can be achieved under ultrahigh rate.

The invention relates to a preparation method of a carbon-based gold-containing bimetallic catalyst. The specific method comprises the following steps: carrying out secondary doping on eigenstate polyaniline, carrying out high-temperature pyrolysis in an inert atmosphere to obtain a heteroatom-doped carbon-based carrier, and changing the variety, the content and the distribution of heteroatoms on the carbon surface of the carrier by adjusting the variety and the content of acid. And preparing gold-containing bimetallic nanoparticles by using a colloid method, and depositing bimetallic particles by virtue of adsorption of the carbon carrier and bimetallic to obtain the carbon-based gold-containing bimetallic catalyst. Wherein the doping element can anchor and disperse the noble metal, and the introduced second metal can improve the hydrogenation activity of the catalyst. The catalyst is simple in preparation process, good in activity, excellent in selectivity and excellent in cycling stability, is particularly suitable for a reaction for preparing 4-chloroaniline through catalytic hydrogenation of 4-chloronitrobenzene, and has good application potential.