KR101418237B1 - Fabrication method of carbon-alloy composite by using intense pulsed light - Google Patents

Abstract

The present invention relates to a method of producing a carbon-metal composite using extreme ultraviolet-white light irradiation, comprising the steps of: 1) depositing two or more metals on a substrate coated with a carbon support, or adding a carbon support to two or more metal precursor solutions Applying on a substrate and drying to form an alloy layer; And 2) irradiating the substrate on which the alloy layer is formed with ultraviolet-white light. When the carbon-metal composite particle is prepared by using the extreme ultraviolet-white light irradiation method, not only the performance of the fuel cell is increased, It is possible to manufacture in a short time at atmospheric pressure, so that efficiency and productivity are high and it is easy to mass production.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a carbon-

The present invention relates to a method for producing a carbon-alloy composite, and more particularly, to a method for producing a carbon-alloy composite at room temperature and atmospheric pressure using an extreme ultraviolet-white light irradiation method.

Fuel cells are currently used in a wide range of applications ranging from small and portable items such as mobile phones, cameras and laptops to large and large items such as automobiles, airplanes, factory machinery, As energy, it is attracting attention as next generation energy.

There are many types of fuel cells, including PEMFC, DMFC, DEFC, SOFC, and MCFC. Fuel cells are attracted attention due to their simplicity of operation as well as their simplicity of operation, but it is not easy to synthesize a metal that is used in a catalyst that plays an important role in this chemical reaction and a carrier that efficiently flows the current generated by the reaction However, metal is expensive because it is based on precious metals such as gold, platinum and palladium, and has a disadvantage in that efficiency is lowered when pure metal is used as a catalyst.

To solve these drawbacks, studies have been actively conducted to form alloys by electrochemical methods, thermal processes, or thermal processes using electromagnetic waves in order to obtain an effect of increasing the efficiency while lowering the price. However, these processes cause the deterioration of the physical properties of the carbon-based support due to the metal nanoparticles being injected while damaging the carbon bonds of the carbon-based support. The process temperature is high and the production time is at least 10 hours. There is a problem.

Korean Patent Publication No. 10-2007-0091936

C.T. Hsieh, J.Y. Lin, S.Y. Yang. Carbon nanotubes embedded with PtRu nanoparticles as methanol fuel cell electrocatalysts. Physica E 2009; 41: 373-378

The object of the present invention is to provide a method for manufacturing a high-efficiency carbon-metal composite capable of large-scale and large-scale production at a low cost through a simple process at a low temperature, A fuel cell catalyst, and a sensor.

According to one aspect of the present invention, there is provided a method of manufacturing a carbon-metal composite using extreme ultraviolet light irradiation, comprising the steps of: 1) depositing two or more metals on a substrate coated with a carbon- Adding and dispersing a carbon carrier on a substrate, drying and coating the carbon carrier to form an alloy layer; And 2) irradiating the substrate on which the alloy layer is formed with ultraviolet-white light.

According to an embodiment of the present invention, the carbon carrier includes carbon black, carbon nanotubes (CNT), carbon nanofibers (CNF), carbon nanocoils (CNC), aligned porous carbon (OPC) Beads (MCMB), multi-wall carbon nanohorns (SWNH), carbon aerogels (CAG), and graphenes.

According to another embodiment of the present invention, the alloy may be at least one selected from platinum-ruthenium (Pt-Ru), platinum-molybdenum (Pt-Mo), platinum-tin (Pt-Sn), palladium- Ruthenium-tin (Pt-Ru-Sn), platinum-tin-nickel (Pt-Ru-Mo), plutonium-molybdenum (Pt-Ru-Ir), platinum-ruthenium-platinum-ruthenium-iridium (Pt-Ru-Ir) But is not limited thereto.

According to an embodiment of the present invention, the metal deposition may be performed using evaporation or sputtering physical vapor deposition (PVD).

According to an embodiment of the present invention, the metal precursor may be selected from the group consisting of hydroxides, nitrates, sulfates, acetates, chlorides, and mixtures thereof. The solvent of the metal precursor solution may be distilled water, dimethylformamide, ethanol, Ethylene glycol, diethyl glycol, or mixtures thereof.

According to an embodiment of the present invention, the extreme ultraviolet white light is irradiated through the xenon flash lamp, wherein the pulse width of the xenon flash lamp is 0.1 to 100 ms, and the pulse gap of the xenon flash lamp is 0.1 to 100 ms, and the pulse number of the xenon flash lamp is preferably 1 to 1000 times. The intensities of the xenon flash lamps are preferably 0.01 J / cm 2 to 100 J / cm 2.

The present invention also provides a fuel cell catalyst or sensor comprising the carbon-alloy composite produced by the method for producing a carbon-metal composite using the extreme ultraviolet light irradiation method.

According to the present invention, when carbon-metal composite particles are prepared by using the extreme ultraviolet-white light irradiation method, the surface area of the noble metal catalyst, which is an abiotic stable catalyst, is maximized and the damage of the carbon-based carrier is minimized, But also can be manufactured in a short time at room temperature and atmospheric pressure, thereby providing high efficiency and productivity and being easy to mass-produce.

FIG. 1 is a flowchart showing a process of manufacturing a carbon-metal composite using a deposition method and an extreme ultraviolet irradiation system according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a process of manufacturing a carbon-metal composite using a sol-gel method and an extreme ultraviolet irradiation system according to another embodiment of the present invention.
3 is a schematic diagram of an extreme ultraviolet irradiation system according to an embodiment of the present invention.
4 is a plan view showing a process of manufacturing a carbon-metal composite according to Example 1 and Example 2 of the present invention.
5 is a waveform diagram of an extreme ultraviolet wave of a xenon lamp used in an embodiment of the present invention.
6 is a schematic diagram showing a mechanism of synthesizing a metal alloy on a carbon support.
7 is an electron micrograph of a carbon-platinum-ruthenium-molybdenum composite prepared by vapor deposition according to Example 1 of the present invention.
8 is a transmission electron micrograph of the carbon-platinum-ruthenium-molybdenum composite prepared according to Example 1 of the present invention.
9 is a Raman spectroscopy graph of a carbon-metal composite of a carbon-platinum-ruthenium-molybdenum composite prepared according to Example 1 of the present invention.
10 is a graph of a cyclic voltammogram of a carbon-platinum-ruthenium-molybdenum composite prepared according to Example 1 of the present invention.
11 is an electron micrograph of a carbon-platinum-ruthenium-tin composite prepared according to Example 2 of the present invention.
12 is a graph of a cyclic voltammogram of a carbon-platinum-ruthenium-tin composite prepared according to Example 2 of the present invention.
13 is an electron micrograph of a carbon-platinum-ruthenium-tin composite prepared according to Example 3 of the present invention.
14 is a graph of a cyclic voltammogram of a carbon-platinum-ruthenium-tin composite prepared according to Example 3 of the present invention.

Hereinafter, the present invention will be described in detail.

The method for producing a carbon-metal composite using the extreme ultraviolet light irradiation method according to the present invention comprises

1) depositing two or more metals on a substrate coated with a carbon support, or adding and dispersing a carbon support to two or more metal precursor solutions, applying the dispersion onto a substrate, and drying to form an alloy layer; And

2) irradiating the substrate on which the alloy layer is formed with extreme ultraviolet light.

FIG. 1 is a flow chart showing a process for producing a carbon-metal composite using a metal deposition method, and FIG. 2 is a flow chart showing a process for producing a carbon- - < / RTI > metal complex.

A method of manufacturing a carbon-metal composite using a metal deposition method according to an embodiment of the present invention will be described in detail as follows. First, a carbon black, a carbon nanotube (CNT), a carbon nanofiber (CNF), a carbon nanocoil (CNC), an aligned porous carbon (OPC) Based carrier selected from mesocarbon microbeads (MCMB), single-walled carbon nanohorn (SWNH), carbon aerogels (CAG), and graphene is referred to as N - It is well dispersed by using a dispersing agent such as dimethylformamide (DMF) and sprayed or sprayed on a substrate such as a silicon wafer or glass well and is sprayed. At the same time, gun or hot plate.

Subsequently, the metal was deposited on a carbon-based support having the same shape as a mat using a vapor deposition apparatus, and carbon-metal composite particles were formed using ultrafine white light. The metal combinations usable as alloys herein include, for example, platinum-ruthenium (Pt-Ru), platinum-molybdenum (Pt-Mo), platinum-tin (Pt-Sn), palladium- Ruthenium-tin (Pt-Ru-Sn), platinum-tin-nickel (Pt-Ru-Mo), ruthenium (Pd-Ru), palladium-molybdenum Ru-Co), platinum-ruthenium-iron (Pt-Ru-Fe), platinum-ruthenium-iridium (Pt-Ru-Ir) and the like.

4 is a plan view showing a process of manufacturing a carbon-metal composite using a metal deposition method and a white light irradiation method, wherein (1) is a substrate, (2) (3) shows the state in which the metal is deposited on the carbon-based support, and (4) shows the state in which the carbon-metal composite particles are formed due to the extreme ultraviolet white light irradiation.

In the present invention, a method of depositing a metal on a substrate can be performed using evaporation or sputtering physical vapor deposition (PVD).

On the other hand, when the alloy layer is formed using the sol-gel method, a metal precursor solution is prepared, and then a carbon support is added to prepare a dispersion. The metal precursor may be, for example, a hydroxide of a metal, a nitrate, a sulfate, an acetate, a chloride, or a mixture thereof, and the solvent may be selected from distilled water, dimethylformamide, ethanol, ethylene glycol, diethyl glycol, .

Dispersion of the carbon carrier is performed using ultrasonic waves or the like, and a mixed solution of the metal precursor and the carbon carrier is applied to the substrate while the solvent is being evaporated while being heated using a hot plate. When the substrate coated with the metal precursor and the carbon support is irradiated with ultraviolet-white light, a carbon-alloy composite can be formed.

In the step of irradiating the alloy layer formed by the metal deposition method or the sol-gel method with extreme ultraviolet light, extreme ultraviolet irradiation may be performed by using pulse width, pulse gap, pulse number, intensity Intensity) changes according to the change of the total light energy up to 100J will emit up to. Depending on the type of the substrate, the type of the carbon-based support, and the kind of the metal, the light irradiation conditions for forming the carbon-metal composite particles may be varied.

In the present invention, the pulse width of the xenon flash lamp is 0.1 to 100 ms, the pulse gap is 0.1 to 100 ms, the pulse number is 1 to 1000, the intensity is 0.01 J / cm 2 To 100 J / cm < 2 >. For the sake of clarity, a graph of the short-pulse white light of a xenon lamp is shown in Fig.

When the extreme ultraviolet light is irradiated, the temperature of the deposited metal (for example, platinum) film instantaneously rises to become a liquid state. At this time, the carbon-based metal complex the surface energy (0.0826 J / m2), the light, since less than the surface energy (1.746 J / m ²⁾ of the molten platinum (6) liquid platinum hemisphere of nanoscale on the CNT surface (e.g., CNT) It coagulates in shape and it gives the effect of widening the surface area.

According to the present invention, carbon-alloy composites prepared by extreme ultraviolet light irradiation can be usefully used in fuel cell catalysts or sensors.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. It will be apparent to those skilled in the art, however, that these examples are provided to further illustrate the present invention, and the scope of the present invention is not limited thereto.

Example  1: Preparation of carbon nanotubes and platinum-ruthenium-molybdenum alloy catalysts

8 mg of multiwalled nanotubes (MWCNT) and 45 ml of DMF are mixed and dispersed for 1 hour using a sonicator. Thereafter, DMF is dried in a mixed solution of MWCNT and DMF using a hot plate at 150 ° C, and is coated on a silicon wafer using a syringe.

1.0 mg of platinum, 0.53 mg of ruthenium and 0.47 mg of molybdenum are sequentially deposited on the silicon wafer to which the MWCNT is applied to form a thin metal layer. Irradiation of extreme ultraviolet-white light of the table condition shown in Table 1 below on a MWCNT silicon wafer substrate with a metal layer formed results in the formation of a platinum-ruthenium-molybdenum alloy (20 wt% Pt-Ru-Mo / MWCNT) on MWCNT.

7 is a photograph of the structure of the resulting carbon-metal composite particle observed with an electron microscope (SEM, JEOL JSM 6700F). As a result of the extreme ultraviolet irradiation and deposition processes according to the present invention, it was confirmed that a three-dimensional nanopowder structure having a very large surface area can be formed on CNTs.

8 is a view showing the structure of the carbon-metal composite particle produced by an electron transmission microscope (TEM). EDS photographs were taken to see the molar ratio of the formed alloy and the results are shown in FIG. As shown in the following Table 2, the molar ratio was 1: 1: 1, and it was confirmed that almost no metal component was present in the absence of the alloy.

9 is a Raman spectroscopy photograph for confirming whether or not the carbon-based carrier (CNT in this embodiment) is damaged. The R value means the I _D / I _G value, and the lower the value, the less defects and damage of the carbon nanotubes. It can be seen that as the energy of the extreme-wave white light increases, the R value becomes smaller. As a result, it can be seen that as the energy increases, the defect and damage are reduced.

FIG. 10 shows the result of the electrochemical reaction of the produced carbon-metal composite particles by a cyclic voltammetry (CV) method using a potential stat (Compact Stat, Ivium Technologies), and 0.5 MH ₂ SO ₄ is used as an electrolyte And the resultant hydrogen adsorption / desorption peaks were formed in the range of -0.3 to 0 V.

Example  2: Preparation of carbon nanotubes and platinum-ruthenium-tin alloy catalysts

8 mg of multi-walled carbon nanotubes (MWCNT) and 45 ml of DMF are mixed and dispersed for 1 hour using a sonicator. Thereafter, DMF is dried in a mixed solution of MWCNT and DMF using a hot plate at 150 ° C, and is coated on a silicon wafer using a syringe.

0.94 mg of platinum, 0.49 mg of ruthenium, and 0.57 mg of tin were sequentially deposited on the silicon wafer to which the MWCNT was applied to form a thin metal layer. A platinum-ruthenium-tin alloy (20 wt% Pt-Ru-Sn / MWCNT) is formed on the MWCNT by irradiating the MWCNT silicon wafer substrate having the metal layer formed thereon with extreme ultraviolet white light having the table condition shown in Table 1 above.

11 is a photograph of the structure of the resulting carbon-metal composite particle observed with a scanning electron microscope (SEM, JEOL JSM 6700F). As a result of the extreme ultraviolet irradiation and the sol-gel process according to the present invention, it was confirmed that a three-dimensional nanopowder structure having a very large surface area can be formed on MWCNT.

FIG. 12 shows the results of the electrochemical reaction of the produced carbon-metal composite particles using a cyclic voltammetry (CV) method using a potential stat (Compact Stat, Ivium Technologies), and 0.5 MH ₂ SO ₄ is used as an electrolyte And the resultant hydrogen adsorption / desorption peaks were formed in the range of -0.3 to 0 V.

Example  3: sol- Gel method  Carbon nanotubes and platinum-ruthenium- Molybdenum  Manufacture of alloy catalysts

1.67 mg of PtCl ₂ , 1.31 mg of RuCl ₃ and 0.28 mg of MoCl ₃ were added to 45 ml of distilled water and dispersed for 2 hours using a sonicator. Thereafter, 8 mg of multi-walled carbon nanotubes (MWCNT) were put into a solution in which the metal chloride was dispersed, and dispersed for 2 hours using a sonicator. Thereafter, using distilled water in a mixed solution of PtCl ₂ , RuCl ₃ , MoCl ₃ , MWCNT and distilled water using a hot plate at 150 ° C, the droplets are coated on a silicon wafer using a syringe.

When a metal wafer and a silicon wafer substrate on which MWCNTs were adsorbed were irradiated with extreme ultraviolet-white light of the table condition shown in Table 1, a platinum-ruthenium-molybdenum alloy (20 wt% Pt-Ru-Mo / MWCNT) was formed on the MWCNT do.

13 is a photograph of the structure of the resulting carbon-metal composite particle observed with a scanning electron microscope (SEM, JEOL JSM 6700F). As a result of the extreme ultraviolet irradiation and the sol-gel process according to the present invention, it was confirmed that a three-dimensional nanopowder structure having a very large surface area can be formed on MWCNT.

FIG. 14 shows the result of the electrochemical reaction of the produced carbon-metal composite particles using a cyclic voltammetry (CV) method using a potential stat (Compact Stat, Ivium Technologies), and 0.5 MH ₂ SO ₄ is used as an electrolyte And the resultant hydrogen adsorption / desorption peaks were formed in the range of -0.3 to 0 V.

Evaluation example : Characteristics of electrochemical catalysts

The properties of the alloy catalyst prepared in the above Example and the conventional alloy catalyst were measured and are shown in Table 3 below.

Among these data, the atomic ratio of Pt to Ru and Mo was determined by EDS analysis, and the average diameter of catalyst particles was determined according to Scherrer's equation. The electrochemical surface area was determined from ECSA = Q _cat / Q _pt . Q _pt is 0.21 mC / cm < ² > , Which represents the amount of electric charge associated with the adsorption of a single layer of hydrogen on Pt. Q _cat represents the charge transfer due to adsorption / desorption of hydrogen in the hydrogen region of the CV.

As a comparative example, a catalyst was prepared by a conventional method (CT Hsieh, JY Lin, SY Yang, Carbon nanotubes embedded with Pt fuel nanoparticles as methanol fuel cell electrocatalysts. Physica E 2009; 41: 373-378) The catalyst and characteristics were compared. As can be seen from the above table, it can be seen that the ECSA is a measure for indirectly showing the electrochemical performance of the result, and the result is 3.6 times higher than the value of the catalyst prepared by the conventional method (comparative example) . The results of the sol - gel method are higher than those of the catalysts prepared by the vapor deposition method, and thus the carbon composites prepared by the sol - gel method are more suitable for the application of fuel cells and sensors.

Claims (13)

A method for producing a carbon-metal composite using extreme ultraviolet light irradiation,
1) spraying a dispersant solvent in which a carbon support is dispersed on a substrate and drying the solvent, and depositing two or more metals on the substrate coated with the obtained carbon support, or adding a carbon support to two or more metal precursor solutions Dispersing it on a substrate, applying it on a substrate, and drying it to form an alloy layer; And
2) irradiating the substrate having the alloy layer formed with extreme ultraviolet-white light. The method according to claim 1,
The carbon support may be selected from the group consisting of carbon black, carbon nanotubes (CNT), carbon nanofibers (CNF), carbon nanocoils (CNC), aligned porous carbon (OPC), mesocarbon microbeads (MCMB) (MWNH), carbon aerogels (CAG), and graphenes. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
The alloy may be selected from the group consisting of Pt-Ru, Pt-Mo, Pt-Sn, Pd-Pt, Ruthenium-molybdenum (Pd-Mo), platinum-ruthenium-molybdenum (Pt-Ru-Mo), platinum-ruthenium-tin (Pt-Ru-Sn), platinum- Wherein the catalyst is selected from the group consisting of cobalt (Pt-Ru-Co), platinum-ruthenium-iron (Pt-Ru-Fe) and platinum-ruthenium-iridium (Pt-Ru-Ir) Way. The method according to claim 1,
Wherein the metal deposition is performed using evaporation or sputtering physical vapor deposition (PVD). ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
Wherein the metal precursor is selected from the group consisting of hydroxides, nitrates, sulfates, acetates, chlorides, and mixtures thereof. The method according to claim 1,
Wherein the solvent of the metal precursor solution is selected from distilled water, dimethylformamide, ethanol, ethylene glycol, diethyl glycol or a mixture thereof. The method according to claim 1,
Wherein the extreme ultraviolet light is irradiated through a xenon flash lamp. 8. The method of claim 7,
Wherein the pulse width of the xenon flash lamp is 0.1 to 100 ms. 8. The method of claim 7,
Wherein a pulse gap of the xenon flash lamp is 0.1 to 100 ms. 8. The method of claim 7,
Wherein the pulse number of the xenon flash lamp is 1 to 1000 times. 8. The method of claim 7,
Wherein the intensities of the xenon flash lamps are in the range of 0.01 J / cm 2 to 100 J / cm 2. A fuel cell catalyst comprising a carbon-alloy composite produced by the method of manufacturing a carbon-metal complex using extreme ultraviolet light irradiation according to claim 1. A sensor comprising a carbon-alloy composite produced by the method of manufacturing a carbon-metal composite using extreme ultraviolet light irradiation according to claim 1.

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