CN104226292A - Multi-level structure material adopting graphitized-carbon coated nanometer-sized metal particles and preparation method of multi-level structure material - Google Patents

Abstract

The invention discloses a graphitized carbon-coated nano-metal particle multi-level structure material and a preparation method thereof. The material is composed of carbon fiber and nano-sheets standing cross on its surface. The carbon fiber is a carbide of high polymer with a diameter of 20-1500 nm. The nano-sheet is composed of nano-metal particles coated with graphitized carbon. The sheet height is 70-300 nm. The thickness of the sheet is 20-100nm, and the diameter of the nano-metal particles is 5-30nm; the method is first to electrospin the polymer solution, and then add the spun polymer fiber to the soluble metal salt solution and place it in a closed state, at a temperature of 80 React at ~200°C to obtain an intermediate product—a polymer fiber with nanosheets standing on its surface. After that, the intermediate product is first placed in a polymer mixture solution or a mixture of a polymer and a soluble metal salt. After drying, place it in a reducing atmosphere and react at 600-1300°C to obtain the target product. It has good poisoning resistance and high specific surface area, and can be widely used in fuel cells, lithium-ion batteries and supercapacitors.

Description

Hierarchical structure material and preparation method of graphitized carbon-coated nano-metal particles

technical field

The invention relates to a multi-level structure material and a preparation method thereof, in particular to a multi-level structure material of graphitized carbon-coated nano metal particles and a preparation method thereof.

Background technique

In the fields of fuel cells, lithium-ion batteries and supercapacitors, various efforts have been made to obtain materials with higher catalytic performance, such as a carbon fiber published in Chinese invention patent application CN 103545536 A on January 29, 2014 Supported metal catalyst and its preparation method and application. The catalyst disclosed in this patent application is obtained by mixing carbon fibers, graphitization additives, and metal particles in a mass ratio of 100:0.01:0.01 to 100:50:90, wherein the diameter of the carbon fibers is 50nm to 5μm, and the graphitization additive is graphitization Carbon materials with a high degree of carbon, the diameter of metal particles is 0.1-50nm; the preparation method of the catalyst is to electrospin the mixed solution of polyacrylonitrile and carbon material additives, and then carbonize it at high temperature to obtain carbon materials containing carbon material additives. Nanofibers, after that, first add metal precursors to the dispersion of carbon nanofibers and stir evenly, adjust the pH value to 9-13 with potassium hydroxide aqueous solution, and stir for reduction reaction, then filter and vacuum dry to obtain The product; the product can be applied in hydrogen storage materials of fuel cells, lithium-ion batteries and supercapacitors. However, both the catalyst and its preparation method have shortcomings. First, the product is only carbon nanofibers containing carbon material additives loaded with nano-metal particles, although it effectively improves the corrosion resistance of the catalyst carrier. However, the toxic damage of carbon monoxide cannot be avoided because the loaded nano-metal particles are still exposed; secondly, the specific surface area of the product is still unsatisfactory, especially as a small-volume high-efficiency fuel cell, lithium-ion battery and supercapacitor. At last, the preparation method cannot obtain a product with good resistance to carbon monoxide toxicity and a large specific surface area.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a multi-level structure material of graphitized carbon-coated nano-metal particles with reasonable structure, anti-poisoning and high catalytic efficiency.

Another technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned hierarchical structure material of graphitized carbon-coated nano-metal particles.

In order to solve the technical problem of the present invention, the adopted technical scheme is: the multi-level structure material of graphitized carbon coating nano metal particle comprises carbon fiber, particularly,

The multi-level structure material is composed of carbon fibers and nanosheets standing on their surfaces;

The carbon fiber is a high polymer carbide with a diameter of 20-1500nm;

The nanosheets have a sheet height of 70-300nm and a sheet thickness of 20-100nm, and are composed of nano-metal particles coated with graphitized carbon;

The particle size of the nano metal particles is 5-30nm.

Further improvement of hierarchically structured materials as graphitized carbon-coated nanometal particles:

Preferably, the high polymer is polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polystyrene, cross-linked polyvinyl alcohol, polyvinyl butyral, cellulose acetate, polyterephthalic acid One or more mixtures of ethylene glycol ester, polybutylene terephthalate, polyetherimide (PEI), polylactic acid, polyamide, polylactic-co-glycolic acid (PLGA) ; Not only makes the sources of raw materials more abundant, but also makes the preparation process easier to implement and flexible.

Preferably, the metal is one or a mixture of two or more of nickel, cobalt, copper, and iron; this not only allows greater room for maneuver in the selection of the metal, but also facilitates the preparation of the target product.

In order to solve another technical problem of the present invention, another technical solution adopted is: the preparation method of the multi-level structure material of above-mentioned graphitized carbon coating nano-metal particle comprises electrospinning method, particularly main steps are as follows:

Step 1, first place a high polymer solution with a concentration of 1 to 35 wt% on an electrospinning machine for spinning to obtain high polymer fibers with a diameter of 20 to 1500 nm, and then according to the weight ratio of 0.1 to 20:80 to 99.9 Add the polymer fiber to the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt, and place them together in a closed state at a temperature of 80~ Solid-liquid separation is carried out after reacting at 200°C for at least 1 hour, wherein the solution of one of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt is composed of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt. One of the salts, urea and ethanol are prepared according to the weight ratio of 0.6-0.8:0.1-0.3:40, and the solution of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt is prepared by Two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt, ethanol aqueous solution with a concentration of 40-60 vol%, and hexamethylenetetramine in a molar ratio of 1.4-1.6: 1.0-1.4: 3 to obtain an intermediate product—a polymer fiber with nanosheets cross-standing on its surface;

Step 2, first place the intermediate product in the mixed solution of high polymer or the mixed solution of high polymer and soluble metal salt according to the weight ratio of 0.01-10:90-99.99, soak it, take it out and dry it, wherein, the high polymer is mixed The solution is polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, polymethyl methacrylate N,N-dimethylformamide (DMF) solution, polyethylene terephthalate solution, polyethylene Alcohol aqueous solution, polyamide n-butanol solution and xylene solution, one or more mixed solutions, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer mixed solution and soluble nickel salt, soluble cobalt salt, One or more mixtures of soluble copper salts and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20, and the surface is covered with high polymers or a mixture of high polymers and soluble metal salts. The intermediate product, and the intermediate product whose surface is covered with a high polymer or a mixture of a high polymer and a soluble metal salt is placed in a reducing atmosphere, and heated at 600-1300 ° C for 1-60 minutes to obtain a graphitized carbon-coated nanometer Hierarchical structure materials of metallic particles.

As a further improvement of the preparation method of the hierarchical structure material coated with graphitized carbon nano-metal particles:

Preferably, before the intermediate product is soaked in the mixed solution of high polymer or the mixed solution of high polymer and soluble metal salt, first use deionized water to clean the precipitated powder on the surface of the intermediate product, and then dry; to ensure the quality of the target product .

Preferably, the high polymer used for spinning is polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polystyrene, cross-linked polyvinyl alcohol, polyvinyl butyral, cellulose acetate, One or both of polyethylene terephthalate, polybutylene terephthalate, polyetherimide (PEI), polylactic acid, polyamide, polylactic-co-glycolic acid (PLGA) mixture of the above.

Preferably, the soluble nickel salt is one or a mixture of two or more of nickel sulfate, nickel chloride, nickel bromide, nickel acetate, nickel sulfamate, nickel nitrate, and nickel hypophosphite.

Preferably, the soluble cobalt salt is one or a mixture of two or more of cobalt sulfate, cobalt chloride, cobalt nitrate and cobalt acetate.

Preferably, the soluble copper salt is one or a mixture of two or more of copper sulfate, copper chloride, copper nitrate and copper acetate.

Preferably, the soluble iron salt is one or a mixture of two or more of ferric sulfate, ferric chloride, and ferric nitrate.

The beneficial effects relative to the prior art are:

First, the obtained target product is characterized by scanning electron microscope, transmission electron microscope, laser Raman spectrometer and X-ray diffractometer respectively. From the results, it can be seen that the target product is covered with cross-standing nanometers on the surface of many fibrous objects. Sheet; wherein, the diameter of the fiber is 20-1500nm, the sheet height of the nano-sheet is 70-300nm, and the sheet thickness is 20-100nm, which is composed of uniformly distributed particles coated with a membrane, and the particle size of the particle is 5-30nm. The fibers are carbides of high polymers, the particles are nanometer metal particles, the metal is one or a mixture of two or more of nickel, cobalt, copper, and iron, and the film is graphitized carbon. This three-dimensional structure target product assembled by carbon fiber, nano-metal particles and graphitized carbon not only lays the foundation for the high specific surface area of the target product because the one-dimensional structure carbon fiber is not easy to agglomerate, but also because the surface of the carbon fiber is covered with cross-standing The specific surface area of the target product is greatly improved, and because the standing nanosheets are composed of uniformly distributed nano-metal particles coated with graphitized carbon, it not only prevents the agglomeration of nano-metal particles, but also facilitates The transfer of electrons in the system avoids the exposure of nano-metal particles and eliminates the poisoning of carbon monoxide, so that the overall catalytic performance and anti-poisoning performance of the target product are greatly improved.

Second, the preparation method is simple, scientific, and efficient. Not only has the target product with reasonable structure, anti-poisoning, and high catalytic efficiency - the multi-level structure material of graphitized carbon-coated nano-metal particles; but also because of its unique morphology and structure It not only greatly improves its catalytic efficiency, but also greatly improves its ability to resist carbon monoxide poisoning; it also has the characteristics of simple process, low cost, and easy industrial production; thus it is expected to be widely used in energy storage, catalysis and other fields commercial applications.

Description of drawings

Figure 1 is one of the results of characterizing the target product prepared by the preparation method using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Wherein, Figure 1a is a SEM image of the target product, Figure 1b is a TEM image of a single target product in the target product shown in Figure 1a, and Figure 1c is a high-magnification TEM image of nanosheets in the target product shown in Figure 1b.

Figure 2 is one of the results of characterizing the target product using a laser Raman spectrometer. From the Raman spectrum, it can be known that the membrane-like material covered by the nano-metal particles is graphitized carbon.

Figure 3 is one of the results of characterizing the target product using an X-ray diffraction (XRD) instrument. The XRD spectrum shows that the nano metal particles are nickel, which is the same as the standard XRD spectrum JCPDS210-2279 of metallic nickel.

Detailed ways

The preferred modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

First purchased from the market or prepared by conventional methods:

High polymers such as polymethyl methacrylate, polyacrylonitrile, polystyrene, cross-linked polyvinyl alcohol, polyvinyl butyral, cellulose acetate, polyethylene terephthalate, polyethylene terephthalate Butylene dicarboxylate, polyetherimide, polylactic acid, polyamide and polylactic-co-glycolic acid;

Nickel sulfate, nickel chloride, nickel bromide, nickel acetate, nickel sulfamate, nickel nitrate and nickel hypophosphite as soluble nickel salts;

Cobalt sulfate, cobalt chloride, cobalt nitrate and cobalt acetate as soluble cobalt salts;

Copper sulfate, copper chloride, copper nitrate and copper acetate as soluble copper salts;

Ferric sulfate, ferric chloride and ferric nitrate as soluble iron salts.

then,

Example 1

The concrete steps of preparation are:

Step 1, first place a high polymer solution with a concentration of 1wt% on an electrospinning machine for spinning; wherein, the high polymer solution is polymethyl methacrylate N,N-dimethylformamide solution, and the diameter 20nm high polymer fiber. Then add the high polymer fiber into the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt according to the ratio of 0.1:99.9 by weight, now take soluble nickel salt, A solution of soluble cobalt salts, soluble copper salts, and soluble iron salts, that is, nickel nitrate hexahydrate solution, and put them together in a closed state, react at a temperature of 80 ° C for 2 hours, and then carry out solid-liquid separation; among them, six Hydrated nickel nitrate solution is prepared by nickel nitrate hexahydrate, urea and ethanol according to the ratio of 0.6:0.3:40 by weight (if the mixture of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt The solution consists of two or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts, and a concentration of 40 to 60 vol% ethanol aqueous solution and hexamethylenetetramine according to the molar ratio of 1.4 to 1.6: 1.0-1.4:3 ratio) to obtain an intermediate product—a high polymer fiber with nanosheets cross-standing on its surface.

Step 2, first use deionized water to clean the precipitated powder on the surface of the intermediate product and dry it, then place the intermediate product in a polymer mixed solution (or a mixed solution of a polymer and a soluble metal salt) according to a weight ratio of 0.01:99.99 After soaking in the medium, take it out and dry; Among them, the polymer mixed solution is polymethyl methacrylate N,N-dimethylformamide solution (or polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, poly One or more mixed solutions of ethylene terephthalate solution, polyvinyl alcohol solution, polyamide n-butanol solution and xylene solution, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer The mixed solution and one or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20), and the surface is covered with high Polymer (or polymer and soluble metal salt mixture) intermediate product. Then put the intermediate product whose surface is covered with polymer (or a mixture of polymer and soluble metal salt) in a reducing atmosphere, and heat it at 600°C for 60 minutes to obtain a product similar to that shown in Figure 1, and as shown in Figure 2. and the graphitized carbon-coated nano-metal particle hierarchical structure material shown in the curves in Fig. 3.

Example 2

The concrete steps of preparation are:

Step 1, first place a high polymer solution with a concentration of 9wt% on an electrospinning machine for spinning; wherein, the high polymer solution is polymethyl methacrylate N,N-dimethylformamide solution, and the diameter It is a 370nm polymer fiber. Then add the high polymer fiber into the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt according to the weight ratio of 1:99, now take soluble nickel salt, A solution of soluble cobalt salts, soluble copper salts, and soluble iron salts, that is, nickel nitrate hexahydrate solution, and put them together in a closed state, react at a temperature of 110 ° C for 1.8 hours, and then carry out solid-liquid separation; Among them, Nickel nitrate hexahydrate solution is prepared from nickel nitrate hexahydrate, urea and ethanol in a weight ratio of 0.65:0.25:40 (if two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt are selected The solution consists of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt, ethanol aqueous solution with a concentration of 40 to 60 vol%, and hexamethylenetetramine in a molar ratio of 1.4 to 1.6 : 1.0-1.4:3 ratio preparation), to obtain an intermediate product—a polymer fiber with nanosheets cross-standing on its surface.

Step 2, first use deionized water to clean the precipitated powder on the surface of the intermediate product and dry it, then place the intermediate product in a polymer mixed solution (or a mixed solution of a polymer and a soluble metal salt) according to a weight ratio of 0.05:99.95 After soaking in the medium, take it out and dry; Among them, the polymer mixed solution is polymethyl methacrylate N,N-dimethylformamide solution (or polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, poly One or more mixed solutions of ethylene terephthalate solution, polyvinyl alcohol solution, polyamide n-butanol solution and xylene solution, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer The mixed solution and one or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20), and the surface is covered with high Polymer (or polymer and soluble metal salt mixture) intermediate product. Then put the intermediate product whose surface is covered with polymer (or a mixture of polymer and soluble metal salt) in a reducing atmosphere, and heat it at 775°C for 45 minutes to obtain a product similar to that shown in Figure 1, and as shown in Figure 2. and the graphitized carbon-coated nano-metal particle hierarchical structure material shown in the curves in Fig. 3.

Example 3

The concrete steps of preparation are:

Step 1, first place a high polymer solution with a concentration of 18wt% on an electrospinning machine for spinning; wherein, the high polymer solution is polymethyl methacrylate N,N-dimethylformamide solution, and the diameter 750nm high polymer fiber. Then add the high polymer fiber into the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt according to the weight ratio of 2:98, now take soluble nickel salt, A solution of soluble cobalt salt, soluble copper salt, and soluble iron salt, that is, nickel nitrate hexahydrate solution, and put it together in a closed state, react at a temperature of 140 ° C for 1.5 hours, and then carry out solid-liquid separation; wherein, Nickel nitrate hexahydrate solution is prepared from nickel nitrate hexahydrate, urea and ethanol in a weight ratio of 0.7:0.2:40 (if two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt are selected The solution consists of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt, ethanol aqueous solution with a concentration of 40 to 60 vol%, and hexamethylenetetramine in a molar ratio of 1.4 to 1.6 : 1.0-1.4:3 ratio preparation), to obtain an intermediate product—a polymer fiber with nanosheets cross-standing on its surface.

Step 2, first use deionized water to clean the precipitated powder on the surface of the intermediate product and dry it, then place the intermediate product in a polymer mixed solution (or a mixed solution of a polymer and a soluble metal salt) according to a weight ratio of 0.1:99.9 After soaking in the medium, take it out and dry; Among them, the polymer mixed solution is polymethyl methacrylate N,N-dimethylformamide solution (or polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, poly One or more mixed solutions of ethylene terephthalate solution, polyvinyl alcohol aqueous solution, polyamide n-butanol solution and xylene solution, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer The mixed solution and one or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20), and the surface is covered with high Polymer (or polymer and soluble metal salt mixture) intermediate product. Then put the intermediate product covered with high polymer (or high polymer and soluble metal salt mixture) on its surface in a reducing atmosphere, and heat it at 950°C for 30 minutes to obtain the product as shown in Figure 1, and as shown in Figure 2 and The curves in Fig. 3 show the graphitized carbon-coated nano-metal particle hierarchical structure material.

Example 4

The concrete steps of preparation are:

Step 1, first place the high polymer solution with a concentration of 27wt% on the electrospinning machine for spinning; wherein, the high polymer solution is polymethyl methacrylate N,N-dimethylformamide solution, and the diameter It is a polymer fiber of 1100nm. Then add the high polymer fiber into the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt according to the weight ratio of 10:90, now take soluble nickel salt, A solution of soluble cobalt salt, soluble copper salt, and soluble iron salt, that is, nickel nitrate hexahydrate solution, and put it together in a closed state, react at a temperature of 170 ° C for 1.3 hours, and then carry out solid-liquid separation; Among them, Nickel nitrate hexahydrate solution is prepared from nickel nitrate hexahydrate, urea and ethanol according to the weight ratio of 0.75:0.15:40 (if two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt are selected The solution consists of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt, ethanol aqueous solution with a concentration of 40 to 60 vol%, and hexamethylenetetramine in a molar ratio of 1.4 to 1.6 : 1.0-1.4:3 ratio preparation), to obtain an intermediate product—a polymer fiber with nanosheets cross-standing on its surface.

Step 2, first use deionized water to clean the precipitated powder on the surface of the intermediate product and dry it, then place the intermediate product in a high polymer mixed solution (or a mixed solution of a high polymer and a soluble metal salt) according to a weight ratio of 1:99 After soaking in the medium, take it out and dry; Among them, the polymer mixed solution is polymethyl methacrylate N,N-dimethylformamide solution (or polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, poly One or more mixed solutions of ethylene terephthalate solution, polyvinyl alcohol solution, polyamide n-butanol solution and xylene solution, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer The mixed solution and one or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20), and the surface is covered with high Polymer (or polymer and soluble metal salt mixture) intermediate product. Then put the intermediate product whose surface is covered with polymer (or a mixture of polymer and soluble metal salt) in a reducing atmosphere, and heat it at 1125°C for 15 minutes to obtain a product similar to that shown in Figure 1, and as shown in Figure 2. and the graphitized carbon-coated nano-metal particle hierarchical structure material shown in the curves in Fig. 3.

Example 5

The concrete steps of preparation are:

Step 1, first place a high polymer solution with a concentration of 35wt% on an electrospinning machine for spinning; wherein, the high polymer solution is polymethyl methacrylate N,N-dimethylformamide solution, and the diameter It is a polymer fiber of 1500nm. Then add the high polymer fiber into the solution of one or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt and soluble iron salt according to the ratio of 20:80 by weight, now take soluble nickel salt, A solution of soluble cobalt salts, soluble copper salts, and soluble iron salts, that is, nickel nitrate hexahydrate solution, and put them together in a closed state, react at a temperature of 200 ° C for 1 hour, and then carry out solid-liquid separation; among them, six Hydrated nickel nitrate solution is prepared by nickel nitrate hexahydrate, urea and ethanol according to the ratio of 0.8:0.1:40 by weight (if the mixture of two or more mixtures of soluble nickel salt, soluble cobalt salt, soluble copper salt, and soluble iron salt The solution consists of two or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts, and a concentration of 40 to 60 vol% ethanol aqueous solution and hexamethylenetetramine according to the molar ratio of 1.4 to 1.6: 1.0-1.4:3 ratio) to obtain an intermediate product—a high polymer fiber with nanosheets cross-standing on its surface.

Step 2, first use deionized water to clean the precipitated powder on the surface of the intermediate product and dry it, then place the intermediate product in a polymer mixed solution (or a mixed solution of a polymer and a soluble metal salt) in a weight ratio of 10:90 After soaking in the medium, take it out and dry; Among them, the polymer mixed solution is polymethyl methacrylate N,N-dimethylformamide solution (or polyvinyl butyral ethanol solution, polylactic acid dichloromethane solution, poly One or more mixed solutions of ethylene terephthalate solution, polyvinyl alcohol solution, polyamide n-butanol solution and xylene solution, the mixed solution of high polymer and soluble metal salt is composed of the aforementioned high polymer The mixed solution and one or more mixtures of soluble nickel salts, soluble cobalt salts, soluble copper salts, and soluble iron salts are prepared according to the weight ratio of 80-99.9:0.1-20), and the surface is covered with high Polymer (or polymer and soluble metal salt mixture) intermediate product. Then put the intermediate product whose surface is covered with polymer (or a mixture of polymer and soluble metal salt) in a reducing atmosphere, and heat it at 1300 ° C for 1 min to obtain a product similar to that shown in Figure 1, and as shown in Figure 2 and the graphitized carbon-coated nano-metal particle hierarchical structure material shown in the curves in Fig. 3.

Then select polymethyl methacrylate, polyacrylonitrile, polystyrene, cross-linked polyvinyl alcohol, polyvinyl butyral, cellulose acetate, polyethylene terephthalate, Polybutylene terephthalate, polyetherimide, polylactic acid, polyamide, polylactic acid-glycolic acid copolymer, or a mixture of two or more, nickel sulfate as a soluble nickel salt, chloride Nickel, nickel bromide, nickel acetate, nickel sulfamate, nickel nitrate, nickel hypophosphite, or a mixture of two or more of them, cobalt sulfate, cobalt chloride, cobalt nitrate, and cobalt acetate as soluble cobalt salts One or more mixtures, one or more mixtures of copper sulfate, copper chloride, copper nitrate, and copper acetate as soluble copper salts, iron sulfate, iron chloride, and nitric acid as soluble iron salts One or two or more mixtures of iron, repeating the above-mentioned embodiments 1 to 5, also produced graphite as shown in or similar to Figure 1, and as shown in Figure 2 and as or similar to the curve shown in Figure 3 A multi-level structure material of carbonized carbon-coated nano-metal particles.

Apparently, those skilled in the art can make various changes and modifications to the graphitized carbon-coated nano-metal particle hierarchical structure material and its preparation method of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. a multilevel structure material for graphitization Carbon-encapsulated Metal Nanoparticles, comprises carbon fiber, it is characterized in that:

The nanometer sheet that described multilevel structure material is stood by carbon fiber and surface crosswise thereof forms;

Described carbon fiber is the carbide of high polymer, and its diameter is 20 ~ 1500nm;

High 70 ~ the 300nm of being of sheet of described nanometer sheet, sheet are thick is 20 ~ 100nm, and it is made up of nano-metal particle outer cladding graphitized carbon;

The particle diameter of described nano-metal particle is 5 ~ 30nm.

2. the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 1, is characterized in that high polymer is one or more the mixture in polymethyl methacrylate, polyacrylonitrile, polystyrene, the polyvinyl alcohol of Cross-linked, polyvinyl butyral, cellulose acetate, poly-para Toluic Acid's glycol ester, polybutylene terephthalate (PBT), PEI, PLA, polyamide, Poly(D,L-lactide-co-glycolide.

3. the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 1, is characterized in that metal is one or more the mixture in nickel, cobalt, copper, iron.

4. a preparation method for the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles described in claim 1, comprises method of electrostatic spinning, it is characterized in that key step is as follows:

Step 1, is first that the high polymeric solution of 1 ~ 35wt% is placed on electrostatic spinning machine and carries out spinning by concentration, obtains the high polymer fibre that diameter is 20 ~ 1500nm, then according to the ratio that weight ratio is 0.1 ~ 20:80 ~ 99.9, high polymer fibre is added soluble nickel salt, soluble cobalt, soluble copper salt, in the solution of one or more mixtures in soluble ferric iron salt, and it is placed in air-tight state together, reacts at temperature is 80 ~ 200 DEG C and at least carry out Separation of Solid and Liquid after 1h, wherein, soluble nickel salt, soluble cobalt, soluble copper salt, a kind of solution in soluble ferric iron salt is by soluble nickel salt, soluble cobalt, soluble copper salt, one in soluble ferric iron salt, urea and ethanol are the proportions of 0.6 ~ 0.8:0.1 ~ 0.3:40 according to weight ratio, soluble nickel salt, soluble cobalt, soluble copper salt, the solution of the two or more mixtures in soluble ferric iron salt is by soluble nickel salt, soluble cobalt, soluble copper salt, two or more mixtures in soluble ferric iron salt, concentration is the ethanol water of 40 ~ 60vol% and hexa is the proportions of 1.4 ~ 1.6:1.0 ~ 1.4:3 according to mol ratio, obtains intermediate product---its surface crosswise is stood the high polymer fibre of nanometer sheet,

Step 2, be first after mixed liquid that intermediate product to be placed in high polymer mixed solution or high polymer and soluble metallic salt by the ratio of 0.01 ~ 10:90 ~ 99.99 infiltrates according to weight ratio, take out dry, wherein, high polymer mixed solution is polyvinyl butyral resin ethanolic solution, PLA dichloromethane solution, polymethyl methacrylate N, N-dimethyl formamide solution, poly-para Toluic Acid's glycol ester solution, polyvinyl alcohol water solution, one or more mixed solution in polyamide butanol solution and xylene solution, the mixed liquid of high polymer and soluble metallic salt is by aforementioned high polymer mixed solution and soluble nickel salt, soluble cobalt, soluble copper salt, one or more mixture in soluble ferric iron salt is the proportions of 80 ~ 99.9:0.1 ~ 20 according to weight ratio, obtain the intermediate product that its surface is covered with high polymer or high polymer and soluble metal salt mixture, the intermediate product again its surface being covered with high polymer or high polymer and soluble metal salt mixture is placed in reducing atmosphere, 1 ~ 60min is heated at 600 ~ 1300 DEG C, the multilevel structure material of obtained graphitization Carbon-encapsulated Metal Nanoparticles.

5. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, it is characterized in that before mixed liquid intermediate product being placed in high polymer mixed solution or high polymer and soluble metallic salt infiltrates, after first using the powder of washed with de-ionized water intermediate product surface precipitation, dry.

6. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, is characterized in that the high polymer of spinning is one or more the mixture in polymethyl methacrylate, polyacrylonitrile, polystyrene, the polyvinyl alcohol of Cross-linked, polyvinyl butyral, cellulose acetate, poly-para Toluic Acid's glycol ester, polybutylene terephthalate (PBT), PEI, PLA, polyamide, Poly(D,L-lactide-co-glycolide.

7. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, it is characterized in that soluble nickel salt is nickelous sulfate, nickel chloride, nickelous bromide, nickel acetate, one or more the mixture in nickel sulfamic acid, nickel nitrate, nickelous hypophosphite.

8. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, is characterized in that soluble cobalt is one or more the mixture in cobaltous sulfate, cobalt chloride, cobalt nitrate, cobalt acetate.

9. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, is characterized in that soluble copper salt is one or more the mixture in copper sulphate, copper chloride, copper nitrate, copper acetate.

10. the preparation method of the multilevel structure material of graphitization Carbon-encapsulated Metal Nanoparticles according to claim 4, is characterized in that soluble ferric iron salt is one or more the mixture in ferric sulfate, iron chloride, ferric nitrate.