KR20200060934A - Fabricating method for composite of nanoparticle on graphene - Google Patents

Abstract

Disclosed is a method for manufacturing a graphene hybrid structure in which nanoparticles are combined. The method for manufacturing the graphene hybrid structure in which nanoparticles are combined according to the present invention comprises: a first step of depositing graphene on a base substrate; a second step of modifying the surface of the graphene by performing surface treatment using plasma with respect to graphene deposited on the base substrate; and a third step of forming metal nanoparticles on the graphene by immersing the graphene deposition base substrate on which the plasma surface treatment is performed in a metal ion aqueous solution using a metal ion reduction method. The present invention can easily control the shape and size density of silver nanoparticles through plasma surface treatment.

Description

Manufacturing method of nanoparticle-linked graphene hybrid structure{Fabricating method for composite of nanoparticle on graphene}

The present invention relates to a method for producing a graphene hybrid structure in which nanoparticles are bound, and more specifically, a structure-derived substance including stabilizing agents, reducing agents, surfactants, and the like. It is possible to manufacture a graphene hybrid structure in which nanoparticles are combined in an environmentally friendly manner without using directing agents, and prevents the inherent deterioration of properties at the nanoparticle-graphene interface due to the use of structure derivatives and plasmas on the graphene surface The present invention relates to a method for manufacturing a graphene hybrid structure in which nanoparticles are combined, which can easily control the shape and size density of silver nanoparticles through surface treatment.

Graphene is a structure in which carbon atoms are arranged in a two-dimensional honeycomb structure, and has unique structural, optical, and electronic characteristics. For example, graphene is known to have a very large specific surface area, high Young's modulus (1,100 GPa), excellent mechanical properties, high thermal and electrical conductivity, high carrier mobility, and high transparency of 95% or more. Based on these excellent properties, graphene can be said to be one of the most researched materials in various fields.

In addition, metal-based nanoparticles have been actively researched in medical fields, including electronic devices, information storage media, catalysts, optoelectronic devices, sensors, and imaging, due to their unique variety of electrical, magnetic, catalyst, and optical properties.

The current nanomaterial synthesis technology has provided a foundation for research by controlling the size and shape of metal nanoparticles at various nanoscale levels. Among them, silver (Ag) has high electrical and thermal conductivity among metals, and has been actively used as a conductive ink material. Recently, silver nanoparticles have a unique optical property of adjustable local surface plasmon resonance, and the surface plasmon resonance technology of these metal nanoparticles dramatically lowers the detection strength, which is one of the disadvantages of the existing Raman spectorscopy analysis technology. Can be increased. In addition, it is expanding its application fields to the chemical and bio-sensing areas.

Here, the localized surface plasmon resonance (LSPR) refers to a phenomenon in which free electrons inside a metal vibrate collectively in response to an external electromagnetic field. As a result, precious metal-based nanoparticles strongly absorb or scatter light of a specific wavelength. Shows the characteristics. The wavelength of light absorbed by metal particles varies depending on the particle size and shape, composition, distance between particles, structure, and external permittivity. It is known that silver (Ag) can cause resonance in the visible region.

Moreover, recently, various studies have been conducted using nanoparticle-graphene hybrid structures in which various nanoparticles such as metal or metal oxide are combined with graphene. At this time, excellent properties and properties of graphene may be added due to the addition of unique excellent physical properties different from the bulk state of the nanoparticles, and sometimes various synergistic effects may be obtained through nanoparticle-graphene bonding.

Metal nanoparticle-graphene hydride structures can be applied in various fields depending on the metal nanoparticles that are combined with graphene. For example, graphene has a very large specific surface area, high electrical conductivity, and excellent mechanical properties, so it can be said to be one of the most suitable supports for complexing with metal nanoparticles for excellent electrochemical catalytic activity. In addition, through the combination of metal nanoparticles and graphene, depending on the Fermi level/work function of each of the metal nanoparticles and graphene, from graphene to metal nanoparticles or from metal nanoparticles to graphene Interfacial charge transfer is achieved.

Therefore, the interface between the bound graphene and the metal nanoparticles acts as a'hot spot', greatly increasing the catalytic activity of the metal particle-graphene hybrid structure. In order to increase the mobility of the interfacial charge, graphene and metal nanoparticles need to form a strong bond.

In the conventional metal nanoparticle-graphene complexation method (binding method), a method of first synthesizing a metal nanoparticle and then complexing it with graphene to obtain a metal nanoparticle-graphene hybrid structure has been mainly used.

For example, a metal nanoparticle solution dispersed in a specific solvent can be obtained according to shape-directing agents containing surfactants on the surface of the metal nanoparticles, and graphene can also be dispersed in a suitable solvent. . When these two solutions are mixed, metal nanoparticles are bound to the graphene surface through surfactant exchange.

However, the metal nanoparticle-graphene hybrid structure obtained by such a conventional method has a disadvantage in that the bond between the metal nanoparticles and graphene is relatively weak, so that the surface charge transfer may not be smooth, and the acid treatment for removing the surfactant is performed. In the process, properties of metal nanoparticles may change, and there are problems such as aggregation of metal nanoparticles during heat treatment.

Republic of Korea Registered Patent Publication No. 10-1359771 (2014.01.29.)

Accordingly, the present invention has an object to provide a method for manufacturing a graphene hybrid structure in which nanoparticles are combined, which can overcome the above-described conventional problems.

Another object of the present invention is to eliminate the use of conventional stabilizers (stabilizing agents), reducing agents (reducing agents), surfactants (Surfactants), and the like, and is eco-friendly, excluding the use of shape-directing agents (surfactants and acids) Graphene hybrid combined with nanoparticles that can prevent the degradation of intrinsic properties at the silver nanoparticle-graphene interface by processes such as treatment and can easily control the shape and size density of metal nanoparticles through plasma surface treatment It is to provide a method for manufacturing a structure.

The object of the present invention is not limited to the above, other objects not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present invention for achieving some of the above technical problems, a method for manufacturing a graphene hybrid structure in which nanoparticles are combined according to the present invention comprises: a first step of depositing graphene on a base substrate; A second step of modifying the surface of the graphene by subjecting the graphene deposited on the base substrate to a surface treatment using plasma; A third step of forming metal nanoparticles on the graphene is provided by immersing the graphene deposition base substrate on which the plasma surface treatment has been performed in a metal ion aqueous solution using a metal ion reduction method.

In the second step or the third step, nanoparticles are combined without using shape-directing agents including stabilizing agents, reducing agents, and surfactants. Fin hybrid structures can be produced.

The base substrate is a copper substrate, and in the first step, the graphene may be formed as a single layer.

The graphene may be deposited using a thermal chemical vapor deposition (T-CVD) method.

The first step includes the steps of loading the base substrate in a thermal chemical vapor deposition (T-CVD) chamber; When the internal temperature of the chamber reaches 600°C, hydrogen having a purity of 99.999% is introduced with a flow rate of 60 sccccm maintained, and the pressure inside the chamber is maintained at 0.3 Torr to the internal temperature of the chamber to 1000°C. Heating and maintaining for 20 minutes; Maintaining a ratio of methane gas (CH ₄ ) and hydrogen gas (H ₂ ) at 2:1 for graphene deposition and maintaining the pressure of the chamber at 0.45 Torr for 5 minutes; A step of stopping graphene deposition using a thermochemical vapor deposition method on the base substrate by stopping gas supply and heating inside the chamber and cooling the chamber may be provided.

The flow rate of the methane gas (CH ₄ ) and the hydrogen gas (H ₂ ) for the deposition of the graphene may be 50 sccm: 25 sccm.

In the second step, surface treatment for the graphene may be performed by using a single gas of nitrogen or plasma using at least two kinds of mixed gas containing nitrogen.

The surface treatment using the plasma is an atmospheric pressure plasma generating device, an inductively coupled plasma (ICP) device, a reactive ion etching (RIE) device, a chemical ion beam etching (CAIBE) device, a reactive ion beam etching (RIBE) device, an electron resonance plasma ( ECR) device.

In the second step, the plasma surface treatment may be performed using an inductively coupled plasma (ICP) device, injecting 100 sccm of nitrogen into the chamber and generating plasma with a low power of 12 W, within 15 minutes.

Before the first step, a step of removing impurities or native oxide on the surface of the base substrate by performing acid treatment on the base substrate using a hydrofluoric acid solution (HF) may be further provided.

In the third step, the aqueous metal ion solution may be an aqueous 98% silver nitrate solution having a concentration of 5 mM.

In the third step, immersing the base substrate on which the graphene has been subjected to the second step in a solution of 98 mM silver nitrate at a concentration of 5 mM at room temperature within 1 minute to grow silver nanoparticles on the graphene. Can be

After the third step, the graphene may further include a step of cleaning and drying a structure in which metal nanoparticles are bonded.

The silver nanoparticles may have a size of 100 nm or less.

The graphene hybrid structure in which the metal nanoparticles are combined may be used for biosensing or manufacturing of a bio-image measuring device.

The graphene hybrid structure in which the metal nanoparticles are combined may be applied to photocatalyst, transparent conductive thin film, or photonics production.

The density of the metal nanoparticles in the third step may be increased as the plasma surface treatment time in the second step is increased.

The shape and density of the metal nanoparticles in the third step are controlled by controlling the plasma surface treatment conditions including the flow rate of the gas injected for the plasma in the second step, the time of the plasma surface treatment and the output of the plasma. can do.

According to the present invention, a graphene hybrid in which metal nanoparticles are environmentally friendly without using shape-directing agents including stabilizing agents, reducing agents, surfactants, etc. The structure can be manufactured, and the shape and size density of the silver nanoparticles can be easily controlled through plasma surface treatment on the graphene surface.

In addition, by excluding the use of metal ion reducing agents during the growth of metal nanoparticles, it prevents the inherent degradation of properties at the silver nanoparticle-graphene interface by processes such as surfactants and acid treatments, and is an environmentally harmful structure derivative. By reducing the use of -directing agents, the environmental and economic costs of post-treatment of these solutions can be reduced.

In addition, the metal nanoparticle-graphene hydride structure according to the present invention has a higher bonding force between the metal nanoparticles and graphene than the conventional case, and thus has excellent interface charge transfer, which may be advantageous in electrochemical catalyst applications.

In addition, it can be applied to Plasmonics applications and sensing fields used for molecular detection, and has the advantage that it can be applied to surface-enhanced Raman Scattering (SERS)-based bio sensing and bio image measurement and photocatalyst. have.

The effects of the present invention are not limited to the above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a process flow chart showing a method of manufacturing a nanoparticle-linked graphene hybrid structure according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of a thermochemical vapor deposition method for graphene deposition in FIG. 1.
3 is a schematic diagram of an inductively coupled plasma (ICP) device for plasma surface treatment in FIG. 1.
4 shows electron microscope (SEM) pictures of metal nanoparticles bound to graphene deposited on a copper substrate.
5 is an electron microscope (SEM) pictures showing the distribution of metal nanoparticles generated by plasma surface treatment time.
FIG. 6 is an electron microscope (SEM) photograph showing changes in metal nanoparticle production depending on changes in each condition.
7 are graphs showing properties of a metal nanoparticle-graphene hybrid structure according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. The present invention can be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In addition, in various embodiments, components having the same configuration will be described only in the exemplary embodiment using the same reference numerals, and in other embodiments, only the configuration different from the exemplary embodiment will be described.

Throughout the specification, when a part is said to be “connected” to another part, this includes not only the case of being “directly connected”, but also “indirectly connected” with other members interposed therebetween. In addition, when a part is said to "include" a certain component, this may mean that other components are not included, but other components are not excluded unless specifically stated to the contrary.

1 is a process flow chart showing a method of manufacturing a nanoparticle-linked graphene hybrid structure according to an embodiment of the present invention.

As illustrated in FIG. 1, a graphene hybrid structure in which nanoparticles are combined according to an embodiment of the present invention comprises depositing graphene on a base substrate (S110) and graphene deposited on a base substrate. Regarding the step of modifying the surface of the graphene by performing a surface treatment using plasma (S120), forming a metal nanoparticle on the graphene (S130), and cleaning the graphene hybrid structure in which nanoparticles are combined And drying (S140).

Each step is described in more detail as follows.

First, a pre-treatment step for removing impurities or native oxide of the base substrate before graphene deposition may be added. The pre-treatment step is a process of preparing a copper substrate as the base substrate and performing an acid treatment on the base substrate using a hydrofluoric acid solution (HF) to remove impurities or native oxide of the copper substrate. Accordingly, impurities or native oxide on the surface of the base substrate is removed.

Next, in the step of depositing graphene on a base substrate (S110), a copper substrate is prepared as the base substrate, and as shown in FIG. 2, thermal chemical vapor deposition on the copper substrate (Thermal Chemical Vapor Deposition: Graphene is deposited using a T-CVD method. Here, the graphene may be formed as a single layer. This is to strengthen the binding force with the metal nanoparticles described later.

Graphene deposition is described in detail through a schematic diagram of a thermochemical vapor deposition method for graphene deposition shown in FIG. 2.

As shown in FIG. 2, the base substrate is loaded in a thermal chemical vapor deposition (T-CVD) chamber for graphene deposition on the base substrate. Thereafter, when the internal temperature of the chamber reaches 600° C., 99.999% purity hydrogen is introduced to maintain the inlet flow rate of 60 sccccm, and the internal temperature of the chamber is 1000° C. while maintaining the pressure of the chamber at 0.3 Torr. It is heated up to 20 minutes. Then, for the deposition of graphene, when the ratio of methane gas (CH ₄ ) and hydrogen gas (H ₂ ) is maintained at 2:1 and the pressure in the chamber is maintained at 0.45 Torr for 5 minutes, graphene is deposited on the base substrate. The pin will be deposited. Then, when the gas supply and heating inside the chamber is stopped and the chamber is cooled, the graphene deposition process is completed. The graphene deposition process is only one example, and graphene deposition may be performed by various methods well known to those skilled in the art.

Next, in the step of modifying the surface of the graphene by performing a surface treatment using plasma (S120), a plasma is formed using a single gas of nitrogen or at least two kinds of mixed gas containing nitrogen, and the plasma is generated. The surface treatment for the graphene may be performed by using.

The surface treatment using the plasma is an atmospheric pressure plasma generating device, an inductively coupled plasma (ICP) device, a reactive ion etching (RIE) device, a chemical ion beam etching (CAIBE) device, a reactive ion beam etching (RIBE) device, an electron resonance plasma ( ECR) device. FIG. 3 schematically shows an inductively coupled plasma (ICP) device as an example of a device for plasma surface treatment.

When the plasma surface treatment is performed using an inductively coupled plasma (ICP) device and a plasma is formed using a single nitrogen gas, for example, surface treatment using plasma for the graphene is 100 sccm nitrogen. Plasma surface treatment can be performed within 15 minutes by injecting into the chamber and generating plasma with a low power of 12W.

When the plasma surface treatment is performed on the graphene deposited on the base substrate as described above, the graphene surface is modified according to the graphene surface chemical reaction, and the graphene deposition layer is formed with a band gap in nitrogen doping. Therefore, it has the properties of n-type doped graphene.

At this time, the plasma surface treatment conditions such as the flow rate of the gas injected for the plasma, the plasma intensity, and the output of the plasma can be controlled, and according to the plasma surface treatment conditions, the metal nanoparticles bound to graphene in the process described below Density and shape will change. Accordingly, it is possible to control the density or shape of the metal nanoparticles by adjusting the plasma surface treatment conditions. For example, it has been confirmed through experiments that the density of the metal nanoparticles increases as the plasma surface treatment time increases.

The method of obtaining the metal nanoparticle-graphene hybrid structure by directly growing the metal nanoparticles on the graphene surface is advantageous in electrochemical catalyst applications due to high binding force between the metal nanoparticles and graphene and relatively excellent interfacial charge transfer. It is used a lot. However, in the conventional case, a method of growing metal nanoparticles on the surface of graphene by reducing metal ions on a solution in which graphene is dispersed by chemical, thermal, or electrochemical methods was used. In this case, hydrophobic graphene is used. The method of inducing nucleation of metal nanoparticles on a fin surface has a very difficult problem.

In order to solve this problem, conventionally, use of shape-directing agents such as stabilizing agents, reducing agents, surfactants, or functional groups containing oxygen through acid treatment Thus, methods such as providing nucleation sites of metal nanoparticles on the graphene surface have been used. In this case, it also poses problems such as environmental problems and reduced interfacial charge transfer in terms of using shape-directing agents.

In the present invention, these problems are solved through a method of plasma surface treatment on graphene, and a structural derivative including stabilizing agents, reducing agents, and surfactants in the manufacturing process. It is possible to manufacture an eco-friendly and excellent graphene-metal nanoparticle hybrid structure by not using -directing agents at all.

Next, in the step of forming metal nanoparticles on the graphene, the metal nanoparticles on the graphene are immersed in a metal ion aqueous solution by immersing the graphene deposition base substrate on which the plasma surface treatment has been performed. To form.

Here, as the aqueous metal ion solution, an aqueous 98% silver nitrate solution having a concentration of 5 mM may be used. Accordingly, the formation of metal nanoparticles is performed by immersing the base substrate in which plasma surface treatment for the above-described graphene is performed in less than 1 minute in a 98% silver nitrate solution at a concentration of 5 mM at room temperature, and the silver nanoparticles are formed on the graphene. By growing, to produce a hybrid structure in which metal nanoparticles are bonded on the graphene.

Using a metal ion reduction method using a silver nitrate solution, a bonding mechanism for growing and bonding silver nanoparticles (metal nanoparticles) on the graphene surface deposited on the copper substrate is described as follows. Since the redox potential of copper (Cu ^{2 +} /Cu) is “0.34V”, it is lower than the redox potential of silver (Ag ⁺ /Ag), “0.8V”, so silver ions Upon contact with silver copper, it is spontaneously reduced to the form of silver particles and copper is oxidized.

The shape and type of the silver precipitate at this time may vary depending on the concentration, solution type, temperature, and the like. In the conventional case, it has been controlled through the use of shape-directing agents including stabilizing agents, reducing agents, surfactants, and the like.

The metal ion reduction method utilizes a phenomenon in which the reduced metal atoms gather together to form metal nanoparticles when the metal ion is reduced using a reducing agent. Size, shape, and crystal structure depend on the characteristics of the reducing agent and shape-directing agents. The back is controlled. However, the use of such a reducing agent has a problem in that it is difficult to completely remove the metal particles after formation, and acts as a functional group or an impurity on the surface of the metal nanoparticles, thereby acting as a factor inhibiting the inherent properties of the metal nanoparticles. In addition, the use of shape-directing agents, including stabilizing agents, reducing agents, and surfactants, poses problems such as causing environmental problems after processing. have.

However, in the present invention, a graphene/copper substrate surface-treated in a solution of silver nitrate (98%) at a concentration of 5 mM at room temperature by a metal ion reduction method according to plasma surface treatment without using any shape-directing agents is used. A method of inducing spontaneous precipitation of silver nanoparticles on a graphene surface by immersion within 1 minute is used, and thus, there is an advantage capable of solving the above-mentioned problems.

The following description shows the results of experiments conducted to investigate the correlation between the plasma surface treatment and the density or shape of the metal nanoparticles, and the properties of the graphene hybrid spheres combined with the metal nanoparticles prepared according to the present invention. This is explained through FIGS. 4 to 7.

FIG. 4 shows electron microscope (SEM) pictures of metal nanoparticles bound to graphene deposited on a copper substrate. FIG. 4(a) is an electron microscope (SEM) photograph of metal nanoparticles in which metal nanoparticles are bonded to a graphene surface without plasma surface treatment, and FIG. 4(b) shows FIG. 4(a). ) Is a partially enlarged view, and (c) of FIG. 4 is an electron microscope (SEM) photograph of silver nanoparticles bound to the graphene surface using a metal ion reduction method after nitrogen plasma surface treatment is performed according to the present invention, FIG. 4(d) is a partially enlarged view of FIG. 4(c).

As shown in (a) and (b) of FIG. 4, when silver nanoparticles are bonded to the graphene surface without plasma surface treatment, it has a dendrite structure in which silver nanoparticles are coarsened, and metal nano It can be seen that the particles are irregularly formed. In addition, it can be seen that the approximate scale has a relatively large size in a micrometer size, and silver nanoparticles less than 100 nm are not observed.

It is judged that silver ions are electrolessly deposited on the surface of the copper substrate exposed to the defect sites of graphene to generate nucleation of silver, and also to form a dendritic structure due to the supersaturation of silver ions at local sites.

On the other hand, as shown in Figure 4 (c), (d), when the metal nanoparticles are bonded to the graphene surface according to the present invention, that is, the silver bound to the surface of the graphene subjected to nitrogen plasma surface treatment It can be seen that the nanoparticles are uniform with high density.

It is known that the method of inducing nucleation of metal nanoparticles on a hydrophobic graphene surface having an inert surface in a solution as described above is very difficult to produce silver nanoparticles on the graphene surface treated with nitrogen plasma. In addition, in the case of silver particles, since the adsorption energy on the graphene surface is very low at 0.51kacl/mol, nuclear growth does not generally occur.

However, as in the case of the present invention, in the case of graphene surface-treated with nitrogen plasma, the CN bonding structure acts as a hydrophilic functional group on the graphene surface, thereby facilitating adsorption of silver particles, thereby strengthening the binding force, and uniforming the graphene surface It enables nucleation of silver nanoparticles.

As described above, it can be seen that the silver nanoparticles bound to the graphene surface subjected to nitrogen plasma surface treatment according to the present invention are uniform at a high density and have a size of 100 nm or less.

That is, it can be seen that by performing the plasma surface treatment, the metal nanoparticles bonded in a subsequent process have a high density and are uniform, and have a size of 100 nm or less.

In the present invention, plasma surface treatment is possible by adjusting plasma surface treatment conditions such as flow rate of gas injected for plasma, plasma intensity, plasma output, and the like, to the graphene through a metal ion reduction method described later according to the plasma surface treatment conditions. It has been described that the density and shape of the metal nanoparticles to be combined are changed. Accordingly, it is possible to control the density or shape of the metal nanoparticles by adjusting the plasma surface treatment conditions. This is explained through FIGS. 5 and 6.

5 is an electron microscope (SEM) pictures showing the distribution of metal nanoparticles generated by plasma surface treatment time. 5(a) shows that the plasma surface treatment time is 2 minutes, FIG. 5(b) shows that the plasma surface treatment time is 5 minutes, and FIG. 5(c) shows that the plasma surface treatment time is 10 minutes, and FIG. 5 (D) shows the change in size and density distribution of silver nanoparticles when the plasma surface treatment time is 15 minutes.

As shown in FIG. 5, it can be seen that as the nitrogen plasma treatment time increases on the graphene surface on the copper substrate, the density of silver nanoparticles generated by the metal ion ring method using silver nitrate solution increases. In addition, it can be seen that silver nanoparticles are uniformly formed over the entire surface of the graphene as the nitrogen plasma treatment time increases.

However, when it is outside these conditions, a problem arises that dendritic coarsened silver nanoparticles are formed due to exposure to the copper substrate by plasma damage. Accordingly, the preferred embodiment of the present invention has been found that the nitrogen plasma treatment condition is preferably a surface treatment within 15 minutes at a low output condition of 12W.

As described above, a preferred embodiment of the present invention is a nitrogen plasma treatment at a low output condition of 12W, within 15 minutes, at a room temperature, the silver nitrate solution precipitates silver nanoparticles from the silver nitrate solution at a metal ion reduction method of 5 mM and It can be seen that the precipitation time (immersion time) within 1 minute. In this case, the silver nanoparticles bound to the graphene are uniform with a high density as shown in FIG. 5(d) and have a size of 100 nm or less.

In order to prove this, we examined changes in the production of metal nanoparticles while changing various conditions. This is shown in FIG. 6.

FIG. 6 is an electron microscope (SEM) photograph showing changes in metal nanoparticle production depending on changes in each condition. FIG. 6(a) shows that when the molar concentration of the silver nitrate (98%) solution is increased from 5 mM to 10 mM, FIG. 6(b) shows the precipitation time of the nanoparticles when the metal ion reduction method is applied, i. When the time is increased from 1 minute to 5 minutes, FIG. 6(c) increases the nitrogen plasma output from 12W to 50W during plasma surface treatment, and FIG. 6(d) increases the nitrogen plasma surface treatment time by 15 minutes. Electron microscopy (SEM) pictures of the silver nanoparticles generated when increased to within 20 minutes.

As shown in FIG. 6, it can be seen that when the conditions according to the preferred embodiment of the present invention are deviated, the production of silver nanoparticles is non-uniform or the silver nanoparticles are generated in a plate shape or a resin shape. This is because, as described above, the growth type, type, and density of the nanoparticles may vary depending on the concentration of the metal ion aqueous solution, the type of the aqueous solution, temperature, and plasma surface treatment conditions.

7 are graphs showing properties of a metal nanoparticle-graphene hybrid structure prepared according to the present invention.

7 (a) is a silver nanoparticle-graphene hybrid structure (Ag deposited on N-Gr/Cu) prepared according to the present invention, and a structure on which only silver nanoparticles are formed on a copper substrate (Ag deposited on Cu) It is a graph showing the change in Raman measurement intensity using R6G (Rhodamine 6G), and FIG. 7(b) shows Raman according to the molar concentration of R6G in the silver nanoparticle-graphene hybrid structure prepared according to the present invention ( Raman) is a graph showing the change in measurement intensity, and FIG. 7(c) shows the Raman (Rman) according to the molar concentration of R6G at Raman shift 611 (cm ^-1 ) in the silver nanoparticle-graphene hybrid structure prepared according to the present invention. Raman) It is a graph showing the change in measurement intensity.

As shown in Figure 7 (a), the surface-enhanced Raman scattering (SERS) effect of the silver nanoparticle-graphene hybrid structure according to the present invention is commonly used to investigate the R6G 10μM Raman of silver nanoparticle-graphene hybrid structure (Ag deposited on N-Gr/Cu) prepared according to the present invention using a molar concentration solution and silver nanoparticle synthesis (Ag deposited on Cu) on a common copper substrate (Raman) Looking at the graph showing the change in the measurement intensity, the Raman strength of R6G is a silver nanoparticle-graphene hybrid structure according to the present invention (Ag deposited on N-Gr/Cu) Raman (Raman) measurement strength on a common copper substrate It can be seen that it appeared very high compared to the structure (Ag deposited on Cu) synthesized with silver nanoparticles.

In addition, as shown in Fig. 7 (b), (c), according to the results of examining the Raman measurement intensity change by changing the molar concentration of R6G of the silver nanoparticle-graphene hybrid structure prepared according to the present invention, The detection limit of R6G Raman measurement of the silver nanoparticle-graphene hybrid structure prepared according to the present invention is approximately 10 nM, and it can be seen that a linear Raman measurement intensity change result is derived from the concentration change of R6G.

As described above, according to the present invention, nanoparticles are environmentally friendly without using shape-directing agents including stabilizing agents, reducing agents, surfactants, etc. The prepared graphene hybrid structure can be manufactured, and the shape and size density of silver nanoparticles can be easily controlled through plasma surface treatment on the graphene surface.

In addition, by excluding the use of metal ion-reducing agents during the growth of silver nanoparticles, it prevents degradation of intrinsic properties at the metal nanoparticle-graphene interface by processes such as surfactants and acid treatments, and environmentally harmful structure derivatives (shape- By reducing the use of directing agents, it is possible to reduce the environmental and economic costs associated with post-treatment of these solutions.

In addition, the metal nanoparticle-graphene hydride structure according to the present invention has a higher bonding force between the metal nanoparticles and graphene than the conventional case, and thus has excellent interface charge transfer, which may be advantageous in electrochemical catalyst applications.

In addition, it can be applied to Plasmonics applications and sensing fields used for molecular detection, and has the advantage of being applicable to bio-sensing based on surface-enhanced Raman Scattering (SERS) and bio-image measurement and photocatalyst. have.

So far, the present invention has been shown and described with reference to preferred embodiments for illustrating the principles of the present invention, but the present invention is not limited to the configuration and operation as described and described as such. Rather, it will be understood by those skilled in the art to which the present invention pertains that many changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims.

Claims (18)

In the manufacturing method of the graphene hybrid structure is nanoparticles coupled,
A first step of depositing graphene on the base substrate;
A second step of modifying the surface of the graphene by subjecting the graphene deposited on the base substrate to a surface treatment using plasma;
Nanoparticles characterized by having; a third step of forming a metal nanoparticles on the graphene by immersing the graphene deposition base substrate on which the plasma surface treatment has been performed in a metal ion aqueous solution using a metal ion reduction method Method for manufacturing a combined graphene hybrid structure.
The method according to claim 1,
In the second step or the third step, nano-particles characterized in that no shape-directing agents including stabilizing agents, reducing agents, and surfactants are used. Preparation method of a combined graphene hybrid structure.
The method according to claim 1 or claim 2,
The base substrate is a copper substrate, the method of manufacturing a graphene hybrid structure in which nanoparticles are combined, characterized in that the graphene is formed as a single layer in the first step.
The method according to claim 3,
The graphene is a method of manufacturing a nanoparticle-coupled graphene hybrid structure, characterized in that it is deposited using a thermal chemical vapor deposition (Thermal Chemical Vapor Deposition: T-CVD) method.
The method according to claim 4,
The first step,
Loading the base substrate in a thermal chemical vapor deposition (T-CVD) chamber;
When the internal temperature of the chamber reaches 600° C., hydrogen having a purity of 99.999% is maintained at an inlet flow rate of 60 sccccm, and the internal temperature of the chamber is maintained at 1000° C. while maintaining the pressure of the chamber at 0.3 Torr. Heating and maintaining for 20 minutes;
Maintaining the ratio of methane gas (CH ₄ ) and hydrogen gas (H ₂ ) at 2:1 for graphene deposition and maintaining the pressure of the chamber at 0.45 Torr for 5 minutes;
Stopping the supply and heating of the gas inside the chamber and cooling the chamber to complete graphene deposition using a thermochemical vapor deposition method on the base substrate; of the nanoparticle-coupled graphene hybrid structure comprising Manufacturing method.
The method according to claim 5,
A method for manufacturing a graphene hybrid structure in which nanoparticles are combined, characterized in that the flow rate of the methane gas (CH ₄ ) and the hydrogen gas (H ₂ ) for the deposition of the graphene is 50 sccm: 25 sccm.
The method according to claim 4,
In the second step, a graphene hybrid structure in which nanoparticles are combined is characterized in that surface treatment is performed on the graphene using a single gas of nitrogen or plasma using at least two kinds of mixed gas containing nitrogen. Manufacturing method.
The method according to claim 7,
The surface treatment using the plasma is an atmospheric pressure plasma generating device, an inductively coupled plasma (ICP) device, a reactive ion etching (RIE) device, a chemical ion beam etching (CAIBE) device, a reactive ion beam etching (RIBE) device, an electron resonance plasma ( ECR) method for manufacturing a graphene hybrid structure in which nanoparticles are combined, characterized in that it is performed using any one device selected from among devices.
The method according to claim 7,
In the second step, the plasma surface treatment is performed using an inductively coupled plasma (ICP) device, injecting 100 sccm of nitrogen into the chamber and generating plasma with a low power of 12 W to perform nanoparticles within 15 minutes. Preparation method of a combined graphene hybrid structure.
The method according to claim 7,
Before the first step, characterized in that it further comprises the step of removing impurities or native oxide on the surface of the base substrate by performing an acid treatment on the base substrate using a hydrofluoric acid solution (HF) Preparation method of graphene hybrid structure to which nanoparticles are bound.
The method according to claim 7,
In the third step, the metal ion aqueous solution is a method for producing a graphene hybrid structure in which nanoparticles are combined, characterized in that the aqueous solution of 98% silver nitrate at a concentration of 5 mM.
The method according to claim 11,
In the third step, immersing the base substrate on which the graphene has been subjected to the second step in a solution of 98% silver nitrate at a concentration of 5 mM at room temperature within 1 minute to grow silver nanoparticles on the graphene. Method of manufacturing a graphene hybrid structure in which nanoparticles are combined, which is characterized in that.
The method according to claim 11,
After the third step, the method of manufacturing a nanoparticle-coupled graphene hybrid structure, characterized in that it further comprises the step of washing and drying the structure in which the metal nanoparticles are bound on the graphene.
The method according to claim 13,
The method of manufacturing a graphene hybrid structure in which nanoparticles are combined, wherein the silver nanoparticles have a size of 100 nm or less.
The method according to claim 14,
The nanoparticle-coupled graphene hybrid structure is a method of manufacturing a nanoparticle-coupled graphene hybrid structure, characterized in that it is used in the manufacture of bio-sensing or bio-image measuring devices.
The method according to claim 14,
The nanoparticle-coupled graphene hybrid structure is a method for producing a nanoparticle-coupled graphene hybrid structure, characterized in that applied to the production of photocatalysts, transparent conductive thin films, or photonics.
The method according to claim 14,
The method of manufacturing a graphene hybrid structure in which nanoparticles are combined, characterized in that the density of the metal nanoparticles in the third step is increased as the plasma surface treatment time in the second step is increased.
The method according to claim 14,
Control the shape and density of the metal nanoparticles in the third step by adjusting the plasma surface treatment conditions including the flow rate of the gas injected for the plasma in the second step, the time of plasma surface treatment and the output of the plasma. Method of manufacturing a graphene hybrid structure is nanoparticles, characterized in that the combination.

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