CN114572971A - Method for preparing graphene on surface of copper powder - Google Patents

Abstract

The invention discloses a method for preparing graphene on the surface of copper powder, and belongs to the field of new material preparation. In the invention, the copper powder is used as the catalytic substrate, and the methane is used as the carbon source. Under the mixed atmosphere of argon, the mixed powder is heated to 500-600 ℃ and kept for a certain period of time, so that anhydrous copper acetate or copper acetylacetonate is converted into nano copper particles coated with carbon film on the surface, so as to hinder the high temperature bonding of copper powder . Then continue to heat up to above 1000°C, and feed methane to realize the preparation of high-quality multi-layer graphene on copper powder. The invention is simple and feasible, can prepare multi-layer graphene on copper powder, is suitable for large-scale industrial production, and has wide potential applications in the fields of powder metallurgy, composite materials, electronic power and the like.

Description

A kind of method for preparing graphene on copper powder surface

technical field

The invention relates to a method for preparing graphene on the surface of copper powder, and belongs to the field of new material preparation.

Background technique

In modern industry, copper powder has a wide range of important applications in many fields, such as catalytic materials, conductive pastes, lubricant additives, and raw materials for powder metallurgy and 3D printing. However, due to the large surface area of copper powder, it is easy to oxidize in the air and reduce its own performance. Therefore, the oxidation of copper powder is the main factor limiting its application. At present, studies have shown that coating multilayer graphene films on copper substrates by chemical vapor deposition can achieve an anti-oxidation effect of up to 6 years. Due to the good metal properties of graphene, it will not affect the thermal conductivity and electrical conductivity of copper powder. Therefore, the preparation of multilayer graphene on copper powder can effectively solve the problem of its easy oxidation. Moreover, multi-layer graphene has strong wear resistance due to its basic graphite structure, so this multi-layer graphene/copper shell-core structure can also be applied to the field of wear-resistant materials.

At present, in the field of copper-based composite materials, copper-based composite materials with graphene as a reinforcing phase are a research hotspot. It is expected to improve the comprehensive properties of copper-based composite materials with the help of the excellent properties of graphene. However, graphene is in the copper matrix. The problem of easy reunification is difficult to solve. Therefore, in-situ preparation of high-quality graphene on the surface of copper powder can achieve uniform dispersion of graphene in the copper matrix. Therefore, coating graphene on the surface of copper powder by chemical vapor deposition has important application prospects.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for preparing graphene on the surface of copper powder, using copper powder as a catalytic substrate and methane as a carbon source, grinding and mixing copper powder with anhydrous copper acetate powder or copper acetylacetonate powder in a certain proportion Evenly, place the mixed powder in the heating zone of the tube furnace; in the mixed atmosphere of hydrogen and argon, heat the mixed powder to 500-600 ° C, and keep it for a certain period of time, so that the anhydrous copper acetate or copper acetylacetonate is converted into surface coating. carbon-coated nano-copper particles to hinder the high-temperature bonding of copper powder; then continue to heat up to above 1000° C. and pass methane to realize the preparation of high-quality multi-layer graphene on copper powder; the invention is simple and feasible, and The multi-layer graphene can be prepared on copper powder, and the preparation process is simple, safe and controllable, which is helpful to promote the industrialized preparation of graphene, and has important theoretical and practical significance.

In order to achieve the above purpose of the invention, the technical scheme of the present invention is:

(1) Pure copper powder is used as a catalytic substrate. Take anhydrous copper acetate or copper acetylacetonate powder, mix the surface-treated copper powder with anhydrous copper acetate or copper acetylacetonate powder, grind to make it evenly mixed, and anhydrous copper acetate Or the mass ratio of copper acetylacetonate powder and copper powder is (2~5):(20~50);

(2) Pour the copper powder and the mixed powder of anhydrous copper acetate or copper acetylacetonate into the corundum crucible, and put it into the heating zone of the tube furnace. Under atmospheric pressure, a mixture of high-purity hydrogen and high-purity argon is introduced. gas, the furnace temperature was raised to 500-600 °C within 40 minutes, and the holding time was 30-50 minutes; after the insulation was completed, the furnace temperature was raised to 1020-1050 °C within 35 minutes, and when the temperature reached 1020-1050 °C, Immediately introduce a 1-20sccm methane carbon source, and the holding time is 20-40min. After the holding, close the methane gas valve, and open the furnace cover under a mixed atmosphere of hydrogen and argon to achieve rapid cooling, and make the sample within 150min. The temperature is lowered to room temperature to obtain graphene-copper composite powder, and graphene is obtained after dissolving the copper powder.

Preferably, the process of surface treatment of copper powder in step (1) of the present invention is as follows: removing oxides and pollutants on the surface of copper powder, and reducing at 500-600 °C for 60 min in a mixed atmosphere of high-purity hydrogen and argon.

Preferably, the grinding time in step (1) of the present invention is 30-60 min.

Preferably, the purity of the copper powder of the present invention is greater than or equal to 99.99%, and the size is 5 μm-200 μm.

Preferably, the purity of hydrogen, argon and methane described in step (3) of the present invention is greater than or equal to 99.999%, the flow rate of hydrogen gas is 20-100 sccm, and the flow rate of argon gas is 150-500 sccm.

Preferably, the purity of anhydrous copper acetate or copper acetylacetonate in step (2) of the present invention is analytically pure.

The principle of the present invention: because the substances containing only carbon, hydrogen, oxygen and copper elements such as anhydrous copper acetate or copper acetylacetonate are calcined under the combined action of a low temperature of 500-600° C. and a mixed atmosphere of hydrogen and argon, the obtained The nano-copper particles wrapped with carbon film on the surface can be used to hinder the high-temperature bonding of copper powder. Then, using copper powder as the catalytic substrate and methane as the carbon source, the copper powder and anhydrous copper acetate powder or copper acetylacetonate powder are ground and mixed uniformly in a certain proportion, and the mixed powder is placed in the heating zone of the tube furnace. In a mixed atmosphere of hydrogen and argon, the mixed powder is heated to 500-600 ℃ and kept for a certain period of time, so that anhydrous copper acetate or copper acetylacetonate is converted into nano-copper particles coated with carbon film on the surface, so as to hinder the copper powder High temperature bonding. Then continue to heat up to above 1000 °C, and pass methane into it, and then the preparation of high-quality multilayer graphene on copper powder can be realized.

Beneficial effects of the present invention:

(1) The present invention achieves the purpose of preparing graphene on copper powder by mixing copper powder with a substance containing only carbon, hydrogen, oxygen and copper elements in a certain proportion, and then realizes the purpose of preparing graphene on copper powder through chemical vapor deposition, which overcomes the problem of copper powder in the past. The problem of easy adhesion to each other at high temperature.

(2) The price of the anhydrous copper acetate or copper acetylacetonate used in the present invention is low, and will not increase the excessive cost to the preparation process of graphene.

(3) The process of the present invention is simple and mature, safe and controllable, and has high repeatability, and is suitable for industrial production.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Figure 2 is a temperature control curve diagram of the present invention.

Figure 3 is an optical micrograph of graphene transferred to a silicon wafer grown at 1020 °C.

FIG. 4 is a Raman spectrogram of the graphene transferred onto the silicon wafer in FIG. 3 .

Figure 5 is an optical micrograph of graphene transferred to a silicon wafer grown at 1050 °C.

FIG. 6 is a Raman spectrum of the graphene transferred onto the silicon wafer in FIG. 5 .

Detailed ways

The present invention will be further elaborated below in conjunction with specific examples, but the protection scope of the present invention is not limited to the content.

Example 1

A method for preparing graphene on the surface of copper powder, specifically comprising the following steps:

(1) Weigh 50 g of pure copper powder as a catalytic substrate, and reduce it at 500 °C for 60 min under a mixed atmosphere of 20 sccm hydrogen and 200 sccm argon to remove oxides and pollutants on the surface of copper powder.

(2) Weigh 5 g of anhydrous copper acetate powder, mix the copper powder and the anhydrous copper acetate powder into an agate mortar and grind for 60 min to make it evenly mixed.

(3) Pour the mixed powder of copper powder and anhydrous copper acetate into the corundum crucible, and put it into the heating zone of the tube furnace. The furnace temperature was raised to 500 °C within 40 min, and the holding time was 30 min; after the heat preservation was completed, the furnace temperature was raised to 1020 °C within 35 min. Adjust the argon flow rate to 500sccm, keep the hydrogen flow rate unchanged, and then keep the holding time for 20min. After the holding period, close the methane gas valve, and open the furnace lid to achieve rapid cooling under a mixed atmosphere of 20sccm high-purity hydrogen and 200sccm high-purity argon. , the sample was lowered to room temperature within 150 min to obtain graphene-copper composite powder.

The prepared graphene-copper composite powder was pasted with a layer of graphene-copper composite powder with thermal release tape, and put into a ferric chloride solution (consisting of 10g of ferric chloride, 10ml of 28% hydrochloric acid and 100ml of deionized water). Dissolve the copper powder in water), remove the heat release tape after 12 hours, rinse with deionized water 4 times, and dry; then, stick the heat release tape to a SiO ₂ /Si sheet with a thickness of 300 nm, and heat it at 120 ° C Under heating for 60s, the graphene was transferred from the surface of copper powder to the surface of SiO ₂ /Si sheet, and the morphology of graphene was observed by metallographic microscope on the silicon wafer and the Raman spectrum was tested to detect the quality of graphene, which was transferred to silicon The optical microscope photo of graphene on the sheet is shown in Figure 3. It can be seen from Figure 3 that the size of graphene is in the micrometer scale; the Raman spectrum is marked at the black spot in Figure 3, and its Raman spectrum is shown in Figure 4 As can be seen from the figure, the Raman spectrum of graphene has a low intensity of the defect peak D peak at 1356.6 cm ^-1 , while the characteristic peak G peak near 1585.7 cm- ¹ has a very high intensity, and I _D /I _G =0.21, the degree of defects is very low, indicating that the quality of graphene is high, and the 2D peak height near 2712 cm ^-1 is lower than the characteristic peak _G peak near 1585.7 cm ^-1 , and I _2D /IG =0.36 , indicating that the number of layers of graphene is greater than 3 layers, therefore, high-quality multi-layer graphene is prepared on copper powder.

Example 2

A method for preparing graphene on the surface of copper powder, specifically comprising the following steps:

(1) Weigh 20 g of pure copper powder as a catalytic substrate, and reduce it at 550 °C for 60 min under a mixed atmosphere of 20 sccm hydrogen and 200 sccm argon to remove oxides and pollutants on the surface of copper powder;

(2) Weigh 2 g of anhydrous copper acetate powder, mix the copper powder and anhydrous copper acetate powder into an agate mortar, grind for 60 minutes, and mix them evenly.

(3) Pour the mixed powder of copper powder and anhydrous copper acetate into the corundum crucible, and put it into the heating zone of the tube furnace. The furnace temperature was raised to 600 °C within 40 min, and the holding time was 50 min; after the heat preservation, the furnace temperature was raised to 1050 °C within 35 min. When the temperature reached 1050 °C, a 1sccm methane carbon source was immediately introduced, and Adjust the argon flow to 500sccm, the hydrogen flow to 20sccm, and then the holding time is 40min. After the holding is completed, close the methane valve, and open the furnace lid to achieve rapid cooling under a mixed atmosphere of 20sccm high-purity hydrogen and 200sccm high-purity argon. , the sample was lowered to room temperature within 150 min to obtain graphene-copper composite powder.

The prepared graphene-copper composite powder was pasted with a layer of graphene-copper composite powder with thermal release tape, and put into a ferric chloride solution (consisting of 10g of ferric chloride, 10ml of 28% hydrochloric acid and 100ml of deionized water). Dissolve the copper powder in water), remove the heat release tape after 12 hours, rinse with deionized water 4 times, and dry; then, stick the heat release tape to a SiO ₂ /Si sheet with a thickness of 300 nm, and heat it at 120 ° C Under heating for 60s, the graphene was transferred from the surface of copper powder to the surface of SiO ₂ /Si sheet, and the morphology of graphene was observed by metallographic microscope on the silicon wafer and the Raman spectrum was tested to detect the quality of graphene, which was transferred to silicon The optical microscope photo of the graphene on the sheet is shown in Figure 5. It can be seen from Figure 5 that the size of the graphene is in the micrometer scale; the Raman spectrum is marked at the black spot in Figure 5, and its Raman spectrum is shown in Figure 6 As can be seen from the figure, the Raman spectrum of graphene has a low intensity of the defect peak D peak at 1358.8 cm ^-1 , while the characteristic peak intensity of the G peak near 1586.9 cm- ¹ is very high, and I _D /I _G =0.17, the degree of defects is very low, indicating that the quality of graphene is high, and the 2D peak height near 2714.3 cm ^-1 is lower than the characteristic peak _G peak near 1586.9 cm ^-1 , and I _2D /IG =0.43 , indicating that the number of layers of graphene is greater than 3 layers, therefore, high-quality multi-layer graphene is prepared on copper powder.

Example 3

A method for preparing graphene on the surface of copper powder, specifically comprising the following steps:

(1) Weigh 30g of pure copper powder as a catalytic substrate, and reduce it at 600℃ for 60min under a mixed atmosphere of 20sccm hydrogen and 200sccm argon to remove oxides and pollutants on the surface of copper powder;

(2) Weigh 4 g of anhydrous copper acetate powder, mix the copper powder and anhydrous copper acetate powder into an agate mortar and grind for 40 minutes to make the mixture uniform.

(3) Pour the mixed powder of copper powder and anhydrous copper acetate into the corundum crucible, and put it into the heating zone of the tube furnace. Under atmospheric pressure, pass a mixed gas of 80sccm high-purity hydrogen and 500sccm high-purity argon, The furnace temperature was raised to 550 °C within 40 min, and the holding time was 40 min; after the heat preservation, the furnace temperature was raised to 1030 °C within 35 min. Adjust the argon flow to 500sccm, the hydrogen flow to 80sccm, and then the holding time is 40min. After the holding, close the methane valve, and open the furnace lid to achieve rapid cooling under a mixed atmosphere of 20sccm high-purity hydrogen and 200sccm high-purity argon. , the sample was lowered to room temperature within 150 min to obtain graphene-copper composite powder.

Through the same detection method as in Example 1, in this example, high-quality multilayer graphene was prepared on copper powder.

Claims (6)

1. a method for preparing graphene on copper powder surface, is characterized in that, specifically comprises the following steps: (1) Pure copper powder is used as a catalytic substrate. Take anhydrous copper acetate or copper acetylacetonate powder, mix the surface-treated copper powder with anhydrous copper acetate or copper acetylacetonate powder, grind to make it evenly mixed, and anhydrous copper acetate Or the mass ratio of copper acetylacetonate powder and copper powder is (2~5):(20~50); (2) Pour the copper powder and the mixed powder of anhydrous copper acetate or copper acetylacetonate into the corundum crucible, and put it into the heating zone of the tube furnace. Under atmospheric pressure, a mixture of high-purity hydrogen and high-purity argon is introduced. gas, the furnace temperature was raised to 500-600 °C within 40 minutes, and the holding time was 30-50 minutes; after the insulation was completed, the furnace temperature was raised to 1020-1050 °C within 35 minutes, and when the temperature reached 1020-1050 °C, Immediately introduce a 1-20sccm methane carbon source, and the holding time is 20-40min. After the holding, close the methane gas valve, and open the furnace cover under a mixed atmosphere of hydrogen and argon to achieve rapid cooling, and make the sample within 150min. The temperature is lowered to room temperature to obtain graphene-copper composite powder, and graphene is obtained after dissolving the copper powder. 2. The method for preparing graphene on the surface of copper powder according to claim 1, characterized in that: in step (1), the process of surface treatment of copper powder is: removing oxides and pollutants on the surface of copper powder; Reduction was carried out at 500-600 °C for 60 min under a mixed atmosphere of argon and argon. 3 . The method for preparing graphene on the surface of copper powder according to claim 1 , wherein the grinding time of step (1) is 30-60 min. 4 . 4. the method for preparing graphene on copper powder surface according to claim 1 is characterized in that: copper powder purity is greater than or equal to 99.99%, and size is 5 μm-200 μm. 5. The method for preparing graphene on the surface of copper powder according to claim 1, characterized in that: the purity of hydrogen, argon and methane described in step (3) is greater than or equal to 99.999%, hydrogen flow rate is 20-100sccm, argon Air flow 150-500sccm. 6 . The method for preparing graphene on the surface of copper powder according to claim 1 , wherein in step (2), the purity of anhydrous copper acetate or copper acetylacetonate is analytically pure. 7 .

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