Method of using chemical reaction transparency of graphene

Abstract

The present invention relates to a method using chemical reaction transparency of graphene, and more specifically to a method capable of forming a desired material by a catalytic reaction on a graphene surface using the graphene which inhibits oxygen diffusion without blocking electron delivery, and an applied method thereof.

Claims

1. A method of performing a catalytic reaction using chemical transparency of graphene on a substrate comprising the steps of: providing a catalyst disposed on a portion of a first layer to form a catalyst layer comprising one or more catalytic regions and one or more non-catalytic regions; and a graphene layer covering the one or more catalytic regions and the one or more non-catalytic regions; contacting a reactant with the graphene layer; and reacting the reactant with the catalyst at the one or more catalytic regions through the graphene layer so that the catalytic reaction occurs on the graphene layer along the catalyst pattern, wherein the one or more non-catalytic regions may be provided in the edge of the one or more catalytic regions so that the catalyst and the reactant does not directly contact.

2. The method of claim 1, wherein the catalyst is a photocatalyst, an electrocatalyst, or an electrode active material.

3. The method of claim 1, wherein the catalyst act as a reducing agent in the catalytic reaction.

4. The method of claim 1, wherein the graphene layer inhibits inactivation of the catalyst.

5. A method of preparing a surface-modified graphene through a catalytic chemical reaction on a substrate comprising a catalyst disposed on a portion of a first layer to form a catalyst layer comprising one or more catalytic regions and one or more non-catalytic regions; and a graphene layer covering the one or more catalytic regions and the one or more non-catalytic regions contacting a reactant with the graphene layer; and performing a catalytic chemical reaction of the reactant with the catalyst at the one or more catalytic regions through the graphene layer so that the catalytic reaction occurs on the graphene layer along the catalyst pattern, wherein the one or more non-catalytic regions may be provided in the edge of the one or more catalytic regions so that the catalyst and the reactant does not directly contact.

6. The method of claim 5, wherein the one or more catalytic regions and the one or more non-catalytic regions forms a catalyst pattern, and the catalytic chemical reaction is performed at the catalyst where the graphene layer is positioned on the one or more catalytic regions, thereby preparing the surface-modified graphene along the catalyst pattern.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of the surface modification using chemical reaction transparency of graphene according to the present invention.

(2) FIG. 2 is a flow chart showing the process of the surface modification using chemical reaction transparency of graphene according to the present invention.

(3) FIG. 3 is a schematic diagram of a layered structure, which can be provided by the method of modifying the graphene surface according to an exemplary embodiment of the present invention, including a first layer (material A) including various catalysts; a second layer comprising graphene formed on the first layer; and a product (material B) formed by the catalytic reaction on the second layer surface.

(4) FIG. 4 is a schematic diagram of a layered structure, which can be provided by the method of modifying the graphene surface according to an exemplary embodiment of the present invention, including a support layer; a first layer including a catalyst formed on the support layer; a second layer comprising graphene formed on the first layer; and a product formed by a catalytic reaction on the second layer. The support layer and the catalyst are SiO.sub.2/Si and ZnO, respectively, and a ZnO nanorod is formed as the product of the catalytic reaction.

(5) FIG. 5 is an electron micrograph of the layered structure which can be provided by the graphene surface modification method according to Example 1 of the present invention. Ge, Al, Al patterned on the SiO.sub.2 layer, Si, GaAs, and Cu are used as a catalyst in (a), (b), (c), (d), (e), and (f), respectively.

(6) FIG. 6 is an electron micrograph of the structure which can be provided by the graphene surface modification method according to Example 2 of the present invention.

(7) FIG. 7 is an image of a hydrogen sensor in which the graphene prepared according to an exemplary embodiment of the present invention and platinum nanoparticles formed on the surface of the graphene, and a hydrogen sensing result.

(8) FIG. 8 shows cell growths on a glass on which graphene is transferred and that on which polylysine is laid and graphene is transferred thereon.

BEST MODE

(9) Hereinafter, the present invention will be described in further detail with reference to exemplary embodiments. These exemplary embodiments are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

Example 1: Modification of Graphene Surface Using Chemical Reaction Transparency

(10) As a substrate for positioning graphene, a copper foil (46986, 99.8% metal basis, Alfa Aesar) of 0.25 μm thickness×6 cm width×6 cm length was prepared. As a method for forming a graphene layer, chemical vapor deposition (CVD) was used to position a graphene layer on one side of a copper foil layer.

(11) For the transfer, polymethyl methacrylate (PMMA), a polymer capable of supporting the graphene layer, was spin-coated on the positioned graphene layer at room temperature for 30 seconds at 2000 rpm using a spin coater (Midas System). A copper etching solution (Transene) was used to dissolve the copper foil. The graphene was transferred on various first material layers, and PMMA, the polymer for support, was removed by dissolving with acetone. For the first material layers, Ge, Al, Al patterned on the SiO.sub.2 layer, Si, GaAs, and Cu were used.

(12) As described above, the top surface of the graphene layer transferred on the first material layers was in contact with a 0.1 mM HAuCl.sub.4 aqueous solution, i.e., a condition where Au can be extracted, for 3 minutes and was then removed therefrom. In other words, by using HAuCl.sub.4 as a second material, a third material layer, i.e., Au layer, was formed.

(13) As a result of investigating the modified graphene surface via an electron microscope, there were Au nanoparticles of the third material layer formed on the graphene surface, as shown in FIG. 5.

Example 2: Modification of Graphene Surface Using Chemical Reaction Transparency

(14) As a substrate for positioning graphene, a copper foil (46986, 99.8% metal basis, Alfa Aesar) of 0.25 μm thickness×6 cm width×6 cm length was prepared. As a method for forming a graphene layer, chemical vapor deposition (CVD) was used to position a graphene layer on one side of the copper foil layer.

(15) For the transfer, polymethyl methacrylate (PMMA), a polymer capable of supporting the graphene layer, was spin-coated on the positioned graphene layer at room temperature for 30 seconds at 2000 rpm using a spin coater (Midas System). A copper etching solution (Transene) was used to dissolve the copper foil. The graphene was transferred on ZnO, the first material layer which is patterned on SiO.sub.2/Si, the support layer, as shown in FIG. 4, and PMMA, the polymer for support, was then removed by dissolving with acetone.

(16) The graphene layer transferred on the first material layer as described above was reacted hydrothermally in 2.5 mM Zn(NH.sub.3).sub.2 and hexamethylenetetramine (HMTA) solution, i.e., a condition in which ZnO nanorod can grow, at 80° C. for an hour. That is, using Zn(NH.sub.3).sub.2 as a second material, the ZnO layer (third material layer) was formed in a nanorod form.

(17) As a result of investigating the modified graphene surface via an electron microscope, there were ZnO nanorods formed on the graphene surface, as shown in FIG. 6. Here, produced ZnO nanorods has a matching atomic arrangement with the bottom ZnO substrate underneath graphene, transparency of graphene enables the growth of epitaxial material.

Example 3: Modification of Graphene Surface on an Element Surface

(18) Based on commercially available graphene sensor device as a device which requires a graphene layer, whether the sensor device can be manufactured by applying the method of modifying the graphene surface of the present invention was tested.

(19) As the result shown in FIG. 7, the platinum nanoparticles were formed on the graphene surface using graphene transparency. It was confirmed that the platinum nanoparticles dissociate hydrogen molecules to hydrogen atoms, and provide electrons to the graphene surface, thereby causing a change in current, so that the modified graphene surface can be used as a hydrogen sensor.

Example 4: Preparation of a Sensor which Uses Surface Plasmon Resonance (SPR) of Gold Nanoparticles-Modified Graphene

(20) Using the transparency of graphene, gold nanoparticles were formed on the graphene surface as in Example 1. The gold nanoparticles were formed in a relatively consistent size on the graphene surface in a high density, and could be used as a transparent SPR sensor.

Example 5: Experimentation on Cell Growth Using Graphene Transparency

(21) A cell can grow on a metal surface using the transparency of graphene. Generally, the metal surface is not appropriate for a cell to be adsorbed thereonto and grow thereon, and thus undergoes a modification process. In the exemplary embodiments of the present invention, polylysine, as a material enabling the cells to be well adsorbed onto the metal surface, was functionalized, and graphene was transferred, followed by a cell culture experiment. As a result, it was confirmed that the feature of electron transfer of metal was maintained, while growing the cells on the metal surface using the graphene layer as a intermediary.

(22) Additionally, in a case of using glass instead of the metal, cell growth can be promoted using the transparency of graphene. Specifically, an experiment on cell growth was conducted on the graphene surface transferred on glass, and on glass on which polylysine is laid and graphene is transferred. The result thereof is shown in FIG. 8. As shown in FIG. 8, it was confirmed that cell growth was more promoted on the substrate where polylysine is laid under graphene.