KR20100085476A - Mixed metal oxide electrode for making sterilized water with hypochlorous acid and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A complex noble metal oxide electrode for generating hypochlorous acid sterilized water and manufacturing method thereof are provided to reduce manufacturing costs by controlling the composition of coating materials and by forming both poles with a high adhesion property. CONSTITUTION: A complex noble metal oxide electrode for generating hypochlorous acid sterilized water comprises a substrate and a coating layer which protects the substrate and expedites a conduction with being coated on the substrate. The coating layer comprises one or more protective layers and one or more catalyst layers. The protective layers protect the substrate in order not to be corroded and improve the adhesion of the coating layer. The catalyst layers expedite the conducting of the substrate and improves hypochlorous acid generation efficiency. The protective layer is made with a mixture of iridium oxide(IrO2) and tantalum oxide(Ta2O5) with 20~50:80~50 mole weight ratio. The catalyst layer is made with a mixture of iridium oxide and tantalum oxide with 80~50:20~50 mole weight ratio.

Description

Mixed Metal Oxide Electrode For Making Sterilized Water With Hypochlorous Acid And Manufacturing Method Thereof}

The present invention relates to a composite noble metal oxide electrode for generating hypochlorite sterilized water and a method for manufacturing the same, and more particularly, hundreds of experiments of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ), which are noble metal oxides, on an electrode substrate By coating at the optimum ratio obtained through the formation of the protective layer and the catalyst layer to form the electrode to maximize the efficiency of hypochlorous acid generation in the positive electrode and excellent adhesion between the protective layer and the catalyst layer of the electrode and excellent oxidation resistance and durability of the electrode The present invention relates to a composite noble metal oxide electrode for generating chloric acid sterilizing water and a method of manufacturing the same.

Increasing national income has led to a great deal of interest in activities to improve people's quality of life, especially in environmental and health issues. Water source is an environment that directly affects people's health as it is widely used for drinking and washing in a real living environment. Waterborne bacteria, various bacteria and viruses, etc. because of the tendency to increase because of pollution of the water source, there is always a possibility of causing the disease. In particular, the number of food poisoning accidents, which have been on the rise for several years, as well as the size of food service facilities, suggest that washing and drinking water contamination may be indirect causes. Therefore, water disinfection management is very important to secure safe drinking water and improve public health.

At present, the most common disinfection method of water source is chlorine disinfection. Chlorine sterilizes or inactivates microorganisms by changing the permeability of microbial cell membranes. Although chlorine disinfection has long been used as a general sterilization method for drinking water sources, there is a move to reconsider chlorine disinfection due to the announcement that THM (Trihalomethane) formed with chlorine treatment causes cancer and due to the smell of drinking water from chlorine disinfection. Very few people use tap water directly as drinking water. In order to minimize the adverse effects of chlorine disinfection, the Ministry of Environment has also drafted an amendment to the Rules on Cleaning and Hygienic Management of Water Facilities to set the chlorine concentration standard from 0.2 mg / l to 0.1 mg / l or more. In the case of 1.5mg / L to 0.4mg / L or more to be adjusted. On the other hand, in foreign countries such as Japan and France, the residual chlorine concentration of tap water is 0.1mg / ℓ, which is lower than that of Korea.

The following describes alternative disinfection methods. Reduction of the input chlorine concentration immediately leads to a decrease in disinfection effect. Especially in indoor piping, viscous material by microorganisms is attached to the pipe, so it is difficult to expect disinfection effect at low concentration of chlorine. Accordingly, alternative disinfection methods that can replace chlorine disinfection have been actively studied. Alternative disinfection methods currently introduced include ozone (O ₃ ), ultraviolet (UV), chlorine dioxide (ClO ₂ ), and sodium hypochlorite (NaOCl).

The ozone disinfection method has a disadvantage that it is difficult to secure safety due to the short residence time of ozone and is not uniformly delivered to the entire water supply equipment.

Ultraviolet disinfection is not suitable for total water disinfection because biofilms do not have residual effects and do not transmit UV light, so they are used only for small-scale disinfection.

Chlorine dioxide disinfection method is relatively effective because there is no problem of THM (Trihalomethane) generation in the existing chlorine disinfectant, and it is corrosive and penetrates and destroys the biofilm containing bacteria. It also has the advantage that no chlorine organic chemicals such as chlorophenol or halogenated hydrocarbons are produced. However, because chlorine dioxide itself is unstable and cannot be stored or transported, it must be produced and used at the site.

Accordingly, an object of the present invention is the generation of THM (Trihalomethane) in the chlorine disinfection, chlorine dioxide itself is a water-soluble toxic gas in chlorine dioxide disinfection, uneven delivery of ozone disinfection, possibility of bacterial habitat in ultraviolet disinfection The problem was solved by producing hypochlorous acid sterilizing water, which is non-hazardous and has excellent sterilizing power, using the electrode. Hundreds of experiments were carried out on the electrode substrate with iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). By coating at the optimum ratio obtained through the formation of a protective layer and a catalyst layer to form an electrode, the efficiency of hypochlorous acid generation at the anode is maximized and the adhesion between the protective layer and the catalyst layer of the electrode is excellent. The present invention provides a composite noble metal oxide electrode for sterilizing water generation and a method of manufacturing the same.

In order to achieve the object as described above, the present invention,

And a coating layer coated on the substrate to protect the substrate and to promote the current while protecting the substrate.

The coating layer is one or more protective layers installed to impart corrosion by the external corrosive environment and adhesion to the coating layer to provide durability, and to protect the substrate to promote electricity supply and increase the efficiency of hypochlorous acid generation Consists of one or more catalyst beds installed on the bed,

The protective layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) 20 to 50: mixed at a ratio of 80 to 50 molar weight,

The catalyst layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). 80 to 50: provides a composite noble metal oxide electrode for hypochlorous acid generation comprising a mixture of 20 to 50 molar weight ratio.

In addition, the method for producing a composite noble metal oxide electrode for hypochlorous acid generation of the present invention,

And a coating layer coated on the substrate to protect the substrate and to promote the current while protecting the substrate.

The coating layer is one or more protective layers installed to impart corrosion by the external corrosive environment and adhesion to the coating layer to provide durability, and the protective layer to promote the current passing through the substrate and increase the efficiency of hypochlorous acid generation A method for producing a composite noble metal oxide electrode for hypochlorous acid generation, comprising one or more catalyst layers disposed thereon,

Degreasing the substrate with an alkaline solution;

Etching the degreased substrate with an aqueous solution;

Washing the etched substrate with water;

Coating the washed substrate by dipping, brushing, roll coating, or spraying with a protective layer or a catalyst layer coating solution;

Drying the coated substrate; And

It provides a method for producing a composite noble metal oxide electrode for hypochlorous acid comprising a; heat treating the dried substrate.

In the present invention, the ratio of the molar weight of iridium oxide (IrO ₂ ) and the tantalum oxide (Ta ₂ O ₅ ) is A: B by setting the ratio of the iridium (Ir) solution and the tantalum (Ta) solution to A: B molar weight. It provides a composite noble metal oxide electrode manufacturing method for hypochlorous acid consisting of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) made of.

The composite noble metal oxide electrode for hypochlorous acid sterilizing water generation and the method of manufacturing the same according to the present invention are obtained by optimizing iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ), which are noble metal oxides, on an electrode substrate at an optimal ratio. By forming a protective layer and a catalyst layer by coating to form an electrode, the efficiency of hypochlorous acid generation at the anode is maximized, and the adhesion between the protective layer and the catalyst layer of the electrode is excellent, thereby providing excellent oxidation resistance and durability of the electrode.

In addition, since the composition of the coating material, which is the core of hypochlorous acid generation, can be optimally controlled and develops a positive electrode having high adhesion, manufacturing cost is drastically lowered.

In addition, the present invention has significant economic and business benefits by developing an electrode material to be used for the generation of hypochlorous acid, which is used as sterilizing water for mass feeding facilities, and establishing an optimal manufacturing process.

The present invention provides a composite noble metal oxide electrode for hypochlorous acid generation, comprising a substrate constituting the electrode to energize electricity and a coating layer coated on the substrate to protect the substrate and promote electricity supply, wherein the coating layer is the substrate. At least one protective layer provided to enhance corrosion damage due to an external corrosive environment and adhesion of the coating layer, and to provide durability, and at least one catalyst layer disposed on the protective layer to promote energization of the substrate and increase the efficiency of hypochlorous acid generation. The protective layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) 20 to 50: a mixture of 80 to 50 molar weight, and the catalyst layer is iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) 80-50: It contains what mixes in the ratio of 20-50 molar weight.

Specifically, the composite noble metal oxide electrode for hypochlorous acid generation is coated with a protective layer by optimizing the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ), which are precious metal oxides, on the electrode substrate at an optimal ratio obtained through hundreds of experiments. By forming a catalyst layer to form an electrode, the efficiency of hypochlorous acid generation at the anode is maximized, and the adhesion between the protective layer of the electrode and the catalyst layer is excellent, thereby providing excellent oxidation resistance and durability of the electrode.

That is, the composite noble metal oxide electrode for hypochlorous acid generation is an electrode used in a sterilization water generation module for generating hypochlorous acid sterilizing water, and in the positive electrode of the electrolysis reaction in which hypochlorous acid is generated from saline containing chlorine ions, Chlorine gas is generated from chlorine ions, and the generated chlorine gas is immediately hydrolyzed in water and decomposed into hypochlorous acid. At the same time, water is decomposed at the anode to generate oxygen because the generation potential of oxygen is lower than that of chlorine, and the amount of oxygen generation directly affects hypochlorous acid generation efficiency. Therefore, the composite noble metal oxide electrode for hypochlorous acid generation was manufactured so that the amount of oxygen generated was small.

Here, the amount of hypochlorous acid can be maximized only when the oxygen generating reaction is suppressed to the maximum. The core of the hypochlorous acid generator is the anode in which electrolysis takes place. First, the efficiency of generating chlorine ions must be high, and second, it must be long. At this time, since the anode is exposed to the oxidation reaction, the composite noble metal oxide electrode for hypochlorous acid generation having a high resistance to corrosion and chemical resistance in solution as well as oxidation was prepared.

In addition, since a gas generating reaction occurs at the anode, adhesion to this is also required. If the coating material of the electrode is dissolved and the surface of the titanium substrate or niobium substrate is exposed, a formula (that is, erosion) occurs and thus the lifetime of the anode is reached. Therefore, the overvoltage difference related to the anode reaction occurs depending on the composition of these coating materials. In order to determine the maximum efficiency of the desired purpose, the composition of the coating layer must be properly controlled according to the use thereof. Thus, the coating layer of the present invention is coated on the titanium substrate and the niobium substrate to obtain the maximum efficiency of hypochlorous acid sterilization water generation.

In addition, since the anode has a very severe oxidation reaction along with chlorine generation, the anode has a very short life due to corrosion degradation, and thus, the present invention has secured reliability such as composition control of the anode and adhesion of the coating layer in order to develop a high efficiency long-life hypochlorous acid generator. A composite noble metal oxide electrode for hypochlorous acid generation was prepared.

That is, the present invention is one or more inlets for supplying brine at one end, two or more outlets for discharging hypochlorite sterilized water and sodium water at the other end; And a passage through which the brine introduced between the anode and the cathode causes electrolysis to be discharged to the discharge port. In the hypochlorous acid sterilization water generating module, the pH of the generated hypochlorous acid sterilized water discharged to the discharge port is within a range of 4.3 to 5.9. In addition, while controlling the concentration of the hypochlorous acid sterilization water to 1.75 ~ 80ppm as a residual chlorine ion concentration, while producing a high-purity high-purity hypochlorous acid sterilization water with a high sterilization ability, no extra cost, breakthrough hypochlorous acid sterilization We have developed a composite noble metal oxide electrode for hypochlorous acid generation in water production modules.

Hypochloric acid is a weak acid with the formula HOCl or HClO and also called hypochlorous acid. According to the use of hypochlorous acid, the effective range (concentration) of the active ingredient of disinfectant disinfectant is not less than 200ppm (effective chlorine) for hospitals, hospitality, etc. Is 200 ppm or less (effective chlorine).

Here, the effective chlorine indicates the amount of chlorine that is effective for sterilization or disinfection by the amount of effective chlorine. If the amount of chlorine is present in the substance, whether the amount of dissociated chlorine or combined chlorine, all the amount of chlorine is called effective chlorine or free chlorine. That is, the amount of all goats contained. For example, if a mixture has a substance called ClO ₃ ^- bound to dissociated Cl ⁻ , then effective chlorine means all Cl in both substances.

Free chlorine ions are hypochlorite and chlorine ions. In other words, free chlorine is generated when reacting chlorine (Cl ₂ ) with water (H ₂ O), and the free chlorine is hypochlorous acid (HClO), that is, hypochlorous acid (HOCl). It is called.

Residual chlorine ions, also called effective chlorine or free chlorine ions, are generic to chlorine ions (Cl-) and hypochlorite (OCl-). The residual chlorine ions are present mainly as chlorine ions under strong acid conditions (pH less than 1.7) depending on the pH, and are mainly present as chlorine ions, and less chlorine ions under mild acid and neutral conditions (pH 1.7 to 7.5). It exists as hypochlorite ion. Under alkaline conditions (pH 7.5 to 11), chlorine ions are extremely low, and hypochlorite ions react with sodium to solidify, so they are hardly present in the aqueous phase.

Hypochlorite water is an aqueous solution containing hypochlorous acid (molecular type HOCl or HClO), and is an aqueous solution 70 to 80 times higher in sterilization and disinfection effect than sodium hypochlorite (NaOCl). Hypochlorite water does not have any irritating odor or risk in its production. In addition, it does not have a pungent odor and does not irritate the skin at all.

Therefore, the disinfection method using the hypochlorous acid sterilizing water is better.

Next, hypochlorite disinfection is described in detail. When the salt water electrolysis as chlorine molecules and a coordinate bond of the chloride ion anion side anodizing hypochlorous acid (HOCl) and hypochlorite ion (OCl ^-) are generated.

Cl ₂ + H ₂ O ⇔ HOCl + HCl

HOCl ⇔ H ^{+ +} OCl ^-

Hypochlorous acid and hypochlorite ions all have a disinfecting effect. However hypochlorous acid (HOCl) is hypochlorite ion (OCl ^-) has at least about 70-fold compared to the oxidizing power. Therefore, in order to obtain a great bactericidal power, a lot of hypochlorous acid should be generated.

Hypochlorite disinfection methods include sodium hypochlorite (NaOCl) injection and electrolysis in the field, followed by injection. The concentration of commercially available sodium hypochlorite is transported by tank lorry to about 5-12% and stored in the storage tank for use, and an automatic bubble generator is required as an accessory. As a direct production method in the field, a small hypochlorous acid generator is used to generate and dilute hypochlorous acid by electrolysis from tap water sterilized by chlorine or salt added salt.

 Anode (pH ↓)

(Note ^{(主)) 2Cl - → Cl} 2 + 2e - (E 0 = 1.395V)

_{Cl 2 + H 2 O → HOCl} + Cl - + H +

HOCl ⇔ H ^{+ +} OCl ^-

(Part _{(副)) 2H 2 O →} O 2 + 4H + + 4e -

 Cathode (pH ↑)

^{_{2H 2 O + 2e - → H}} 2 + 2OH - (E 0 = 1.228V)

In fact, in the electrolysis reaction in which hypochlorous acid is generated from brine added with chlorine ions, chlorine gas is generated from chlorine ions in solution at the positive electrode. The generated chlorine gas is immediately hydrolyzed in water and decomposed into hypochlorous acid. At the same time, water is decomposed at the anode to generate oxygen because the generation potential of oxygen is lower than that of chlorine, and the amount of oxygen generation directly affects hypochlorous acid generation efficiency. That is, the amount of hypochlorous acid can be maximized only when the oxygen generating reaction is suppressed to the maximum.

The core of the hypochlorous acid generator is the anode in which electrolysis takes place. First, the efficiency of generating chlorine ions must be high, and second, it must be long.

That is, since the anode is exposed to the oxidation reaction, the corrosion resistance and chemical resistance in the solution, as well as the oxidation resistance according to the oxidation reaction should be large. In addition, since a gas generating reaction occurs at the anode, adhesion to this is required. If the coating material of the electrode is dissolved and the surface of the titanium substrate or niobium substrate is exposed, a formula (ie, erosion) occurs and thus the lifetime of the anode is reached.

On the other hand, insoluble anodes are used to prevent formulas, which are generally manufactured by coating oxides of platinum group elements such as platinum, iridium, ruthenium, and tantalum on titanium or niobium substrates. Insoluble electrodes have been originally used for cathodic anodes, seawater cooling seaweed sterilization anodes, wastewater electrolysis device anodes, and water decomposition electrolysis device anodes. Since the overvoltage difference related to the anodic reaction occurs depending on the composition of these coating materials, the maximum efficiency for the desired purpose is determined by controlling the composition of the coating layer appropriately according to its use. In addition, the anode has a very short lifespan due to corrosion deterioration because oxidization occurs with chlorine. Therefore, in order to develop a high-efficiency long-life hypochlorous acid generator, it is possible to secure reliability such as composition control of anode and adhesion of coating layer.

As a related art, Japanese Patent Publication No. 58-136790 discloses a manganese oxide 2-50 mole% + titanium oxide 50-98 mole% mixed layer two-layer coating layer on a platinum-iridium oxide mixed layer, but the catalyst layer is peeled off. Or dissolution occurred and wear resistance was also poor.

Japanese Patent Publication No. 02-038668 has applied an anode coating of platinum 70 mole%-iridium oxide 30 mole% (molar weight) to titanium to lower the chlorine overvoltage, but has problems in durability such as peeling phenomenon and easy dissolution. In order to improve this, a second layer of a mixture of 10 mole% iridium oxide-15 mole% ruthenium oxide-75 mole titanium oxide (molar weight) on the platinum-iridium oxide coating layer was shown to improve the durability. Again, there was a problem in the adhesion and durability of the electrode.

In Japanese Patent Laid-Open Publication No. 2008-050675, a durable electrolytic electrode having a stable and high chlorine generation efficiency is produced even when the anode / cathode polarity is changed in lean saline, which is an electroplated porous platinum coating layer on the titanium electrode, but a platinum layer This problem was difficult to form properly.

The lead oxide electrode invented in Japanese Patent Laid-Open Publication No. 2006-322026 has a large oxidation effect and is capable of ozone treatment, but has not been used due to environmental problems. In addition, the tin oxide electrode was applied, but the oxygen overvoltage was more effective than organic hypochlorite generation, rather than hypochlorous acid generation, and there was a problem that the electrode was instantaneously destroyed when reverse current flowed.

Accordingly, the present invention is a composite noble metal oxide electrode for hypochlorous acid generation, consisting of a substrate constituting the electrode to energize electricity and a coating layer coated on the substrate to protect the substrate and at the same time to promote electricity, the coating layer is One or more protective layers installed to impart corrosion to the substrate due to external corrosive environment and adhesion to the coating layer to impart durability, and one installed on the protective layer to promote energization of the substrate and increase the efficiency of hypochlorous acid generation. The protective layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). 20 to 50: a mixture of 80 to 50 molar weight, and the catalyst layer is iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) 80-50: It contains what mixes in the ratio of 20-50 molar weight.

In the present invention, the electrode substrate was formed by coating a noble metal oxide of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) at the optimum ratio obtained through hundreds of experiments on the electrode substrate to form a protective layer and a catalyst layer. .

The coating layer of the present invention is composed of a composite oxide coating layer consisting of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). Ta: the iridium oxide (IrO ₂₎ and tantalum oxide (Ta ₂ O _5), compound Ir of the oxide coating layer consisting of; the concentration ratio of (iridium oxide (IrO _2), tantalum oxide (Ta ₂ O ₅₎ or less equal to) 8: In the case of 2, hypochlorous acid generation efficiency is the maximum, whereas, if the Ir: Ta concentration ratio is 2: 8, the durability is maximum.

Thus, the iridium oxide (IrO ₂₎ and tantalum oxide (Ta ₂ O ₅₎ Ir of the composite oxide coating consisting of: Ta (iridium oxide (IrO _2): tantalum oxide (Ta ₂ O _5); hereinafter the same) the concentration ratio The protective layer and the coating layer may be formed in different ratios according to the purpose of improving hypochlorous acid generation efficiency and durability.

The composite noble metal oxide electrode for hypochlorous acid generation has a protective layer of ruthenium oxide (RuO ₂ ) or tin oxide (SnO ₂ ) based on 100 molar parts by weight of the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). It is made by further mixing 10 to 50 molar parts.

Here, the protective layer further mixes 10 to 50 mole parts by weight of ruthenium oxide (RuO ₂ ) or tin oxide (SnO ₂ ) based on 100 mole parts by weight of the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). Thus, durability, corrosion resistance, and oxidation resistance of the electrode can be increased.

In the composite noble metal oxide electrode for hypochlorous acid generation, a catalyst layer includes ruthenium oxide (RuO ₂ ) or tin oxide (SnO ₂ ) 10 based on a total of 100 mole parts by weight of the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). It is made by further mixing-50 molar parts.

Here, the catalyst layer is further mixed with 10 to 50 mole parts by weight of ruthenium oxide (RuO ₂ ) or tin oxide (SnO ₂ ) based on 100 mole parts by weight of the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). Hypochlorite sterilizing water generation efficiency, corrosion resistance, oxidation resistance of the electrode can be increased.

In addition, the composite noble metal oxide electrode for hypochlorous acid generation has a dual structure having a single protective layer and a catalyst layer having a single composition or a gradient composition having a protective layer having a plurality of compositions and a catalyst layer having a plurality of compositions.

The double electrode has a single composition of one to several dozen protective layers, and a single composition of one to several tens of catalyst layers may be the same as or different from the composition of the single protective layer and the single catalyst layer.

In the electrode having the gradient composition, the composition of one to several dozen protective layers is continuously or discontinuously different, and the composition of the one to several tens of catalyst layers is also continuously or discontinuously different. It may also be included, the catalyst composition of the plurality of compositions may also include the same composition. In addition, the composition of the protective layer of the plurality of compositions and the catalyst layer of the plurality of compositions may be the same or different.

Here, the protective layer is made of a combination of a plurality of protective layers formed in a different ratio sequentially in the ratio range of 20: 80 to 50: 50 molar weight of iridium oxide (IrO ₂ ): tantalum oxide (Ta ₂ O ₅ ). . However, the present invention is not limited thereto, and the protective layer may be formed in different ratios or the same ratio.

The number of protective layers is 1-80.

Here, the number of the protective layer is determined to increase the durability, oxidation resistance, corrosion resistance, etc. of the composite noble metal oxide electrode for hypochlorous acid generation.

The catalyst layer is composed of a combination of a plurality of catalyst layers in which iridium oxide (IrO ₂ ): tantalum oxide (Ta ₂ O ₅ ) is sequentially formed at different ratios within a ratio range of 80: 20 to 50: 50 molar weight. However, the present invention is not limited thereto, and the catalyst layers may be formed in different ratios or in the same ratio.

The number of catalyst layers is 1-80.

Here, the number of the catalyst layer is determined to increase the hypochlorous acid generation efficiency, oxidation resistance, corrosion resistance, etc. of the composite noble metal oxide electrode for hypochlorous acid generation.

Based on this, as an example, by forming a double-layered coating layer, it is possible to obtain a positive electrode that maximizes both hypochlorous acid generation efficiency and durability at the same time.

1) Top layer: Iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) with Ir: Ta = 8: 2 with minimum hypochlorite generation overvoltage and maximum oxygen generation overvoltage to maximize hypochlorous acid generation efficiency. Complex oxide catalyst layer

2) Lower layer: composite oxide protective layer of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) with good corrosion resistance and adhesion to Ir: Ta = 2: 8 to give durability.

3) This double structure has a double layer structure in which a catalyst layer and a protective layer are at least two layers as shown in FIG.

In addition, as an example, as illustrated in FIG. 2, an anode having a gradient composition layer structure in which the catalyst layer and the protective layer are each four or more layers can be manufactured.

1) Gradient-forming catalyst layer: Iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) with Ir: Ta = 8: 2 with minimum hypochlorite generation overvoltage and maximum oxygen generation overvoltage to maximize hypochlorous acid generation efficiency ) From the composite oxide catalyst layer Ir: Ta = 7: 3; Ir: Ta = 6: 4; Gradient forming catalyst layer of a composite oxide catalyst layer having a composition of Ir: Ta = 5: 5 continuously or discontinuously

2) Gradient protective layer: From the composite oxide protective layer of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) whose corrosion resistance and adhesion are good Ir: Ta = 2: 8 to give durability, Ir: Ta = 3: 7; Ir: Ta = 4: 6; Gradient protective layer of the composite oxide protective layer having a composition of Ir: Ta = 5: 5 continuously or discontinuously

The composite noble metal oxide electrode for hypochlorous acid generation is an anode or a cathode.

The composite noble metal oxide electrode for hypochlorous acid generation may be used as an anode for generating hypochlorous acid, or may be used as a cathode for generating hydrogen.

In addition, the method for producing a composite noble metal oxide electrode for hypochlorous acid generation of the present invention,

And a coating layer coated on the substrate to protect the substrate and to promote the current while protecting the substrate.

The coating layer is one or more protective layers installed to impart corrosion by the external corrosive environment and adhesion to the coating layer to provide durability, and the protective layer to promote the current passing through the substrate and increase the efficiency of hypochlorous acid generation A method for producing a composite noble metal oxide electrode for hypochlorous acid generation, comprising one or more catalyst layers disposed thereon,

Degreasing the substrate with an alkaline solution;

Etching the degreased substrate with an aqueous solution;

Washing the etched substrate with water;

Coating the washed substrate by dipping, brushing, roll coating, or spraying with a protective layer or a catalyst layer coating solution;

Drying the coated substrate; And

And heat-treating the dried substrate.

For example, as a pretreatment, after alkali degreasing, etching for 5 to 30 minutes in a boiling 0.1M ~ 1.0M aqueous solution, washed with water and then coated with a protective layer or a catalyst layer coating solution. The coating can be applied by either dip, brush, roll coating or spray methods. Sandblasting is also helpful to improve the adhesion of the coating layer. After the coating is dried in air at 80 ~ 150 ℃ for 5 to 30 minutes, put into a heat treatment furnace of 350 ~ 600 ℃ as heat treatment, after 10 to 40 minutes, and air-cooled. The coating process is repeated 1 to 80 times for the protective and catalyst layers, respectively, and the last time the heat treatment time is extended to 30 to 120 minutes.

Here, the protective layer coating liquid is formed by sequentially mixing different iridium (Ir) solution: tantalum (Ta) solution in a ratio of 20: 80 to 50: 50 by weight ratio. However, the present invention is not limited thereto, and the protective layer coating solution may be formed by mixing different ratios or the same ratio.

In addition, the catalyst layer coating liquid is formed by sequentially mixing different iridium (Ir) solution: tantalum (Ta) solution in a ratio of 80: 20 to 50: 50 by weight ratio. However, the present invention is not limited thereto, and the catalyst layer coating solution may be formed by mixing different ratios or the same ratio.

The iridium (Ir) solution includes hexachloroiridium acid (H ₂ IrCl ₆ ) 0.02 to 5.0 M, lavender oil 50 to 800 ml / l, terepin oil 20 to 200 ml / l and isopropyl alcohol 200 to 980 ml / l .

The hexachloroiridium acid (H ₂ IrCl ₆ ) is a black brown oily acid that is a raw material of the iridium oxide electrode.

In addition, the tantalum (Ta) solution includes pentachlorotantalum (TaCl ₅ ) 0.02 to 5.0 M, lavender oil 50 to 800 ml / l, terepin oil 20 to 200 ml / l and isopropyl alcohol 200 to 980 ml / l.

The pentachloro tantalum (TaCl ₅ ) is a yellow powder and is a raw material of the tantalum oxide electrode.

In one example, a coating solution was prepared. The first solution is an iridium solution and the second solution is a tantalum solution as follows.

The first solution is an iridium solution and has the following composition.

[First Solution: Iridium Solution]

① H ₂ IrCl ₆ : 0.1M (47.89g / ℓ)

     ② lavender oil: 300ml / ℓ

     ③ turpentine oil: 60ml / ℓ

     ④ isopropyl alcohol: 640ml / l

[Second solution: tantalum solution]

① TaCl ₅ : 0.1M (35.82g / ℓ)

     ② lavender oil: 300ml / ℓ

     ③ turpentine oil: 60ml / ℓ

     ④ isopropyl alcohol: 640ml / l

[Preparation of Coating Solution]

Since the composition of the coating layer exactly matches the composition of the solution [FIG. 3], in order to determine the composition of the coating layer, the composition of the coating layer may be controlled by adjusting the mixing ratio of the first solution and the second solution.

In the present invention, the ratio of the molar weight of iridium oxide (IrO ₂ ) and the tantalum oxide (Ta ₂ O ₅ ) is A: B by setting the ratio of the iridium (Ir) solution and the tantalum (Ta) solution to A: B molar weight. It provides a composite noble metal oxide electrode manufacturing method for hypochlorous acid consisting of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) made of.

The ratio of A: B is 20 to 80:80 to 20.

For example, as shown in FIG. 3 (X-axis: molar weight concentration of iridium (Ir) in the solution; Y-axis: molar weight concentration of iridium (Ir) in the coating layer), the iridium (Ir) concentration in the solution and iridium in the coating layer (Ir) concentration is proportional,

In order to coat the protective layer, the first solution and the second solution are mixed at 2: 8, and the composition of the coating layer thus obtained is Ir 20% and Ta 80%.

In order to coat the catalyst layer, the first solution and the second solution are mixed at 8: 2, and the composition of the coating layer thus obtained is Ir 80% and Ta 20%.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

[Example]

The composite noble metal oxide electrode for hypochlorous acid generation, in which the double-layered coating layer of Examples 1 to 4 was formed, was manufactured by the following manufacturing method, thereby obtaining a positive electrode to maximize hypochlorous acid generation efficiency and durability.

(Sandblast)-Alkaline Degreasing-Washing-Etching (0.2M boiling fish, 10 minutes)-[Coating (Dipping, Brushing, Roll Coating, Spraying)-Drying (120 ℃, 10min)-Heat Treatment (450 ℃, 20min , 60 minutes at the last heat treatment)] (repetitive) using the positive electrode produced by the following method to confirm the amount and durability of hypochlorous acid.

Hypochlorite Generation Experiment

The amount of hypochlorous acid generated in the aqueous solution containing sodium chloride (NaCl) as a positive electrode using the electrode made of the present invention, as a cathode using a platinum electrode or an electrode prepared in the present invention such that a constant current density between the two poles The amount of hypochlorous acid applied at this time was measured by measuring the pH through a free chlorine (residual chlorine ion, effective chlorine or free chlorine ion) measuring device to determine the concentration by calculating the dissociation degree of hypochlorous acid. The concentrations of sodium chloride (NaCl) were 0.3% and 3%, and the current density was 5A / dm 2.

Durability experiment

The endurance test was stopped at 50 ° C and 2M HClO ₄ + 1M NaCl solution (conductivity 900 ~ 1,000mS) with a positive current at 200A / dm2, and when the interpotential potential rises above 30V, the time indicated by the endurance life. It was.

4 is a SEM (scanning electron microscopy) photograph of the protective layer surface of the composite noble metal oxide electrode for hypochlorous acid sterilization water generation of the present invention, Figure 5 is a SEM of the catalyst layer surface of the composite noble metal oxide electrode for hypochlorous acid sterilization water generation (Scanning Electron Microscopy)

First solution: iridium solution

① H ₂ IrCl ₆ : 0.1M (47.89g / ℓ)

     ② lavender oil: 300ml / ℓ

     ③ turpentine oil: 60ml / ℓ

     ④ isopropyl alcohol: 640ml / l

Second solution: tantalum solution

① TaCl ₅ : 0.1M (35.82g / ℓ)

     ② lavender oil: 300ml / ℓ

     ③ turpentine oil: 60ml / ℓ

     ④ isopropyl alcohol: 640ml / l

Example 1

Solution Mixing: First Solution: Second Solution = 8: 2

Catalyst layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 8: 2)

Protective layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 5: 5)

pH: 4.400-4.750 (3% NaCl); 4.046-5.502 (0.3 wt% NaCl)

sample Number of coatings on each of catalyst and protective layers Domestic Life (Hour) Hypochlorous acid generation (ppm) 3 wt% NaCl 0.3 wt% NaCl One 3 72 60 10 2 6 168 65 10 3 10 288 65 10

Here, it can be seen that as the number of coating of the catalyst layer and the protective layer increases, the service life of the electrode increases. While the pH of the produced hypochlorous acid sterilizing water is within the range of 4.3 ~ 5.9, the concentration of the hypochlorous acid sterilizing water is controlled to 1.75 ~ 80ppm as the residual chlorine ion concentration, and the hypochlorous acid sterilizing water having a high sterilizing power is highly purified and has a large amount. Produced.

[Example 2]

Solution Mixing: First Solution: Second Solution = 5: 5

Catalyst layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 5: 5)

Protective layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 5: 5)

pH: 4.400-4.750 (3% NaCl); 4.046-5.502 (0.3 wt% NaCl)

sample Number of coatings on each of catalyst and protective layers Domestic Life (Hour) Hypochlorous acid generation (ppm) 3 wt% NaCl 0.3 wt% NaCl 4 3 96 55 10 5 6 144 60 10 6 10 264 60 10

Here, it can be seen that as the number of coating of the catalyst layer and the protective layer increases, the service life of the electrode increases. While the pH of the produced hypochlorous acid sterilizing water is within the range of 4.3 ~ 5.9, the concentration of the hypochlorous acid sterilizing water is controlled to 1.75 ~ 80ppm as the residual chlorine ion concentration, and the hypochlorous acid sterilizing water having a high sterilizing power is highly purified and has a large amount. Produced.

Example 3

Solution Mixing: First Solution: Second Solution = 2: 8

Protective layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 2: 8)

Catalyst layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 5: 5)

pH: 4.400-4.750 (3% NaCl); 4.046-5.502 (0.3 wt% NaCl)

sample Number of coatings on each of catalyst and protective layers Domestic Life (Hour) Hypochlorous acid generation (ppm) 3 wt% NaCl 0.3 wt% NaCl 7 3 72 35 8 8 6 168 40 8 9 10 420 40 8

Here, it can be seen that as the number of coating of the catalyst layer and the protective layer increases, the service life of the electrode increases. In particular, when the protective layer coating layer composition is IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 2: 8) it can be seen that the service life is much increased. While the pH of the produced hypochlorous acid sterilizing water is within the range of 4.3 ~ 5.9, the concentration of the hypochlorous acid sterilizing water is controlled to 1.75 ~ 80ppm as the residual chlorine ion concentration, and the hypochlorous acid sterilizing water having a high sterilizing power is highly purified and has a large amount. Produced.

Example 4

Solution Mixing: First Solution: Second Solution = 2: 8

Catalyst layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 8: 2)

Protective layer coating layer composition: IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 2: 8)

pH: 4.400-4.750 (3% NaCl); 4.046-5.502 (0.3 wt% NaCl)

sample Number of catalyst layer coatings Protective layer coating count Domestic Life (Hour) Hypochlorite Generation
(ppm) Ir: Ta = 8: 2 Ir: Ta = 2: 8 3 wt% NaCl 0.3 wt% NaCl 6 0 10 420 40 8 10 2 8 424 45 8 11 4 6 745 50 10 12 6 4 869 55 10 13 8 2 773 60 10 3 10 0 288 65 10

Here, it can be seen that as the number of coating of the catalyst layer and the protective layer increases, the service life of the electrode increases. In particular, when the catalyst layer coating layer composition is IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 8: 2), and the protective layer coating layer composition is IrO ₂ + Ta ₂ O ₅ (Ir: Ta = 2: 8), the service life is high. It was found to be large. In addition, as the number of coating of the catalyst layer increases, the service life of the electrode increases, and when it is similar to the number of coatings of the protective layer, it can be seen that the maximum service life increases. While the pH of the produced hypochlorous acid sterilizing water is within the range of 4.3 ~ 5.9, the concentration of the hypochlorous acid sterilizing water is controlled to 1.75 ~ 80ppm as the residual chlorine ion concentration, and the hypochlorous acid sterilizing water having a high sterilizing power is highly purified and has a large amount. Produced.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a cross-sectional view of a composite noble metal oxide electrode for hypochlorous acid sterilization water generation formed of a double composition structure of the present invention.

2 is a cross-sectional view of the composite noble metal oxide electrode for hypochlorous acid sterilization water generation formed by the gradient composition of the present invention.

3 is a graph showing the compositional relationship between the coating solution and the coating layer of the present invention.

Figure 4 is a SEM (Scanning Electron Microscopy) photograph of the protective layer surface of the composite noble metal oxide electrode for hypochlorous acid sterilization water generation of the present invention.

5 is a SEM (Scanning Electron Microscopy) photograph of the catalyst layer surface of the composite noble metal oxide electrode for hypochlorous acid sterilization water generation.

Claims (16)

And a coating layer coated on the substrate to protect the substrate and to promote the current while protecting the substrate. The coating layer is one or more protective layers installed to impart corrosion by the external corrosive environment and adhesion to the coating layer to provide durability, and the protective layer to promote the current passing through the substrate and increase the efficiency of hypochlorous acid generation It consists of one or more catalyst beds installed above The protective layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) 20 to 50: mixed at a ratio of 80 to 50 molar weight, The catalyst layer is formed of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). 80 to 50: a composite noble metal oxide electrode for hypochlorous acid generation comprising a mixture of 20 to 50 molar weight ratio. The composite noble metal oxide electrode for hypochlorous acid generation according to claim 1, wherein the protective layer is formed of ruthenium oxide (RuO ₂ ) or 100 mol parts by weight of the total of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). Tin oxide (SnO ₂ ) A composite noble metal oxide electrode for hypochlorous acid generation, characterized in that the mixture further comprises 10 to 50 molar parts. The composite noble metal oxide electrode for hypochlorous acid generation according to claim 1, wherein the catalyst layer comprises ruthenium oxide (RuO ₂ ) or tin based on 100 mole parts by weight of the iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). Oxide (SnO ₂ ) The composite noble metal oxide electrode for hypochlorous acid generation, characterized in that the mixture further comprises 10 to 50 molar parts. The method of claim 1, wherein the composite noble metal oxide electrode for hypochlorous acid generation has a dual structure having a single protective layer and a single catalyst layer or a gradient structure having a protective layer and a plurality of catalyst layers of a single composition. Composite noble metal oxide electrode for hypochlorous acid generation. The protective layer of claim 1, wherein the protective layer is formed of iridium oxide (IrO ₂ ): tantalum oxide (Ta ₂ O ₅ ) at different ratios sequentially formed within a ratio of 20:80 to 50:50 molar weight. Composite noble metal oxide electrode for hypochlorous acid generation, characterized in that consisting of. The composite noble metal oxide electrode for hypochlorous acid generation according to claim 1, wherein the number of protective layers is 1 to 80. According to claim 1, wherein the catalyst layer is iridium oxide (IrO ₂ ): tantalum oxide (Ta ₂ O ₅ ) is a combination of a plurality of catalyst layers formed in a different ratio sequentially in the ratio range of 80: 20 to 50: 50 molar weight Composite noble metal oxide electrode for hypochlorous acid generation, characterized in that consisting of. The composite noble metal oxide electrode for hypochlorous acid generation according to claim 1, wherein the number of the catalyst layers is 1 to 80. The composite noble metal oxide electrode for hypochlorous acid generation according to claim 1, wherein the composite noble metal oxide electrode for hypochlorous acid generation is an anode or a cathode. And a coating layer coated on the substrate to protect the substrate and to promote the current while protecting the substrate. The coating layer is one or more protective layers installed to impart corrosion by the external corrosive environment and adhesion to the coating layer to provide durability, and the protective layer to promote the current passing through the substrate and increase the efficiency of hypochlorous acid generation A method for producing a composite noble metal oxide electrode for hypochlorous acid generation, comprising one or more catalyst layers disposed thereon, Degreasing the substrate with an alkaline solution; Etching the degreased substrate with an aqueous solution; Washing the etched substrate with water; Coating the washed substrate by dipping, brushing, roll coating, or spraying with a protective layer or a catalyst layer coating solution; Drying the coated substrate; And Heat treating the dried substrate; Method for producing a composite noble metal oxide electrode comprising hypochlorous acid. 11. The method of claim 10, wherein the protective layer coating solution is formed by mixing iridium (Ir) solution: tantalum (Ta) solution in a different ratio sequentially in the range of 20: 80 to 50: 50 weight ratio Composite noble metal oxide electrode manufacturing method. The method of claim 10, wherein the catalyst layer coating liquid is formed by mixing the iridium (Ir) solution: tantalum (Ta) solution sequentially different ratios within the range of 80: 20 to 50: 50 by weight for hypochlorous acid generation Composite noble metal oxide electrode manufacturing method. The method of claim 11 or 12, wherein the iridium (Ir) solution is hexachloroiridium acid (H ₂ IrCl ₆ ) 0.02 ~ 5.0M, lavender oil 50 ~ 800ml / l, terepin oil 20 ~ 200ml / l and iso Method for producing a composite noble metal oxide electrode for hypochlorous acid generation, characterized in that it comprises 200 ~ 980ml / l propyl alcohol. The method of claim 11 or 12, wherein the tantalum (Ta) solution is pentachloro tantalum (TaCl ₅ ) 0.02 ~ 5.0M, lavender oil 50 ~ 800ml / l, terepin oil 20 ~ 200ml / l and isopropyl alcohol 200 Method for producing a composite noble metal oxide electrode for hypochlorous acid generation, characterized in that it comprises ~ 980ml / l. Iridium oxide which makes the ratio of molar weight of iridium oxide (IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ) to A: B by setting the ratio of the iridium (Ir) solution and the tantalum (Ta) solution to A: B molar weight. Method for producing a composite noble metal oxide electrode for hypochlorous acid generation consisting of IrO ₂ ) and tantalum oxide (Ta ₂ O ₅ ). The method of claim 15, wherein the ratio of A: B is 20 to 80:80 to 20.

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