CN112077329B - Preparation method of carbon-based-metal composite material - Google Patents

Abstract

The invention discloses a method for preparing a carbon-based-metal composite material, which comprises the following steps: (1) Mixing carbon-based fluoride and halide metal salt, heating and washing the mixture in vacuum or protective atmosphere, and drying the mixture in vacuum or protective atmosphere to obtain carbon-based-metal fluoride; (2) Mixing the carbon-based-metal fluoride with a reducing agent, wherein the reducing agent is potassium, magnesium, lithium naphthalene-tetrahydrofuran or sodium naphthalene-tetrahydrofuran. When the reducing agent is potassium or magnesium, heating and cooling the reducing agent under a vacuum condition or a protective atmosphere, dropwise adding methanol into the reduction product until no bubbles emerge, and then filtering, washing and vacuum drying the product to obtain the carbon-based-metal composite material; when the reducing agent is naphthalene lithium-tetrahydrofuran or naphthalene sodium-tetrahydrofuran, stirring at room temperature under the protection of argon atmosphere, dropwise adding methanol into the reaction liquid until no bubbles emerge, and then filtering, washing and vacuum drying to obtain the carbon-based-metal composite material; the method can realize uniform compounding of carbon and metal.

Description

A kind of carbon-based-metal composite material preparation method

technical field

The invention belongs to the technical field of material preparation, in particular to a method for preparing a carbon-based-metal composite material.

Background technique

Carbon materials have excellent mechanical properties, electrical properties and good chemical stability, and have a wide range of applications in energy storage, catalysis, and electromagnetic shielding. In order to further enrich and improve the properties of carbon materials, doping and compounding with carbon materials as basic materials has become a hot spot of current application research. Among them, the use of carbon materials as a carrier to support metal materials is an important application aspect.

At present, the composite processes of carbon materials and metal materials mainly include electroplating, electroless plating and co-precipitation. In these processes, due to the high chemical inertness of carbon materials, they often need to be pretreated to modify their surfaces to improve the wettability of metals on their surfaces. Conventional technical processes include strong oxidation treatment of carbon materials. Improve the hydrophilicity, and then perform further sensitization and activation according to the experimental requirements to improve the adhesion of metals to carbon materials and the uniformity of adhesion, but the above process is difficult to obtain uniform carbon/metal material composites. Moreover, due to the poor wettability of metals and carbon materials, the formation process of metals on the surface of carbon materials is often to form metal nuclei or islands on the surface of carbon materials, and then use this as the nucleation point to control the reaction time and the amount of reacted metals, so as to realize the metal in the carbon material. Surface coverage, and to achieve complete metal coverage of carbon materials, the surface metal composite layer is often thicker.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a carbon-based metal composite material. The present invention not only overcomes the problem of non-wetting of metal and carbon, but also achieves uniform composite of carbon and metal.

The present invention is achieved through the following technical solutions:

A method for preparing a carbon-based-metal composite material, comprising the following steps:

(1) Mixing carbon-based fluoride and halide metal salt, in parts by weight, the carbon-based fluoride is 1-1.5 parts, and the halide metal salt is 2-6 parts, under vacuum or protective atmosphere , heated to 280-500 °C, kept for 6-120 h, naturally cooled to 20-25 °C, the obtained reactant was washed with a cleaning agent, and dried at 60-100 °C for 12-48 h under vacuum or protective atmosphere to obtain carbonyl - metal fluoride; the halide metal salt is chloride metal salt, bromide metal salt or iodide metal salt, and the cleaning agent is ethanol or tetrahydrofuran;

(2) mixing the carbon-based-metal fluoride with a reducing agent, the reducing agent is at least one of potassium, magnesium, lithium naphthalene-tetrahydrofuran or sodium naphthalene-tetrahydrofuran: when the reducing agent is potassium or magnesium , in parts by weight, the carbon-based-metal fluoride is 1-1.5 parts, the metal element reducing agent is 3-6 parts, under vacuum conditions or protective atmosphere, heated to 300-600 ° C, keep 12 ~120h, naturally cooled to 20 ~ 25 ℃, methanol was added dropwise to the obtained reduction product until no bubbles emerged, and then filtered, washed with water, and vacuum-dried at 60 ~ 100 ℃ for 12 ~ 48h to obtain a carbon-based metal composite material; When the reducing agent is lithium naphthalene-tetrahydrofuran or sodium naphthalene-tetrahydrofuran, in terms of weight fraction, the carbon-based metal fluoride is 1 part, and the metal element reducing agent in the lithium naphthalene-tetrahydrofuran and sodium naphthalene-tetrahydrofuran is 5～ 7 parts, under the protection of argon atmosphere, stir at room temperature for 48-168 hours, add methanol dropwise to the reaction solution until no bubbles emerge, then filter, wash with water, and vacuum dry at 60-100 ℃ for 12-48 hours to obtain the carbon-based metal composite material;

In the above technical solution, the carbon-based fluoride is at least one of fluorinated graphite, fluorinated graphite microplatelets, fluorinated carbon black, fluorinated carbon nanotubes, and fluorinated graphene.

In the above technical solution, the heating process is all carried out in a reaction kettle, and the material of the reaction kettle is stainless steel or quartz.

In the above technical scheme, the halide metal salt is ferric chloride, cobalt chloride, nickel chloride, bismuth chloride, platinum chloride, tantalum chloride, ruthenium chloride, cupric chloride, cupric bromide, At least one of copper iodide.

In the above technical solution, the protective atmosphere is argon gas, and the absolute vacuum degree of the vacuum condition is 10 ^-5 Pa to 10 ⁴ Pa.

In the above technical scheme, the preparation method of the lithium naphthalene-tetrahydrofuran is as follows: under an argon atmosphere, lithium is added to the anhydrous tetrahydrofuran in which naphthalene is dissolved, and the molar mass ratio of the lithium to the naphthalene is 3:1, Stir for 4-24 h to obtain the lithium naphthalene-tetrahydrofuran.

In the above technical scheme, the preparation method of the sodium naphthalene-tetrahydrofuran is as follows: under an argon atmosphere, sodium is added to the anhydrous tetrahydrofuran in which naphthalene is dissolved, and the molar mass ratio of the sodium and naphthalene is 3:1, Stir for 4-24 h to obtain the sodium naphthalene-tetrahydrofuran.

In the above technical solution, in the heating process of the step (1), the heating rate is 1～5°C/min;

In the above technical solution, during the heating process of the step (2), the heating rate is 1-3°C/min.

In the above technical solution, in the step (1), the mass ratio of the carbon-based fluoride to the halide metal salt is 1:3, and in the step (2), the carbon-based-metal fluoride and The mass ratio of reducing agent is 1:3.

The beneficial effects of the present invention are:

At present, the preparation process of metal-carbon-based composite materials is mostly electroplating, electroless plating, co-precipitation, evaporation and other processes. Due to the poor wettability of metal and carbon-based materials, the composite process of metal-carbon-based materials is generally the first in carbon materials. An island-shaped metal nucleation point is formed on the surface, and then by controlling the reaction time and the input of reaction raw materials, it spreads along the nucleation point to form a metal covering layer on the surface of the carbon-based material. The metal covering layer formed by the above process has a scale of nanometers.

The present invention aims at poor wettability between the metal material and the carbon-based material, and it is difficult to achieve a uniform metal layer covering the surface of the carbon-based material. The present invention takes fluorinated carbon-based material as the original material, and forms uniform and stable metal fluoride on the surface of the carbon-based material through fluorine substitution reaction for chlorine.

The metal is attached to the carbon-based material through fluorine. Fluorine and carbon are connected by a C-F bond. The form of metal (X) in carbon-based materials is C-F-X. Then, through metal vapor reduction, the fluoride on the surface of the carbon-based material is reduced to metal, so that a uniform metal coating layer is formed on the surface of the carbon-based material.

Compared with the previous metal-carbon material composite process, the present invention uses fluorine in the atomic distribution state on the surface of the carbon-based material as the nucleation point to anchor the metal atoms in the form of fluoride, and the atomic-scale metal coverage can be obtained after reduction. layer to obtain atomic-scale metal-carbon matrix composites.

Description of drawings

Fig. 1 is the preparation flow schematic diagram of the embodiment of the present invention 1;

Fig. 2 is the iron-graphene element distribution schematic diagram of the embodiment of the present invention 1;

Fig. 3 is the iron-graphene high-power transmission electron microscope diagram of the embodiment of the present invention 1;

Fig. 4 is the iron-graphene energy spectrogram of the embodiment of the present invention 1;

Fig. 5 is the iron-carbon nanotube high magnification transmission electron microscope picture of the embodiment of the present invention 2;

FIG. 6 is an energy spectrum diagram of iron-carbon nanotubes in Example 2 of the present invention.

For those of ordinary skill in the art, other related drawings can be obtained from the above drawings without any creative effort.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions of the present invention are further described below with reference to specific embodiments.

The purity and manufacturer of the medicines involved in the examples

Models and manufacturers of instruments involved in the examples

Examples 1-12

(1) grinding and mixing the carbon-based fluoride and the halide metal salt, put into the reaction kettle, vacuumize, seal, and place the reaction kettle in a box furnace to be heated to 280～500 ℃, and the heating rate is 5 ℃ /min, keep for 6~120h, cool down to 20~25℃ with the furnace, open the reaction kettle, wash off the unreacted halide metal salt with a cleaning agent, and dry the washed reactant in vacuum at 60~100℃ for 12~48h to obtain Carbon-based-metal fluoride; the carbon-based fluoride is at least one of fluorinated graphite, fluorinated graphite microplates, fluorinated carbon black, fluorinated carbon nanotubes, and fluorinated graphene; the halide metal salt For chloride, bromide and iodide metal salt; Described cleaning agent is ethanol or tetrahydrofuran;

(2) Mixing the carbon-based-metal fluoride with a reducing agent, the reducing agent is at least one of potassium, magnesium, lithium naphthalene-tetrahydrofuran or sodium naphthalene-tetrahydrofuran. When the reducing agent is potassium or magnesium, the reducing agent is mixed with the carbon-based-metal fluoride, put into a reactor, evacuated, sealed, and the reactor is heated in a box furnace to 300～600℃, the heating rate is 3℃/min, keep for 12～120h, cool down to 20～25℃ with the furnace, open the reactor, add methanol dropwise to the reduced product until no bubbles emerge, then filter, wash with water, The carbon-based-metal composite material is obtained by vacuum drying at 60-100 °C for 12-48 h; when the reducing agent is lithium naphthalene-tetrahydrofuran or sodium naphthalene-tetrahydrofuran, the reducing agent is mixed with the carbon-based-metal fluoride, Pour it into the reaction kettle, seal it, under the protection of argon atmosphere, stir at room temperature for 48-168 hours, add methanol dropwise to the reaction solution until no bubbles emerge, then filter, wash with water, and vacuum dry at 60-100 ℃ for 12-48 hours to obtain carbonyl- Metal composite materials;

Wherein, each reactant and its mass in the preparation process of the carbon-based-metal composite material are shown in Table 1; the reaction conditions in the preparation process of the carbon-based-metal composite material are shown in Table 2

Table 1

Table 2

Wherein, embodiment 7, on the basis of other embodiments, adopts lithium naphthalene-tetrahydrofuran as reducing agent in step (2), wherein the preparation method of sodium naphthalene-tetrahydrofuran is to add 0.69g of sodium to dissolved 1.28 g of sodium naphthalene-tetrahydrofuran under argon atmosphere. g naphthalene in 30 ml of anhydrous tetrahydrofuran, stirring for 6 h to obtain sodium naphthalene-tetrahydrofuran; magnetic stirring, stirring speed 200 rpm.

Wherein, Example 8, on the basis of other examples, adopts sodium naphthalene-tetrahydrofuran as reducing agent in step (2), wherein the preparation method of lithium naphthalene-tetrahydrofuran is to add 0.21 g of lithium to dissolved 1.28 g of lithium under argon atmosphere. g naphthalene in 30 ml of anhydrous tetrahydrofuran, stirring for 5 h to obtain lithium naphthalene-tetrahydrofuran; magnetic stirring, stirring speed 200 rpm.

Analysis of results: Figure 2 is a schematic diagram of the distribution of iron-graphene elements in Example 1. It can be observed that iron is uniformly distributed on the graphene surface without obvious aggregation. The iron-graphene surface of Example 1 was observed by high magnification transmission electron microscope (FIG. 3), and the formation of iron nanoparticles was not observed. Combined with elemental composition analysis energy spectrogram (Fig. 4), distribution characterization and microstructure characterization, it can be inferred that uniform iron is formed on the graphene surface through the above process.

5 is a high-power transmission electron microscope image of the iron-carbon nanotubes of Example 2. The surface and internal components of the carbon tubes are observed by transmission electron microscope to be uniform, and no nanoparticles are observed. Fig. 6 is the energy spectrogram of the elemental composition analysis of iron-carbon nanotubes. The energy spectrum analysis shows that the carbon tube sample treated by the above process contains iron with an atomic ratio of 2.83%, and it can be inferred that the iron distribution formed on the carbon tube by the above process can be inferred. evenly.

The present invention has been exemplarily described above. It should be noted that, without departing from the core of the present invention, any simple deformation, modification, or other equivalent replacements that can be performed by those skilled in the art without any creative effort fall into the scope of the present invention. the scope of protection of the invention.

Claims (9)

1. A preparation method of a carbon-based-metal composite material is characterized by comprising the following steps:

step 1, mixing carbon-based fluoride and halide metal salt, wherein the carbon-based fluoride accounts for 1 to 1.5 parts by weight, the halide metal salt accounts for 2~6 parts by weight, heating to 280 to 500 ℃ in vacuum or protective atmosphere, keeping for 6 to 120h, naturally cooling to 20 to 25 ℃, washing the obtained reactant with a cleaning agent, and drying at 60 to 100 ℃ in vacuum or protective atmosphere for 12 to 48h to obtain the carbon-based metal fluoride; the halide metal salt is chloride metal salt, bromide metal salt or iodide metal salt, and the cleaning agent is ethanol or tetrahydrofuran;

step 2 mixing the carbon-based-metal fluoride with a reducing agent,

when the reducing agent is potassium or magnesium, 1 to 1.5 parts of carbon-based-metal fluoride and 3~6 parts of reducing agent are calculated by weight, the mixture is heated to 300 to 600 ℃ under a vacuum condition or a protective atmosphere, the mixture is kept for 12 to 120h, the mixture is naturally cooled to 20 to 25 ℃, methanol is dripped into the obtained reduction product until no bubbles emerge, and then the mixture is filtered, washed by water and dried in vacuum at 60 to 100 ℃ for 12 to 48h to obtain the carbon-based-metal composite material;

when the reducing agent is naphthalene lithium-tetrahydrofuran or sodium naphthalene-tetrahydrofuran, 1 part of carbon-based-metal fluoride is calculated according to weight fraction, 5~7 parts of a metal simple substance reducing agent in the naphthalene lithium-tetrahydrofuran or the sodium naphthalene-tetrahydrofuran is stirred at room temperature for 48 to 168h under the protection of argon atmosphere, methanol is dripped into the reaction liquid until no bubbles emerge, and then the carbon-based-metal composite material is obtained through filtration, water washing and vacuum drying at 60 to 100 ℃ for 12 to 48h;

the halide metal salt is at least one of ferric chloride, cobalt chloride, nickel chloride, bismuth chloride, platinum chloride, tantalum chloride, ruthenium chloride, copper bromide and copper iodide.

2. The preparation method according to claim 1, wherein the carbon-based fluoride is at least one of graphite fluoride, graphite fluoride micro-sheets, carbon black fluoride, carbon fluoride nanotubes and graphene fluoride.

3. The preparation method according to claim 1, wherein the heating process is carried out in a reaction kettle made of stainless steel or quartz.

4. The method according to claim 1, wherein the protective atmosphere is argon, and the absolute degree of vacuum of the vacuum condition is 10 ^-5 Pa~10 ⁴ Pa。

5. The method according to claim 1, wherein the lithium naphthalene-tetrahydrofuran is prepared by: adding lithium to anhydrous tetrahydrofuran dissolved with naphthalene under an argon atmosphere, wherein the molar mass ratio of the lithium to the naphthalene is 3:1, stirring for 4 to 24h to obtain the naphthalene lithium-tetrahydrofuran.

6. The method according to claim 1, wherein the sodium naphthalenide-tetrahydrofuran is prepared by: adding sodium into anhydrous tetrahydrofuran dissolved with naphthalene under an argon atmosphere, wherein the molar mass ratio of the sodium to the naphthalene is 3:1, stirring for 4 to 24h to obtain the sodium naphthalene-tetrahydrofuran.

7. The method as claimed in claim 1, wherein the heating process of step 1 has a temperature rise rate of 1~5 ℃/min.

8. The method as claimed in claim 1, wherein the heating process of step 2 is performed at a temperature increase rate of 1~3 ℃/min.

9. The method according to claim 1, wherein the mass ratio of the carbon-based fluoride to the halide metal salt in step 1 is 1:3, and the mass ratio of the carbon-based-metal fluoride to the reducing agent in step 2 is 1:3.

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