KR101206869B1 - Ring Type Palladium Nano Structure Body And The Hydrogen Sensor Using The Palladium Nano Structure Body - Google Patents

Abstract

The present invention relates to a cyclic Pd nano structure and a hydrogen sensor using the Pd nano structure. More specifically, cyclic Pd nanostructures including cyclic Pd nanostructures reassembled cubic Pd nanoparticles by controlling the direction and speed of crystal growth of nanoparticles with voltage and current, and hydrogen sensors using the Pd nanostructures It is about.

According to the present invention described above, the cyclic Pd nanostructure has a high energy and surface area of the structure itself, can control chemical properties physically, and uses the Pd nanostructure due to the specific action of the nanostructure that is a highly stable material. Hydrogen sensor, a hydrogen alarm produced by connecting a hydrogen alarm electronic circuit to the hydrogen sensor, a hydrogen concentration meter produced by connecting a hydrogen concentration meter electronic circuit to the hydrogen sensor exhibits excellent effects in various fields. In addition, the nanostructures can be easily formed at room temperature and atmospheric pressure, which is low energy, so that high-purity ultra-precision Pd nanostructures can be produced.

Nano, catalyst, hydrogen, cyclic Pd nano structure, hydrogen sensor, hydrogen alarm, hydrogen concentration meter

Description

Ring type Palladium Nano Structure Body And The Hydrogen Sensor Using The Palladium Nano Structure Body}

The present invention provides a cyclic Pd nanostructure reassembled cubic Pd nanoparticles by controlling the direction and speed of crystal growth of nanoparticles with voltage and current, and a hydrogen sensor using the Pd nanostructure, and a hydrogen alarm electronic circuit in the hydrogen sensor. Hydrogen alarm produced by connecting the, is a technology related to the hydrogen concentration meter produced by connecting the hydrogen concentration meter electronic circuit to the hydrogen sensor.

Research into the application of shape-controlled nanoparticles as a catalyst is still in its infancy and proof of concept.

In addition, the technology to mass-produce high-purity shape-controlled nanoparticles is indispensable, but the synthesis is difficult and the reproducibility is lacking.

Accordingly, the present invention provides a high-purity controlled cyclic Pd nanostructure mass-produced by using the cyclic Pd nanostructures as a hydrogen sensor, a hydrogen alarm produced by connecting a hydrogen alarm electronic circuit to the hydrogen sensor, the A hydrogen concentration meter manufactured by connecting a hydrogen concentration meter electronic circuit to a hydrogen sensor can be provided.

The present invention provides a cyclic Pd nanostructure reassembled cubic Pd nanoparticles by controlling the direction and speed of crystal growth of nanoparticles with voltage and current.

In addition, the present invention is a metal nano containing at least one of palladium oxide (PdO), titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ) or iron oxide (Fe ₂ O ₃ ) in the cyclic Pd nanostructures Provided is a cyclic Pd nanostructure mixture in which oxides are mixed.

In addition, the present invention provides a hydrogen sensor formed by coating at least one of the cyclic Pd nanostructure or the cyclic Pd nanostructure mixture on a paper, glass, plastic or ceramic substrate and installing a porous printed circuit board (PCB) do.

The present invention also provides a hydrogen alarm manufactured by connecting an electronic circuit to the hydrogen sensor.

The present invention also provides a hydrogen concentration meter manufactured by connecting an electronic circuit to the hydrogen sensor.

As described above, the cyclic Pd nanostructure has a high energy and surface area of the structure itself, and is able to control chemical properties physically, and due to the unique action of the nano structure, a hydrogen sensor using the Pd nanostructure In addition, the hydrogen alarm produced by connecting the hydrogen alarm electronic circuit to the hydrogen sensor, the hydrogen concentration meter produced by connecting the hydrogen concentration meter electronic circuit to the hydrogen sensor exhibits excellent effects in various fields.

In addition, the nanostructures can be easily formed at room temperature and atmospheric pressure, which is low energy, so that high-purity ultra-precision Pd nanostructures can be produced.

The present invention is a cyclic Pd nanostructure reassembled cubic Pd nanoparticles by adjusting the crystal growth direction and speed of the nanoparticles with a voltage and a current as a structure in which the nanoparticles of the shape-controlled nanoparticles with a particle diameter of 1 ~ 30nm is reassembled It is a technique for forming a cyclic Pd nanostructure by controlling the distance between particles.

That is, the present invention provides a cyclic Pd nanostructure in which cubic Pd nanoparticles are reassembled by controlling the direction and speed of crystal growth of nanoparticles with voltage and current.

Here, the current is in the range of 0.01A ~ 10A, the voltage is 2V ~ 40V.

In this method, nanoparticles are resynthesized by controlling the reduction rate by adjusting the direction and speed of crystal growth of nanometals with a change in voltage and current.

Here, the cyclic Pd nanostructure is formed by reassembling the cubic Pd nanoparticles by adjusting the pH in the range of 6 ~ 10.

At this time, the cubic Pd nanoparticles are those whose shape is controlled to a particle size of 1 ~ 30nm.

Here, the present invention is a technique for forming a cyclic Pd nanostructure through the shape control of the Pd nanoparticles during the molecular reassembly process while making the Pd metal nanoparticle sized Pd nanoparticles. In this method, the cyclic Pd nanostructure is manufactured by controlling the reduction rate by adjusting the direction and speed of crystal growth of Pd nanometals to pH with a change in voltage and current.

1 to 30nm cubic Pd nanoparticles and Pd nanostructure manufacturing method of the present invention by using the Pd rod electrolysis in the electrolyte to produce 100% pure Pd nanoparticles of 1 ~ 30nm cubic nanoparticles, Pd nanoparticles produced by adjusting the hydrogen ion concentration is to produce a cyclic Pd structure having a size of 10 ~ 300nm in which a certain shape that is self-assembled, that is, a ring shape is controlled.

Each Pd nanoparticle (1 ~ 30nm) synthesized in this way has a large specific surface area, and the formed nanostructure (10 ~ 300nm) has a high optical activity than the conventional commercial photocatalyst with a special high energy.

In this case, nanomaterials exhibit different properties from the bulk state, and if the chemical properties such as the size, composition, and shape of the material are controlled at a size of 100 nm or less, the physical properties such as optical properties, electrical properties, and magnetic properties of the materials can be freely changed. You can. Nanostructures formed using these nanomaterials have various characteristics. First, they have a very large surface because of their small size. Second, they can control physical properties chemically. Third, they have excellent target binding properties. It is a very stable substance. The extraordinary high energy of these nanostructures themselves and the unique action of the nanostructures can cause a variety of functions in all of you.

The shape of the nanostructures is shown in FIG. 1. 1 is an analysis of the face centered cubic (FCC) of the Pd element.

In the case of FIG. 1, the Pd is a pure Pd metal, and a scanning transmission electron microscopy (STEM) photograph showing the state in which the crystal structure is almost perfectly arranged. These Pd nanoparticles are re-integrated, which may be said to be due to molecular self-assembly, and even after they are integrated, they have an annular hollow shape. Even if this integration continues, it continues to show a ring shape to some extent, and has a tendency like a fractal. In the end, this means that Pd has high crystallization at the atomic level, and it is assumed that it has high reactivity and selectivity.

The Pd nanostructure has a very high hydrogen adsorption force. In particular, the hydrogen adsorption force is referred to as "normal temperature and pressure in the laboratory" (hereinafter, "normal temperature and pressure", where "normal temperature and pressure" means the temperature and 1 atmosphere of water to maintain a liquid state Of course, it also appears to be more than 100 times the volume. The reaction can be carried out even under 1 atm, and of course, even when the pressure exceeds this.

In addition, the Pd nanostructure exhibits excellent performance as a hydrogen sensor. Hydrogen sensors are used to identify faults in power transformers, monitor hydrogen density in fuel cells, leak checks during transportation and storage of hydrogen, gas monitoring processes in industry, hydrogen accumulation in lead-acid batteries in automobiles, and desulfurization of ammonia, methanol manufacturers and petroleum products. It is applied to the hydrogen leakage test.

As a conventional hydrogen sensor, a Pd metal thin film and a Pd alloy have been used. This is because palladium (Pd) selectively reacts only with hydrogen. Palladium (Pd) hydrogen sensor is based on the principle that when hydrogen molecules diffuse into the palladium (Pd), the Pd metal thin film or Pd alloy increases in volume, which reduces the concentration of free electrons and increases the electrical resistance.

However, when the Pd nanostructure of the present invention is exposed to hydrogen, the electrical resistance of the Pd metal thin film or Pd alloy which is not nano is reversed, and the electrical resistance rapidly decreases. That is, when hydrogen is sucked or adsorbed to the Pd nanostructure of the present invention, the resistance dissociates into H ⁺ and e ⁻ , and the flow of electrons becomes active. In addition, the conventional hydrogen sensor is installed on the Pd metal thin film or Pd alloy heating wire to measure the resistance change by burning hydrogen, whereas the Pd nano-structure hydrogen sensor of the present invention is a sensor that directly detects hydrogen without the need to install a heating wire As a result, the Pd nanostructure of the present invention can realize higher performance as a sensor than the conventional hydrogen sensors, and its performance is more than tens of times.

In addition, the Pd nanostructure mixture of the present invention, the electrical resistance of the Pd nanostructure of the present invention is opposite to the electrical resistance is rapidly increased when exposed to hydrogen. That is, when hydrogen is sucked or adsorbed to the Pd nanostructure mixture of the present invention, the flow of electrons is interrupted, and the electrical resistance of the Pd nanostructure mixture is rapidly increased, and when hydrogen is removed, the electrical resistance is decreased to return to the original state. In addition, the conventional hydrogen sensor is installed on the Pd metal thin film or Pd alloy heating wire to measure the resistance change by burning hydrogen, whereas the Pd nano-structure mixture hydrogen sensor of the present invention does not need to install a heating wire sensor to detect hydrogen directly Since it acts as a Pd nano-structure mixture of the present invention than the conventional hydrogen sensors can realize a high performance as a sensor, the performance is several times more.

In addition, the conventional hydrogen sensor has a disadvantage that it must be replaced once exposed, but the Pd nano-structure hydrogen sensor or Pd nano-structure mixture hydrogen sensor of the present invention has the advantage that it can continue to use even after exposure to hydrogen.

That is, the Pd nano-structure hydrogen sensor or the Pd nano-structure mixture hydrogen sensor can continue to be used for hydrogen exposure, long life, ultra-small, can be produced in cold, can be produced in a variety of shapes, such as cylindrical, rectangular, Excellent hydrogen response rate of 500ppm / sec, detects minute amount of hydrogen below 100ppm, reacts only to hydrogen without reacting to other gases, and does not need to attach additional devices such as heaters and fans to the sensor It is possible to display the concentration of the initial exposure to hydrogen, and there is no effect of measuring temperature at all.

In addition, since the Pd nano structure and the Pd nano structure mixture is superior to conventional Pd particles or Pd thin film, the hydrogen adsorption power does not require electric supply (heating wire) when coated on an optical fiber, so there is no danger of hydrogen explosion due to electric discharge. It can be used for and miniaturization is possible.

The Pd nanostructure is manufactured as follows.

In the nanostructure manufacturing method of the present invention, Pd nanoparticles are 100% pure Pd nanoparticles, which are 1-30 nm cubic nanoparticles by electrolysis in an electrolyte using Pd rods, and Pd nanoparticles are produced by controlling hydrogen ion concentration. It is to mass produce a cyclic Pd structure having a size of 10 ~ 300nm, the shape of which is self-assembled, the shape of which is controlled in a ring shape.

At this time, the electrode and water are electrolyzed in the electrolyte using a Pd rod as an electrode.

Here, the electrolyte may be used in various ways, but the concentration is 0.01% to 5% based on sodium chloride (NaCl), and the current and voltage are alternately adjusted between 0.01A to 10A and 2V to 40V, so that the anode has chloride ion ( Cl ⁻ ) combines with palladium (Pd) to form metal salts of Pd and Cl.

This process is performed in the process of evenly stirring the generated Pd nanoparticles and the electrolyte.

Pd and Cl metal salts of palladium chloride (PdCl ₂ ) are formed by the palladium (Pd) atom, which is a cubic Pd nanoparticle of 1 to 30 nm, with the chloride ion (Cl ⁻ ) dropping by hydrogen ions (H ⁺ ) generated around the cathode. Is generated. The resulting palladium (Pd) atoms undergo molecular self-assembly (aggregation) to form Pd nanostructures and settle to the bottom of the production vessel. In the precipitated Pd, palladium chloride and Pd nanostructures are mixed. Here, the Pd nanostructure precipitated to the bottom or the Pd nanostructure gradually precipitated to the bottom is separated from the sodium chloride solution to obtain a pure Pd nanostructure. At this time, the chloride ion (Cl ⁻ ) is a chlorine gas (Cl ₂ ) to fly or re-enter the sodium chloride (NaCl) solution, the hydrogen ion (H ⁺ ) receives the electron becomes a hydrogen gas (H ₂ ). Here, the pH control of the solution is very important because the pH is related to the aggregation form of the Pd nanostructure. It can be seen that smooth aggregation usually occurs at pH 6-10. Here, pH adjustment of the solution protons (H ⁺⁾ and hydroxide ions (OH ^-) to adjust the voltage and current, the pH is adjusted as to control the amount of. At this time, the crystal growth direction and speed of the nanoparticles are controlled by voltage and current to form a cyclic Pd nanostructure reassembled cubic Pd nanoparticles.

Another achievement of the present invention is that the method of obtaining the Pd nanostructures is again greatly improved.

When the Pd rod (pure Pd metal mass) used as an electrode in the process was used to absorb (storage and store) hydrogen before using as an electrode, the production efficiency of Pd nanostructures could be significantly increased. Here, hydrogen occlusion refers to injection of hydrogen between Pd lattice.

The method of occluding hydrogen in Pd metal is widely known, and any method may be used. One of the hydrogen occlusion methods is that hydrogen is occluded in Pd when the Pd metal is raised in pressure and temperature in a hydrogen gas atmosphere. At this time, the hydrogen storage amount is proportional to the pressure, temperature and time.

In addition, since the storage amount of hydrogen is important to continuously discharge hydrogen in water, it is necessary to occlude as much hydrogen as possible.

The subsequent process is similar to using Pd without occluding hydrogen, as follows.

Electrodes and water are electrolyzed in electrolyte using Pd absorbed hydrogen.

In this case, various electrolytes may be used, but the concentration is 0.01% to 5% based on sodium chloride (NaCl), and the current and voltage are alternately controlled between 0.01A to 10A and 2V to 40V to allow chloride ion ( Cl ⁻ ) combines with palladium (Pd) to form metal salts of Pd and Cl.

This process is performed in the process of evenly stirring the resulting nanoparticles and the electrolyte.

Pd and Cl metal salts of palladium chloride (PdCl ₂ ) are formed by the hydrogen ions (H ⁺ ) generated around the cathode, and the chloride ions (Cl ⁻ ) are dropped. However, most of the stored hydrogen is released and the chloride ions (Cl ⁻ ) And palladium (Pd) atoms, which are cubic Pd nanoparticles of 1 to 30 nm, are produced. The resulting palladium (Pd) atoms undergo molecular self-assembly (aggregation) to form Pd nanostructures and settle to the bottom of the production vessel. In the precipitated Pd, palladium chloride and Pd nanostructures are mixed. Here, the Pd nanostructure precipitated to the bottom or the Pd nanostructure gradually precipitated to the bottom is separated from the sodium chloride solution to obtain a pure Pd nanostructure. At this time, the chloride ion (Cl ⁻ ) is a chlorine gas (Cl ₂ ) to fly or re-enter the sodium chloride (NaCl) solution, the hydrogen ion (H ⁺ ) receives the electron becomes a hydrogen gas (H ₂ ). Here, the pH control of the solution is very important because the pH is related to the aggregation form of the Pd nanostructure. It can be seen that smooth aggregation usually occurs at pH 6-10. In this case, pH adjustment of the solution has a hydrogen ion (H ⁺⁾ and hydroxide ions (OH ^-) to adjust the voltage and current, the pH is adjusted as to control the amount of.

Particularly, when Pd containing hydrogen is used, a large amount of Pd nanostructures can be produced over several hours. When Pd without hydrogen is used, production of Pd nanostructures can be inferior compared to stopping production within minutes. .

In addition, when using Pd rods that do not occlude hydrogen, palladium chloride and Pd nanostructures are mixed in the precipitated Pd. However, when Pd rods that occupy hydrogen are used, pure Pd nanostructures can be obtained. have.

Here, the hydrogen-containing Pd rod produces 100% purity Pd nanoparticles, which are 1-30 nm cubic nanoparticles in electrolysis, and the Pd nanoparticles produced are self-assembled by occluding hydrogen. It has a cyclic Pd structure having a size of 10 to 300 nm whose shape is cyclically controlled.

In addition, the process of fixing the Pd nanostructure to minimize the change in shape can be performed.

The cyclic Pd nanostructure is characterized in that the shape of the structure is fixed by treatment in an atmosphere from which oxygen is removed for 60 minutes to 120 minutes at a pressure of 10 to 100 atmospheres while maintaining the temperature 10 ℃ ~ 200 ℃.

At this time, after removing oxygen to prevent oxidation of Pd into PdO, argon and nitrogen, which are inert gases, are added, and the pressure is applied to fix the shape of the cyclic Pd nanostructure.

In other words, in order to fix the resulting nanostructures, the temperature is maintained at 10 to 200 ° C. and treated under an atmosphere from which oxygen is removed for 60 to 120 minutes at a pressure of 10 to 100 atmospheres.

The treated Pd is mainly formed of a cyclic Pd nanostructure.

The nanostructures thus produced proved to have excellent effects as photosensitivity catalysts.

The structure of this catalyst generally has a structure capable of amplifying more than about 1.23 eV of energy, which is the principle energy required to oxidize or reduce water, to sunlight in the visible range, and is actually higher than many studies obtained on single crystal surfaces. It can be seen that it is a catalyst having reactivity and selectivity.

The unique catalytic properties of the shape-controlled nanoparticles can control the optical properties by varying the distance between the nanoparticles, and show not only the large surface response of the nanoparticles, but also the quantum dot energy of the nanostructures. .

In other words, the development of this technology means the invention of the core technology of the artifical photosystem that the world intends to do.

In addition, the present invention is a metal nano containing at least one of palladium oxide (PdO), titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ) or iron oxide (Fe ₂ O ₃ ) in the cyclic Pd nanostructures Provided is a cyclic Pd nanostructure mixture in which oxides are mixed.

Here, the particle size of the cyclic Pd nanostructure mixture is preferably the same as the particle size of the cyclic Pd nanostructure.

At this time, the particle size of the cyclic Pd nanostructure is 10 ~ 300nm, preferably 40 ~ 70nm. Therefore, the particle size of the cyclic Pd nanostructure mixture is 10 ~ 300nm, preferably 40 ~ 70nm.

According to the present invention, it is possible to produce a Pd nanostructure that can amplify a large energy by a simple method, and produced a hydrogen sensor, a hydrogen alarm, a hydrogen concentration meter using the Pd nanostructure thus proved excellent performance.

In addition, the present invention provides a hydrogen sensor formed by coating at least one of the cyclic Pd nanostructure or the cyclic Pd nanostructure mixture on a paper, glass, plastic or ceramic substrate and installing a porous printed circuit board (PCB) do.

Here, the coating thickness of coating at least one of the cyclic Pd nanostructure or the cyclic Pd nanostructure mixture on a non-conductive paper, glass, plastic or ceramic substrate is preferably 0.002 to 2 mm. However, the present invention is not limited thereto and can be changed to suit the purpose. The number of the substrate may be one or more. That is, the cyclic Pd nanostructures may be coated on both the front and back of one substrate, and the cyclic Pd nanostructure mixture may be coated on both the front and back of one substrate, and the cyclic Pd may be coated on the front of one substrate. The nanostructure may be coated and the cyclic Pd nanostructure mixture may be coated on the back side of the same substrate. Alternatively, two, three, four or more substrates coated by the above method may be used.

At this time, the shape and size of the hydrogen sensor to the coating and install a porous printed circuit board (PCB) can also be adjusted according to the application. Here, the pore with several holes is a part for making hydrogen absorbable easily.

For example, the hydrogen sensor may be assembled into a PCB type contact. In this case, the contact portion of the PCB-type contact may be inserted into the socket.

The present invention also provides a hydrogen alarm manufactured by connecting an electronic circuit to the hydrogen sensor.

That is, the present invention coats at least one of the cyclic Pd nanostructure or the mixture of the cyclic Pd nanostructure on a paper, glass, plastic or ceramic substrate and install a porous printed circuit board (PCB) to form a hydrogen sensor It provides a hydrogen alarm produced by connecting a hydrogen alarm electronic circuit to the hydrogen sensor.

Here, the components of the hydrogen alarm electronic circuit includes the hydrogen sensor, CPU, charge and discharge battery, reset, warning LED, power LED, buzzer, display, external output signal.

At this time, the hydrogen alarm is configured to emit a warning sound upon hydrogen exposure by installing the hydrogen alarm electronic circuit in the hydrogen sensor.

The present invention also provides a hydrogen concentration meter manufactured by connecting an electronic circuit to the hydrogen sensor.

That is, the present invention coats at least one of the cyclic Pd nanostructure or the mixture of the cyclic Pd nanostructure on a paper, glass, plastic or ceramic substrate and install a porous printed circuit board (PCB) to form a hydrogen sensor It provides a hydrogen concentration meter manufactured by connecting a hydrogen concentration meter electronic circuit to the hydrogen sensor.

Here, the components of the hydrogen concentration meter electronic circuit includes the hydrogen sensor, CPU, power LED, hydrogen injection unit, display.

In this case, since the electrical resistance is changed according to the concentration of hydrogen in the hydrogen sensor, the hydrogen concentration can be accurately measured from the change data of the value of the electrical resistance.

In addition, the cyclic Pd nanostructure analysis may be performed using a transmission electron microscope (TEM), a high-resolution transmission electron microscopy (HREM), and a scanning transmission electron microscope (STEM). Analyzed.

Figure 2 shows the results of TEM analysis of the metal powder specimen of the cyclic Pd nanostructures.

As shown in FIG. 2, the size of the cyclic Pd nanostructure to which the Pd nanoparticles are attached to form a ring is about 10 nm, and the A region (most regions) is almost composed of Pd elements.

3 shows the results of STEM analysis of the metal powder specimen of the cyclic Pd nanostructure.

3 shows that the Pd nanoparticles form a complete structure with a cyclic Pd nanostructure. That is, Figure 3 is a face centered cubic (FCC) analysis of the Pd nanoparticles, the Pd nanoparticles are pure Pd metal scanning electron microscope showing the state that the crystal structure is almost perfectly arranged (scanning transmission electron microscopy; STEM). Here, the ringing of the light shows that every single nanoparticle is exactly a crystal.

FIG. 4 is a high-resolution transmission electron microscopy (HREM) photograph of a metal powder specimen of a cyclic Pd nanostructure, showing analysis of a contrast image by a transmitted electron beam.

As shown in FIG. 4, the Pd nanostructure of the present invention is cyclic.

FIG. 5 is a Scanning Transmission Electron Microscopy (STEM) picture of the metal powder specimen of the cyclic Pd nanostructure, the left picture is BF, that is, the Z-contrast of STEM, and the right picture is HAADF, The picture shows the z-contrast of STEM.

As shown in FIG. 5, the Pd nanostructure of the present invention is cyclic.

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 1

The electrode and water were electrolyzed in 500 g of 3% sodium chloride electrolyte using 300 g of Pd rod as an electrode, thereby producing 100 g of 100% pure Pd nanoparticles, which are 1-30 nm cubic nanoparticles. At this time, the current and voltage are alternately adjusted between 0.01A ~ 10A and 2V ~ 40V to adjust the pH to 8. At the positive electrode, chloride ion (Cl ⁻ ) is combined with palladium (Pd), which is a metal salt of Pd and Cl. 280 g of (PdCl ₂ ) was produced. The palladium chloride (PdCl ₂ ) is ions (Cl ⁻ ) drop by the hydrogen ions (H ⁺ ) generated around the cathode and a palladium (Pd) atom, a cubic Pd nanoparticle of 1 to 30nm was produced. The resulting palladium (Pd) atoms were molecularly self-assembled (aggregated) to form Pd nanostructures and settled to the bottom of the production vessel. The Pd nanostructures precipitated to the bottom or Pd nanostructures gradually settled to the bottom are separated from the sodium chloride solution to control the hydrogen ion concentration, and the Pd nanoparticles produced by self-assembly are uniformly shaped, that is, the shape is controlled. 50 g of a cyclic Pd structure having a size of 10 to 300 nm was produced.

Example 2

A hydrogen sensor was manufactured using the cyclic Pd nanostructure produced in Example 1. First, as shown in FIG. 6, the annular Pd nanostructure was coated with 0.01 mm on a paper that is a non-conductor having a width of 20 mm and a length of 7 mm. Then, as shown in Figure 7, a porous printed circuit board was installed and assembled into a PCB-type contact.

Example 3

A hydrogen sensor was manufactured in the same manner as in Example 2, except that the cyclic Pd nanostructure mixture produced in Example 1 was used.

Example 4

Put the hydrogen sensor produced in Example 2 and the hydrogen sensor produced in Example 3 in a container of 1L as shown in Fig. 8, respectively, and injected hydrogen according to the concentration as shown in Table 1 below, and a digital tester (trade name: Agilent) 34970A) was used to measure the electrical resistance and shown in FIG. 9 (in the case of the cyclic Pd nanostructure hydrogen sensor of Example 2) and FIG. 10 (in the case of the cyclic Pd nanostructure mixture hydrogen sensor of Example 3). .

으로 나타내었다.Here, the electrical resistance ratio (%) is

As shown.

unit Hydrogen concentration % 0.01 0.05 0.1 0.5 One 2 3 4 cc 0.1 0.5 One 5 10 20 30 40 ppm 100 500 1000 5000 10000 20000 30000 40000

* The syringes used were 500cc, 10cc, 5cc and 1cc.

As shown in FIG. 9, in the case of the cyclic Pd nanostructure hydrogen sensor of Example 2, it was found that as the hydrogen concentration increased for 10 seconds after the hydrogen exposure, the electrical resistance rapidly decreased.

In addition, as shown in Figure 10, in the case of the cyclic Pd nano-structure mixture hydrogen sensor of Example 3 it can be seen that the electrical resistance increases rapidly as the hydrogen concentration increases for 10 seconds after hydrogen exposure.

Example 5

An electronic circuit was constructed in the hydrogen sensor manufactured in Example 2 or Example 3 as shown in FIG. 11 to produce a hydrogen alarm having a warning sound when hydrogen was exposed.

When hydrogen is exposed to the hydrogen sensor manufactured in Example 2 or Example 3, the CPU scans the sensor every 33 seconds. Then, the initial resistance value and the change value are sensed, and the hydrogen concentration is applied to the display by integrating the already stored data of FIG. 9 or FIG. 10 and displaying the hydrogen concentration. The LED and the buzzer were activated. In addition, in order to prevent damage caused by hydrogen exposure, 3V power was supplied to the external output signal terminal to remove the equipment causing the hydrogen exposure.

When I heard the beep and pressed the reset button, it went to standby, and all of this information was displayed on the display.

Example 6

The hydrogen sensor of Example 2 and the hydrogen sensor of Example 3 should be operated simultaneously by simultaneously utilizing the electrical characteristics of FIGS. 9 and 10 by using the hydrogen sensor of Example 2 and the hydrogen sensor of Example 3 together. A hydrogen alarm was produced in the same manner as in Example 5 except that the warning was possible.

Example 7

An electronic circuit was constructed in the hydrogen sensor manufactured in Example 2 or Example 3 as shown in FIG. 11 to prepare a hydrogen concentration meter.

 When hydrogen is supplied to the hydrogen sensor manufactured in Example 2 or Example 3, the CPU scans the hydrogen sensor every 33 seconds. Thereafter, the initial resistance value and the change value were sensed and the hydrogen concentration was applied to the display by integrating the already stored data of FIG. 9 or FIG. 10 to display the hydrogen concentration on the display.

At this time, the hydrogen sensor is designed as an electronic circuit main PCB-ON socket type for easy replacement.

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 intended to illustrate rather than limit the scope of 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 scanning transmission electron microscopy (STEM) photograph of a cyclic Pd nanostructure prepared according to the present invention.

Figure 2 is a photograph showing the results of TEM analysis of the metal powder specimen of the cyclic Pd nanostructures.

3 is a photograph showing the results of STEM analysis showing a state in which the crystal structures of the metal powder specimens of the cyclic Pd nanostructure are almost perfectly arranged.

FIG. 4 is a high-resolution transmission electron microscopy (HREM) photograph of a metal powder specimen of a cyclic Pd nanostructure, showing analysis of a contrast image by a transmitted electron beam.

FIG. 5 is a Scanning Transmission Electron Microscopy (STEM) picture of the metal powder specimen of the cyclic Pd nanostructure, the left picture is BF, that is, the Z-contrast of STEM, and the right picture is HAADF, The picture shows the z-contrast of STEM.

Figure 6 is a view showing the production of a hydrogen sensor by nano-coating with a Pd nanostructure according to an embodiment of the present invention.

FIG. 7 is a view illustrating a hydrogen sensor manufactured by installing a porous printed circuit board on the nano-coated Pd nanostructure of FIG. 6.

8 is a view showing an experimental apparatus for measuring the electrical resistance according to the hydrogen concentration by the Pd nano hydrogen sensor according to an embodiment of the present invention.

9 is a graph showing electrical resistance ratios by measuring electrical resistance for each hydrogen concentration with a Pd nanostructure hydrogen sensor according to an exemplary embodiment of the present invention.

10 is a graph showing the electrical resistance ratio by measuring the electrical resistance of each hydrogen concentration with a Pd nano-structure mixture hydrogen sensor according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating a hydrogen alarm configured by installing a hydrogen alarm electronic circuit in a Pd nano hydrogen sensor according to an embodiment of the present invention.

FIG. 12 is a diagram illustrating a hydrogen concentration meter configured by installing a hydrogen concentration meter electronic circuit in a Pd nano hydrogen sensor according to an embodiment of the present invention.

Claims (8)

A cyclic Pd nanostructure formed by agglomerating cubic Pd nanoparticles by self-assembly by controlling the direction and speed of crystal growth of nanoparticles with voltage and current, and adjusting the pH in a range of 6 to 10. The cyclic Pd nanostructure of claim 1, wherein the current is 0.01A to 10A and the voltage is 2V to 40V. The cyclic Pd nanostructure of claim 1, wherein the cubic Pd nanoparticles are shape-controlled to have a particle diameter of 1 to 30 nm. The method of claim 1, wherein the cyclic Pd nano structure is characterized in that the shape of the structure is fixed by treating in an atmosphere from which oxygen is removed for 60 minutes to 120 minutes at a pressure of 10 to 100 atm while maintaining the temperature 10 ℃ ~ 200 ℃ Cyclic Pd nanostructures. The metal containing any one or more of palladium oxide (PdO), titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), or iron oxide (Fe ₂ O ₃ ) in the cyclic Pd nanostructure of claim 1 Cyclic Pd nanostructure mixture of nano oxides. The coating of any one or more of the cyclic Pd nanostructures according to any one of claims 1 to 4 or the mixture of the cyclic Pd nanostructures according to claim 5 on a paper, glass, plastic or ceramic substrate and porous printing Hydrogen sensor formed by installing a circuit board (PCB). A hydrogen alarm produced by connecting an electronic circuit to the hydrogen sensor of claim 6. A hydrogen concentration measuring instrument manufactured by connecting an electronic circuit to the hydrogen sensor of claim 6.

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