KR101829120B1 - Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member - Google Patents
Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member Download PDFInfo
- Publication number
- KR101829120B1 KR101829120B1 KR1020160023032A KR20160023032A KR101829120B1 KR 101829120 B1 KR101829120 B1 KR 101829120B1 KR 1020160023032 A KR1020160023032 A KR 1020160023032A KR 20160023032 A KR20160023032 A KR 20160023032A KR 101829120 B1 KR101829120 B1 KR 101829120B1
- Authority
- KR
- South Korea
- Prior art keywords
- metal oxide
- gas sensor
- nano
- oxide nano
- catalyst
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
- C01B13/14—Methods for preparing oxides or hydroxides in general
-
- B01J32/00—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D1/00—Processes for applying liquids or other fluent materials
- B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
- B05D1/04—Processes for applying liquids or other fluent materials performed by spraying involving the use of an electrostatic field
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/483—Physical analysis of biological material
- G01N33/497—Physical analysis of biological material of gaseous biological material, e.g. breath
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
- C01P2004/32—Spheres
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
- C01P2004/32—Spheres
- C01P2004/36—Spheres fragmented
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/16—Pore diameter
Abstract
The present invention relates to a member for a gas sensor, a gas sensor using the same and a method of manufacturing the same, and more particularly, to a polymer bead-catalyst having a three-dimensional hierarchical structure by spraying a solution containing a catalyst, a polymer template, and metal oxide nanoparticles - forming a nano-agglomerate based on a metal oxide and forming pores on the surface and inside of the nano-agglomerate through a subsequent heat treatment to form a porous three-dimensional hierarchical structure of catalyst-metal oxide complex nano-agglomerates having an open structure . In addition, after incorporating a heterogeneous polymer bead template, the polymer template is removed through a subsequent heat treatment process to form a member for a gas sensor having a multi-pore distribution, thereby improving the surface area and increasing the pore distribution, The present invention can be applied to a high-sensitivity expiratory sensor and a hazardous environment sensor which are capable of smooth gas infiltration and diffusion and have selectivity by binding a catalyst thereto.
Description
The present invention relates to a member for a gas sensor and a method of manufacturing the same, and more particularly, to a method of manufacturing a member for a gas sensor and a method of manufacturing the member using the sacrificial layer template of a polymer based on electrostatic spraying. Metal oxide composite nano-agglomerates having a porous three-dimensional hierarchical structure obtained by using the catalyst-metal oxide composite nano-agglomerates and gas sensor members and gas sensors using the catalyst-metal oxide composite nano aggregates.
Metal oxides, which use a simple principle that electrical resistance changes through surface adsorption and desorption reactions when exposed to a specific gas, have been widely applied in the field of gas sensors. Such a resistance change type based gas sensor is operated through the thickness modulation of the electron depletion layer formed by the adsorption of oxygen on the surface of the metal oxide semiconductor constituting the sensing material. When exposed to a reducing target gas, the resistance increases as the thickness of the electron-doping layer increases, and when the oxidizing target gas is exposed, the thickness of the electron-doping layer decreases and the resistance decreases. In addition to these simple principles, it is easy to miniaturize, low cost and does not require a preprocessing process. Therefore, many researches have been made to apply a resistance change type based gas sensor as a low cost portable sensor. Particularly, exhaled breath sensors capable of detecting a very small amount of volatile organic compound (VOCs) contained in a human body's exhalation have been researched and applied. Biomarkers that can detect diabetes, lung cancer, bad breath, and kidney disease can be identified from the concentration of specific volatile organic compounds such as acetone, toluene, hydrogen sulfide, and ammonia in the body's exhalation. However, in order to diagnose disease, it is necessary to be able to selectively detect the gases coming from the mouth of a person to very minute concentrations of ppm (parts per billion) or ppb (part per billion). For example, diabetes, which can be judged by the concentration of acetone in the exhalation, contains acetone at a concentration of 900 ppb or less in the exhalation of a healthy person, but acetone at a concentration of 1800 ppb or more is contained in the exhalation of the diabetic patient. For lung cancer, 30 ppb of toluene should be detectable and for kidney disease, 100 ppb of ammonia should be detectable. Therefore, it is essential to develop an ultra-sensitive sensing material that can effectively detect low-concentration gases.
A variety of nanostructures have been studied for the development of ultra-sensitive sensing materials. Basically, the gas sensing using metal oxide changes the electrical resistance through the surface reaction. Therefore, nanofibers, nanowires, nanotubes, hollow structures, 3D hierarchical structures for maximizing the specific surface area that can be reacted, nanostructure shape has been studied.
The present invention relates to a method of forming a pore in a nano-aggregate of a self-assembled three-dimensional hierarchical structure by micro-bead milling a metal oxide powder, electrospinning a dispersion solution retaining colloidal particle shape without precipitation and aggregation in a solvent Metal oxide sensing material which can simultaneously form microcapsules and macropores and can simultaneously bind the catalysts. The present invention also provides a gas sensor member having a high sensitivity characteristic that can be applied to the development of various catalyst-metal oxide sensing materials and can detect a trace amount of gas through a simple manufacturing method, a gas sensor using the same, and a manufacturing method thereof .
In one embodiment of the present invention for solving the above problems, there is provided a three-dimensional hierarchical structure formed by self-assembling by an electric spraying method in which an electric powder fraction containing a dispersion of metal oxide nanoparticles is subjected to electric spraying under an electric field Wherein the metal oxide nano-agglomerate is a metal oxide nano-agglomerate.
In another aspect, the electrolytic solution may further include a polymer template, and the metal oxide nano-aggregate may be formed by subjecting the polymer template contained in the surface and inside of the three-dimensional hierarchical structure to heat treatment And the micropores and macropores formed along the surface and the interior are simultaneously included.
According to another aspect of the present invention, the metal oxide nano-aggregate has a domain in which the content of metal oxide nanoparticles is relatively larger than that of the polymer template and a domain in which the content of the polymer template is relatively larger than that of the metal oxide nano- And a plurality of pores formed by the removal of the polymer template after the heat treatment are connected to each other to have an open structure.
In another aspect, the polymer template used as a sacrificial layer may be formed by an electrodispersion method, including a polymer having at least one shape selected from a spherical ball structure, a triangular shape, a square shape, a pentagon shape, and a hexagonal shape .
In another aspect, the size of the polymer template may be in the range of 100 to 750 nm, and may include a polymer having the same diameter or different diameters.
According to another aspect of the present invention, the electrolytic solution further comprises a catalyst, and the metal oxide nano-agglomerate is characterized in that the catalyst is bound to the three-dimensional hierarchy according to the electric injection.
According to another aspect of the present invention, the catalyst to be bound includes at least one selected from Pt, Pd, Ag, Au, IrO 2 , RuO 2 and Rh 2 O 3 . There are no restrictions on the catalyst preparation method. As a specific embodiment, a catalyst produced by a polyol method was used.
In yet another aspect, the three-dimensional hierarchical structure may be characterized by having at least one structure of a spherical shape, a donut shape, an elliptical shape, and a partially broken spherical shape.
In another aspect, the size of the three-dimensional hierarchy may be in the range of 150 nm - 3 μm.
In another aspect, the diameter of the metal oxide nanoparticles constituting the metal oxide nano-agglomerate is in the range of 5 to 100 nm.
In another aspect, in the metal oxide nanoparticles and the self-assembled metal oxide nano-agglomerates contained in the metal oxide nanoparticle dispersion, the metal oxide may include SnO 2 , ZnO, WO 3 , Fe 2 O 3 , Fe 3 O 4 , NiO, TiO 2, CuO, In 2 O 3,
In another aspect, a metal oxide nano-agglomerate having a three-dimensional hierarchy can be bound to a catalyst simultaneously with the formation of a plurality of pores.
In another embodiment of the present invention, the above-mentioned metal oxide nano-aggregate is applied on a sensor substrate capable of recognizing the change in resistance to manufacture at least one of biological indicator gas and environmentally harmful gas for diagnosis, And a gas sensor for detecting the gas.
Here, the semiconductor type gas sensor can measure at least one of the volatile organic compounds contained in the human exhalation.
In another embodiment of the present invention, there is provided a method for producing a metal oxide nano-aggregate as such a sensing material, comprising the steps of: (a) preparing an electrolytic solution containing a metal oxide nanoparticle dispersion; And (b) electro-spraying the prepared electrolytic solution under an electric field to form a self-assembled metal oxide nano-agglomerate.
According to another aspect, in the step (a), a polymer template may be added to the metal oxide nanoparticle dispersion, and the method of manufacturing the metal oxide nano-agglomerate may include: (c) Forming a plurality of pores on the surface and inside of the metal oxide nano-aggregate by removing the polymer template included in the surface and inside of the metal oxide nano-aggregate through heat treatment.
According to another aspect of the present invention, the metal oxide nano-aggregate of the three-dimensional hierarchical structure includes a domain in which the metal oxide nanoparticles have a relatively larger content than the polymer template and a domain in which the polymer template has a relatively larger content than the metal oxide nanoparticles The plurality of pores formed by the removal of the polymer template after the heat treatment are connected to each other to have an open structure.
According to another aspect, the addition amount of the polymer template is in the range of 10 - 25 wt%.
According to another aspect, the polymeric template is selected from the group consisting of polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl acetate, polyurethane, polyurethane copolymer, polyether urethane, cellulose derivative, polymethyl acrylate (PMA) , Polyacrylic copolymers, polyvinyl acetate copolymers, polyvinyl alcohol (PVA), polyperfuryl alcohol (PPFA), polystyrene copolymers, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene oxide copolymers, poly Propylene oxide copolymer, polycarbonate (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinylpyrrolidone (PVP), polyvinyl fluoride, polyvinylidene fluoride copolymer, polyacrylonitrile , A polyamide, a pitch, and a phenol resin.
According to another aspect of the present invention, in the step (a), a catalyst may be added to the dispersion of the metal oxide nanoparticles, and the catalyst is bound to the three-dimensional hierarchy according to the electric injection.
According to another aspect, the catalyst may be added in an amount of 0.01 to 20 wt%.
According to another aspect of the present invention, there is provided a method for producing a nano-agglomerate of metal oxide, comprising the steps of: (d) applying the nano-agglomerate of metal oxide on a sensor substrate capable of recognizing resistance change to generate a biomarker gas (oxidizing gas: nO 2, nO, reducing gas: H 2, CO, C 2 H 5 OH, H 2 S, CH 4 , and so on) at least one of detecting comprises a step of manufacturing a semiconductor type gas sensor capable more of . ≪ / RTI >
According to another aspect, the step (d) comprises applying the metal oxide nano-agglutinate using one of spray coating, drop coating, screen printing, EHD, direct coating through electrospinning and application via transfer onto the sensor substrate .
According to the present invention, a self-assembled nano-agglomerated metal oxide semiconductor thin film having a three-dimensional hierarchical structure including a small mesopore and a large macropore fabricated by electrospinning and polymer templating technology, A metal nanoparticle catalyst is used to constitute a member for a gas sensor, thereby making it possible to easily penetrate the gas to be detected and to have a faster reaction speed and a recovery speed, a high sensitivity characteristic capable of detecting a trace amount of gas, Mechanical stability capable of enduring physical stress of the gas sensor and selectivity capable of detecting various gases, and a manufacturing method thereof.
BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a method of manufacturing a metal oxide nano-aggregate and a gas sensor according to embodiments of the present invention. FIG.
2 is a schematic view of a member for a gas sensor using a self-assembled three-dimensional hierarchical structure of metal oxide nano-aggregates to describe Embodiment 1 of the present invention.
FIG. 3 is a graph showing the relationship between the catalyst-metal structure of a three-dimensional hierarchical structure of a polystyrene bead-catalyst-metal oxide composite nano-aggregate containing a spherical polymer to explain the third embodiment of the present invention and a porous three- A schematic view of a member for a gas sensor using oxide composite nano agglomerates.
4 is a scanning electron microscope (SEM) photograph of a self-assembled three-dimensional hierarchical structure of metal oxide aggregates prepared according to Example 1 of the present invention.
5 is a scanning electron micrograph of spherical polymer polystyrene beads having diameters of 100 nm and 500 nm used in Example 2 of the present invention.
6 is a scanning electron microscope (SEM) image of a polystyrene bead-tin oxide composite nano-aggregate having a three-dimensional hierarchical structure with polystyrene bead templates of 100 nm diameter prepared according to Example 2 of the present invention.
7 is a scanning electron microscope (SEM) image of a porous three-dimensional hierarchical structure of tin oxide nano-aggregates obtained after heat treatment at a high temperature of polystyrene bead-tin oxide composite nano aggregates of 100 nm diameter prepared according to Example 2 of the present invention.
8 is a scanning electron microscope (SEM) image of a porous three-dimensional hierarchical structure of tin oxide nano-aggregates obtained after heat treatment of a polystyrene bead-tin oxide composite nano-agglomerate of 500 nm diameter prepared according to Example 2 of the present invention at a high temperature.
FIG. 9 is a graph showing the results of a three-dimensional hierarchical structure of tin oxide nano-aggregate injections obtained after heat treatment at a high temperature of nano-aggregates composed of 100 nm diameter and 500 nm diameter polystyrene beads combined with tin oxide prepared according to Example 2 of the present invention Electron microscope pictures.
10 is a graph showing the results of the injection of a Pt catalyst-tin oxide nano-aggregate of porous three-dimensional hierarchical structure obtained after heat treatment of a polystyrene bead-Pt catalyst-tin oxide composite nano-agglomerate prepared according to Example 3 of the present invention at a high temperature Electron microscope pictures.
FIG. 11 is a graph showing the results of a three-dimensional hierarchical tin oxide nano-scale structure obtained by electrospinning an additional metal salt solution on a three-dimensional hierarchical tin oxide nano-agglomerated thin film coated on a sensor substrate prepared in Example 4 of the present invention. Agglutination scanning electron micrograph.
12 is a graph showing the relationship between the tin oxide nano-aggregate of three-dimensional hierarchical structure and the tin oxide nano-aggregate of porous three-dimensional hierarchical structure produced according to Example 1 and Example 2 of the present invention, A comparison graph of acetone gas sensing characteristics measured at 400 ° C by lowering the resistance.
FIG. 13 is a graph showing the results of thermal compression bonding of the porous three-dimensional hierarchical structure of tin oxide nano-agglomerates prepared in Example 2, Picture.
14 is a graph showing the results of thermal compression bonding of the tin oxide nano-agglomerate of porous three-dimensional hierarchical structure and the porous three-dimensional hierarchical structure of catalyst-tin oxide composite nano aggregates obtained according to Example 2 and Example 3 of the present invention, To 400 < 0 > C.
BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments will be described in detail below with reference to the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
Embodiments of the present invention are directed to metal oxide nano-agglomerates, gas sensors using metal oxide nano-agglomerates, metal oxide nano-agglomerates, and a method of manufacturing a gas sensor, which have characteristics of sensing a low concentration of gas with high sensitivity, .
FIG. 1 is a flowchart illustrating a method of manufacturing a metal oxide nano-aggregate and a gas sensor according to embodiments of the present invention. The method comprises the steps of: (S110) preparing an electrolytic solution containing a dispersion of metal oxide nanoparticles (S110); and electroforming the electrolytic solution under an electric field to form a self-assembled three-dimensional hierarchical structure of metal oxide nano-aggregates (S120).
When metal oxide nanoparticles to be included in the dispersion of metal oxide nanoparticles are commercially available, the size of the powder is as large as 100 nm or more, and metal oxide nanoparticles may precipitate and aggregate in the solvent. In order to prevent this, nanoparticles having a size ranging from 20 to 100 nm can be obtained through microbead milling, and a colloidal solution can be obtained in which no aggregation or precipitation occurs in the solvent. In this case, the micro-bead milling is performed using a micro-bead having a diameter of 0.1 mm or less in the specific embodiment. In a more specific embodiment of the manufacturing method according to the embodiments of the present invention, zirconia microbeads were used.
In another embodiment, a polymeric template may be added to the metal oxide nanoparticle dispersion of step S110. In this case, the manufacturing method includes a step (S130) of forming a plurality of pores on the surface and inside of the nano-agglomerated metal oxide by removing the polymer template included in the surface and inside of the three-dimensional hierarchical structure by heat treatment through electric spraying .
In yet another embodiment, a catalyst (e. G., A metal nanoparticle catalyst) may be added to the metal oxide nanoparticle dispersion of step SlOl. In this case, the catalyst can be bound to the three-dimensional hierarchy according to the electric injection.
In another embodiment, the method comprises applying a nano-agglomerate of metal oxide onto a sensor substrate capable of recognizing the change in resistance to generate biomarker gas (oxidizing gas: NO 2 , NO, reduction, (S140) of producing a semiconductor type gas sensor capable of detecting at least one of gas, H 2 , CO, C 2 H 5 OH, H 2 S, CH 4, and the like.
In other words, the electrolytic solution described above may include at least one kind of metal oxide nanoparticle dispersion, and may further include at least one of a polymer template and a metal nanoparticle catalyst in the metal oxide nanoparticle dispersion according to an embodiment .
At this time, in step S140, a small amount of binder may be included in the sensing material of the metal oxide nano-aggregate. By including a small amount of the polymer binder, the adhesion between the sensing material of the metal oxide nano-aggregate of the three-dimensional hierarchical structure and the sensor substrate can be further strengthened. Here, the polymer binder may include one or more materials selected from the group consisting of polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyacrylonitrile (PAN), styrene acrylonitrile Can be used.
After the sensing material is applied to the sensor substrate in step S140, a pressure in the range of 30 to 120 kgf / cm < 2 > and a pressure in the range of 30 A pressing time in the range of-600 seconds, and a pressing temperature in the range of 25-120 [deg.] C. The pressing process can increase the contact area between the metal oxide nano-agglomerates, thereby lowering the high contact resistance.
In addition, in order to lower the contact resistance of the metal oxide nano-aggregate sensing material too high in step S140, the solution containing the metal salt may further be electrosprayed. For example, a metal salt solution having a concentration of 0.1 to 0.5 M is used to perform electrical spraying with an electric spraying time of 0.1 to 1 ml / min at an electric spraying rate of 10 to 20 kV and 10 to 30 min, Can reduce contact resistance by covering between three-dimensional nano-aggregates coated on the sensor substrate.
In addition, the heat treatment in step S130 is preferably performed at a high temperature of 500 DEG C or higher (400-800 Lt; 0 > C). Here, materials such as a polymer template, an organic material such as a polymer that may remain in the nanoparticle catalyst synthesis, and a binder may be all removed by a high-temperature heat treatment process.
2 is a schematic view of a self-assembled three-dimensional hierarchical structure of a metal oxide nano-agglomerate by using an electrospray method and an electrospray technique according to an embodiment of the present invention. The
The method of preparing an electrolytic solution for forming the metal oxide nano-agglomerate 400 is to uniformly disperse the
As shown in FIG. 2, the
FIG. 3 is a cross-sectional view of a polymer bead-catalyst-metal oxide composite nano-
At this time, the polymer bead used as the polymeric bead template 300 does not have any particular restriction on the kind of the polymeric bead. The polymeric bead used in the polymeric bead templated 300 may be selected from the group consisting of polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl acetate, polyurethane, Polyolefins such as polyether urethane, cellulose derivatives, polymethyl acrylate (PMA), polyacrylic copolymer, polyvinyl acetate copolymer, polyvinyl alcohol (PVA), polyperfuryl alcohol (PPFA), polystyrene copolymer, polyethylene oxide (PEO) , Polypropylene oxide (PPO), polyethylene oxide copolymer, polypropylene oxide copolymer, polycarbonate (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinylpyrrolidone (PVP), polyvinyl fluoride , A polyvinylidene fluoride copolymer, a polyacrylonitrile, a polyamide, a pitch, or a phenol resin. Two or more materials may be used. The size of the polymer beads may range from 100 to 750 nm. In the present invention, polystyrene beads having a diameter of 100 nm and a diameter of 500 nm are used in the present invention. In order to further improve the sensitivity and selectivity, the catalyst may be incorporated in the electrolytic solution to bind to the surface and inside of the nano-aggregate. The catalyst to be bound is Pt, Pd, Ag, Au, IrO 2 , RuO 2 , Rh 2 O 3 can be selected. The catalyst preparation method is not limited, and can be included in the electrolytic solution in an amount in the range of 0.01 - 20 wt%.
When the polystyrene bead-catalyst-metal oxide composite nano-agglomerate is subjected to a high-temperature heat treatment at a temperature in the range of 400 to 800 ° C, the polystyrene beads are decomposed or carbonized, and pores are formed at the site where the polystyrene beads are present, And a porous three-dimensional hierarchical structure of catalyst-metal oxide composite nano aggregates having increased porosity can be formed. In addition, impurities that may remain in the synthesis of the nanocatalyst used in the specific embodiment can be removed at the same time.
Example 1: 3D Tin oxide with a hierarchical structure ( SnO 2 ) Manufacture of nano-aggregates
In this embodiment, ethanol is used as a solvent for dispersing tin oxide nanoparticles, and a solution in which tin oxide nanoparticles having a size of 100 nm or less is dispersed in ethanol to 2 wt% is used as an electrolytic solution. The above-mentioned metal oxide electro-liquoring solution was placed in a syringe (Henke-Sass Wolf, 10 ml NORM-JECT) and connected to a syringe pump. The solution was pushed at a discharge rate of 0.2 ml / min, A needle (21 gauge) is adjusted to 10 cm between the collector and the nano agglomerate, and a voltage of 11 kV is applied to form a self-assembled three-dimensional hierarchical structure of tin oxide nano-aggregates.
4 is a scanning electron micrograph of a self-assembled three-dimensional hierarchical structure of tin oxide nano-aggregates obtained by the above-mentioned electric spraying method. From the enlarged scanning electron micrographs, it can be seen that the nanoparticles are well agglomerated to form a three-dimensional hierarchical nano-aggregate with a size in the range of 700 nm - 1.4 μm.
Example 2: polymer Bead Template Using the porous three-dimensional hierarchical structure of tin oxide (SnO 2 ) Manufacture of nano-aggregates
In order to increase the surface area and to increase the porosity of the three-dimensional hierarchical tin oxide nano-agglomerates prepared above, electrospun can be manufactured by incorporating polystyrene beads together. More specifically, the electrospray solution is prepared by mixing 0.5 g of a solution (polystyrene latex microsphere, Alfa Aesar) in which 2.5 wt% of spherical polystyrene is dispersed in water, to 4 ml of the solution in which the tin oxide nanoparticles are dispersed. The electrospray was carried out in the same manner as the electric spraying conditions described above. Specifically, the polystyrene bead-added metal oxide electrification solution was placed in a syringe (Henke-Sass Wolf, 10 ml NORM-JECT) Then, the fractional solution was pushed out at a discharge rate of 0.2 ml / min, and the fractional solution was adjusted to 10 cm between a needle (21 gauge) to be discharged and a collector substrate for obtaining nano-aggregates, Voltage is applied to form a self-assembled three-dimensional hierarchical structure of polystyrene bead-tin oxide composite nano-aggregates.
A scanning electron micrograph of the spherical polystyrene beads used above can be seen in FIG. In FIG. 5, polystyrene beads having a diameter of 100 nm and polystyrene beads having a diameter of 500 nm are shown in a specific example, and the polystyrene beads used in the present invention have a uniform size. In the present invention, when only polystyrene beads having a diameter of 100 nm were used as the template, and when only the polystyrene beads having the diameter of 500 nm were used as the template, two cases of using 100 nm and 500 nm beads as the double template were prepared.
6 is a scanning electron micrograph of a polystyrene bead-tin oxide composite nano-agglomerate of a self-assembled three-dimensional hierarchical structure obtained by the above electric injection method. The enlarged scanning electron microscope image shows that polystyrene beads and tin oxide nanoparticles having a diameter of 100 nm are uniformly and well aggregated, forming a self-assembled three-dimensional hierarchical structure of nano-aggregates. The three-dimensional hierarchical structure of polystyrene bead-tin oxide nano-aggregates formed at this time was found to be in the range of 1 μm to 3 μm. Polystyrene bead-tin oxide nano-agglomerates made by electrospinning may have an elliptical shape during the formation process.
In order to remove the polystyrene beads, a heat treatment was performed in a high-temperature air atmosphere. The high temperature heat treatment process was performed at 600 ℃ for 2 hours and the temperature rise and fall rate was kept constant at 4 ℃ / min. In FIG. 7, it is possible to confirm the disappearance of the polystyrene beads mixed with the tin oxide on the surface and the pores formed in the surface by the scanning electron micrograph of the tin oxide nano-aggregate of the porous three-dimensional hierarchical structure completed with the heat treatment. It can be confirmed that the polystyrene beads were uniformly distributed not only on the surface of the tin oxide nano-agglomerate but also on the inside during the electric spraying from the plural pores formed inside. Also, as adjacent polystyrene beads are decomposed together, part of the polystyrene bead template may have a pore size slightly larger than the size of the initially used polystyrene bead template. In some cases, a portion of the polystyrene bead template protruding to the surface is 1/4 , When the pores formed by the polystyrene beads are seen from the surface, it is possible to confirm the portion which is smaller than the size of the polymer bead template initially used.
In the same way, if the size of polystyrene beads dispersed in water is made different, the size of pores formed after heat treatment can be easily controlled. In FIG. 8, it can be seen that the size of pores formed is 350-500 nm by using polystyrene beads having a diameter of 500 nm. The pores that can be identified on the surface for the reasons described above may vary depending on the degree of exposure of the polystyrene beads to the surface, but may include pores having a size similar to that of the initially used polystyrene. Therefore, even when a polymer template other than polystyrene is used to form the nano-aggregate, the size of the pore to be formed in the nano-agglomerate of the metal oxide can be easily controlled by controlling the size of the polymer used as the template.
In the same way, two kinds of polystyrene beads having different sizes are injected, and then, after heat treatment, various types of pores formed in the three-dimensional nano-aggregate can be controlled in various ways. 9 is a scanning electron microscope photograph of a porous three-dimensional hierarchical structure of tin oxide nano-aggregates prepared by mixing and spraying polystyrene beads of 100 nm in size and polystyrene beads of 500 nm in size after heat treatment, From the electron micrograph, the size of pores formed by polystyrene of 100 nm size and the size of pores formed by polystyrene of 500 nm size are clearly distinguished.
By using the polymer template, the self-assembled nano-agglomerate surface and the pores formed in the interior thereof have the effect of widening the specific surface area. Also, through the pore distribution, Excellent detection characteristics can be exhibited.
Example 3: Polymeric beads Tin oxide ( SnO 2 ) composite nano-agglomerate having porous three-dimensional hierarchical structure prepared by forming pores using a template and binding Pt catalyst
The present invention relates to a porous three-dimensional metal oxide nano-agglomerate to form a large number of pores on the surface and inside to improve the specific surface area and the porosity, as well as to bind the metal nanoparticle catalyst together, . However, the conventional process for improving the specific surface area and porosity and the process for synthesizing and binding the catalyst have a disadvantage in that a separate process is required. However, in this study, the catalyst and the polymer template are merely included in the electrolytic solution The catalyst-metal oxide composite nano-agglomerate having a porous three-dimensional hierarchical structure to which a catalyst is bound can be easily produced by performing an electric spray.
The catalytic-metal oxide composite nano-agglomerate having a porous three-dimensional hierarchy structure can be obtained easily by injecting the catalytic nanoparticles synthesized in the liquid preparation prepared in Example 2 and subjecting the mixture to a heat treatment. More specifically, the electrospray solution was prepared by dissolving 0.5 g of a solution (polystyrene latex microsphere, Alfa Aesar) in which 2.5 wt% of spherical polystyrene having a diameter of 100 nm was dispersed in water in 4 ml of the solution in which the tin oxide nanoparticles were dispersed And 80 μl of a platinum nanoparticle catalyst, which is synthesized by the polyol method and dispersed in ethanol, is added to prepare an electric discharge liquid. The electrospray was carried out in the same manner as described above, and specifically, the above-mentioned polystyrene beads and a metal oxide electrodeposition solution to which a platinum nanoparticle catalyst was added were placed in a syringe (Henke-Sass Wolf, 10 ml NORM-JECT) And connected to a syringe pump, the fraction was pushed out at a discharge rate of 0.2 ml / min, and the fraction was adjusted to 10 cm between a needle (21 gauge) to be discharged and a collector substrate to obtain nano-aggregates And a voltage of 11 kV is applied to form a self-assembled three-dimensional hierarchical structure of polystyrene bead-platinum catalyst-tin oxide composite nano-aggregates.
The polystyrene beads were removed from the prepared polystyrene bead-platinum catalyst-tin oxide composite nano-agglomerate, and heat treatment was performed in a high-temperature air atmosphere to remove impurities contained in the synthesized platinum catalyst. The high temperature heat treatment process was performed at 600 ℃ for 2 hours and the temperature rise and fall rate was kept constant at 4 ℃ / min. In FIG. 10, a pore formed by the polystyrene bead having a diameter of 100 nm on the surface can be confirmed with a scanning electron microscope photograph of a platinum catalyst-tin oxide composite nano-agglomerate of a porous three-dimensional hierarchical structure completed with heat treatment. In Example 2 Compared with the scanning electron microscopic photographs of nano-agglomerates prepared by adding only polystyrene beads having a size of 100 nm, even when the catalyst is added during the electrospinning process, the porous three-dimensional nano-agglomerate structure .
Example 4: Evaluation of gas sensing properties of the manufactured sensing materials
The three-dimensional hierarchical tin oxide nano-agglomerate, porous three-dimensional hierarchical tin oxide nano-agglomerate, porous three-dimensional hierarchical structure platinum catalyst-tin oxide nano-agglutination detection fabricated through Examples 1, 2, The gas sensing characteristics of the material sensors were evaluated. Sensitivity of the sensor is measured by Agilent's Model 34972A when the specific gas is flowed. The response of each gas (Response: R air / R gas resistance change, R air : Resistance in air, R gas : Resistance at the time of flowing the measuring gas). In order to evaluate the characteristics according to the gas concentration, the concentration of the flowing gas was changed to 5 ppm, 4 ppm, 3 ppm, 2 ppm and 1 ppm in order. In addition, a platinum micro heater is patterned on the backside of the sensor alumina substrate, and a DC voltage (Agilent's DC voltage generator E3647 model) is applied to the rear micro-heater to vary the substrate temperature to 300-450 ° C., The sensing characteristics were evaluated. The gas sensing characteristics were evaluated by maintaining the relative humidity at 85-95% in order to create an environment similar to human exhalation.
In order to fabricate the sensing materials of Examples 1 and 2 as a sensor, a three-dimensional hierarchical tin oxide nano-aggregate and a porous three-dimensional hierarchical tin oxide nano-aggregate dispersed in ethylene glycol (EG) Coated on an alumina substrate through a drop coating method and then fabricated with a sensor base by wire bonding using a Pt wire. In this process, the contact resistance between the nanoparticles constituting the three-dimensional nano-agglomerate and the contact resistance between the nano-agglomerates are judged to be somewhat high to be applied to a gas sensor practically commercialized. As a result, Further comprising the step of spraying a solution in which the salt is dissolved, onto the alumina sensor substrate coated with the sensing material. Specifically, 3 mg of the electrosprayed sensing material of Example 1 and Example 2 were uniformly dispersed in 18 μl of ethylene glycol, respectively, and the dispersion was applied on a 2 mm × 2 mm alumina substrate. After a certain amount of ethylene glycol was blown off from a hot plate at 80 ° C, a solution containing tin salt (SnCl 2 2H 2 O) at a concentration of 0.1 M was placed in a syringe, and the syringe was pumped with a syringe pump at a discharge rate of 0.27 ml / The solution is pushed out, and the distance between the injection needle and the sensor substrate on which the sensing object is applied is adjusted to 10 cm, and a voltage of 17 kV is applied to perform additional electric injection for 15 minutes. In addition, the salt solution injected by electric spray penetrates between the three-dimensional nano-aggregates, which are the sensing material on the sensor substrate, and can reduce the contact resistance while forming the bridge between the nano aggregates. The tin salt impregnated between the nano-agglomerates is oxidized to tin oxide and subjected to heat treatment in a high temperature atmosphere of 600 ° C to remove polystyrene beads. FIG. 11 is a graph showing the results of an experiment in which tin oxide nano-aggregates of three-dimensional hierarchical structure in which tin oxide nanoparticles are self-agglomerated through electric spraying are applied on a sensor substrate, It is a microscopic photograph. Additional tin salt solution electrospinning produces a small amount of bridging bridge between the nano-agglomerates in a small amount for a short period of time. It can be used to form three-dimensional hierarchical nano-aggregates without noticeable difference in shape when viewed by scanning electron microscope .
FIG. 12 is a graph showing the results of evaluating the sensitivity characteristic of acetone at 400 ° C after the resistance of the sensing material of Example 1 and Example 2 was lowered so that an additional tin salt could be sprayed by the above method so that it could be used as a practical gas sensor to be. As shown in FIG. 12, the porous three-dimensional hierarchical structure of tin oxide nano-aggregates prepared by using polystyrene beads as a template is a tin oxide nano-aggregate of a three-dimensional hierarchical structure having a low porosity and made without using polystyrene bead templates It is possible to confirm that the acetone detection property is remarkably improved as compared with the conventional method. This improved sensing property can be expected because the pores formed during the removal of the polystyrene bead template at high temperature are effectively developed, thereby increasing the surface area where the gas can react and providing a diffusion space in which the gas can effectively penetrate . It is possible to produce a porous three-dimensional metal oxide nano-aggregate sensor having a high surface porosity and easy penetration of a sensing gas and having a large surface area by deriving a result that excellent sensor characteristics can be obtained in a sensing material having such a wide pore distribution It can be clearly confirmed by the present invention.
In order to further improve the gas sensing property, the metal catalyst is bound to the porous metal oxide nano-aggregate having a three-dimensional hierarchical structure. To confirm this fact, in order to fabricate the sensing materials of Examples 2 and 3 as a sensor, a porous three-dimensional hierarchical tin oxide nano-aggregate dispersed in ethylene glycol (EG) and a porous three- The nano - aggregates of tin oxide composite were coated on an alumina substrate by drop coating method and then fabricated with a sensor base and wire bonding using Pt wire as one sensor. Also in this case, it is judged that the contact resistance between the nanoparticles constituting the three-dimensional nano-agglomerate and the contact resistance between the nano-agglomerates are somewhat high enough to be applied to a gas sensor practically commercialized. Thus, another method A thermocompression step was included as an example. Specifically, the electrosprayed sensing materials of Examples 2 and 3 were uniformly dispersed in an amount of 3 mg of ethylene glycol (18 μl), respectively, and applied on an alumina substrate having a size of 2 mm × 2 mm. After a certain amount of ethylene glycol is blown off on a hot plate at 80 DEG C, the thermocompression is carried out at 60 DEG C under a pressure of 50 kgf / cm < 2 > for 30 seconds. The contact resistance can be lowered by increasing the contact area between the nano aggregates through the thermocompression process. The sensor substrate subjected to the thermocompression process is subjected to a high-temperature heat treatment at 600 ° C. to form a porous three-dimensional nano-aggregate from which the polystyrene bead template has been removed. 13 is a scanning electron microscope (SEM) image of a sensing material in which a polystyrene bead template is removed through thermo-compression of a nano-aggregate formed through the above-described electric injection and a high-temperature heat treatment process. From scanning electron microscope photographs at a low magnification of 5000 times, it can be seen that the gap between the nano-agglomerates becomes closer through thermocompression and the contact area between the nano-agglomerates increases. On the other hand, when one nano-aggregate was confirmed with a 50000 times high magnification scanning electron microscope, it was confirmed that spherical three-dimensional hierarchy was maintained well after thermocompression and porosity by the polystyrene bead template was maintained well.
14 is an example in which the sensing material of Example 2 and Example 3 is manufactured by an electrospray method, the resistance is lowered by the thermocompression method, and the acetone gas sensing characteristic is evaluated at 400 ° C. As shown in FIG. 14, the platinum catalyst-tin oxide nano-aggregate of the porous three-dimensional hierarchical structure to which the platinum catalyst was bound was highly 6.55 times higher than that of the porous three-dimensional hierarchical tin oxide nano- It can be confirmed that it exhibits the reaction characteristics. The catalyst-metal oxide nano-aggregate sensor of the porous three-dimensional hierarchy is improved by the suitability of the nano-aggregate structure design of the porous three-dimensional hierarchical structure proposed in the present invention and the effective reaction of the well- Can be clearly confirmed by the present invention.
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 described in the present invention are not intended to limit the technical spirit of the present invention but to illustrate the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.
100: metal oxide nanoparticles
200: metal nanoparticle catalyst
300: polymer bead template
400: self-assembled three-dimensional hierarchical metal oxide nano-aggregate
500: Immediately after electric spraying, a self-assembled three-dimensional hierarchical polymer bead-catalyst-metal oxide composite nano-aggregate
600: self-assembled porous three-dimensional hierarchical metal oxide nano-aggregate
Claims (20)
A sensor substrate on which the plurality of metal oxide nano-aggregates are applied and which can recognize resistance change; And
In order to lower the contact resistance between the plurality of metal oxide nano-agglomerates, the metal salt additionally electrosprayed on the sensor substrate coated with the plurality of metal oxide nano-agglomerates is impregnated between the plurality of metal oxide nano-agglomerates and then oxidized A metal oxide formed between the plurality of metal oxide nano-aggregates
Wherein the gas sensor comprises a gas sensor.
Wherein the electrolytic solution further comprises a polymer template,
Wherein each of the plurality of metal oxide nano-agglomerates includes fine pores and large pores formed on the surface and inside of the three-dimensional hierarchical structure according to the electric spraying as the polymer template contained in the three-dimensional hierarchical structure is removed by heat treatment To do
Wherein the gas sensor is a gas sensor.
Each of the plurality of metal oxide nano-aggregates has a domain in which the content of the metal oxide nanoparticles is relatively larger than that of the polymer template and a domain in which the content of the polymer template is relatively larger than that of the metal oxide nanoparticles, A plurality of pores formed by removal of the polymer template are connected to each other to have an open structure
Wherein the gas sensor is a gas sensor.
The polymer template used as a sacrificial layer may be one prepared by an electrospinning method including a spherical ball structure, a polymer having at least one shape selected from a triangle, a quadrangle, a pentagon, and a hexagon
Wherein the gas sensor is a gas sensor.
The size of the polymer template is in the range of 100 to 750 nm and includes polymers having the same diameter or different diameters
Wherein the gas sensor is a gas sensor.
Wherein the electrolytic solution further comprises a catalyst,
Wherein each of the plurality of metal oxide nano-agglomerates is formed by binding the catalyst to the three-dimensional hierarchy according to the electric injection
Wherein the gas sensor is a gas sensor.
The three-dimensional hierarchical structure may be one having at least one of a spherical shape, a donut shape, an elliptical shape, and a partially broken spherical shape
Wherein the gas sensor is a gas sensor.
The diameter of the metal oxide nano-aggregate of the three-dimensional hierarchical structure is in the range of 150 nm to 3 μm
Wherein the gas sensor is a gas sensor.
The diameter of the metal oxide nanoparticles constituting the metal oxide nano-aggregate is in the range of 5 to 100 nm
Wherein the gas sensor is a gas sensor.
In the metal oxide nanoparticles included in the metal oxide nanoparticle dispersion, the metal oxide may be SnO 2 , ZnO, WO 3 , Fe 2 O 3 , Fe 3 O 4 , NiO, TiO 2 , CuO, In 2 O 3 , Zn 2 SnO 4, Co 3 O 4, PdO, LaCoO 3, NiCo 2 O 4, Ca 2 Mn 3 O 8, V 2 O 5, Ag 2 V 4 O 11, Ag 2 O, MnO 2, InTaO 4, InTaO 4, among CaCu 3 Ti 4 O 12, Ag 3 PO 4, BaTiO 3, NiTiO 3, SrTiO 3, Sr 2 Nb 2 O 7, Sr 2 Ta 2 O 7 and Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-7 which is selected Being one or more complex
Wherein the gas sensor is a gas sensor.
(b) forming a plurality of metal oxide nano-aggregates having a three-dimensional hierarchical structure in which the metal oxide nanoparticles are self-assembled by spraying the produced electrolytic solution under an electric field;
(c) coating the plurality of metal oxide nano-agglomerates on a sensor substrate capable of recognizing the resistance change to manufacture a semiconductor type gas sensor; And
(d) a step of spraying an additional metal salt on the sensor substrate coated with the plurality of metal oxide nano-aggregates to lower the contact resistance between the plurality of metal oxide nano-agglomerates, Metal oxide nano-agglomerates
Wherein the gas sensor comprises a gas sensor.
The step (a)
A polymer template was added to the metal oxide nanoparticle dispersion,
The step (b)
And the polymer template included in the surface and inside of the three-dimensional hierarchical structure is removed through heat treatment to form a plurality of pores on the surface and inside of the metal oxide nano-agglomerate, ≪ / RTI >
Since the metal oxide nano-aggregate of the three-dimensional hierarchical structure has a domain in which the metal oxide nanoparticles have a relatively larger content than the polymer template and a domain in which the polymer template has a relatively larger content than the metal oxide nanoparticles, A plurality of pores formed by the removal of the polymer template after the heat treatment are connected to each other to have an open structure
Wherein the gas sensor is a gas sensor.
The addition amount of the polymer template is in the range of 10 to 25 wt%
Wherein the gas sensor is a gas sensor.
The polymeric template may be selected from the group consisting of polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl acetate, polyurethane, polyurethane copolymer, polyether urethane, cellulose derivatives, polymethyl acrylate (PMA) (PPO), polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene oxide copolymer, polypropylene oxide copolymer, polypropylene oxide copolymer, polyvinyl acetate copolymer, polyvinyl acetate copolymer, polyvinyl alcohol (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinylpyrrolidone (PVP), polyvinyl fluoride, polyvinylidene fluoride copolymer, polyacrylonitrile, polyamide, pitch pitch) and phenol resin (phenol resin)
Wherein the gas sensor is a gas sensor.
The step (a)
Adding a catalyst to the metal oxide nanoparticle dispersion,
The catalyst is bound to the three-dimensional hierarchy according to the electric injection
Wherein the gas sensor is a gas sensor.
The amount of the catalyst added is in the range of 0.01 to 20 wt%
Wherein the gas sensor is a gas sensor.
The step (c)
Applying the plurality of metal oxide nano-agglutinates onto the sensor substrate using one of spray coating, drop coating, screen printing, EHD, direct coating through electrospinning and application via transfer
Wherein the gas sensor is a gas sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160023032A KR101829120B1 (en) | 2016-02-26 | 2016-02-26 | Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160023032A KR101829120B1 (en) | 2016-02-26 | 2016-02-26 | Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20170100770A KR20170100770A (en) | 2017-09-05 |
| KR101829120B1 true KR101829120B1 (en) | 2018-02-13 |
Family
ID=59924756
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020160023032A KR101829120B1 (en) | 2016-02-26 | 2016-02-26 | Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101829120B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20220022348A (en) | 2020-08-18 | 2022-02-25 | 한국과학기술원 | Light-activated gas sensor based on 3d nanostructure for high performance and operation at low temperature |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102191531B1 (en) * | 2019-03-18 | 2020-12-15 | 한국과학기술원 | Wearable gas sensors with metal particles deposited nanofiber yarn and manufacturing method thereof |
-
2016
- 2016-02-26 KR KR1020160023032A patent/KR101829120B1/en active IP Right Grant
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20220022348A (en) | 2020-08-18 | 2022-02-25 | 한국과학기술원 | Light-activated gas sensor based on 3d nanostructure for high performance and operation at low temperature |
| US11906457B2 (en) | 2020-08-18 | 2024-02-20 | Korea Advanced Institute Of Science And Technology | Light-activated gas sensor based on 3D nanostructure operable at low temperature with high performance and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20170100770A (en) | 2017-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101716966B1 (en) | Gas sensor and member using metal oxide semiconductor nanotubes composed of thin-wall including mesopores and macropores, and manufacturing method thereof | |
| KR101633549B1 (en) | Composite metal oxide sensing materials composed of polycrystalline nanofibers, nanoparticles and microparticles, gas sensors using the composite metal oxide sensing materials, and manufacturing method thereof | |
| KR101633554B1 (en) | Gas sensor and member using metal oxide semiconductor nanofibers including nanoparticle catalyst functionalized by bifunctional nano-catalyst included within apoferritin, and manufacturing method thereof | |
| KR101521417B1 (en) | Gas sensor and member using composite of metal oxide material semiconductor nano structure and graphene, and manufacturing method thereof | |
| KR101792438B1 (en) | Catalysts functionalized metal oxide nanotubes via electrospinning and etching process, fabrication method for preparing the same, and gas sensor comprising the same | |
| KR101408105B1 (en) | Composite materials of graphene and one dimensional metal oxide, method for fabricating the same and sensors comprising the same | |
| KR101552323B1 (en) | Gas sensor and member using porous metal oxide semiconductor nano structure including nano-catalyst from ferritin, and manufacturing method thereof | |
| KR101665911B1 (en) | Composite metal oxide sensing materials composed of polycrystalline nanofibers, nanoparticles and microparticles, gas sensors using the composite metal oxide sensing materials, and manufacturing method thereof | |
| KR20180065493A (en) | Gas sensor and member using metal oxide nanotubes including nanoscale heterogeneous catalysts by using metal-organic framework, and manufacturing method thereof | |
| KR101837287B1 (en) | Gas sensor and member using ultrasmall catalyst loaded porous hollow metal oxide semiconductor composite nanospheres, and manufacturing method thereof | |
| KR101829120B1 (en) | Composite of 3-D hierarchically-assembled metal oxide sphere by functionalized nano metal catalysts, gas sensor member using the same and method for manufacturing gas sensor member | |
| KR101850249B1 (en) | Catalysts functionalized metal oxide nanotubes via electrospinning and etching process, fabrication method for preparing the same, and gas sensor comprising the same | |
| KR101552326B1 (en) | Gas sensor member using metal oxide semiconductor nanofiber and dual catalysts, and manufacturing method thereof | |
| KR101719422B1 (en) | Porous Metal Oxide Composite Nanofibers including Nanoparticle Catalysts Functionalized by using Nanoparticle Dispersed Emulsion Solution, Gas Sensors using the same and Manufacturing Method thereof | |
| KR101893267B1 (en) | Gas sensor using interconnected multi-dimensional porosity loaded METAL OXIDE nanofiberS functionalized by nanoparticle catalyst, and manufacturing method thereof | |
| KR101684738B1 (en) | Gas Sensor Fabrication method of catalyst-loaded porous metal oxide nanofiber metal oxide nanofiber networks prepared by transferring of catalyst-coated polymeric sacrificial colloid template, and gas sensors using the same | |
| KR101559465B1 (en) | Gas sensor and member using grain growth metal oxide material semiconductor nano structure, and manufacturing method thereof | |
| KR101893326B1 (en) | Gas sensor using interconnected multi-dimensional porosity loaded METAL OXIDE nanofiberS functionalized by nanoparticle catalyst, and manufacturing method thereof | |
| KR101714961B1 (en) | Gas Sensor Fabrication method of catalyst-loaded porous metal oxide nanofiber metal oxide nanofiber networks prepared by transferring of catalyst-coated polymeric sacrificial colloid template, and gas sensors using the same | |
| KR101539526B1 (en) | Metal oxide nanofibers including nanoscale pores, fabrication method for preparing the same, and gas sensor comprising the same | |
| WO2016105012A1 (en) | Member for gas sensor, having a metal oxide semiconductor tube wall with micropores and macropores, gas sensor, and method for manufacturing same | |
| KR101746301B1 (en) | Composite oxide semiconductors with hierarchical hollow structures and manufacturing method thereof | |
| KR20190046320A (en) | Porous Metal Oxide Nanotube, Gas Sensing Layers Using the Same, and Their Fabrication Method | |
| KR101738774B1 (en) | Metal oxide compoties nanotubes including multiple pores and nanocatalysts, fabrication method for preparing the same, and gas sensor comprising the same | |
| KR101832110B1 (en) | Gas sensor and member using catalyst functionalized macroporous tungsten oxide nanofibers synthesized by catalyst decorated polymeric colloid templates, and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |