268 results about "Nitrogen doped carbon nanotube" patented technology

The invention belongs to the field of preparation and application of energy source materials and discloses a nitrogen-doped carbon nanotube / Co composite catalyst and a preparation method and application thereof. The preparation method includes: 1), respectively preparing melamine, cobalt salt and P123 into water solutions; 2), adding the melamine solution into the P123 solution, stirring for mixing, adding the cobalt salt solution, stirring for mixing, performing ultrasonic treatment, and heating while stirring until water is evaporated to obtain a precursor material; 3), pre-calcining the precursor material at 200-400 DEG C in an inert gas atmosphere, calcining at 450-600 DEG C and at 750-900 DEG C respectively, using an acid solution for soaking, cleaning, and drying to obtain the composite catalyst. The catalyst is high in oxygen reduction and oxygen evolution catalytic activity and stability and has high hydrogen evolution catalytic activity and stability in an acidic condition. The preparation method is simple, extensive in raw material source, low in cost and suitable for large-scale production. The composite catalyst is used in the field of integrated regenerative fuel cells.

The invention discloses a preparation method of a cobalt electro-catalysis oxygen reduction material wrapping a nitrogen-doped carbon nanotube. The method includes the following steps of making melamine, cobalt nitrate hexahydrate and glucose react to obtain a self-assembled melamine precursor, and baking the self-assembled melamine precursor to obtain a cobalt nanoparticle hybrid material electro-catalysis oxygen reduction agent wrapping the nitrogen-doped carbon nanotube. In preparation of the precursor, a self-assembled body can be formed through the electrostatic interaction and the hydrogen-bond interaction by means of nitrate radicals and melamine under the acid condition, cobalt ions are adsorbed into the self-assembled body, ordered arrangement and assembly of materials in the high-temperature baking process are facilitated by the pre-assembled precursor, and therefore more catalysis active sites are exposed, and the improvement of the performance of a catalyst is facilitated.

The invention discloses a method for synthesis of a cobalt nanoparticle and bamboo-like nitrogen doped carbon nanotube composite material. The method includes: dissolving a soluble cobalt salt and an amine polymer in a hydrophilic reagent according to a mole ratio of 1:(2-200), performing evaporation at 60DEG C, conducting grinding after cooling, performing calcination at 400-1400DEG C under nitrogen atmosphere, then treating the sample with acid, and carrying out washing, centrifugation and drying so as to obtain the cobalt nanoparticle and bamboo-like nitrogen doped carbon nanotube composite material. The obtained cobalt nanoparticles have small particle size and are employed to coat the head of a carbon nanotube evenly so as to combine tightly with the carbon nanotube. The composite material has application prospects in fuel cell anode materials, lithium ion battery cathode materials and the like. The method designed by the invention has the advantages of easily available raw materials, simple process and no pollution, short preparation period, mild reaction conditions, low cost, and mass synthesis capability, etc.

The invention discloses a nitrogen-doped carbon nanotube-loaded nitrogen-doped carbon-coated iron-cobalt alloy bifunctional catalyst and a preparation method and an application thereof. The catalyst is characterized in that for a structural unit, nitrogen-doped carbon nanotubes (NCNTs) are utilized as a conductive network, and iron-cobalt alloy nanoparticles wrapped by a nitrogen-doped ultrathin carbon layer are loaded on the nitrogen-doped ultrathin carbon layer. The preparation method comprises steps of pretreatment of carbon nanotubes, removing impurities on surfaces of the carbon nanotubesthrough cleaning, and generating a large number of defects and oxygen-containing surface functional groups on the surfaces of the carbon nanotubes through acid treatment; carrying out grafting reaction of an iron-cobalt organic ligand and melamine on the surfaces of the functionalized carbon nanotubes; calcining the iron-cobalt organic ligand and the melamine-grafted functionalized carbon nanotubes under a high-temperature condition to obtain the nitrogen-doped carbon nanotube-loaded nitrogen-doped carbon-coated iron-cobalt alloy bifunctional catalyst.

The invention discloses a preparation method of a metallic oxide / N-doped carbon nano tube composite material. The preparation method comprises the following steps of: (1) ultrasonically dispersing an N-doped carbon nano tube in a mixed solution of water and alcohol to obtain a solution A; (2) under the condition of stirring, dripping a solution B into the solution A, and stirring to obtain a mixed solution, wherein the solution B is water and / or alcoholic solution containing metal ions; and (3) carrying out solid-liquid separation on the mixed solution, and washing, drying and roasting to obtain the metallic oxide / N-doped carbon nano tube composite material. The invention also provides the composite material obtained through the method and an application thereof. According to the preparation method disclosed by the invention, as a method of solution phase synthesis under the condition of room temperature is adopted, hydrothermal reaction and solvothermal reaction with high temperature and high pressure are avoided, and the composite material with tighter combination of the metallic oxnide and the / N-doped carbon nano tube can be obtained. By adopting the preparation method, the preparation cost is low, the operation is simple, the preparation condition is mild, and the reaction period is also short.

Belonging to the technical field of material preparation, the invention relates to a preparation method of a nitrogen-doped carbon nanotube wrapped metal iron-cobalt alloy composite material (FeCo-NCNTs). The technical scheme includes: firstly, dissolving a metal salt and a carbon-nitrogen source in water, ethanol or ethylene glycol, mixing the substances evenly, and then performing drying and grinding to obtain a precursor; then putting the precursor in a tubular furnace, in a nitrogen atmosphere, conducting programmed heating to a roasting temperature, and conducting high temperature roasting and grinding to obtain a black powder sample; and then subjecting the black sample to pickling treatment until the pH value of the solution is neutral, and conducting pumping filtration and naturaldrying, thus obtaining the nitrogen-doped carbon nanotube wrapped metal iron-cobalt alloy composite material (FeCo-NCNTs). The obtained composite material can be used as a good electrocatalytic hydrogen evolution catalyst. The composite material prepared by the method provided by the invention has the characteristics of easily available raw materials and low cost, and has important significance inelectrochemical application.

The invention discloses a preparation method of a platinum based / nitrogen doped carbon quantum dot-carbon nanotube catalyst. The preparation method comprises the following steps: 1, weighing a certain amount of a carbon source to mix with deionized water, and performing ultrasonic dispersion for 1-3 hours; 2, weighing a certain amount of carbon nanotubes to mix with a solution of the carbon source, thereby obtaining a mixture A; 3, putting the mixture A into a reaction kettle, heating at 140-180 DEG C for 1-12 hours, cooling, washing with deionized water, filtering, and performing vacuum drying to obtain a material B; and 4, preparing a platinum based catalyst by virtue of a microwave assisted ethylene glycol reduction method by taking the material B as a carrier, thereby obtaining the platinum based / nitrogen doped carbon quantum dot-carbon nanotube catalyst. According to the preparation method disclosed by the invention, nitrogen doped carbon quantum dots are used for modifying untreated carbon nanotubes and are compounded with the carbon nanotubes, so that the dispersity of platinum ions in the composite carrier is improved, and then the activity of the catalyst is promoted. The preparation method disclosed by the invention is simple and feasible, promotes the activity of the platinum based catalyst to a greater degree, and is hopeful for commercial application.

The invention discloses a graphite electric arc discharge method for preparing a nitrogen-doped carbon nano-tube, the nitrogen-doped carbon nano-tube, and a carbon nano-tube element using the nitrogen-doped carbon nano-tube. In the electric arc discharge method for preparing the nitrogen-doped carbon nano-tube, a mixture comprising graphite, a catalyst and a nitrogenous organic compound used as a nitrogen source is used to prepare an anode, and the anode and a cathode are used for electric arc discharge to prepare the nitrogen-doped carbon nano-tube.

The invention relates to preparation and application of a nitrogen-doped carbon nanotube nickel-iron coated oxygen evolution catalytic material for water electrolysis. A general formula of the composite electrode material is Ni0.9Fe0.1@CNx, wherein CN is nitrogen-doped carbon, and x is greater than or equal to 0.01 and less than or equal to 0.1. The specific preparation method of the catalytic material comprises the steps of uniformly mixing nickel acetate and ferric chloride with citric acid and thiourea according to certain molar percentages, and then carrying out calcinations for 1-10h under an N2 gas flow rate of 10-100 mL / min at 600-900 DEG C to prepare the catalytic material. The preparation method provided by the invention effectively achieves one-step preparation of the Ni0.9Fe0.1@CNx oxygen evolution catalytic material with set ratios of Ni, Fe, C and N by an in-situ solid-phase method, and the product is nanotube-shaped, porous and large in specific surface area, and has excellent performance when being used as an oxygen evolution electrode material for water electrolysis. The method provided by the invention is convenient to operate, the process is simple and easy to control, raw materials are low in price and easy to obtain, and the catalytic material is suitable for large-scale production.

Metal-free fuel cell cathodes having a catalytic layer of vertically-aligned, nitrogen-doped carbon nanotubes (VA-NCNTs) are provided. The fuel cell cathodes comprise a cathode body, a binder layer attached to an outer surface of the cathode body, and the catalytic layer, which is supported by the binder layer. The binder layer may comprise a composite of a conductive polymer and doped or undoped nonaligned carbon nanotubes. In a method for forming the fuel cell cathodes, the VA-NCNTs may be formed by pyrolysis of a metalorganic compound and integration of the nanotubes with nitrogen. The binder layer is applied, and the resulting supported nanotube array may be attached to the cathode body. Fuel cells comprising the fuel cell cathodes are provided. The fuel cell cathodes comprising VA-NCNTs demonstrate superior oxygen-reduction reaction performance, including for electrocatalytic activity, operational stability, tolerance to crossover effects, and resistance to CO poisoning.

The invention discloses an MOF (metal organic frameworks)-based magnetic nitrogen-doped carbon nano-tube material, a method for preparing the same and application of the MOF-based magnetic nitrogen-doped carbon nano-tube material. The MOF-based magnetic nitrogen-doped carbon nano-tube material can be used as an adsorption material. MOF are calcined at the high temperatures to obtain the MOF-basedmagnetic nitrogen-doped carbon nano-tube material. Carbon nano-tubes with large quantities of free N elements are generated on the surfaces of the MOF-based magnetic nitrogen-doped carbon nano-tube material while the appearance of the MOF is reserved. The MOF-based magnetic nitrogen-doped carbon nano-tube material, the method and the application have the advantages that the MOF are used as templates for the MOF-based magnetic nitrogen-doped carbon nano-tube material which is a magnetic carbon material prepared by the aid of the method, and are directly calcined at the high temperatures to obtain the magnetic carbon material; the carbon material is high in environmental stability as compared with MOF adsorption materials, and pi-pi conjugation can be formed by the carbon material and targetobjects by the aid of strong conjugation surfaces of the carbon nano-tubes; the MOF-based magnetic nitrogen-doped carbon nano-tube material is extremely high in magnetism as compared with commercialcarbon nano-tubes, and target object detection procedures can be simplified by the aid of MSPE (magnetic solid-phase extraction) methods; processes for preparing the MOF-based magnetic nitrogen-dopedcarbon nano-tube material are simple, and the MOF-based magnetic nitrogen-doped carbon nano-tube material which is a magnetic nitrogen-doped carbon nano-material is high in magnetism and super-high inenvironmental stability, has large specific surface areas, can be specifically bound with the target objects and has an excellent application prospect in the field of detection on the content of microcystin in lake water and the like.

The invention belongs to the technical field of preparation of nano-functional materials, in particular to a method for preparing a nitrogen doped carbon nanotube three-dimensional composite materialby in-situ growth of a few layers of titanium carbide, immersing ternary layered Ti3AlC2 ceramic powder in hydrofluoric acid solution, heating and stirring, centrifugally cleaning with ultrapure waterand absolute ethanol, drying to obtain two-dimensional layered titanium carbide nano-powder, adding it into tetramethylammonium hydroxide solution, heating and stirring, centrifuging with deionized water to obtain a few layers of titanium carbide nano-sheet dispersion; Adding cobalt salt into a dispersion of a few layers of titanium carbide nano-sheets for reaction, adding dicyandiamide, heatingand stirring until dicyandiamide is completely dissolved, freezing, and freeze-drying to obtain precursor powder; Nitrogen-doped carbon nanotubes (CNTs) three-dimensional composites were prepared by in-situ growth of a few layers of titanium carbide after grinding the precursor powder and heat treatment. A three-dimensional composite material is prepared by a simple pyrolysis method using a few layers of titanium carbide as a carrier, cobalt as a catalyst, dicyandiamide as a carbon and nitrogen source, and the electrochemical performance of the few layers of titanium carbide can be improved.

The invention provides a chemical vapor deposition method, which takes liquidoid organic precursor as the carbon source and the nitrogen source, adopts an injection pump to inject the precursor into a reaction chamber, regulates the variety and input of the precursor, the variety and load of catalyst, the flow speed of protective atmosphere, and the reaction temperature, so as to produce high-quality carbon nano-tubes of different sizes and appearances, or nitrogen-mixed carbon nano-tubes with different nitrogen contents, classes, sizes and appearances in large quantity. For the chemical vapor phase deposition method of the invention, the carbon atoms in the precursor are transformed into carbon nano-tubes or nitrogen-mixed carbon nano-tubes with the transformation rate up to more than 60%, and the nitrogen content in the obtained nitrogen-mixed carbon nano-tubes is comparatively high; the diameter of the obtained tubes is comparatively uniform and the purity is relatively high; by adopting the CVD method to produce carbon nano-tubes or nitrogen-mixed carbon nano-tubes, the chemical vapor deposition method in the invention has the advantages of easy feasibility, convenient control of the reaction conditions, and no special requirements on the physical properties of the precursor by adopting the injection pump to inject the precursor, and larger selectable range of the precursor.

The present invention discloses a nitrogen-doped carbon nanotube / carbonitride composite material preparation method, nitrogen-doped carbon nanotube and solid hydrogen cyanamide powder are mixed and ground, the mixed nitrogen-doped carbon nanotube / solid hydrogen cyanamide powder is calcined for reaction, and a nitrogen-doped carbon nanotube / carbonitride composite material is obtained by washing respectively with ethanol and ultrapure water, centrifuging and drying. The present invention also discloses application of the nitrogen-doped carbon nanotube / carbonitride composite material in microbial fuel cells. The preparation method of a catalytic electrode from the nitrogen-doped carbon nanotube / carbonitride composite material is as follows: the nitrogen-doped carbon nanotube / carbonitride composite material, a conductive material and a binder are mixed nitrogen doping, a solvent is added into the mixture for evenly mixing and ultrasonically dispersing, a conductive substrate is uniformly coated with the ultrasonic mixture, and the conductive substrate is naturally dried to obtain the nitrogen-doped carbon nanotube / carbonitride composite material catalytic electrode. The method has the advantages of simple process, low cost, short cycle, and environmental friendliness, and the like.

The invention discloses a preparation method of a nano molybdenum disulfide / nitrogen-doped carbon nanotube array hybrid composite electrode. A carbon fiber fabric coated with a conductive carbon black layer is used as a substrate; a nitrogen-doped carbon nano tube array carrier is controllably prepared on a carbon fiber substrate through a chemical vapor deposition technology; then nitrogen-doped carbon nano tubes are oxidized to realize surface functionalization; and then the nitrogen-doped carbon nano tubes are firmly combined with a nano molybdenum disulfide material in a chemical bond form to form an electrode material with an integrated three-dimensional parallel hole structure and a bidirectional catalysis function. According to the invention, the carrier provided by the invention has excellent conductivity and relatively high mass transfer and load transfer capabilities; the nano molybdenum disulfide material combined by chemical bonds has good bidirectional catalytic activity of oxygen electroreduction and oxygen anion electrooxidation; the diffusion resistance and ion transmission resistance of oxygen species are reduced; the electrochemical activity and the structural stability of an electronic conductor are improved; and the preparation method has wide application prospects in electrode materials such as metal-air batteries, proton exchange membrane hydrogen fuel cells and direct methanol fuel cells.

The invention relates to a nitrogen-doped carbon nanotube adopting a hierarchical structure and a preparation method. The material is doped with nitrogen and adopts the obvious hierarchical structure, and the carbon nanotube comprises tinier nitrogen-doped carbon particles. The preparation method comprises steps as follows: aniline is uniformly dispersed in an acid solution through stirring, an aniline suspension is obtained and subjected to ice bath treatment for 20-60 min, and stirring is kept in the ice bath process; an oxidizing agent is dissolved in deionized water through stirring and subjected to ice bath treatment for 5-30 min; stirring is stopped, an oxidizing agent solution is quickly poured into an aniline suspension mixed solution and subjected to ice bath treatment for 8-28 h, centrifugal washing is performed by the aid of deionized water and ethanol until a supernatant is clarified, and a sample is dried in an oven; the dried sample is ground, subjected to heat treatment in air and naturally cooled; a treated composite is calcined at the high temperature in an inert atmosphere and naturally cooled. The nitrogen-doped carbon nanotube has the advantages of high capacity, good rate capability and good circulating performance and can be used as an anode material for a lithium ion battery.

The invention discloses a method for using biomass waste for preparing a nitrogen-doped carbon nanotube coated metal particle composite material. The method includes the following steps that firstly, the biomass waste and KOH are evenly mixed in deionized water, an obtained heterogeneous mixture is carbonized under the protection of inert gas, and biomass charcoal is obtained; and then, the biomass charcoal, a nitrogenous nonmetallic compound and water-soluble divalent metal salt are evenly mixed in methyl alcohol, the obtained heterogeneous mixture is subjected to pyrolysis under the protection of the inert gas, and therefore a target product is obtained. By the adoption of the method, a two-step pyrolysis technology is adopted for achieving growth of carbon nanotubes, and dispersion of metal nanoparticles and formation of a cooperative acting mechanism are promoted; the stability of the composite material is reinforced through the structure of carbon nanotube coated metal nanoparticles; the surface activity and dispersity of a carbon layer are improved through in-situ decoration of the nitrogen element; and the contact and active site point number is increased through the formation of a rich pore structure and the high specific surface area.

The invention discloses a flexible three-dimensional porous nitrogen-doped carbon nanotube / cobalt phosphide composite material and a preparation method and application thereof. According to the flexible three-dimensional porous nitrogen-doped carbon nanotube / cobalt phosphide composite material and the preparation method and application thereof, low-cost commercial melamine sponges are used as a three-dimensional carbon material skeleton template, a zeolite imidazole structure metal organic framework is used as a cobalt source, phosphorization is carried out by a low-temperature vapor deposition method, and the flexible three-dimensional porous nitrogen-doped carbon nanotube / cobalt phosphide composite material with high conductivity and a high specific surface area is obtained. The preparation process of the flexible three-dimensional porous nitrogen-doped carbon nanotube / cobalt phosphide composite material is relatively simple, the cost is low, and the preparation process is suitable for industrial application. The flexible three-dimensional porous nitrogen-doped carbon nanotube / cobalt phosphide composite material is used as an electrode material for hydrogen evolution catalysis ofelectrolyzed water, and has lower hydrogen evolution catalysis overpotential, a larger electrocatalytic active area and excellent cycle stability.

The invention relates to a carbon nanotube / molybdenum disulfide nanosphere composite material and a preparation method thereof. The preparation method comprises the steps of firstly preparing a nitrogen-doped carbon nanotube, and then reacting to generate a nitrogen-doped carbon nanotube / flower-like molybdenum disulfide nanosphere composite material. The composite material serves as a super-capacitor electrode material and shows excellent electrochemical performance. In addition, the preparation process is simple, green and environmental protection, serves as a new energy material and has great potential applications in the field of equipment such as a super-capacitor and a lithium ion battery.

The invention discloses a molybdenum trioxide in-situ cladding nitrogen-doped carbon nanotube composite electrode material as well as a preparation method and application. The preparation method of the molybdenum trioxide in-situ cladding nitrogen-doped carbon nanotube composite electrode material comprises the following steps of (1) preprocessing nickel foam; (2) growing a nitrogen-doped carbon nanotube onto a nickel foam substrate by utilizing a chemical vapor deposition method; (3) in-situ compounding molybdenum trioxide onto the nitrogen-doped carbon nanotube by utilizing an electric deposition method; and (4) annealing. The molybdenum trioxide in-situ cladding nitrogen-doped carbon nanotube composite electrode material is used as a lithium ion battery positive electrode material. The preparation method is simple in operation, simple in process and applicable to the mass production; the molybdenum trioxide in-situ cladding nitrogen-doped carbon nanotube composite electrode material is high in specific capacity and cycling performance, good in multiplying performance, and is a lithium ion battery positive electrode material with good performance.

The invention belongs to the technical field of micro devices, and particularly relates to a core shell structure composite fiber based on a carbon nano tube and a preparation method and application thereof. In the invention, the flexible composite fiber material with a core shell structure is obtained by in-situ growing of a netlike nitrogen-doped carbon nano tube on the surface of an oriented carbon nano tube; and the composite fiber shows excellent oxygen reduction performance by combining perfect three-dimensional jump electrical conductivity of the carbon nano tube and good electrocatalysis performance of the nitrogen-doped carbon nano tube. The current density of oxygen reduction of a micro electrode made from the composite fiber material is 5 times that of a platinum wire electrodeunder the same conditions. The carbon nano tube composite fiber electrode also has a remarkably high sensitivity (up to 1.0 muAmM<-1>) to the trace detection of H2O2. Moreover, the composite fiber has low preparation cost and high efficiency, can be industrially amplified more easily to solve problems in practical application, and has a wide application prospect when being used as a novel electrode material widely applied to photoelectric devices.

The invention provides a preparation method of nitrogen-doped graphene / nitrogen-doped carbon nanotube / tricobalt tetraoxide composite paper, which comprises the following steps: a) preparing a graphene oxide dispersion solution; b) preparing an oxidized carbon nanotube dispersion solution; c) mixing the graphene oxide dispersion solution and oxidized carbon nanotube dispersion solution with a cobalt nitrate water solution to obtain a slurry, applying the slurry onto a substrate, and drying to obtain the cobalt-ion-containing graphene oxide / oxidized carbon nanotube composite paper; and d) immersing the cobalt-ion-containing graphene oxide / oxidized carbon nanotube composite paper in an ammonia water solution, and carrying out hydrothermal reaction to obtain the final nitrogen-doped graphene / nitrogen-doped carbon nanotube / tricobalt tetraoxide composite paper. The method is simple to operate and mild in reaction conditions, can implement large-scale preparation of soft composite paper with favorable ORR catalytic property, and has favorable application prospects in the field of electrocatalysis.

The invention discloses a preparation method and application of a nitrogen-doped carbon nanotube to preparing a cathode of a microbial fuel cell, wherein nitrogen-doped carbon nanotube powder is used as an oxygen reduction catalyst of the microbial fuel cell. The specific preparation method comprises the steps of: mixing the nitrogen-doped carbon nanotube, a conductive material and a binder in a certain proportion; adding a solvent in the mixture, mixing evenly and carrying out ultrasonic dispersion; evenly coating the ultrasonic mixture on a conductive substrate; and naturally air-drying to form the cathode of the microbial fuel cell. Compared with the microbial fuel cells which are assembled by using the conventional noble metal platinum as the cathode oxygen reduction catalyst, the microbial fuel cell which takes the nitrogen-doped carbon nanotube as the cathode oxygen reduction catalyst has higher output power and better running stability. Compared with the platinum catalyst, the nitrogen-doped carbon nanotube has low cost.

The invention provides a preparation method of a metal organic framework (MOFs) derived Co embedded nitrogen doped carbon nanotube modified mesoporous carbon supported platinum catalyst (Pt / NCNTs (at)MC800-4). According to the method is characterized by taking ZIF-67 as a precursor and melamine as an external nitrogen source, preparing the Co-embedded nitrogen-doped carbon nanotube modified mesoporous carbon at proper temperature and time by a high-temperature calcination method, then taking the Co-embedded nitrogen-doped carbon nanotube modified mesoporous carbon as the carbon carrier, and taking the chloroplatinic acid as a platinum source and the ethylene glycol as a reducing agent, and adopting a hot reflux method to prepare the Pt-based composite catalyst Pt / NCNTs (at) MC800-4. The prepared composite catalyst has good methanol oxidation electrocatalytic activity, carbon monoxide poisoning resistance and stability, so that the catalyst has potential application prospects in the field of fuel cells.

The invention relates to a nitrogen-doped carbon nanotube oxygen-reduction electrocatalyst and a preparation method thereof. The preparation method comprises the steps of growing a bimetal zeolite imidazate framework structure material (ZIF) on sheet-shaped graphite-phase carbon nitride (g-C3N4) in an in-situ way, and then performing high-temperature thermal processing, wherein g-C3N4 is obtainedby pyrolysis of a low-cost biologic material. The electrocatalyst is a porous nitrogen-doped carbon nanotube material wrapped with transition metal or a compound thereof. The preparation method is simple in process and low in cost, the low-cost biological material is introduced and is calculated at a low temperature to generate the g-C3N4 material, the bimetal ZIF material is carried, and the effective nitrogen-doped carbon nanotube electrocatalyst is obtained by high-temperature pyrolysis. The prepared nitrogen-doped carbon nanotube oxygen-reduction catalyst has a large amount of mesopores and high specific area, shows high catalytic activity on oxygen-reduction reaction and can be used as a negative catalyst widely applied to the field of a fuel cell and a metal-air battery.

The invention relates to a preparation of a carbon nano fiber composite material coated by nitrogen-doped carbon nanotube and an application thereof. The preparation method is characterized in that an electrospinning technology and a heat treatment technology are combined to prepare the metal nanoparticles-loaded carbon nano fiber composite material; the carbon nano fiber composite material is taken as a carbon substrate, Based on the advantages of large specific surface area, good conductivity and biocompatibility of three dimensional nitrogen-doped carbon nanotube nano structure, the composite material can be directly used as an electrode material for high-loading capacity and high activity loading of glucose oxidase, and glucose oxidase electrode with high sensitivity can be constructed.

The invention discloses application of a metal-free hydrogenation catalyst in catalyzing hydrogenation reaction of nitrobenzene and derivatives thereof. The metal-free hydrogenation catalyst is nitrogen-doped carbon nanotubes prepared by an impregnation process by using melamine as a nitrogen source, or nitrogen-doped carbon nanotubes prepared by an in-situ synthesis process by using ammonia gas as a nitrogen source; and the catalyst is applied to hydrogenation reaction of nitrobenzene and derivatives thereof. The nitrogen-doped carbon nanotubes used as the nitrobenzene hydrogenation catalyst do not support any metal active component, and can achieve the goal of hydrogenation catalysis only by using the nitrogen doping modification process. The whole reaction process avoids the use of noble metals, thereby saving the cost and avoiding environment pollution; and meanwhile, the catalyst can be recycled. The catalyst has the advantages of simple preparation method, low production cost, favorable hydrogenation effect, controllable reaction and environment friendliness, can not cause secondary pollution to the environment, and can be widely used in various hydrogenation reactions.

The invention discloses an undone nitrogen doped carbon nanotubes derivative with good electrochemical performance and a preparation method thereof. Undoing bamboo-like nitrogen doped multi-walled carbon nanotubes along the longitudinal direction is conducted through a solution chemical oxidation method, and the nitrogen doped carbon nanotubes derivative is obtained; through controlling the degree of undoing, caterpillar-shaped nitrogen doped graphene / carbon tube composite materials with heterojunction structures are obtained when undoing is conducted half and nitrogen doped graphene nanobelts are obtained when undoing is completed. The undone carbon nano tube is used for modifying a glassy carbon electrode. It is indicated by the test of electrochemical performance that the materials obtained from the undone nitrogen doped carbon nanotubes derivative with good electrochemical performance have the advantages that the specific surface area is high, more reaction active sites are achieved, and the electron transfer rate is higher, so that the wide application prospects in the field of electrochemistry, such as capacitors, lithium batteries, electro-catalysis, and electrochemical sensors are achieved.

The invention relates to a preparation method for a phosphorus-nitrogen doped carbon nanotube. The method comprises the following steps: 1) putting a Fe / Y catalyst and red phosphorus into a ceramic boat, heating a quartz tube type furnace to 900 to 1,100 K, introducing Ar / diethylamine mixed gas, maintaining the constant temperature for 0.5 to 1.51 hours and naturally cooling to obtain a mixture of the black phosphorus-nitrogen doped carbon nanotube and the Fe / Y catalyst, wherein the chemical formula of the phosphorus-nitrogen doped carbon nanotube is CNxPy; x is more than 0.5 and less than 1; and y is more than 0.5 and less than 1; and 2) removing a Fe / NaY molecular sieve from dilute solution of HF to obtain the phosphorus-nitrogen doped carbon nanotube. The phosphorus-nitrogen is doped, so that light transition absorption and heat conductivity coefficient of a single-wall carbon nanotube can be obviously changed. The research on the density functional theory of the phosphorus-nitrogen doped single-wall carbon nanotube shows that the phosphorus is replaced to serve as a scattering center, so that local electronic state electron can be established and the transportation characteristic of the single-wall carbon nanotube is modified. In addition, the phosphorus-nitrogen is doped, so the mechanical strength of the single-wall carbon nanotube is changed, and the breaking elongation is reduced by 50 percent.