A method for mass production of graphene nanoribbons

Abstract

The application relates to a method for mass production of graphene nanoribbons. Graphene-coated metal powder is used as raw material; firstly, the raw material is sintered into a block by hot-pressing sintering; then the block is extruded rheologically at high temperature to obtain a metal matrix composite block material reinforced by graphene nanoribbons; the metal matrix composite block material is completely dissolved by etching agent, and then filtering, washing and drying are carried out to finally obtain high-quality graphene nanoribbons. The method has the advantages of simple raw material, mass production and preparation of high-hydrophilic graphene nanoribbons.

Description

Technical Field

[0001] This invention provides a method for large-scale preparation of graphene nanoribbons, belonging to the field of two-dimensional new material preparation. Background Technology

[0002] Graphene nanoribbons, characterized by their small size, high aspect ratio, and band gap, are an important member of the graphene family. They can be applied not only to novel electronic devices but also serve as ideal reinforcing agents or additives for metal-based materials, catalytic materials, and electrode materials.

[0003] Currently, methods for preparing graphene nanoribbons include: carbon nanotube breaking (CN102666378A, CN101913599A, 201210084629X, etc.), template growth (CN102243990A, 2011102066086, etc.), graphene etching (CN102701196A, etc.), and molecular self-assembly (CN103635423A, CN104379497A, etc.). These methods are all costly and difficult to meet the needs of large-scale preparation.

[0004] Therefore, it is particularly important to develop a method for large-scale preparation of graphene nanoribbons. Summary of the Invention

[0005] The purpose of this invention is to provide a method for large-scale preparation of graphene nanoribbons. The core technology of this method involves first sintering graphene-coated metal powder into a bulk material, fixing the graphene film at the grain boundaries; then, using a high-temperature extrusion rheological process, increasing the surface area of ​​the bulk material, forcing the graphene film on the surface of the grains inside the bulk material to be strongly torn into graphene nanoribbons, thus preparing a metal-based composite material reinforced with graphene nanoribbons; finally, dissolving the metal in the metal-based composite material yields the graphene nanoribbons.

[0006] The present invention is achieved through the following technical solution.

[0007] A method for large-scale preparation of graphene nanoribbons, the specific steps of which are as follows:

[0008] Using graphene-coated metal powder as raw material, the raw material is first sintered into a block by hot pressing; then the block is subjected to extrusion rheology at high temperature so that the surface area of ​​the block after rheology is 1.5 times or more than that before rheology, thus obtaining a metal-based composite block material reinforced by graphene nanoribbons; the metal in the metal-based composite block material is completely dissolved by an etchant, and then filtered, washed with deionized water, and dried to finally obtain high-quality graphene nanoribbons.

[0009] The metal powder is one or more of copper, aluminum, zinc, tin, antimony, bismuth, and silver.

[0010] The hot pressing sintering mentioned above is hot isostatic pressing sintering or electric discharge plasma sintering.

[0011] The sintering is carried out at a temperature of 0.55 to 0.95 times the melting point of the corresponding metal.

[0012] The high temperature mentioned is 0.6 to 0.9 times the melting point temperature of the corresponding metal.

[0013] The extrusion rheology described herein is a rheology in which the radial dimension increases or decreases.

[0014] The etching agent is a solution containing acid (one or a combination of sulfuric acid, nitric acid, and hydrochloric acid) or alkali (one or a combination of sodium hydroxide and potassium hydroxide).

[0015] The drying process is freeze drying, vacuum drying, or forced-air drying.

[0016] The beneficial effects of this invention are: the raw materials are simple and can be produced on a large scale; the metal matrix composite material reinforced by graphene nanoribbons has the structural characteristics of pure metal; the graphene nanoribbons hardly hinder the sintering connection between metal grains; and highly hydrophilic graphene nanoribbons can be prepared. Attached Figure Description

[0017] Figure 1 This is an optical photograph of the copper in the copper-based composite bulk material in Example 1 after etching, where the small black dots are graphene nanoribbons.

[0018] Figure 2 This is a TEM image of the graphene nanoribbons in Example 1. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] Example 1

[0021] The method for large-scale preparation of graphene nanoribbons comprises the following steps:

[0022] Using graphene-coated copper powder as raw material, the material was first sintered into a block with a diameter of 1 cm and a height of 2 cm by hot isostatic pressing at a temperature 0.74 times the melting point of copper. Then, the block was subjected to radial dimension reduction extrusion rheology at a temperature 0.6 times the melting point of copper, resulting in a surface area 1.5 times that before rheology, thus obtaining a copper-based composite bulk material reinforced with graphene nanoribbons. The copper in this copper-based composite bulk material was then completely dissolved using an etchant containing nitric acid (see...). Figure 1 After filtration, washing with deionized water, and freeze-drying, graphene nanoribbons with a width of 20–30 nm are finally obtained (see...). Figure 2 ).

[0023] Example 2

[0024] The method for large-scale preparation of graphene nanoribbons comprises the following steps:

[0025] Using graphene-coated aluminum powder as raw material, the material was first sintered into a block with a diameter of 1 cm and a height of 2 cm at a temperature 0.55 times the melting point of aluminum using discharge plasma sintering. Then, the block was subjected to radial dimension reduction extrusion rheology at a temperature 0.8 times the melting point of aluminum, so that the surface area of ​​the block after rheology was 2.5 times that before rheology, thus obtaining an aluminum-based composite block material reinforced with graphene nanoribbons. The aluminum in the aluminum-based composite block material was completely dissolved by an etchant containing sodium hydroxide, and then filtered, washed with deionized water, and freeze-dried to finally obtain graphene nanoribbons with a width of 10-25 nm.

[0026] Example 3

[0027] The method for large-scale preparation of graphene nanoribbons comprises the following steps:

[0028] Using graphene-coated tin powder as raw material, the material was first sintered into a block with a diameter of 1 cm and a height of 2 cm by hot isostatic pressing at a temperature 0.95 times the melting point of tin. Then, the block was subjected to extrusion rheology to increase its radial size at a temperature 0.9 times the melting point of tin, so that the surface area of ​​the block after rheology was 10 times that before rheology, thus obtaining a tin-based composite block material reinforced by graphene nanoribbons. The tin-based composite block material was completely dissolved by concentrated hydrochloric acid etchant, and then filtered, washed with deionized water, and dried by forced air to finally obtain graphene nanoribbons with a width of 3-12 nm.

Claims

1. A method for large-scale preparation of graphene nanoribbons, characterized in that: Using graphene-coated metal powder as raw material, the raw material is first sintered into a block by hot pressing; then the block is extruded and rheologically modified at high temperature so that the surface area of ​​the modified block is 1.5 times or more than that before rheological modification, thus obtaining a metal-based composite block material reinforced by graphene nanoribbons; the metal in the metal-based composite block material is completely dissolved by an etchant, and then filtered, washed with deionized water, and dried to finally obtain high-quality graphene nanoribbons.

2. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The metal powder is one or more of copper, aluminum, zinc, tin, antimony, bismuth, and silver.

3. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The hot pressing sintering mentioned above is hot isostatic pressing sintering or electric discharge plasma sintering.

4. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The sintering is carried out at a temperature of 0.55 to 0.95 times the melting point of the corresponding metal.

5. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The high temperature mentioned is 0.6 to 0.9 times the melting point temperature of the corresponding metal.

6. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The extrusion rheology described herein is a rheology in which the radial dimension increases or decreases.

7. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The etching agent is an acidic or alkaline solution.

8. The method for large-scale preparation of graphene nanoribbons according to claim 1, characterized in that: The drying process is freeze drying, vacuum drying, or forced-air drying.

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