Preparation method of graphene

Abstract

The invention relates to a preparation method of graphene, which mainly comprises the following steps: firstly, preparing a metal acetylide with the thickness of 0.2-1000 nanometers on a substrate, and covering a water film; by utilizing a photo-thermal reaction, the metal acetylide is initiated to be decomposed and graphene is formed; and finally, stripping the substrate from the graphene, and cleaning to obtain the graphene with a specific size. Compared with the like, the invention is more economical, efficient, stable and environment-friendly, and has obvious overall advantages.

Description

Technical Field

[0001] This invention relates to the field of graphene preparation technology, specifically a simple, efficient, economical, and stable method for preparing graphene of any size. Background Technology

[0002] Graphene is a two-dimensional carbon atom crystal, typically existing as a single layer or several layers. Single-layer graphene possesses excellent electrical and thermal conductivity and a low coefficient of thermal expansion, making it suitable for applications such as transistors, electrode materials, composite materials, liquid crystal display materials, and sensors. Graphene's unique structure and optoelectronic properties have made it a research hotspot in fields such as carbon materials, nanotechnology, condensed matter physics, and functional materials.

[0003] Since the discovery of graphene in 2004, numerous methods have been developed for its industrial applications, including micromechanical exfoliation, redox methods, epitaxial growth, chemical vapor deposition, and electrolysis. Micromechanical exfoliation is the simplest method, but it yields only a very small quantity of graphene, limited in size. Redox methods are currently widely used, involving the exfoliation of oxidized graphite to obtain graphene oxide, which is then reduced to obtain graphene. This method introduces numerous defects during preparation, which cannot be completely repaired during reduction, severely impacting its performance and applications. Furthermore, this method has a complex production process, low yield, and severe environmental pollution. Epitaxial growth and chemical vapor deposition can produce high-quality graphene, but these two methods require demanding preparation conditions, have low yields, high production costs, high energy consumption, and cause severe environmental pollution.

[0004] Therefore, it is necessary to develop an environmentally friendly, efficient, economical, stable, and scalable method for preparing graphene. Summary of the Invention

[0005] The present invention provides a method for preparing graphene, comprising the following steps: First, a metal acetylide with a thickness of 0.2~1000 nanometers was prepared on the substrate and coated with a water film; Photothermal initiation of stable decomposition of metal acetylides to form graphene; Finally, the substrate is peeled off from the graphene and cleaned to obtain graphene of a specific size.

[0006] In the method for preparing graphene, step 1 includes: Preferably, the substrate is metal, such as a copper plate; Preferred metal acetylation compounds, copper acetylation and silver acetylation; Preferably, the thickness of the metal acetylation is 0.2~1000 nanometers; In the method for preparing graphene, step 2 includes: Preferably, the photothermal reaction is initiated by light, heating, or a combination of both; Preferably, the photothermal reaction light source is visible light or laser; Preferably, the photothermal reaction temperature is 0~490℃.

[0007] Following the steps described above, graphene of any size can be prepared as needed. Compared with mechanical exfoliation and expansion methods, the proportion of monolayer graphene products is higher, and the size can be larger. Compared with oxidation methods, it does not involve oxidation, has fewer product defects, is not limited in size, and all materials used can be recycled. Compared with epitaxial growth and vapor deposition methods, it has advantages such as mild reaction conditions, can be prepared at room temperature or low temperature, low equipment requirements, no need for vacuum or high temperature, and no size limitation. Detailed Implementation This invention provides a method for preparing graphene. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0008] The present invention will now be described in detail with reference to specific embodiments.

[0009] Example 1 A 1 mm thick copper plate, measuring 1 square meter, was used as a substrate. The copper plate was placed in a sealed container on the experimental platform, and acetylene copper was prepared by reacting acetylene with copper salts. By controlling the concentration and amount of copper salts, as well as the flow rate and concentration of acetylene gas, a 50 nm thick acetylene copper compound layer was prepared and coated with a water film. Irradiation with a 0.5 W / cm² light source for 30 minutes caused the acetylene copper to decompose, forming graphene. The substrate, along with the formed graphene, copper powder, and other products, was placed in dilute acid for exfoliation. The metal salts produced during the exfoliation process were recycled as reaction reagents. The exfoliated graphene was washed, dried, and stored for later use. Comprehensive testing showed a graphene conversion rate (based on carbon content of acetylene) of 90%, with 80% of the graphene in layers 1-3.

[0010] Example 2 A 1 mm thick copper plate, measuring 1 square meter, was used as a substrate. The copper plate was placed in a sealed container on the experimental platform, and acetylene copper was prepared by reacting acetylene with copper salts. By controlling the concentration and amount of copper salts, as well as the flow rate and concentration of acetylene gas, a 5 nm thick acetylene copper compound layer was prepared and coated with a water film. Irradiation with a 0.5 W / cm² light source for 10 minutes caused the acetylene copper to decompose, forming graphene. The substrate, along with the formed graphene, copper powder, and other products, was placed in dilute acid for exfoliation. The metal salts produced during the exfoliation process were recycled as reaction reagents. The exfoliated graphene was washed, dried, and stored for later use. Comprehensive testing showed a graphene conversion rate (based on carbon content of acetylene) of 91%, with 90% of the graphene in layers 1-3.

[0011] Example 3 A 1 mm thick copper plate, measuring 1 square meter, was used as a substrate. The copper plate was placed in a sealed container on the experimental platform, and acetylene copper was prepared by reacting acetylene with copper salts. By controlling the concentration and amount of copper salts, as well as the flow rate and concentration of acetylene gas, a 5 nm thick acetylene copper compound layer was prepared and coated with a water film. The substrate was heated to 115 °C, causing the acetylene copper to decompose and graphene to form. The substrate, along with the formed graphene, copper powder, and other products, was placed in dilute acid for exfoliation. The metal salts produced during the exfoliation process were recycled as reaction reagents. The exfoliated graphene was washed, dried, and stored for later use. Comprehensive testing showed a graphene conversion rate (based on carbon content of acetylene) of 91%, with 92% of the graphene in layers 1-3.

[0012] Example 4 A 1 mm thick, 1 square meter silver plate was used as a substrate. The silver plate was placed in a sealed container on the experimental platform, and acetylene silver was prepared by reacting acetylene with silver salt. By controlling the concentration and amount of silver salt, as well as the flow rate and concentration of acetylene gas, an acetylene silver compound layer with a thickness of 49 nm was prepared and coated with a water film. Irradiation with a 0.5 W / cm² light source for 30 minutes resulted in the decomposition of acetylene silver and the formation of graphene. The substrate, along with the formed graphene, silver powder, and other products, was electrolytically exfoliated in dilute acid. The exfoliated graphene was cleaned, dried, and stored for later use. Comprehensive testing showed that the graphene conversion rate (based on carbon content of acetylene) was 92%, with graphite accounting for 85% of the first 1-3 layers.

[0013] Example 5 A 1 mm thick, 1 square meter silver plate was used as a substrate. The silver plate was placed in a sealed container on the experimental platform, and acetylene silver was prepared by reacting acetylene with silver salt. By controlling the concentration and amount of silver salt, as well as the flow rate and concentration of acetylene gas, a 3 nm thick acetylene silver compound layer was prepared and coated with a water film. Irradiation with a 0.5 W / cm² light source for 10 minutes caused the acetylene silver to decompose, forming graphene. The substrate, along with the formed graphene, silver powder, and other products, was electrolytically exfoliated in dilute acid. The exfoliated graphene was washed, dried, and stored for later use. Comprehensive testing showed that the graphene conversion rate (based on carbon content of acetylene) was 92%, with 91% of the graphene in layers 1-3.

[0014] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for preparing graphene includes the following steps: First, a metal acetylide with a thickness of 0.2~1000 nanometers was prepared on the substrate and coated with a water film; Photothermal initiation of stable decomposition of metal acetylides to form graphene; Finally, the substrate is peeled off from the graphene and cleaned to obtain graphene of a specific size.

2. The method for preparing graphene as described in claim 1, characterized in that, A metal acetylation of a certain thickness was prepared on a substrate and coated with a water film.

3. The method for preparing graphene as described in claim 2, characterized in that, The metal acetylation is one or more combinations of all metal acetylations, such as copper acetylation, silver acetylation, copper propyne, etc., with copper acetylation and silver acetylation being preferred.

4. The method for preparing graphene as described in claim 2, characterized in that, Its substrate can be metal or other inorganic materials, preferably metal.

5. The method for preparing graphene as described in claim 2, characterized in that, The thickness of the metal acetylide is 0.2~1000 nanometers.

6. The method for preparing graphene as described in claim 1, characterized in that, Photothermal reactions are initiated by light, heating, or a combination of both, which promote the decomposition of metal acetylides.

7. The method for preparing graphene as described in claim 6, characterized in that, The light source for the photothermal reaction is visible light or laser light.

8. The method for preparing graphene as described in claim 6, characterized in that, The photothermal reaction temperature is 0~490℃.