23 results about "Catalytic growth" patented technology

Methods for catalytically growing carbon nanotubes on carbonaceous substrates and hybrid materials prepared by the methods.

A method for catalytically growing carbon nanotubes on a carbonaceous substrate, and hybrid materials prepared by the method.

The invention provides a method for preparing a silicon-carbon negative electrode material by using a waste photovoltaic module, which comprises the following steps of: (1) disassembling and crushing to obtain silicon / silver / aluminum / EVA (Ethylene Vinyl Acetate) mixed powder; (2) carrying out alkali etching to obtain etched silicon / silver / EVA (Ethylene Vinyl Acetate) powder; (3) synergistic carbonization coating: constructing a double-layer carbon coating structure of'inner layer hard carbon-outer layer soft carbon 'on the surface of the silicon particles in situ to obtain a silicon-carbon composite material; (4) carrying out heat-moisture treatment, so that the catalytic active component is stably anchored on the surface of the material, and the transition metal salt is decomposed into metal oxide to obtain a graphite / silicon carbon material; and (5) performing in-situ catalytic growth of a carbon nanotube on the graphite / silicon carbon material to obtain the silicon carbon negative electrode material with a porous silicon-carbon tube-double carbon layer three-dimensional conductive network structure. The silicon-carbon negative electrode material obtained by the invention has high specific capacity, excellent cycle stability and rate capability.

Provided are a preparation method and continuous production system for single-walled carbon nanotubes. The preparation method for single-walled carbon nanotubes comprises the following steps: catalyst pretreatment: using a microwave plasma generator (4) to excite a catalyst to form nanoscale particles, then sequentially using gases having decreasing densities to perform gradient screening on the nanoscale catalyst particles, and forming a catalyst dispersion from the screened nanoscale catalyst particles together with a liquid carbon source and a promoter; and catalytic growth: atomizing the catalyst dispersion by means of an atomizer (5), then bringing the atomized catalyst dispersion into a reactor (6) by means of a carrier gas, and heating the reactor (6) to 1000-1500°C to grow single-walled carbon nanotubes. In the provided preparation method for single-walled carbon nanotubes, the microwave plasma generator (4) is used to excite the catalyst, so that the catalyst forms nanoscale particles, and gas screening is then performed on the nanoscale particles to obtain a catalyst having a smaller size and a narrower particle size, so that the purity of the finally obtained single-walled carbon nanotubes is high.

The invention relates to the technical field of neuroscience detection, in particular to a preparation method of an implantable multi-channel flexible linear neural microelectrode for long-term monitoring of deep brain function, comprising the following steps: S1, catalytically growing carbon nanotube fibers at high temperature by chemical vapor deposition; s2, polyimide and other insulating materials are dissolved and uniformly prepared into a film, the uniform film is formed through spin coating, coating or dipping and other methods, and the film is crosslinked and stabilized through heat treatment or thermocuring; and S3, cutting the insulating film into a proper size, flatly placing the CNT fiber on the film, and leading out an exposed CNT flexible electrode port from the edge of the film as an electric signal interface. According to the invention, the neural electrode which can be implanted into brain tissue for a long time is successfully constructed by preparing the flexible carbon-based fiber, the multi-layer insulating film and a double-direction multi-channel structure. The electrode can collect neural signals of multiple channels from two directions at the same time, and the spatial resolution and the coverage range of the signals are remarkably improved.

This invention belongs to the field of flexible strain sensor technology, and particularly relates to the preparation of a carbon nanotube coil flexible strain sensor based on the evaporation-induced phase separation method guided by Hansen's solubility parameter theory. The method involves screening the solvent-solute system based on Hansen's solubility parameter theory, first modifying the carbon nanotube coil with Fe-Sn bimetallic catalytic growth and acidification functionalization, then preparing a carbon nanotube coil / thermoplastic polyurethane composite porous membrane via a one-step evaporation-induced phase separation method, and finally encapsulating the membrane with electrodes to obtain the finished flexible strain sensor. The method includes three steps: formulation screening based on HSP theory, growth and functionalization modification of CNCs, and one-step sensor preparation. By controlling the precipitation behavior of the polymer phase and conductive filler phase during the evaporation-induced phase separation process, thermoplastic polyurethane is first precipitated to form a porous framework, and then CNCs are directionally enriched and deposited on the pore wall surface, thereby constructing a highly exposed three-dimensional conductive network and obtaining a monolithic integrated flexible strain sensor.

The invention relates to the technical field of nano material preparation, in particular to a method for preparing a fullerene tube through catalytic chemical vapor deposition. A catalytic chemical vapor deposition method is utilized, carbon is orderly assembled at a certain temperature by means of a catalyst, reaction conditions influencing catalyst-carbon interface bonding are further controlled, and direct preparation of the fullerene tube from bottom to top is achieved. The fullerene tube is in a molecular form and is composed of hemispherical fullerene cap ends at the two ends and a carbon nano tube tubular structure in the middle section, the length-diameter ratio is larger than 1, the length is within or below the range of short carbon nano tubes, and the diameter is 0.4-3 nm. According to the method, the design of the catalyst and the control of the dynamic process of catalytic growth of the nano carbon material are taken as the core, the direct preparation of the quasi-one-dimensional fullerene tube is finally realized, the bottleneck that the controllable preparation method of the fullerene tube at the present stage is few and the existing method has more byproducts is broken through, and the method has the characteristics of good controllability, simple process, low cost, suitability for large-scale preparation and the like; and a new way is provided for realizing efficient and controllable preparation of the fullerene tube.

The application discloses a process method for directly growing patterned graphene on an integrated circuit chip, and comprises the following steps: attaching an ultrathin single-crystal copper foil to the integrated circuit chip by compression as a base material for catalytically growing graphene; performing patterned treatment on the copper foil through a photoetching and etching process; and placing the chip in a three-temperature-zone thermal CVD system to grow graphene, so that the graphene is only grown in the area covered by the copper foil, thereby achieving the purpose of directly growing patterned graphene on the integrated circuit chip. The method provides a new idea for the development of graphene-based integrated circuits, and is beneficial to accelerating the commercialization application process of graphene.

This invention discloses a method for preparing LDH-induced M@N-CNT bifunctional electrocatalysts. Two-dimensional ultrathin LDH nanosheets are prepared using a co-precipitation method and a liquid-phase exfoliation method. By changing the types and ratios of metal ions, the types of metal ions and the structure of the layers are adjusted. An LDH-ZIF-8 composite material is synthesized via in-situ growth and further subjected to high-temperature pyrolysis. LDH is used as a sacrificial template to catalyze the growth of the M@N-CNT bifunctional catalyst. By optimizing the synthesis conditions, the obtained M@N-CNT bifunctional electrocatalyst is rich in high-density ORR / OER bifunctional catalytic active sites. This catalyst exhibits a hierarchical porous structure with a high specific surface area, achieving ORR / OER catalytic activity comparable to commercial noble metal catalysts Pt / C and IrO2, and possesses good cycle stability, resulting in higher power density and cycle life for zinc-air batteries.

This invention provides a method for preparing axially periodic core-shell heterojunction nanostructures. First, Al-M nanowires with endpoints are obtained using a catalytic growth method. Then, the endpoints A1 of the Al-M nanowires are removed using alkylphosphine to obtain pure colloidal M nanowires. Next, a silver source solution is mixed with a dispersion of the pure colloidal M nanowires for an ion exchange reaction to obtain M@A2 uniform core-shell heterojunction nanowires. Finally, the M@A2 core-shell nanowires are dispersed in a solvent and subjected to heat treatment. The Rayleigh fluid instability in inorganic solids causes deformation, leading to structural evolution of the uniform core-shell heterojunction nanowires and the formation of axially periodic core-shell heterojunctions. Compared with existing technologies, this invention is the first to utilize the principle of Rayleigh fluid instability in inorganic solids to precisely synthesize axially periodic nanostructures with adjustable size and periodicity, opening a new avenue for the design and synthesis of axially periodic nanostructures.

The present application relates to a new material and its application field, and in particular to a preparation method of a large-size high-quality three-dimensional hexagonal boron nitride (h-BN) network. A porous metal is used as a template, a boron source is uniformly fixed on the surface of the template hole wall through pretreatment, then a chemical vapor deposition (CVD) process is used, a nitrogen-containing gas is used as a nitrogen source, the h-BN is catalytically grown on the surface of the porous metal skeleton under suitable temperature and atmosphere conditions, and after the metal substrate is removed, a high-quality three-dimensional h-BN network is obtained. By adjusting the substrate template and other reaction parameters, the pore size, morphology, layer number and other parameters of the three-dimensional h-BN network can be precisely controlled. Compared with the existing preparation process of the three-dimensional h-BN network, the present application can avoid the uneven growth of the h-BN network caused by the difficulty of the boron source to diffuse in the bulk phase during the CVD process, and the layer number, network morphology and porosity of the h-BN are adjustable, the process is simple, the production cost is low, and the production is easy to scale up. The prepared h-BN has a high crystalline quality and can be applied in many fields.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a silicon-based negative electrode material with a three-dimensional conductive network and a preparation method and application of the silicon-based negative electrode material. The preparation method comprises the following steps: firstly, forming an ultrathin metal catalyst layer on the surface of a silicon-based particle through physical vapor deposition, and then in-situ growing a carbon nanotube on the metal layer through a chemical vapor deposition method in a hydrogen-containing atmosphere. The carbon nanotubes on the outermost layer are mutually connected to form a three-dimensional conductive network penetrating through the whole material, and the metal layer in the middle has the functions of catalytic growth and buffer support. According to the method, a stable multi-stage structure of a silicon core-metal layer-carbon nanotube network is innovatively constructed on the surfaces of the nano silicon particles, and the problems that a silicon-based material is poor in conductivity and large in volume expansion are effectively solved. The prepared negative electrode material shows high specific capacity, excellent first coulombic efficiency and stable long cycle life, and is suitable for high-energy-density lithium ion batteries.

The application provides a kind of biomass carbon load silicon nanowire composite material and its preparation method and purposes, the preparation method is by chemical activation method and physical activation method is combined, on the surface and inside of biomass material layer by layer etching, form multilayer biomass porous carbon material of different pore size, effectively improve the problem of incomplete etching or excessive etching of biomass porous carbon prepared by using single activator;The specific surface area of the prepared multilayer porous carbon is large, the void fraction is high, and the metal catalyst particles of different scales can be planted in the interior to play a grading role for large particle catalyst;Silicon nanowires are directionally grown in the carrier by catalytic growth, and the space network structure of this multilayer porous carbon can effectively withstand the volume expansion of silicon nanowires and inhibit the repeated growth of SEI film.

The invention relates to the technical field of preparation of carbon nano tube catalyst materials, in particular to a low-temperature carbon nano tube catalyst, a preparation method of the low-temperature carbon nano tube catalyst and a preparation method of a carbon nano tube. The carbon nanotube can be efficiently catalyzed and grown in a low temperature range of 300-600 DEG C, the preparation process is simple, the cost is low, and the method is suitable for large-scale production; meanwhile, the composition and the structure of the catalyst are optimized, and the growth efficiency, the structural uniformity and the conductivity of the carbon nanotubes are remarkably improved.

The invention relates to a porous ceramic / carbon nanotube photo-thermal material and a preparation method and application thereof. The porous ceramic / carbon nanotube photo-thermal material takes silicate as a substrate, and porous ceramic of carbon nanotubes grows under the catalysis of iron. The preparation method comprises the following steps: dissolving kaolin, a catalyst, silicate and polyethylene glycol according to a certain ratio, fully stirring, air-drying, taking out, drying in a muffle furnace, firing to obtain a primary blank, placing melamine as a carbon source in a tubular furnace, growing carbon nanotubes in an argon atmosphere through a chemical vapor deposition method, and sintering to obtain the carbon nanotube / kaolin composite material. The thickness of the carbon nanotubes in silicate can be regulated and controlled by regulating and controlling the particle size, proportion and temperature of the catalyst, and high-density carbon tube growth is constructed. The photo-thermal material has full-spectrum light absorption, the photo-thermal conversion capacity of silicate is greatly improved, the temperature of the surface of the photo-thermal material can be increased to about 55 DEG C under one sun, and the evaporation rate of 2.5 kg.m <-2 >. H <-1 > or above is achieved. The device is suitable for the fields of solar photo-thermal conversion, sewage treatment, interface evaporation and the like.

The application belongs to the technical field of lithium ion batteries, and particularly relates to a silicon-based negative electrode material with a three-dimensional conductive network and a preparation method and application thereof. Firstly, a physical vapor deposition is used to form an ultrathin metal catalytic layer on the surface of silicon-based particles, and then carbon nanotubes are in-situ grown on the metal layer by a chemical vapor deposition method in an atmosphere containing hydrogen. The outermost carbon nanotubes are connected to each other to form a three-dimensional conductive network penetrating through the whole material, and the intermediate metal layer has the functions of catalytic growth and buffer support. The method innovatively realizes the construction of a stable multi-level structure of "silicon core-metal layer-carbon nanotube network" on the surface of nanosilicon particles, and effectively solves the problems of poor conductivity and large volume expansion of silicon-based materials. The prepared negative electrode material has high specific capacity, excellent initial coulomb efficiency and stable long cycle life, and is suitable for high-energy-density lithium ion batteries.

The invention relates to the technical field of fiber reinforcement, in particular to a method for improving the braid ability of carbon nanotube fibers through continuous surface modification, which comprises the following steps: S1, preparing carbon nanotube fibers, and carrying out catalytic growth on a reaction liquid containing a carbon source, an additive and a catalyst under a chemical vapor deposition condition to obtain carbon nanotube fiber monofilaments; s2, carrying out continuous surface modification sizing treatment on the carbon nanotube fiber monofilaments, and sequentially drafting and introducing the carbon nanotube fibers into a slurry tank containing chlorosulfonic acid and ethylene glycol for infiltration and densification treatment; s3, twisting and bundling the carbon nano tube fibers subjected to surface modification treatment, and twisting and drafting the carbon nano tube fibers through a twisting device, so that a plurality of carbon nano tube fibers form a bundled fiber bundle; through a continuous surface modification process, the original properties such as the force, the electrical property and the wear resistance of the carbon nanotube fiber are changed, so that the weaving property of the carbon nanotube fiber is improved.

The invention discloses a preparation method and application of a carbon nanotube-carbon black hybrid structure. The preparation method of the carbon nanotube-carbon black hybrid structure comprises the following steps: (1) carbon black pretreatment: pretreating conductive carbon black by adopting an acid solution; (2) catalyst loading: adding a metal catalyst precursor, so that metal ions of the catalyst are uniformly adsorbed and deposited on the surface of the carbon black; and (3) in-situ chemical vapor deposition growth: putting the carbon black powder loaded with the catalyst into a CVD reaction furnace, heating under a protective atmosphere, and introducing a mixed gas of a carbon source gas and a diluent gas for reaction to obtain a carbon nanotube-carbon black hybrid structure. The preparation method takes low-cost carbon black as a raw material, prepares the carbon nanotubes on the surface of the carbon black through in-situ catalytic growth of the carbon nanotubes, and combines the advantages of the carbon black and the carbon nanotubes: carbon black particles are used as an isolation support to prevent excessive winding of the CNTs, so that the viscosity of final slurry is remarkably reduced; and a high-conductivity network of the CNT is utilized, and meanwhile, the advantage of low cost of the carbon black is inherited.

This invention belongs to the field of new materials technology, and specifically relates to a high-purity single-walled carbon nanotube, its preparation method, and system. The method utilizes the high-temperature conditions of a plasma arc to evaporate catalyst material floating on the surface of a liquid anode, forming fine catalyst particles. These particles combine with simultaneously decomposed organic carbon sources, catalytically growing into single-walled carbon nanotubes. The particles are then discharged from the reactor with the exhaust gas, yielding the final product. This method effectively avoids the shortcomings of insufficient graphite crucible lifespan, catalyst metal contamination, and uncontrollable catalyst concentration during the reaction, significantly improving product purity and preparation efficiency. It is an effective means for the large-scale preparation of high-quality single-walled carbon nanotubes and has significant economic value.

The invention discloses a method and a device for preparing a single-walled carbon nanotube, and belongs to the technical field of semiconductor materials. The method comprises: providing an anode comprising a carbon source, a first metal element, and a second metal element; applying arc discharge to form core-shell structure catalyst nanoparticles having a core rich in a second metal element and a first metal carbide shell layer in situ, and catalytically growing single-walled carbon nanotubes; and at the same time of stopping the arc discharge or within an extremely short time after the arc discharge, performing a quenching step on the reaction region at an ultrahigh cooling rate of more than or equal to 105K / s, and suddenly reducing the temperature of the reaction region from no less than 1000 DEG C to no more than 400 DEG C. According to the method disclosed by the invention, the problems of overlarge pipe diameter and wide distribution caused by high-temperature agglomeration of the catalyst and uncontrollable growth process in the prior art are solved through cooperative regulation and control of catalyst source size clamping and dynamic freezing in the growth process, and controllable preparation of the high-quality single-walled carbon nanotube with the average pipe diameter smaller than 1.2 nm and extremely narrow distribution is realized.

The invention discloses a three-dimensional graphene-based wave-absorbing material with an egg yolk shell structure and a preparation method of the three-dimensional graphene-based wave-absorbing material. The method comprises the following steps: 1, preparing polyvinylpyrrolidone, soluble transition metal salt and urea into a mixed solution; 2, drying and grinding to obtain a powder precursor; 3, carrying out heat treatment to obtain the wave-absorbing material; the interiors of powdery monomer particles of the wave-absorbing material are of three-dimensional porous structures, magnetic metal nanoparticles are used as yolk structures, and three-dimensional porous graphene is used as an eggshell structure. According to the preparation method, polyvinylpyrrolidone is taken as a carbon source, soluble transition metal salt and urea are taken as a foaming agent and a catalyst, in-situ catalytic growth and three-dimensional porous assembly of graphene as well as in-situ growth of magnetic metal nanoparticles on graphene are simultaneously realized through one-step heat treatment, and the three-dimensional graphene-based wave-absorbing material with an egg yolk shell structure is obtained. And by utilizing the synergistic effect of the magnetic metal nanoparticles and the three-dimensional porous graphene, a wide wave-absorbing frequency band and high wave-absorbing strength are realized, and the material is suitable for the field of aviation weaponry.

The present application relates to the technical field of new materials and its application, and in particular to a preparation method of a graphene-based heat-conducting / conducting composite material. Open-cell foam metal with a three-dimensionally connected structure is laminated and pressed, and the pressed foam metal is annealed under suitable temperature and atmosphere conditions. A graphene layer is catalytically grown on the surface of the foam metal template by using a chemical vapor deposition process. After the metal substrate is removed, a foam graphene network skeleton with an open-cell close-packed structure is obtained. A polymer matrix is filled into the pores of the foam graphene network skeleton with the close-packed three-dimensionally connected structure by using a vacuum impregnation process, and solidification is completed by selecting a suitable process. The present application has a simple process and low production cost. The graphene-based composite material prepared has excellent heat-conducting and conducting properties, and has great application potential in the fields of heat conduction, electricity conduction, electromagnetic shielding, etc.