WO2015023072A1 - Capacitive deionization electrode and method for manufacturing same - Google Patents

Capacitive deionization electrode and method for manufacturing same Download PDF

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WO2015023072A1
WO2015023072A1 PCT/KR2014/006986 KR2014006986W WO2015023072A1 WO 2015023072 A1 WO2015023072 A1 WO 2015023072A1 KR 2014006986 W KR2014006986 W KR 2014006986W WO 2015023072 A1 WO2015023072 A1 WO 2015023072A1
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activated carbon
electrode
catalytic
carbon
gasified
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PCT/KR2014/006986
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French (fr)
Korean (ko)
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정두환
백동현
김상경
이병록
이선호
김지영
장진성
Seong-Yop Lim (임성엽)
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한국에너지기술연구원
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Publication of WO2015023072A1 publication Critical patent/WO2015023072A1/en

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/042—Electrodes formed of a single material
    • C25B11/043—Carbon, e.g. diamond or graphene
    • C25B11/044—Impregnation of carbon
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • C02F1/46109—Electrodes
    • C02F1/46114—Electrodes in particulate form or with conductive and/or non conductive particles between them
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
    • C02F1/4691—Capacitive deionisation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • C02F1/46109—Electrodes
    • C02F2001/46133—Electrodes characterised by the material
    • C02F2001/46138—Electrodes comprising a substrate and a coating
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2305/00—Use of specific compounds during water treatment
    • C02F2305/08—Nanoparticles or nanotubes

Definitions

  • the present invention relates to a capacitive desalination electrode used for various carbon electrodes including a capacitive desalination apparatus used for the production of carbon electrodes, and a method of manufacturing the same, and more particularly, to mesopore by performing catalytic gasification using a metal catalyst on activated carbon.
  • the present invention relates to a capacitive desalination electrode having an extended mesopore, an improved specific capacitance, and a high-performance deionizing effect, and a method of manufacturing the same.
  • the basic principle of the capacitive desalination (CDI) process is to electrically adsorb ions using a carbon electrode based on an electric double layer, and apply a voltage of about 1 to 2 V to two porous carbon electrodes.
  • a voltage of about 1 to 2 V to two porous carbon electrodes.
  • positive ions are absorbed on the negative electrode and negative ions are absorbed on the positive electrode.
  • Saturated electrodes can be easily regenerated by applying opposite charges or connecting electrodes to desorb ions.
  • Porous carbon electrodes are advantageous as electrodes used in capacitive desalination (CDI) processes. Porous carbon electrodes have a large surface area and low reactivity, and thus are used in various applications.
  • porous carbon material When the porous carbon material is used as an electrode, the surface area and pore size distribution should be considered as physicochemical properties. Pores with dimensions (diameter or width) less than 2 nm are defined as micropores, and pores with dimensions greater than 50 nm are defined as macropores and have dimensions between 2 nm and 50 nm. Pores are defined as mesopores. Activated carbon among porous carbon materials has excellent pore volume, high specific surface area, high de-adsorption performance, and long lifetime.
  • Adsorption of ions on capacitive desalination (CDI) electrode surfaces is divided into physical adsorption and adsorption in an electrical double layer.
  • the main mechanism in the capacitive desalination (CDI) process is the adsorption in the electric double layer, which is caused by the electrostatic attraction between the ions and the electrodes.
  • the capacitance of the carbon electrode is determined according to the amount of charge accumulated in the electric double layer, and the amount of charge increases as the surface area of the electrode increases. Since activated carbon has a high specific surface area, it is suitable as an electrode material for carbon electrodes requiring a large surface area. However, since activated carbon has low electrical conductivity, a conductive material is added to the activated carbon for this purpose.
  • the conductive material enables electrical connection between activated carbon particles and particles, and between the activated carbon particles and the current collector by point contact, and particulate conductive materials such as carbon black and fine graphite powder having small particles and excellent dispersion It is used a lot.
  • a fibrous conductive material having a high ratio of fiber length to fiber diameter and excellent electrical conductivity and electrochemical stability may be used alone or in combination with a particulate conductive material.
  • the particulate conductive material such as carbon black has to be added in excess for the purpose of increasing the electrical conductivity because the electrical conductivity of the particles themselves is low as well as the electrical connection by the point contact.
  • the amount of added activated carbon is relatively small and the specific storage capacity is lowered.
  • the volume of the conductive material is increased compared to the total volume of the electrode active material, there is a problem that the capacity per unit weight (F / g) is dramatically reduced.
  • the excessive use of the particulate conductive material having a low capacity and bulk density has contributed to the desalination performance of the capacitive desalination apparatus.
  • the fibrous conductive material is also difficult to uniformly disperse the activated carbon and the conductive material when manufacturing the electrode has a problem that the electrical conductivity is lowered in the local portion of the electrode.
  • the conductive material added to improve the electrical conductivity is to be added in excess in order to increase the electrical conductivity because the electrical connection by the point contact with the activated carbon particles, in this case, when the conductive material is added in excess, the relative amount of activated carbon As the content is reduced, the surface area of the electrode is reduced, and the reduction of the surface area of the electrode has a problem that leads to a decrease in desalination performance.
  • the problem to be solved by the present invention is to expand the meso pores of activated carbon and to synthesize plate-like carbon nanofibers containing a large number of free edges on the surface, thereby having an excellent specific surface area and a specific capacitance. It is to provide a capacitive desalination electrode that can be improved.
  • the problem to be solved by the present invention is to provide a method for producing a capacitive desalination electrode capable of uniform dispersion and high density.
  • Method of manufacturing a capacitive desalination electrode the step of supporting a metal catalyst on the surface of the activated carbon; Injecting activated carbon loaded with the metal catalyst into the reactor to perform catalytic gasification; Growing a plate-like carbon nanofiber on the surface of the catalytic gasified activated carbon by injecting and synthesizing a reaction gas including carbonization gas and reducing gas into the catalytic gasified activated carbon; And preparing the catalytic gasified activated carbon in which the plate-shaped carbon nanofibers are grown as a capacitive desalination electrode.
  • the activated carbon is added to the mixed solution to form a metal catalyst-activated carbon mixed solution, and then the solvent contained in the mixed solution It may be a step of supporting by evaporation.
  • the process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor may be performed at 350 to 450.
  • the process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor may be performed for 1 hour.
  • the catalytic gasification may use air, oxygen (O 2 ), or hydrogen (H 2 ).
  • the reaction gas consisting of carbonized gas and reducing gas into the catalytic gasified activated carbon to grow plate-like carbon nanofibers on the surface of the catalytic gasified activated carbon
  • the reaction gas may be synthesized at 600. .
  • the reaction gas consisting of carbonization gas and reducing gas may be added to the catalytic gasified activated carbon and synthesized to grow plate-like carbon nanofibers on the surface of the catalytic gasified activated carbon, which may be performed for 30 minutes.
  • the reducing gas uses hydrogen (H 2 ), the carbonized gas is used ethylene gas (C 2 H 4 ), the hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) at the same time, the Hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) may be added in a ratio of 1: 1.
  • the capacitive desalination electrode according to the embodiment of the present invention may be manufactured by the above-described manufacturing method.
  • the capacitive desalination membrane-electrode assembly includes: an anode electrode; A cathode electrode positioned to face the anode electrode; And an ion exchange membrane positioned between the anode electrode and the cathode electrode, wherein the anode electrode or the cathode electrode may be a capacitive desalination electrode manufactured by the above-described manufacturing method.
  • the capacitive desalination cell may include the capacitive desalination membrane-electrode assembly.
  • the capacitive desalination system at least one comprising an anode electrode, a cathode electrode facing the anode electrode, an ion exchange membrane positioned between the anode electrode and the cathode electrode Membrane-electrode assembly; And a separator, wherein the electrode may include a capacitive desalination electrode manufactured by the above-described manufacturing method.
  • the capacitive desalination electrode according to the embodiment of the present invention has an excellent specific surface area by expanding meso pores of activated carbon and synthesizing plate-like carbon nanofibers containing many free edges on its surface.
  • the specific storage capacity can be improved.
  • the capacitive desalination electrode according to the embodiment of the present invention has excellent electrical connection between the activated carbon particles and the particles, between the activated carbon particles and the current collector, the capacity per unit weight (F / g) is improved, and the resistance is reduced. Can be.
  • the manufacturing method of the capacitive desalination electrode according to the embodiment of the present invention it is possible to implement a uniform dispersion and high density, it is possible to manufacture a capacitive desalination electrode that can prevent the problem of lowering the local electrical conductivity.
  • 1 is a TEM and SEM picture of the plate-shaped carbon nanofibers in one embodiment of the present invention.
  • FIG. 2 is a schematic view illustrating a method of manufacturing activated carbon according to an embodiment of the present invention, and is a view for showing that plate-shaped carbon nanofibers are grown on a surface of catalytic gasified activated carbon.
  • FIG 3 is a cross-sectional view of a cell of a capacitive desalination device in one embodiment of the present invention.
  • FIG. 4 is an electron micrograph of a catalytic gasified activated carbon according to an embodiment of the present invention.
  • FIG. 5 is an electron micrograph of activated carbon according to an embodiment of the present invention, in which a plate-like carbon nanofiber is grown on a surface of a catalytic gasified activated carbon.
  • FIG. 6 is a graph according to Examples and Comparative Examples of the present invention, (a) desalting amount per weight, (b) desalting amount per specific surface area.
  • FIG. 7 is a graph of specific capacitance according to unit weight in the present invention, which shows (a) activated carbon, (b) catalytic gasified activated carbon, and (c) catalytic gasified activated carbon in which plate-like carbon nanofibers are grown.
  • first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.
  • the first component may be referred to as the second component, and similarly the second component may be referred to as the first component.
  • top, bottom, top, bottom, or top, bottom, etc. are used to distinguish relative positions in the component.
  • the upper part may be called the lower part and the lower part may be named the upper part without departing from the scope of the present invention. .
  • FIG. 1 is a TEM and SEM picture of the plate-shaped carbon nanofibers in one embodiment of the present invention
  • Figure 2 is a schematic diagram for explaining a method for producing activated carbon according to an embodiment of the present invention
  • the surface of the catalytic gasified activated carbon 3 is a cross-sectional view of a capacitive desalination apparatus according to an embodiment of the present invention
  • FIG. 4 is a view illustrating the catalytic gasification of activated carbon according to an embodiment of the present invention.
  • 5 is an electron micrograph
  • FIG. 5 is an electron micrograph of activated carbon according to one embodiment of the present invention, which is a view showing that plate-shaped carbon nanofibers are grown on the surface of catalytic gasified activated carbon
  • FIG. 7 is a graph of the specific capacitance according to the unit weight in the present invention The graph shows (a) activated carbon, (b) catalytic gasified activated carbon, and (c) catalytic gasified activated carbon in which plate-like carbon nanofibers are grown.
  • the activated carbon electrode according to the present invention grows mesopores by converting activated carbon into a metal catalyst gas, and then activates activated carbon having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon. It manufactures as.
  • the catalytic gasified activated carbon is a plate-shaped carbon nanofibers having excellent electrical conductivity on the surface of activated carbon particles, which is a unitary structure of activated carbon and plate-shaped carbon nanofibers.
  • the plate-like carbon nanofibers grow on the surface of the activated carbon particles may be various methods.
  • the substrate may be grown using activated carbon using a chemical vapor deposition (CVD) method, a vapor phase growth method, or the like.
  • CVD chemical vapor deposition
  • the plate-shaped carbon nanofibers have a graphite structure perpendicular to the fiber axis, have many free edges, and have excellent electrical conductivity. Very advantageous.
  • a metal catalyst is supported on the surface of active carbon (AC).
  • the metal catalyst may act as a catalyst when carbon nanofibers (CNF) are produced, and may be capable of catalytic gasification.
  • the metal catalyst may be a metal such as iron (Fe), nickel (Ni), platinum (Pt), or a metal compound containing these metal elements.
  • the metal compound may include nickel nitrate hexahydrate or ferric nitrate nonahydrate.
  • the activated carbon may be divided into macropore, mesopore, and micropore according to the pore size. Most of the pores of the activated carbon are made of micropores. The micropores do not show rapid adsorption and desorption performance due to interference with ions. Therefore, mesopores can be expanded through catalytic gasification to increase the specific capacitance of activated carbon and also improve the desalination performance.
  • the metal catalyst when the metal catalyst is supported on the activated carbon, the metal catalyst is mixed with a solvent such as distilled water so that the metal catalyst is uniformly supported on the entire surface of the activated carbon. Subsequently, after the activated carbon is added to the mixed solution, the solvent is evaporated to uniformly disperse and support the metal catalyst on the entire surface of the activated carbon.
  • a solvent such as distilled water
  • the activated carbon loaded with the metal catalyst was introduced into the quartz boat of the reactor.
  • the temperature of the reactor is maintained at 350 to 450 for catalytic gasification, and air or oxygen and hydrogen are passed through for 3 to 5 hours.
  • the temperature of the reaction furnace is raised to 600, which is the growth temperature of the plate-shaped carbon nanofibers.
  • a reaction gas including carbonized gas which is a carbon source of plate-shaped carbon nanofibers, and a reducing gas for reducing the same, are simultaneously introduced into the reactor.
  • ethylene gas (C 2 H 4 ), carbon monoxide (CO), carbon dioxide (CO 2 ), etc. may be used as the carbonization gas
  • hydrogen (H 2 ) may be used as the reducing gas.
  • the reduction and growth reaction proceeds in the reactor.
  • carbon (C) is continuously deposited on the surface of the activated carbon particles to grow the plate-shaped carbon nanofibers. At this time, if the growth amount of the carbon nanofibers is too small, the electrical conductivity is lowered, and if the amount is too large, the volume is large and the capacity is decreased.
  • the activated carbon electrode according to the present invention is composed of activated carbon having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon after growing mesopores (mesopore) by converting the activated carbon into a metal catalyst gas. Specifically, after the activated carbon is metal-catalyzed gas to grow mesopores (mesopore), the activated carbon carbon and the plate-shaped carbon nanofibers are grown on the surface of the catalytic gasified activated carbon, and the composition comprising a binder for bonding the composites.
  • polytetrafluoroethylene PTFE
  • PVdF polyvinylidene fluoride
  • CMC carboxymethylcellulose
  • PVA poly vinylalcohol
  • PVB polyvinyl butyral
  • PVP poly-N-vinylpyrrolidone
  • SBR styrene butadiene rubber
  • the blending amount of the activated carbon electrode according to the present invention preferably comprises 9: 1 of activated carbon and a binder having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon.
  • Activated carbon electrode according to the present invention is used in the production of electrodes of the capacitive desalination apparatus.
  • FIG. 3 is a schematic view showing a capacitive desalination cell as a use state diagram of the present invention.
  • the activated carbon electrode according to the present invention is applied as an electrode. More specifically, the activated carbon electrode according to the present invention is coated on a carbon graphite (carbon graphite), and then cut to a certain size after drying to use as a carbon electrode.
  • a carbon graphite carbon graphite
  • FIG. 5 is an electron micrograph of activated carbon in which plate-shaped carbon nanofibers are grown on the surface of catalytic gasified activated carbon prepared by the above process. Referring to FIG. 5, it can be seen that carbon nanofibers are appropriately grown on the surface of activated carbon particles.
  • activated carbon having plate-like carbon nanofibers grown on the surface of the catalytic gasified activated carbon and polyvinylidene fluoride (PVdF; polyvinylidenefloride) as a binder were blended in a weight ratio of 9: 1, and a slurry was prepared using DMAc as a solvent. After the casting on the carbon graphite with a doctor blade to prepare an activated carbon electrode.
  • PVdF polyvinylidene fluoride
  • Table 1 shows changes in specific surface area of activated carbon in which plate-like carbon nanofibers are grown on the surface of catalytic gasified activated carbon prepared in Examples according to the inventive concept. Referring to ⁇ Table 1>, it can be seen that the specific surface area is greatly reduced due to the pore blockage of the existing activated carbon without the catalytic gasification process.
  • Activated carbon in which plate-shaped carbon nanofibers were grown on the surface of catalytic gasified activated carbon prepared according to an embodiment of the present invention was manufactured as a cell of a capacitive desalination apparatus as shown in FIG. 3. After cutting to 5 x 5 cm 2 , a spacer (120 mesh, polyamide) having a thickness of 100 was installed to allow fluid to pass through while preventing two electrodes from contacting between the anode and the cathode. A 1 cm hole was drilled in the center of the electrode to allow the solution to exit the center through the spacer on the slope of the electrode.
  • a single cell for capacitive desalination was constructed by bolting an acrylic plate having a size of 15 x 15 cm 2 to the outside of the anode and the cathode as an end plate. 250 mg / L of NaCl solution was supplied at a rate of 30 mL / min while the electrode potential was constantly applied at 1.5 V. Desalination efficiency was analyzed by measuring the change in conductivity of the effluent. After adsorbing for 3 minutes, the electrode potential was changed to a short for 3 minutes, and then operated by detaching.
  • an activated carbon electrode was manufactured in the same manner as in the above-described embodiment using only activated carbon (P-60). .
  • activated carbon having plate-like carbon nanofibers grown on the surface of the catalytic gasified activated carbon prepared in the above-described embodiment as Comparative Example 3
  • activated carbon was used in the same manner as described above using 10% conductive fibers (CNFs) as a conductive material in activated carbon.
  • An electrode was prepared.
  • a catalyst slurry was prepared by mixing 20 mg of activated carbon having plate-shaped carbon nanofibers, 40 wt% PVdF solution (DMAc solvent) 40, and distilled water 40 on the surface of the catalytic gasified activated carbon prepared for specific capacitance measurement.
  • a working electrode was prepared by applying the catalyst slurry to 10 glass carbons having an area of 1 cm 2 and drying. Electrochemical experiments were conducted with a three-electrode system using the prepared working electrode, counter electrode platinum mesh and Ag / AgCl (ALS. RE-1B, standard hydrogen electrode: NHE) as reference electrode.
  • the electrochemical experiment was performed at -0.4 to 0.6V based on NHE electrode in 1M NaCl aqueous solution sufficiently purged with argon gas (CV).
  • the potential sweep rate was fixed at 50 mV / sec.
  • FIG. 7 shows (a) an electrode using only activated carbon (P-60), (b) shows an electrode which has undergone catalytic gasification, and (c) shows charge / discharge performance of an electrode in which plate-shaped nanofibers are grown after catalytic gasification. It can be seen that the charge and discharge capacity of about 80% increases when the catalyst gasification is performed than the electrode using only activated carbon, and the growth of the plate-shaped nanofibers increases the charge and discharge capacity of 2.5 times. In addition, when the catalyst gasification temperature is increased from 350 to 450, it can be seen that the charge and discharge capacity increases by about 25 to 30%.

Abstract

A method for manufacturing a capacitive deionization electrode according to an embodiment of the present invention may comprise the steps of: supporting a metal catalyst on a surface of activated carbon; putting the metal catalyst-supported activated carbon into a reaction furnace to perform catalytic gasification; putting reaction gases composed of a carbonizing gas and a reducing gas into the catalytically gasified activated carbon, followed by synthesis, thereby growing plate-shaped carbon nanofibers on the surface of the catalytically gasified activated carbon; and manufacturing the catalytically gasified activated carbon, on which the plate-shaped carbon nanofibers are grown, into a capacitive deionization electrode.

Description

축전식 탈염 전극 및 그의 제조방법Capacitive desalination electrode and its manufacturing method
본 발명은 탄소 전극 제조에 사용되는 축전식 탈염 장치를 포함한 각종 탄소 전극에 사용되는 축전식 탈염 전극 및 그의 제조방법에 관한 것으로, 더욱 상세하게는 활성탄에 금속 촉매를 이용한 촉매 가스화를 진행하여 메조세공(mesopore)을 확장하고, 비축전 용량이 향상되며, 고성능의 탈이온 효과를 가지는 축전식 탈염 전극 및 그의 제조방법에 관한 것이다. The present invention relates to a capacitive desalination electrode used for various carbon electrodes including a capacitive desalination apparatus used for the production of carbon electrodes, and a method of manufacturing the same, and more particularly, to mesopore by performing catalytic gasification using a metal catalyst on activated carbon. The present invention relates to a capacitive desalination electrode having an extended mesopore, an improved specific capacitance, and a high-performance deionizing effect, and a method of manufacturing the same.
물의 수요는 지속적으로 증가하고 있는데 반하여, 물의 공급은 대부분 강수량에 의존하고 있고, 환경문제로 인한 수질악화는 심화되고 있어 사용 가능한 물의 양은 급격히 감소하고 있다. 우리나라의 경우도 물 기근 국가군으로 분류되며, 지역적으로 물부족으로 인한 문제를 경험하고 있다.While demand for water continues to increase, the supply of water is mostly dependent on precipitation, and the deterioration of water quality due to environmental problems is intensifying. Korea is also classified as a water famine country and is experiencing problems due to lack of water locally.
이와 같은 물부족 현상을 해결하기 위한 여러 가지 방안이 연구되어 왔고, 그 중에서 바닷물을 이용하여 이를 극복하려는 연구가 활발하게 진행되고 있다. 바닷물을 이용하려는 생각은 오래전부터 연구되어 왔으며, 중동지역을 중심으로 물부족 해결을 위해서 연구되고 있다. 지역의 특성과 상황에 따라 다양한 방법이 연구되고 있으며, 증발법과 역삼투압법, 그리고 전극과 전기 석출에 의해 바닷물을 처리하는 연구가 진행되고 있다.Various methods for solving such water shortages have been studied, and researches for overcoming them by using sea water have been actively conducted. The idea of using seawater has been studied for a long time, and has been studied to solve water shortages in the Middle East. Various methods are being studied according to the characteristics and circumstances of the region, and researches on treating seawater by evaporation method, reverse osmosis method, and electrode and electroprecipitation are being conducted.
하지만 기존에 사용되던 방법들은 개선해야 할 여러 단점들을 가지고 있다. 담수화 방법으로 가장 오래되고 많이 사용되고 있는 증발법의 경우 원리 및 장치가 단순하고 고 순도의 담수를 얻을 수 있는 장점이 있으나 다른 방법들에 비해 월등히 많은 에너지 비용을 필요로 하며, 전기투석법의 경우 값비싼 이온 교환막과 높은 농도에서는 높은 전압을 사용해야한다는 점 때문에 주로 저 농도 처리용으로 사용되고 있다. 또한, 역삼투압법은 고압펌프를 사용해야하며, 사용되는 막을 관리하는데 어려움이 있다.However, existing methods have several disadvantages that need to be improved. The oldest and most widely used evaporation method for desalination has the advantage of simple and high purity fresh water, but requires much more energy cost than other methods. It is mainly used for low concentration treatment because of high ion exchange membrane and high voltage at high concentration. In addition, the reverse osmosis method has to use a high pressure pump, there is a difficulty in managing the membrane used.
이처럼, 기존에 사용되고 있던 담수처리 방법들의 단점들을 보완하기 위해 새로운 연구들이 진행되고 있으며, 이와 같은 새로운 연구 중 축전식 탈염(Capacitive deionization; CDI) 공정은 다른 방법들에 비해 에너지 소비량이 적으며, 이온 교환법의 경우와 같이 이온교환수지 막의 재생시에 사용되는 H2SO4나 HNO3와 같은 산 세정 및 NaOH 등의 염기 세정에 의한 2차 오염이 없어 환경 친화적인 공정이며, 또한 유지 보수도 간단하다는 장점을 가지고 있어, 새로운 담수처리 방법으로 개발이 진행되고 있다.As such, new studies are being conducted to compensate for the shortcomings of the existing desalination methods. Among these new studies, capacitive deionization (CDI) process consumes less energy than other methods, and As in the case of the exchange method, there is no secondary contamination by acid washing such as H2SO4 or HNO3 and base washing such as NaOH, which is used for regeneration of the ion exchange resin membrane, and it is an environmentally friendly process, and it is easy to maintain. Development is underway with a new desalination method.
상기 축전식 탈염(CDI) 공정의 기본 원리는 전기이중층(Electric double layer)에 기초하여 탄소 전극을 사용하여 전기적으로 이온을 흡착시키는 것으로, 두 개의 다공성 탄소 전극에 1 ~ 2V 내외의 전압을 걸어주고 그 사이로 이온이 함유된 물을 흘려주면 양 이온은 음극에 음 이온은 양극에 흡착되어 이온을 제거하는 원리이다. 포화된 전극은 반대 전하를 가하거나 전극을 연결시켜 주어 이온을 탈착시킴으로 전극을 쉽게 재생할 수 있다.The basic principle of the capacitive desalination (CDI) process is to electrically adsorb ions using a carbon electrode based on an electric double layer, and apply a voltage of about 1 to 2 V to two porous carbon electrodes. In the meantime, when water containing ions flows, positive ions are absorbed on the negative electrode and negative ions are absorbed on the positive electrode. Saturated electrodes can be easily regenerated by applying opposite charges or connecting electrodes to desorb ions.
축전식 탈염(CDI) 공정에 사용하는 전극으로는 다공성 탄소 전극이 유리하다. 다공성 탄소전극은 넓은 표면적을 가지고 반응성이 적기 때문에 다양한 용도로 사용되고 있다.Porous carbon electrodes are advantageous as electrodes used in capacitive desalination (CDI) processes. Porous carbon electrodes have a large surface area and low reactivity, and thus are used in various applications.
다공성 탄소재료가 전극으로 사용될 때 물리화학적 특성으로 표면적, 세공크기분포도를 고려해야 한다. 2㎚ 미만의 치수(직경 또는 폭)를 갖는 세공은 마이크로 세공(micropore)으로서 정의되고, 50㎚보다 큰 치수를 갖는 세공은 매크로 세공(macropore)으로서 정의되며, 2㎚ 내지 50㎚의 치수를 갖는 세공은 메조 세공(mesopore)으로 정의된다. 다공성 탄소재료 중 활성탄소(Activated carbon)는 우수한 세공 용적, 높은 비표면적, 높은 탈-흡착 성능, 그리고 오랜 수명을 가진다.When the porous carbon material is used as an electrode, the surface area and pore size distribution should be considered as physicochemical properties. Pores with dimensions (diameter or width) less than 2 nm are defined as micropores, and pores with dimensions greater than 50 nm are defined as macropores and have dimensions between 2 nm and 50 nm. Pores are defined as mesopores. Activated carbon among porous carbon materials has excellent pore volume, high specific surface area, high de-adsorption performance, and long lifetime.
축전식 탈염(CDI) 전극 표면에 이온의 흡착은 물리흡착과 전기 이중층에서의 흡착으로 나눈다. 전극 표면의 흡착점과 이온의 상호작용에 의해 전해질이 흡착되는 물리흡착과 전극에 인가된 전위차에 의해 이온이 전극에 흡착되는 전기 이중층에서의 흡착이 있다. 축전식 탈염(CDI) 공정에서 주된 메카니즘은 이온들과 전극 사이의 정전기적 인력 때문에 발생하는 전기이중층에서의 흡착이라 할 수 있다.Adsorption of ions on capacitive desalination (CDI) electrode surfaces is divided into physical adsorption and adsorption in an electrical double layer. There are physical adsorption in which the electrolyte is adsorbed by the interaction between the adsorption point of the electrode surface and the ions, and adsorption in the electric double layer in which ions are adsorbed to the electrode due to the potential difference applied to the electrode. The main mechanism in the capacitive desalination (CDI) process is the adsorption in the electric double layer, which is caused by the electrostatic attraction between the ions and the electrodes.
한편, 탄소전극의 정전용량은 전기이중층에 축적되는 전하량에 따라 정해지며, 그 전하량은 전극의 표면적이 클수록 커지게 된다. 활성탄은 높은 비표면적을 가지므로, 큰 표면적을 필요로 하는 탄소전극의 전극재료로서 적합하다. 그러나, 활성탄은 전기전도도가 떨어지기 때문에 이를 위해 활성탄에는 도전재가 첨가되고 있다.On the other hand, the capacitance of the carbon electrode is determined according to the amount of charge accumulated in the electric double layer, and the amount of charge increases as the surface area of the electrode increases. Since activated carbon has a high specific surface area, it is suitable as an electrode material for carbon electrodes requiring a large surface area. However, since activated carbon has low electrical conductivity, a conductive material is added to the activated carbon for this purpose.
상기 도전재로는 활성탄 입자와 입자 사이, 그리고 상기 활성탄 입자와 집전체 사이에서 점접촉에 의해 전기적 연결을 가능하게 하는 것으로서, 입자가 작고 분산도가 뛰어난 카본블랙, 미세 흑연 분말 등의 입자상 도전재가 많이 사용되고 있다. 또한, 상기 도전재로는 섬유직경에 대한 섬유길이 비율이 크고 전기전도도와 전기화학적 안정성이 우수한 섬유상의 도전재가 단독으로 사용되거나 또는 입자상 도전재와 함께 사용되기도 한다.The conductive material enables electrical connection between activated carbon particles and particles, and between the activated carbon particles and the current collector by point contact, and particulate conductive materials such as carbon black and fine graphite powder having small particles and excellent dispersion It is used a lot. In addition, as the conductive material, a fibrous conductive material having a high ratio of fiber length to fiber diameter and excellent electrical conductivity and electrochemical stability may be used alone or in combination with a particulate conductive material.
그러나, 카본블랙과 같은 입자상 도전재는 입자 자체의 전기전도도가 낮을 뿐만 아니라 점접촉에 의한 전기적 연결을 하기 때문에 전기전도도를 증가시킬 목적을 위해서는 과량으로 첨가되어야 한다. 이와 같이 과량으로 첨가되는 경우, 상대적으로 활성탄의 첨가량이 적어져 비축전용량이 떨어지는 문제점이 있다. 특히, 전극활물질의 전체 부피 대비 도전재의 부피가 높아져 단위 중량당 용량(F/g)이 극대로 감소하는 문제점이 있다. 뿐만 아니라, 낮은 용량과 벌크 밀도(bulk density)를 갖는 입자상 도전재의 과량 사용은 축전식 탈염 장치의 탈염 성능을 저하시키는 원인이 되었다. However, the particulate conductive material such as carbon black has to be added in excess for the purpose of increasing the electrical conductivity because the electrical conductivity of the particles themselves is low as well as the electrical connection by the point contact. When added in an excessive amount as described above, there is a problem in that the amount of added activated carbon is relatively small and the specific storage capacity is lowered. In particular, the volume of the conductive material is increased compared to the total volume of the electrode active material, there is a problem that the capacity per unit weight (F / g) is dramatically reduced. In addition, the excessive use of the particulate conductive material having a low capacity and bulk density has contributed to the desalination performance of the capacitive desalination apparatus.
또한, 섬유상 도전재 역시 전극을 제조할 때 활성탄과 도전재를 균일하게 분산시키는 것이 어려워 전극의 국부적인 부분에서는 전기전도도가 저하되는 문제점이 발생하였다.In addition, the fibrous conductive material is also difficult to uniformly disperse the activated carbon and the conductive material when manufacturing the electrode has a problem that the electrical conductivity is lowered in the local portion of the electrode.
또한, 전기전도도의 향상을 위해 첨가되고 있는 도전재는 활성탄 입자와 점접촉에 의한 전기적 연결을 하기 때문에 전기전도도를 증가시키기 위해서는 과량으로 첨가되어야 하는데, 이와 같이 도전재가 과량으로 첨가되는 경우, 활성탄의 상대적 함량이 적어져 전극의 표면적이 감소하고, 이러한 전극의 표면적 감소는 탈염 성능의 하락으로 이어지는 문제점이 발생하였다.In addition, the conductive material added to improve the electrical conductivity is to be added in excess in order to increase the electrical conductivity because the electrical connection by the point contact with the activated carbon particles, in this case, when the conductive material is added in excess, the relative amount of activated carbon As the content is reduced, the surface area of the electrode is reduced, and the reduction of the surface area of the electrode has a problem that leads to a decrease in desalination performance.
본 발명이 해결하고자 하는 과제는, 활성탄의 메조 세공(meso pore)을 확장하고, 표면에 많은 자유단(free edges)을 내포한 판상형 탄소나노 섬유를 합성함으로써, 우수한 비표면적을 가져 비축전 용량을 향상시킬 수 있는 축전식 탈염 전극을 제공하는데 있다.The problem to be solved by the present invention is to expand the meso pores of activated carbon and to synthesize plate-like carbon nanofibers containing a large number of free edges on the surface, thereby having an excellent specific surface area and a specific capacitance. It is to provide a capacitive desalination electrode that can be improved.
또한, 본 발명이 해결하고자 하는 과제는, 균일한 분산과 고밀도 구현이 가능한 축전식 탈염 전극의 제조방법을 제공하는데 있다.In addition, the problem to be solved by the present invention is to provide a method for producing a capacitive desalination electrode capable of uniform dispersion and high density.
본 발명이 해결하고자 하는 다양한 과제들은 이상에서 언급한 과제들에 제한되지 않으며, 언급되지 않은 또 다른 과제들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.Various problems to be solved by the present invention are not limited to the above-mentioned problems, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.
본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염 전극의 제조방법은, 활성탄의 표면에 금속촉매를 담지하는 단계; 상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계; 상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계; 및 상기 판상형 탄소나노 섬유가 성장한 촉매가스화된 활성탄을 축전식 탈염 전극으로 제조하는 단계;를 포함할 수 있다.Method of manufacturing a capacitive desalination electrode according to an embodiment of the present invention, the step of supporting a metal catalyst on the surface of the activated carbon; Injecting activated carbon loaded with the metal catalyst into the reactor to perform catalytic gasification; Growing a plate-like carbon nanofiber on the surface of the catalytic gasified activated carbon by injecting and synthesizing a reaction gas including carbonization gas and reducing gas into the catalytic gasified activated carbon; And preparing the catalytic gasified activated carbon in which the plate-shaped carbon nanofibers are grown as a capacitive desalination electrode.
상기 활성탄의 표면에 금속촉매를 담지하는 단계는, 상기 금속촉매를 용매에 혼합한 후, 상기 혼합 용액에 활성탄을 첨가하여 금속촉매-활성탄 혼합용액을 형성한 다음, 상기 혼합용액에 포함된 용매를 증발시켜 담지하는 단계일 수 있다.In the step of supporting the metal catalyst on the surface of the activated carbon, after mixing the metal catalyst in a solvent, the activated carbon is added to the mixed solution to form a metal catalyst-activated carbon mixed solution, and then the solvent contained in the mixed solution It may be a step of supporting by evaporation.
상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계는, 350 내지 450에서 진행하는 단계일 수 있다.The process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor may be performed at 350 to 450.
상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계는, 1 시간 동안 진행하는 단계일 수 있다.The process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor may be performed for 1 hour.
상기 촉매가스화는 공기(Air), 산소(O2) 또는 수소(H2)를 사용할 수 있다.The catalytic gasification may use air, oxygen (O 2 ), or hydrogen (H 2 ).
상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계는, 상기 반응가스를 투입하고 600에서 합성시키는 단계일 수 있다.Injecting and synthesizing the reaction gas consisting of carbonized gas and reducing gas into the catalytic gasified activated carbon to grow plate-like carbon nanofibers on the surface of the catalytic gasified activated carbon, the reaction gas may be synthesized at 600. .
상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계는, 30분 동안 진행하는 단계일 수 있다.The reaction gas consisting of carbonization gas and reducing gas may be added to the catalytic gasified activated carbon and synthesized to grow plate-like carbon nanofibers on the surface of the catalytic gasified activated carbon, which may be performed for 30 minutes.
상기 환원가스는 수소(H2)를 사용하고, 상기 탄화가스는 에틸렌가스(C2H4)를 사용하며, 상기 수소(H2) 및 에틸렌가스(C2H4)를 동시에 투입하되, 상기 수소(H2) 및 에틸렌가스(C2H4)는 1 : 1의 비율로 투입될 수 있다.The reducing gas uses hydrogen (H 2 ), the carbonized gas is used ethylene gas (C 2 H 4 ), the hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) at the same time, the Hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) may be added in a ratio of 1: 1.
또한, 본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염 전극은, 상기한 제조방법에 의해 제조된 것일 수 있다.In addition, the capacitive desalination electrode according to the embodiment of the present invention may be manufactured by the above-described manufacturing method.
또한, 본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염용 막-전극 어셈블리는, 애노드 전극; 상기 애노드 전극과 대향하여 위치하는 캐소드 전극; 및 상기 애노드 전극과 상기 캐소드 전극 사이에 위치하는 이온교환막;을 포함하고, 상기 애노드 전극 또는 캐소드 전극은 상기한 제조방법에 의해 제조된 축전식 탈염 전극일 수 있다.In addition, the capacitive desalination membrane-electrode assembly according to an embodiment of the present invention includes: an anode electrode; A cathode electrode positioned to face the anode electrode; And an ion exchange membrane positioned between the anode electrode and the cathode electrode, wherein the anode electrode or the cathode electrode may be a capacitive desalination electrode manufactured by the above-described manufacturing method.
또한, 본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염용 셀은 상기 축전식 탈염용 막-전극 어셈블리를 포함할 수 있다.In addition, the capacitive desalination cell according to an embodiment of the inventive concept may include the capacitive desalination membrane-electrode assembly.
또한, 본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염 시스템은, 애노드 전극, 상기 애노드 전극과 대향하여 위치하는 캐소드 전극, 상기 애노드 전극과 캐소드 전극 사이에 위치하는 이온교환막을 포함하는 하나 이상의 막-전극 어셈블리; 및 세퍼레이터를 포함하고, 상기 전극은 상기한 제조방법에 의해 제조된 축전식 탈염 전극을 포함할 수 있다.In addition, the capacitive desalination system according to an embodiment of the present invention, at least one comprising an anode electrode, a cathode electrode facing the anode electrode, an ion exchange membrane positioned between the anode electrode and the cathode electrode Membrane-electrode assembly; And a separator, wherein the electrode may include a capacitive desalination electrode manufactured by the above-described manufacturing method.
기타 실시 예들의 구체적인 사항들은 상세한 설명 및 도면들에 포함되어 있다.Specific details of other embodiments are included in the detailed description and drawings.
본 발명의 실시예에 의한 축전식 탈염 전극은, 활성탄의 메조 세공(meso pore)을 확장하고, 표면에 많은 자유단(free edges)을 내포한 판상형 탄소나노 섬유를 합성함으로써, 우수한 비표면적을 가져 비축전 용량을 향상시킬 수 있다.The capacitive desalination electrode according to the embodiment of the present invention has an excellent specific surface area by expanding meso pores of activated carbon and synthesizing plate-like carbon nanofibers containing many free edges on its surface. The specific storage capacity can be improved.
또한, 본 발명의 실시예에 의한 축전식 탈염 전극은, 활성탄 입자와 입자 사이, 활성탄 입자와 집전체 사이의 전기적 연결이 우수하고, 단위 중량당 용량(F/g)이 향상되며, 저항이 감소될 수 있다.In addition, the capacitive desalination electrode according to the embodiment of the present invention has excellent electrical connection between the activated carbon particles and the particles, between the activated carbon particles and the current collector, the capacity per unit weight (F / g) is improved, and the resistance is reduced. Can be.
또한, 본 발명의 실시예에 의한 축전식 탈염 전극의 제조방법은, 균일한 분산과 고밀도 구현이 가능하며, 국부적인 전기전도도 저하 문제를 방지할 수 있는 축전식 탈염 전극을 제조할 수 있다.In addition, the manufacturing method of the capacitive desalination electrode according to the embodiment of the present invention, it is possible to implement a uniform dispersion and high density, it is possible to manufacture a capacitive desalination electrode that can prevent the problem of lowering the local electrical conductivity.
본 발명의 기술적 사상의 다양한 실시예들은, 구체적으로 언급되지 않은 다양한 효과를 제공할 수 있다는 것이 충분히 이해될 수 있을 것이다. It will be fully understood that various embodiments of the inventive concept may provide various effects not specifically mentioned.
도 1은 본 발명의 일 실시예에서 판상형 탄소나노 섬유의 TEM 및 SEM 사진이다. 1 is a TEM and SEM picture of the plate-shaped carbon nanofibers in one embodiment of the present invention.
도 2는 본 발명의 일 실시예에 따른 활성탄을 제조하는 방법을 설명하기 위한 모식도로서, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 것을 보여주기 위한 도면이다.FIG. 2 is a schematic view illustrating a method of manufacturing activated carbon according to an embodiment of the present invention, and is a view for showing that plate-shaped carbon nanofibers are grown on a surface of catalytic gasified activated carbon.
도 3은 본 발명의 일 실시예에서 축전식 탈염 장치의 셀 단면도이다.3 is a cross-sectional view of a cell of a capacitive desalination device in one embodiment of the present invention.
도 4는 본 발명의 일 실시예에 따른 촉매 가스화된 활성탄의 전자현미경 사진이다.4 is an electron micrograph of a catalytic gasified activated carbon according to an embodiment of the present invention.
도 5는 본 발명의 일 실시예에 따른 활성탄의 전자현미경 사진으로, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 것을 보여주기 위한 도면이다.5 is an electron micrograph of activated carbon according to an embodiment of the present invention, in which a plate-like carbon nanofiber is grown on a surface of a catalytic gasified activated carbon.
도 6은 본 발명의 실시예 및 비교예에 따른 그래프로서, (a) 중량당 탈염량, (b) 비표면적당 탈염량을 나타내는 그래프이다.6 is a graph according to Examples and Comparative Examples of the present invention, (a) desalting amount per weight, (b) desalting amount per specific surface area.
도 7은 본 발명에서 단위중량에 따른 비정전용량의 그래프로서, (a) 활성탄, (b) 촉매가스화한 활성탄, (c) 판상형 탄소나노 섬유를 성장한 촉매 가스화한 활성탄을 나타내는 그래프이다.FIG. 7 is a graph of specific capacitance according to unit weight in the present invention, which shows (a) activated carbon, (b) catalytic gasified activated carbon, and (c) catalytic gasified activated carbon in which plate-like carbon nanofibers are grown.
본 발명의 이점 및 특징, 그리고 그것들을 달성하는 방법은 첨부되는 도면과 함께 상세하게 후술되어 있는 실시예를 참조하면 명확해질 것이다. 그러나 본 발명은 여기서 설명되는 실시예들에 한정되지 않고 다른 형태로 구체화될 수도 있다. 오히려, 여기서 소개되는 실시예들은 개시된 내용이 철저하고 완전해질 수 있도록 그리고 당업자에게 본 발명의 사상이 충분히 전달될 수 있도록 하기 위해 제공되는 것이다. 도면들에 있어서, 층 및 영역들의 두께는 명확성을 기하기 위하여 과장된 것이다.Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity.
제 1, 제 2 등의 용어는 다양한 구성요소들을 설명하는데 사용될 수 있지만, 상기 구성요소들은 상기 용어들에 의해 한정되는 것은 아니다. 상기 용어들은 하나의 구성요소를 다른 구성요소로부터 구별하는 목적으로만 사용된다. 예를 들어, 본 발명의 권리 범위를 벗어나지 않으면서 제 1 구성요소는 제 2 구성요소로 명명될 수 있고, 유사하게 제 2 구성요소는 제 1 구성요소로 명명될 수 있다.Terms such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly the second component may be referred to as the first component.
상단, 하단, 상면, 하면, 또는 상부, 하부 등의 용어는 구성요소에 있어 상대적인 위치를 구별하기 위해 사용되는 것이다. 예를 들어, 편의상 도면상의 위쪽을 상부, 도면상의 아래쪽을 하부로 명명하는 경우, 실제에 있어서는 본 발명의 권리 범위를 벗어나지 않으면서 상부는 하부로 명명될 수 있고, 하부는 상부로 명명될 수 있다.The terms top, bottom, top, bottom, or top, bottom, etc. are used to distinguish relative positions in the component. For example, in the case of naming the upper part on the drawing as the upper part and the lower part on the drawing for convenience, the upper part may be called the lower part and the lower part may be named the upper part without departing from the scope of the present invention. .
본 출원에서 사용한 용어는 단지 특정한 실시예를 설명하기 위해 사용된 것으로, 본 발명을 한정하려는 의도가 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다. 본 출원에서, "포함하다" 또는 "가지다" 등의 용어는 명세서상에 기재된 특징, 숫자, 단계, 동작, 구성요소, 부분품 또는 이들을 조합한 것이 존재함을 지정하려는 것이지, 하나 또는 그 이상의 다른 특징들이나 숫자, 단계, 동작, 구성요소, 부분품 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof.
다르게 정의되지 않는 한, 기술적이거나 과학적인 용어를 포함해서 여기서 사용되는 모든 용어들은 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자에 의해 일반적으로 이해되는 것과 동일한 의미가 있다. 일반적으로 사용되는 사전에 정의되어 있는 것과 같은 용어들은 관련 기술의 문맥상 가지는 의미와 일치하는 의미가 있는 것으로 해석되어야 하며, 본 출원에서 명백하게 정의하지 않는 한, 이상적이거나 과도하게 형식적인 의미로 해석되지 않는다.Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.
이하, 첨부된 도면을 참조하여 본 발명의 기술적 사상의 일 실시예에 따른 축전식 탈염 전극 및 그의 제조방법에 대한 바람직한 실시예를 더욱 상세하게 설명한다.Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the capacitive desalination electrode according to an embodiment of the present invention and a manufacturing method thereof.
도 1은 본 발명의 일 실시예에서 판상형 탄소나노 섬유의 TEM 및 SEM 사진이고, 도 2는 본 발명의 일 실시예에 따른 활성탄을 제조하는 방법을 설명하기 위한 모식도로서, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 것을 보여주기 위한 도면이며, 도 3은 본 발명의 일 실시예에서 축전식 탈염 장치의 셀 단면도이고, 도 4는 본 발명의 일 실시예에 따른 촉매 가스화된 활성탄의 전자현미경 사진이며, 도 5는 본 발명의 일 실시예에 따른 활성탄의 전자현미경 사진으로, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 것을 보여주기 위한 도면이고, 도 6은 본 발명의 실시예 및 비교예에 따른 그래프로서, (a) 중량당 탈염량, (b) 비표면적당 탈염량을 나타내는 그래프이며, 도 7은 본 발명에서 단위중량에 따른 비정전용량의 그래프로서, (a) 활성탄, (b) 촉매가스화한 활성탄, (c) 판상형 탄소나노 섬유를 성장한 촉매 가스화한 활성탄을 나타내는 그래프이다.1 is a TEM and SEM picture of the plate-shaped carbon nanofibers in one embodiment of the present invention, Figure 2 is a schematic diagram for explaining a method for producing activated carbon according to an embodiment of the present invention, the surface of the catalytic gasified activated carbon 3 is a cross-sectional view of a capacitive desalination apparatus according to an embodiment of the present invention, and FIG. 4 is a view illustrating the catalytic gasification of activated carbon according to an embodiment of the present invention. 5 is an electron micrograph, and FIG. 5 is an electron micrograph of activated carbon according to one embodiment of the present invention, which is a view showing that plate-shaped carbon nanofibers are grown on the surface of catalytic gasified activated carbon, and FIG. As a graph according to Examples and Comparative Examples, (a) a desalting amount per weight, (b) a desalting amount per specific surface area, Figure 7 is a graph of the specific capacitance according to the unit weight in the present invention The graph shows (a) activated carbon, (b) catalytic gasified activated carbon, and (c) catalytic gasified activated carbon in which plate-like carbon nanofibers are grown.
도 1 내지 도 7을 참조하면, 본 발명에 따른 활성탄 전극은 활성탄을 금속촉매 가스화하여 메조 세공(mesopore)을 성장시킨 후, 상기 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄을 전극으로 하여 제조한다. 상기 촉매 가스화된 활성탄은 활성탄 입자 표면 자체에 전기전도성이 우수한 판상형 탄소나노섬유가 성장된 것으로서, 이는 활성탄과 판상형 탄소나노 섬유의 일원적 구조체이다.Referring to FIGS. 1 to 7, the activated carbon electrode according to the present invention grows mesopores by converting activated carbon into a metal catalyst gas, and then activates activated carbon having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon. It manufactures as. The catalytic gasified activated carbon is a plate-shaped carbon nanofibers having excellent electrical conductivity on the surface of activated carbon particles, which is a unitary structure of activated carbon and plate-shaped carbon nanofibers.
상기 활성탄 입자 표면 자체에 판상형 탄소나노 섬유가 성장하는 방법은 다양한 방법이 이용될 수 있다. 예를 들어, 기판을 활성탄으로 하여 열 화학증착(CVD; Chemical Vapor Deposition)법, 기상성장법 등을 이용하여 성장시킬 수 있다.The plate-like carbon nanofibers grow on the surface of the activated carbon particles may be various methods. For example, the substrate may be grown using activated carbon using a chemical vapor deposition (CVD) method, a vapor phase growth method, or the like.
도 1에 도시된 바와 같이, 상기 판상형 탄소나노 섬유는 흑연구조가 섬유축과 수직방향이고, 많은 자유단(free edges)을 가지고 있어 전기전도도가 우수하며, 높은 비표면적으로 인해 전기적 흡, 탈착에 매우 유리하다.As shown in FIG. 1, the plate-shaped carbon nanofibers have a graphite structure perpendicular to the fiber axis, have many free edges, and have excellent electrical conductivity. Very advantageous.
이하, 본 발명의 기술적 사상의 일 실시예에서, 활성탄을 금속촉매 가스화하여 활성탄의 메조 세공(mesopore)를 확장한 후, 촉매가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄을 제조하는 방법에 대하여 더욱 상세하게 설명한다.Hereinafter, in one embodiment of the present invention, a method of producing activated carbon in which plate-like carbon nanofibers are grown on the surface of catalytic gasified activated carbon after expanding the mesopores of activated carbon by gasifying activated carbon with a metal catalyst gas. It will be described in more detail.
도 2를 참조하면, 먼저 활성탄(AC; Active Carbon) 표면에 금속 촉매를 지지시킨다. 상기 금속 촉매는 탄소나노 섬유(CNF; Carbon Nano Fiber)가 생성될 때 촉매 작용을 할 수 있으며, 촉매가스화(Catalytic gasification) 작용이 가능할 수 있다. 상기 금속 촉매는 철(Fe), 니켈(Ni), 백금(Pt) 등의 금속, 또는 이들 금속원소를 포함하는 금속화합물을 사용할 수 있다. 예를 들어, 금속화합물은 질산니켈육수화물(Nickel nitrate hexahydrate) 또는 질산철구수화물(Ferricnitrate nonahydrate) 등을 사용할 수 있다. 상기 활성탄은 세공(pore)의 크기에 따라 매크로 세공(Macropore), 메조 세공(Mesopore), 마이크로 세공(Micropore)으로 나눌 수 있다. 상기 활성탄의 세공은 대부분은 마이크로 세공(micropore)으로 이루어져 있는데, 상기 마이크로 세공(micropore)은 이온의 출입에 방해를 받아 빠른 흡, 탈착 성능을 보여주지 못한다. 따라서, 촉매가스화를 통하여 메조 세공(mesopore)을 확장하여 활성탄의 비정전용량을 증가시키고, 또한, 탈염성능도 향상시킬 수 있다.Referring to FIG. 2, first, a metal catalyst is supported on the surface of active carbon (AC). The metal catalyst may act as a catalyst when carbon nanofibers (CNF) are produced, and may be capable of catalytic gasification. The metal catalyst may be a metal such as iron (Fe), nickel (Ni), platinum (Pt), or a metal compound containing these metal elements. For example, the metal compound may include nickel nitrate hexahydrate or ferric nitrate nonahydrate. The activated carbon may be divided into macropore, mesopore, and micropore according to the pore size. Most of the pores of the activated carbon are made of micropores. The micropores do not show rapid adsorption and desorption performance due to interference with ions. Therefore, mesopores can be expanded through catalytic gasification to increase the specific capacitance of activated carbon and also improve the desalination performance.
이를 위해 금속촉매를 활성탄에 담지할 때, 금속 촉매가 상기 활성탄 표면 전체에 균일하게 지지되도록 금속 촉매를 증류수 등의 용매에 혼합한다. 이어서, 상기 혼합용액에 활성탄을 첨가 후 용매를 증발시켜 활성탄 표면 전체에 금속촉매가 균일하게 분산, 담지되도록 한다.To this end, when the metal catalyst is supported on the activated carbon, the metal catalyst is mixed with a solvent such as distilled water so that the metal catalyst is uniformly supported on the entire surface of the activated carbon. Subsequently, after the activated carbon is added to the mixed solution, the solvent is evaporated to uniformly disperse and support the metal catalyst on the entire surface of the activated carbon.
다음으로, 상기 금속촉매가 담지된 활성탄을 반응로의 석영보트에 투입한 다음. 촉매가스화를 위해 반응로의 온도를 350~450로 유지하고, 공기(air) 또는 산소 및 수소를 3~5 시간 동안 통과시킨다.Next, the activated carbon loaded with the metal catalyst was introduced into the quartz boat of the reactor. The temperature of the reactor is maintained at 350 to 450 for catalytic gasification, and air or oxygen and hydrogen are passed through for 3 to 5 hours.
이어서, 반응로의 온도를 판상형 탄소나노 섬유의 성장 온도인 600로 승온한다. 그리고, 상기 반응로의 온도를 500~700로 유지한 상태에서 반응로에 판상형 탄소나노 섬유의 탄소원(carbonsource)인 탄화가스와, 이의 환원을 위한 환원가스로 이루어진 반응가스를 동시에 투입한다. 예를 들어, 상기 탄화가스로는 에틸렌가스(C2H4), 일산화탄소(CO), 이산화탄소(CO2) 등을 사용할 수 있으며, 환원가스로는 수소(H2)를 사용할 수 있다. 이때, 반응로에서는 환원 및 성장 반응이 진행된다. 즉, 탄화가스가 환원가스에 의해 환원되면서, 활성탄 입자 표면에 계속적으로 탄소(C)가 증착되어 판상형 탄소나노 섬유가 성장된다. 이때, 탄소나노 섬유의 성장량이 너무 작으면 전기전도도가 떨어지고, 너무 많으면 중량대비 부피가 커져 용량이 떨어지므로, 상기 반응시간은 30분 동안 진행시켜 적당량 성장시키는 것이 바람직하다.Next, the temperature of the reaction furnace is raised to 600, which is the growth temperature of the plate-shaped carbon nanofibers. In addition, while maintaining the temperature of the reactor at 500 to 700, a reaction gas including carbonized gas, which is a carbon source of plate-shaped carbon nanofibers, and a reducing gas for reducing the same, are simultaneously introduced into the reactor. For example, ethylene gas (C 2 H 4 ), carbon monoxide (CO), carbon dioxide (CO 2 ), etc. may be used as the carbonization gas, and hydrogen (H 2 ) may be used as the reducing gas. At this time, the reduction and growth reaction proceeds in the reactor. That is, as the carbonized gas is reduced by the reducing gas, carbon (C) is continuously deposited on the surface of the activated carbon particles to grow the plate-shaped carbon nanofibers. At this time, if the growth amount of the carbon nanofibers is too small, the electrical conductivity is lowered, and if the amount is too large, the volume is large and the capacity is decreased.
본 발명에 따른 활성탄전극은 상술한 바와 같이 활성탄을 금속촉매 가스화하여 메조 세공(mesopore)을 성장시킨 후, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄을 필수적으로 함유하여 조성되며, 구체적으로는, 상기 활성탄을 금속 촉매 가스화하여 메조 세공(mesopore)을 성장시킨 후, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄과, 이 복합체들을 결합시키는 결합재를 포함하여 조성된다.As described above, the activated carbon electrode according to the present invention is composed of activated carbon having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon after growing mesopores (mesopore) by converting the activated carbon into a metal catalyst gas. Specifically, after the activated carbon is metal-catalyzed gas to grow mesopores (mesopore), the activated carbon carbon and the plate-shaped carbon nanofibers are grown on the surface of the catalytic gasified activated carbon, and the composition comprising a binder for bonding the composites.
예를 들어, 상기 결합재로는 폴리테트라플루오르에틸렌(PTFE ; poly-tetrafluoroethylene), 폴리비닐리덴플로라이드(PVdF ; polyvinylidenefloride), 카르복시메틸셀룰로오스(CMC ; carboxymethylcellulose), 폴리비닐알코올(PVA ; poly vinylalcohol), 폴리비닐부티랄(PVB ; poly vinyl butyral), 폴리비닐피롤리돈(PVP ; poly-N-vinylpyrrolidone), 스티렌부타디엔고무(SBR ; styrene butadiene rubber) 등으로부터 선택된 적어도 1종 이상을 혼합하여 사용할 수 있다.For example, as the binder, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF; polyvinylidenefloride), carboxymethylcellulose (CMC), carboxymethylcellulose, polyvinyl alcohol (PVA; poly vinylalcohol), At least one selected from polyvinyl butyral (PVB), poly-N-vinylpyrrolidone (PVP) and styrene butadiene rubber (SBR) may be used in combination. .
본 발명에 따른 활성탄 전극의 배합량은 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄과 결합재를 9:1로 조성하는것이 바람직하다.The blending amount of the activated carbon electrode according to the present invention preferably comprises 9: 1 of activated carbon and a binder having plate-shaped carbon nanofibers grown on the surface of the catalytic gasified activated carbon.
본 발명에 따른 활성탄 전극은 축전식 탈염 장치의 전극 제조에 사용된다.Activated carbon electrode according to the present invention is used in the production of electrodes of the capacitive desalination apparatus.
도 3은 본 발명의 사용 상태도로서, 축전식 탈염 장치 셀(cell)을 보인 모식도이다. 본 발명에 따른 활성탄 전극은 전극(electrode)으로 적용된다. 더욱 구체적으로는, 본 발명에 따른 활성탄 전극은 탄소 그라파이트(carbon graphite) 상에 코팅된 다음, 건조 후 일정한 크기로 재단하여 탄소전극으로 사용한다.3 is a schematic view showing a capacitive desalination cell as a use state diagram of the present invention. The activated carbon electrode according to the present invention is applied as an electrode. More specifically, the activated carbon electrode according to the present invention is coated on a carbon graphite (carbon graphite), and then cut to a certain size after drying to use as a carbon electrode.
이하, 본 발명의 기술적 사상의 일 실시예에 따른 구체적인 시험 실시예를 설명한다. 하기의 실시예는 본 발명을 보다 상세히 설명하기 위해 제공되는 것일뿐, 이에 의해 본 발명의 기술적 범위가 한정되는 것은 아니다.Hereinafter, a specific test embodiment according to an embodiment of the technical idea of the present invention. The following examples are provided only to explain the present invention in more detail, whereby the technical scope of the present invention is not limited.
[실시예]EXAMPLE
활성탄은 일본 Kuraray Chemical이 제조한 P-60을 사용하였다.As activated carbon, P-60 manufactured by Kuraray Chemical, Japan was used.
먼저, 질산철 구수화물(Ferric nitrate nonahydrate)과 질산니켈육수화물(Nickel nitrate hexahydrate)를 각각 0.2694g 1.1633g를 500ml 증류수에 녹여 금속화합물 촉매용액을 제조하였다. 이 촉매용액에 P-60 2.2821g을 마그네틱 교반기에서 교반하면서 첨가하였다. 이때 P-60에 대해 금속 촉매의 몰비는 0.1이었다. 그리고, 상기 혼합 용액을 80에서 회전 증발기를 이용해 감압 증류하여 용매를 증발시켜, 활성탄 표면에 금속촉매를 균일하게 담지하였다. 그리고, 반응로를 이용하여 가스 촉매화된 활성탄 위에 판상형 탄소나노 섬유를 성장시켰다.First, 0.2694 g 1.1633 g of ferric nitrate nonahydrate and nickel nitrate hexahydrate were dissolved in 500 ml distilled water to prepare a metal compound catalyst solution. 2.2821 g of P-60 was added to this catalyst solution with stirring in a magnetic stirrer. At this time, the molar ratio of the metal catalyst to P-60 was 0.1. The mixed solution was distilled under reduced pressure using a rotary evaporator at 80 to evaporate the solvent to uniformly support the metal catalyst on the surface of the activated carbon. Then, plate-like carbon nanofibers were grown on gas-catalyzed activated carbon using a reactor.
상기 공정을 구체적으로 설명하면, 먼저 200mg의 금속화합물-활성탄 혼합물을 석영보트 위에 올려놓고, 반응로의 온도를 350, 400, 450로 승온한 다음, 공기(air)와 질소(N)의 혼합가스(air : N = 1 : 3)를 1시간 동안 촉매가스화하였다. 도 4는 상기한 공정에 의해 제조된 활성탄의 전자현미경 사진이다. 이어서, 촉매가스화로 인하여 활성탄의 메조 세공(mesopore)의 변화를 측정한 후, 반응로의 온도를 600까지 승온하였다. 다음으로, 600의 온도로 유지한 상태에서, 반응로에 질소(N), 수소(H2) 및 에틸렌가스(C2H4)를 동시에 투입한 다음 30분 동안 합성하여 활성탄 표면에 판상형 탄소나노 섬유를 성장하였다. 이때, 질소(N), 수소(H2) 및 에틸렌가스(C2H4)는 4 : 1 : 1의 비율로 투입하였다. Specifically, the 200 mg metal compound-activated carbon mixture is placed on a quartz boat, the temperature of the reactor is raised to 350, 400, and 450, and then a mixed gas of air and nitrogen (N) is used. (air: N = 1: 3) was catalyzed for 1 hour. Figure 4 is an electron micrograph of the activated carbon produced by the above process. Subsequently, after measuring the change of mesopore of activated carbon due to catalytic gasification, the temperature of the reactor was raised to 600. Next, while maintaining the temperature of 600, nitrogen (N), hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) at the same time to the reactor and then synthesized for 30 minutes to form a plate-like carbon nano The fibers were grown. At this time, nitrogen (N), hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) was added in a ratio of 4: 1: 1.
도 5는 상기와 같은 공정에 의해 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄의 전자현미경 사진이다. 도 5를 참조하면, 활성탄 입자 표면에 탄소나노 섬유가 알맞게 성장되어 있음을 알 수 있었다. FIG. 5 is an electron micrograph of activated carbon in which plate-shaped carbon nanofibers are grown on the surface of catalytic gasified activated carbon prepared by the above process. Referring to FIG. 5, it can be seen that carbon nanofibers are appropriately grown on the surface of activated carbon particles.
이어서, 상기 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄과, 결합재로 폴리비닐리덴플로라이드(PVdF ;polyvinylidenefloride)를 중량비 9:1로 배합하였고, 용매로 DMAc를 사용하여 슬러리를 제조한 후 카본 그라파이트 상에 닥터블레이드로 캐스팅하여 활성탄 전극을 제조하였다.Subsequently, activated carbon having plate-like carbon nanofibers grown on the surface of the catalytic gasified activated carbon and polyvinylidene fluoride (PVdF; polyvinylidenefloride) as a binder were blended in a weight ratio of 9: 1, and a slurry was prepared using DMAc as a solvent. After the casting on the carbon graphite with a doctor blade to prepare an activated carbon electrode.
하기 <표 1>은 본 발명의 기술적 사상에 따른 실시예에서 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄에 대한 비표면적 변화를 나타낸 것이다. <표 1>을 참조하면, 촉매가스화 과정이 없다면 기존 활성탄의 포어 막힘 현상으로 인해 비표면적이 매우 감소함을 알 수 있다. Table 1 shows changes in specific surface area of activated carbon in which plate-like carbon nanofibers are grown on the surface of catalytic gasified activated carbon prepared in Examples according to the inventive concept. Referring to <Table 1>, it can be seen that the specific surface area is greatly reduced due to the pore blockage of the existing activated carbon without the catalytic gasification process.
표 1
reaction Specific surface area(m2/g)
Gasification Temp(oC) SynthesisTemp(oC) Time(min)
Activated carbon 1708.2
Non-gasification 600 30 1222.9
350 600 30 2240.7
400 30 2219.5
450 30 2401.5
Table 1
reaction Specific surface area (m 2 / g)
Gasification Temp ( o C) SynthesisTemp ( o C) Time (min)
Activated carbon 1708.2
Non-gasification 600 30 1222.9
350 600 30 2240.7
400 30 2219.5
450 30 2401.5
본 발명의 기술적 사상의 일 실시예에 따라 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄을 도 3에 도시된 바와 같은 축전식탈염 장치의 셀로 제조하였다. 5 x 5 cm2로 절단한 후 양극과 음극 사이에 두 전극이 접촉되는 것을 방지하면서 유체가 통과할 수 있도록 100 두께의 스페이서(120 mesh, 폴리아미드)를 장착하였다. 전극의 중앙에 1cm의 구멍을 뚫어 용액이 전극의 사면에서 스페이서를 통과해 중앙으로 빠져나갈 수 있도록 하였다. 양극과 음극의 외부에 15 x 15cm2 크기의 아크릴 판을 엔드 플레이트(end plate)로 하여 볼트로 고정하여 축전식 탈염용 단일 셀을 구성하였다. 전극 전위를 1.5V로 일정하게 인가하면서 250mg/L의 NaCl 용액을 30mL/min의 속도로 공급하였다. 유출수의 전도도(conductivity) 변화를 측정하여 탈염 효율을 분석하였다. 3분 동안 흡착시킨 후 전극전위를 3분 동안 쇼트로 변화시켜 가면서 탈착시키는 방식으로 운전하였다.Activated carbon in which plate-shaped carbon nanofibers were grown on the surface of catalytic gasified activated carbon prepared according to an embodiment of the present invention was manufactured as a cell of a capacitive desalination apparatus as shown in FIG. 3. After cutting to 5 x 5 cm 2 , a spacer (120 mesh, polyamide) having a thickness of 100 was installed to allow fluid to pass through while preventing two electrodes from contacting between the anode and the cathode. A 1 cm hole was drilled in the center of the electrode to allow the solution to exit the center through the spacer on the slope of the electrode. A single cell for capacitive desalination was constructed by bolting an acrylic plate having a size of 15 x 15 cm 2 to the outside of the anode and the cathode as an end plate. 250 mg / L of NaCl solution was supplied at a rate of 30 mL / min while the electrode potential was constantly applied at 1.5 V. Desalination efficiency was analyzed by measuring the change in conductivity of the effluent. After adsorbing for 3 minutes, the electrode potential was changed to a short for 3 minutes, and then operated by detaching.
[비교예 1]Comparative Example 1
비교예 1로 상술한 실시예에서 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄 대신, 활성탄 (P-60)만을 사용하여 상술한 실시예와 동일한 방법으로 활성탄전극을 제조하였다.Instead of activated carbon having plate-like carbon nanofibers grown on the surface of the catalytic gasified activated carbon prepared in the above-described embodiment as Comparative Example 1, an activated carbon electrode was manufactured in the same manner as in the above-described embodiment using only activated carbon (P-60). .
[비교예 2]Comparative Example 2
비교예 2로 상술한 실시예에서 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄 대신, 활성탄에 전도성 물질로 카본 블랙(Cabot Vulcan XC72R)을 10% 사용하여 상술한 것과 동일한 방법으로 활성탄 전극을 제조하였다.The same method as described above using 10% of carbon black (Cabot Vulcan XC72R) as a conductive material on the activated carbon instead of the activated carbon in which the plate-like carbon nanofibers were grown on the surface of the catalytic gasified activated carbon prepared in the above-described embodiment as Comparative Example 2 Activated carbon electrode was prepared.
[비교예 3]Comparative Example 3
비교예 3으로 상술한 실시예에서 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄 대신, 활성탄에 전도성 물질로 도전성 섬유(CNFs)를 10% 사용하여 상술한 것과 동일한 방법으로 활성탄 전극을 제조하였다.Instead of activated carbon having plate-like carbon nanofibers grown on the surface of the catalytic gasified activated carbon prepared in the above-described embodiment as Comparative Example 3, activated carbon was used in the same manner as described above using 10% conductive fibers (CNFs) as a conductive material in activated carbon. An electrode was prepared.
도 6은 실시예와 비교예 1, 2, 3에서 제조된 셀로 탈염 실험을 진행 한 후, 전도도(conductivity)를 측정한 후 중량당 염 제거량을 측정한 그래프이다.6 is a graph of salt removal amount per weight after conducting desalination experiments with the cells prepared in Examples and Comparative Examples 1, 2, and 3 after measuring conductance.
도 6을 참조하면, 비정전용량 측정을 위해 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄 20mg, 10 중량% 농도 PVdF 용액(DMAc 용매) 40, 증류수 40를 혼합하여 촉매 슬러리를 제조하였다. 상기 촉매 슬러리를 1cm2 면적을 갖는 글래시 카본에 10 도포하고 건조함으로써, 작동 전극을 제조하였다. 제조된 작동 전극, 대극으로 백금 메쉬, 참조 전극으로 Ag/AgCl(ALS. RE-1B, 표준 수소 전극: NHE로 표기)를 사용하는 3 전극 시스템으로 전기화학적 실험을 실시하였다.Referring to FIG. 6, a catalyst slurry was prepared by mixing 20 mg of activated carbon having plate-shaped carbon nanofibers, 40 wt% PVdF solution (DMAc solvent) 40, and distilled water 40 on the surface of the catalytic gasified activated carbon prepared for specific capacitance measurement. Prepared. A working electrode was prepared by applying the catalyst slurry to 10 glass carbons having an area of 1 cm 2 and drying. Electrochemical experiments were conducted with a three-electrode system using the prepared working electrode, counter electrode platinum mesh and Ag / AgCl (ALS. RE-1B, standard hydrogen electrode: NHE) as reference electrode.
상기 전기화학적 실험은 사이클릭볼타메트리(CV)는 아르곤가스로 충분히 퍼징된 1M NaCl 수용액에서, NHE 전극 기준으로 -0.4 내지 0.6V에서 실시하였다. 또한, 전위 스윕 속도(potential sweep rate)는 50mV/sec로 고정하여 실시하였다.The electrochemical experiment was performed at -0.4 to 0.6V based on NHE electrode in 1M NaCl aqueous solution sufficiently purged with argon gas (CV). In addition, the potential sweep rate was fixed at 50 mV / sec.
[비교예 4][Comparative Example 4]
비교예 4로 상술한 실시예에서 제조된 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄 대신, 오직 활성탄 (P-60)만을 사용하여 상술한 방법과 동일하게 작동 전극을 제조하였다.Instead of activated carbon in which plate-like carbon nanofibers were grown on the surface of the catalytic gasified activated carbon prepared in the above-described example as Comparative Example 4, only the activated carbon (P-60) was used to produce a working electrode in the same manner as described above.
상기 사이클릭볼타메트리 실험 결과는 도 7에 도시된 바와 같다. 도 7은 (a)는 오직 활성탄 (P-60)만을 사용한 전극이며 (b)는 촉매가스화를 진행한 전극이고 (c)는 촉매가스화 이후 판상형나노섬유를 성장한 전극의 충방전성능을 나타내고 있다. 오직 활성탄 만을 사용한 전극보다 촉매 가스화를 진행하였을시 약 80%의 충방전 용량이 증가함을 알 수 있으며, 여기에 판상형 나노섬유를 성장하면 최대 2.5배의 충방전 용량이 증가함을 알 수 있다. 또한 촉매 가스화 온도를 350에서 450 으로 증가하였을시 약 25~30%정도 충방전 용량이 증가함을 알 수 있다. 따라서 활성탄을 그냥 사용하는 것 보다, 촉매 가스화된 활성탄의 표면에 판상형 탄소나노 섬유가 성장된 활성탄을 사용함으로서 다공성 구조의 확장에 따른 충방전에서 그 영향이 확실하게 나타남을 볼 수 있다. 즉 전극의 성능을 비약적으로 향상시킬 수 있음을 알 수 있다.The cyclic voltametry experiment results are shown in FIG. 7. FIG. 7 shows (a) an electrode using only activated carbon (P-60), (b) shows an electrode which has undergone catalytic gasification, and (c) shows charge / discharge performance of an electrode in which plate-shaped nanofibers are grown after catalytic gasification. It can be seen that the charge and discharge capacity of about 80% increases when the catalyst gasification is performed than the electrode using only activated carbon, and the growth of the plate-shaped nanofibers increases the charge and discharge capacity of 2.5 times. In addition, when the catalyst gasification temperature is increased from 350 to 450, it can be seen that the charge and discharge capacity increases by about 25 to 30%. Therefore, rather than just using activated carbon, it can be seen that the effect of charging and discharging due to the expansion of the porous structure by using the activated carbon in which the plate-shaped carbon nanofibers are grown on the surface of the catalytic gasified activated carbon. In other words, it can be seen that the performance of the electrode can be significantly improved.
이상, 첨부된 도면을 참조하여 본 발명의 바람직한 일 실시예를 설명하였지만, 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자라면 본 발명이 그 기술적 사상이나 필수적인 특징을 변경하지 않고서 다른 구체적인 형태로 실시될 수 있다는 것을 이해할 수 있을 것이다. 그러므로 이상에서 기술한 일 실시예는 모든면에서 예시적인 것이며 한정적이 아닌 것으로 이해해야만 한다.As mentioned above, although an exemplary embodiment of the present invention has been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may realize the present invention in another specific form without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, it should be understood that one embodiment described above is illustrative in all respects and not restrictive.

Claims (12)

  1. 활성탄의 표면에 금속촉매를 담지하는 단계;Supporting a metal catalyst on the surface of activated carbon;
    상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계;Injecting activated carbon loaded with the metal catalyst into the reactor to perform catalytic gasification;
    상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계; 및Growing a plate-like carbon nanofiber on the surface of the catalytic gasified activated carbon by injecting and synthesizing a reaction gas including carbonization gas and reducing gas into the catalytic gasified activated carbon; And
    상기 판상형 탄소나노 섬유가 성장한 촉매가스화된 활성탄을 축전식 탈염 전극으로 제조하는 단계;를 포함하는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.And manufacturing the catalytic gasified activated carbon in which the plate-shaped carbon nanofibers are grown as a capacitive desalination electrode.
  2. 제 1항에 있어서, The method of claim 1,
    상기 활성탄의 표면에 금속촉매를 담지하는 단계는, Supporting the metal catalyst on the surface of the activated carbon,
    상기 금속촉매를 용매에 혼합한 후, 상기 혼합 용액에 활성탄을 첨가하여 금속촉매-활성탄 혼합용액을 형성한 다음, 상기 혼합용액에 포함된 용매를 증발시켜 담지하는 단계인 것을 특징으로 하는 축전식 탈염 전극의 제조방법.After the metal catalyst is mixed in a solvent, the activated carbon is added to the mixed solution to form a metal catalyst-active carbon mixed solution, and then capacitive desalting is carried out by evaporating the solvent contained in the mixed solution. Method of manufacturing the electrode.
  3. 제 1항에 있어서,The method of claim 1,
    상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계는,The process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor,
    350 내지 450℃에서 진행하는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.Process for producing a capacitive desalination electrode, characterized in that proceeding at 350 to 450 ℃.
  4. 제 3항에 있어서, The method of claim 3, wherein
    상기 금속촉매가 담지된 활성탄을 반응로에 투입하여 촉매가스화를 진행하는 단계는, The process of catalytic gasification by adding the activated carbon loaded with the metal catalyst to the reactor,
    1 시간 동안 진행하는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.Method of producing a capacitive desalination electrode, characterized in that for 1 hour.
  5. 제 1항에 있어서, The method of claim 1,
    상기 촉매가스화는 공기(Air), 산소(O2) 또는 수소(H2)를 사용하는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.The catalytic gasification method of manufacturing a capacitive desalination electrode, characterized in that using the air (Air), oxygen (O 2 ) or hydrogen (H 2 ).
  6. 제 1항에 있어서,The method of claim 1,
    상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계는,The step of growing a plate-like carbon nanofiber on the surface of the catalytic gasified activated carbon by adding and synthesizing the reaction gas consisting of carbonized gas and reducing gas into the catalytic gasified activated carbon,
    상기 반응가스를 투입하고 600℃에서 합성시키는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.The reaction method of producing a capacitive desalination electrode characterized in that the reaction gas is added and synthesized at 600 ° C.
  7. 제 1항에 있어서,The method of claim 1,
    상기 촉매가스화된 활성탄에 탄화가스와 환원가스로 이루어진 반응가스를 투입하고 합성시켜 촉매가스화된 활성탄 표면에 판상형 탄소나노 섬유를 성장시키는 단계는,The step of growing a plate-like carbon nanofiber on the surface of the catalytic gasified activated carbon by adding and synthesizing the reaction gas consisting of carbonized gas and reducing gas into the catalytic gasified activated carbon,
    30분 동안 진행하는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.Process for producing a capacitive desalination electrode, characterized in that for 30 minutes.
  8. 제 1항에 있어서, The method of claim 1,
    상기 환원가스는 수소(H2)를 사용하고, 상기 탄화가스는 에틸렌가스(C2H4)를 사용하며, 상기 수소(H2) 및 에틸렌가스(C2H4)를 동시에 투입하되, The reducing gas uses hydrogen (H 2 ), the carbonized gas is used ethylene gas (C 2 H 4 ), the hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) at the same time,
    상기 수소(H2) 및 에틸렌가스(C2H4)는 1 : 1의 비율로 투입되는 것을 특징으로 하는 축전식 탈염 전극의 제조방법.The hydrogen (H 2 ) and ethylene gas (C 2 H 4 ) is a method of manufacturing a capacitive desalination electrode, characterized in that the input ratio of 1: 1.
  9. 제 1항 내지 제 8항 중 어느 한 항에 의해 제조된 것을 특징으로 하는 축전식 탈염 전극.Capacitive desalination electrode prepared by any one of claims 1 to 8.
  10. 애노드 전극;An anode electrode;
    상기 애노드 전극과 대향하여 위치하는 캐소드 전극; 및A cathode electrode positioned to face the anode electrode; And
    상기 애노드 전극과 상기 캐소드 전극 사이에 위치하는 이온교환막;을 포함하고,And an ion exchange membrane disposed between the anode electrode and the cathode electrode.
    상기 애노드 전극 또는 캐소드 전극은 제 1항 내지 제 8항 중 어느 한 항에 의해 제조된 축전식 탈염 전극인 것을 특징으로 하는 축전식 탈염용 막-전극 어셈블리.The anode electrode or the cathode electrode is a capacitive desalination electrode prepared by any one of claims 1 to 8, characterized in that the capacitive desalination membrane-electrode assembly.
  11. 제 7항에 따른 축전식 탈염용 막-전극 어셈블리를 포함하는 축전식 탈염용 셀.A capacitive desalting cell comprising a capacitive desalting membrane-electrode assembly according to claim 7.
  12. 애노드 전극, 상기 애노드 전극과 대향하여 위치하는 캐소드 전극, 상기 애노드 전극과 캐소드 전극 사이에 위치하는 이온교환막을 포함하는 하나 이상의 막-전극 어셈블리; 및At least one membrane-electrode assembly comprising an anode electrode, a cathode electrode positioned opposite the anode electrode, and an ion exchange membrane positioned between the anode electrode and the cathode electrode; And
    세퍼레이터를 포함하고,Including a separator,
    상기 전극은 제 1항 내지 제 8항 중 어느 한 항에 의해 제조된 축전식 탈염 전극을 포함하는 막-전극 어셈블리인 것을 특징으로 하는 축전식 탈염 시스템.9. The capacitive desalination system according to claim 1, wherein the electrode is a membrane-electrode assembly comprising a capacitive desalination electrode prepared by any one of claims 1-8.
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KR102151994B1 (en) * 2019-03-21 2020-09-04 두산중공업 주식회사 Method for manufacturing capacitive deionization electrode
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