阅读说明：本技术 水分解装置及其制造方法 (Water splitting device and method of manufacturing the same ) 是由 朴丈秀 金熙濬 李台源 白正民 于 2018-11-16 设计创作，主要内容包括：本发明提供了水分解装置及其制造方法。一种水分解装置可以包括：氢气生成电极,该氢气生成电极包括第一外部电极和与第一外部电极一体形成的至少一个第一内部电极；以及氧气生成电极,该氧气生成电极包括第二外部电极和与第二外部电极一体形成的至少一个第二内部电极。第一外部电极和第二外部电极被设置成彼此面对,且第一内部电极和第二内部电极沿垂直于其纵向方向的方向交替地设置。因此,该水分解装置可以同时保证透明度和耐用性,即使当对其使用不透明材料时也是如此。(The invention provides a water splitting device and a manufacturing method thereof. A water-splitting device can include: a hydrogen generating electrode including a first outer electrode and at least one first inner electrode integrally formed with the first outer electrode; and an oxygen generating electrode including a second external electrode and at least one second internal electrode integrally formed with the second external electrode. The first and second external electrodes are disposed to face each other, and the first and second internal electrodes are alternately disposed in a direction perpendicular to a longitudinal direction thereof. Therefore, the water-splitting apparatus can simultaneously secure transparency and durability even when an opaque material is used therefor.)

1. A water-splitting device comprising:

a hydrogen generating electrode including a first outer electrode and at least one first inner electrode integrally formed with the first outer electrode; and

an oxygen generating electrode including a second external electrode and at least one second internal electrode integrally formed with the second external electrode,

wherein the first external electrode and the second external electrode are disposed to face each other,

and wherein the first internal electrodes and the second internal electrodes are alternately arranged in a direction perpendicular to a longitudinal direction thereof.

2. The water splitting device of claim 1, wherein the first and second internal electrodes are spaced apart from each other at a pitch of 10 μ ι η to 500 μ ι η.

3. The water-splitting device of claim 1, wherein at least one of the first outer electrode, the first inner electrode, the second outer electrode, and the second inner electrode has at least one aperture formed therein.

4. The water-splitting device of claim 3, wherein the at least one aperture has a circular shape.

5. The water-splitting device of claim 4, wherein a diameter of the at least one aperture is 80-95% of a width of a corresponding one of the first outer electrode, the first inner electrode, the second outer electrode, and the second inner electrode.

6. The water-splitting device of claim 5, wherein each of the first outer electrode, the first inner electrode, the second outer electrode, and the second inner electrode has a width of 100 μm or less.

7. The water-splitting device of claim 5, wherein the diameter of the at least one aperture is 80 μm to 95 μm.

8. The water-splitting device of claim 5,

wherein the at least one hole comprises a hole having a regular polygonal shape, and

wherein the area of the hole having the polygonal shape is the same as the area of the hole having a circular shape.

9. The water-splitting device of claim 5, wherein the at least one aperture formed in a corresponding one of the first outer electrode, the first inner electrode, the second outer electrode, and the second inner electrode comprises at least two apertures.

10. The water-splitting device of claim 9, wherein the at least two apertures are formed such that respective centers are aligned with a center of a width of a corresponding one of the first outer electrode, the first inner electrode, the second outer electrode, and the second inner electrode.

11. The water-splitting device of claim 10, wherein when the at least two apertures have the same diameter as each other, the shortest distance from the center of one aperture to the other aperture of the at least two apertures is equal to the length: the length corresponds to a half width of the corresponding one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode.

12. The water-splitting device of claim 11, wherein the shortest distance is 50 μ ι η or less.

13. The water splitting device of claim 1, wherein at least one of the hydrogen generating electrode and the oxygen generating electrode comprises:

a substrate;

an electrode layer formed on a surface of the substrate; and

a catalyst layer electrodeposited on a surface of the electrode layer.

14. The water-splitting device of claim 13, wherein the substrate is made of at least one selected from the group consisting of: polyethylene terephthalate, polyethylene naphthalate, and polydimethylsiloxane.

15. The water-splitting device of claim 13, wherein the electrode layer is made of at least one selected from the group consisting of: nickel, titanium, copper, iron, aluminum, stainless steel, indium tin oxide, and fluorinated tin oxide.

16. The water splitting device of claim 15, wherein the thickness of the electrode layer is less than a skin depth relative to a visible frequency range.

17. The water-splitting device of claim 13, wherein the catalyst layer is made of at least one selected from the group consisting of: nickel, nickel oxide, nickel sulfide, nickel copper phosphide, platinum, iridium, and rubidium.

18. The water splitting device of claim 17, wherein the thickness of the catalyst layer is greater than 150nm and less than 5 μ ι η.

19. A method of manufacturing a water splitting apparatus, the method comprising:

forming a predetermined pattern on at least one of the first substrate and the second substrate using one of a photoresist lithography technique and a nanoimprint lithography technique;

forming a metal layer on a surface of the at least one of the first and second substrates having the predetermined pattern; and

and electrodepositing a catalyst layer on the surface of the metal layer.

20. The method of claim 19, wherein the predetermined pattern comprises:

a first outer wire and at least one first inner wire integrally formed with the first outer wire, the first outer wire and the first inner wire being formed on the first substrate; and

a second outer wire and at least one second inner wire integrally formed with the second outer wire, the second outer wire and the second inner wire being formed on the second substrate,

wherein the first and second outer lines face each other, and the first and second inner lines are alternately arranged in a direction perpendicular to a longitudinal direction thereof.

21. The method of claim 20 wherein the first and second internal wires are spaced apart from each other at a predetermined pitch of 10 to 500 μ ι η.

22. The method of claim 20 wherein at least one of the first outer wire, the first inner wire, the second outer wire, and the second inner wire has at least one aperture formed therein.

23. The method of claim 22, wherein the at least one hole has a circular shape.

24. The method of claim 23 wherein the diameter of the at least one hole is 80% to 95% of the width of a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

25. The method of claim 24, wherein the first and second light sources are selected from the group consisting of,

wherein the at least one hole comprises a hole having a regular polygonal shape, and

wherein the area of the hole having the polygonal shape is the same as the area of the hole having a circular shape.

26. The method of claim 22 wherein the at least one hole formed in a corresponding one of the first outer wire, the first inner wire, the second outer wire, and the second inner wire comprises at least two holes.

27. The method of claim 26, wherein the at least two apertures are formed such that respective centers are aligned with a center of a width of a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

28. The method of claim 27, wherein when the at least two holes have the same diameter as each other, the shortest distance from the center of one hole to the other hole of the at least two holes is equal to the length: the length corresponds to a half width of the corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

29. The method of claim 19, wherein the metal layer has a thickness less than a skin depth relative to a visible frequency range.

30. The method of claim 19, wherein the catalyst layer has a thickness greater than 150nm and less than 5 μ ι η.

Technical Field

The present invention relates to a water splitting apparatus and a method of manufacturing the same, and more particularly, to a water splitting apparatus including a hydrogen generating electrode and an oxygen generating electrode and a method of manufacturing the same.

Background

Vehicle headlamps are designed to illuminate an area in front of the vehicle. Such headlights must have sufficient light distribution capability for safe driving. However, when the vehicle is running, a large temperature difference occurs between the inside and the outside of the headlight. In particular, in a high humidity environment, for example, during a rainy season or during vehicle washing, the headlight is covered with fog due to introduction of moisture thereto, whereby the light distribution capability of the headlight is reduced to less than half.

As a method for solving the problem, application of a hydrophilic material on the surface of the lens can be considered. However, the hydrophilic coating layer has a relatively short service life, is easily soiled after use, and thus incurs a relatively high cost.

It is also contemplated to use moisture absorbents including Acrylic Acid Polymers (AAP), silica, alumina-based zeolites, and the like. However, such moisture absorbents cannot be reused in a high humidity environment, and may deteriorate the light distribution capability of the headlamp due to low transparency of the porous material.

It is also contemplated to use a heat exchange system or an air conditioning system. However, when the heat exchange system or the air conditioning system is used alone, it does not exhibit sufficient effects compared to the energy and cost required for the system. Also, when two systems are used together, the structure may become complicated.

In the case of the water splitting technology using the hydrogen separator, there are problems associated with the bonding because it uses a polymer separator. Thus, it is difficult to apply a catalytic material other than noble metals (e.g., platinum (Pt), iridium (Ir), etc.). In addition, it is difficult to ensure transparency of the structure, and durability is also poor.

The information disclosed in this background section of the invention is only for enhancement of understanding of the general background of the invention and may not be considered as admissions or proposing in any way that prior art known to those skilled in the art.

Disclosure of Invention

Various aspects of the present invention are directed to provide a water-splitting device that can simultaneously secure transparency and durability even when an opaque material is used therefor.

According to an aspect of the present invention, the above and other objects can be accomplished by the provision of a water splitting device comprising: a hydrogen generating electrode including a first outer electrode and at least one first inner electrode integrally formed with the first outer electrode; and an oxygen generating electrode including a second external electrode and at least one second internal electrode integrally formed with the second external electrode, wherein the first and second external electrodes are disposed to face each other, and the first and second internal electrodes are alternately disposed in a direction perpendicular to a longitudinal direction thereof.

The first and second internal electrodes may be spaced apart from each other by a pitch of 10 μm to 500 μm.

At least one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode may have at least one hole formed therein.

The holes may have a circular shape.

The diameter of the hole may be 80% to 95% of the width of a corresponding one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode.

Each of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode may have a width of 100 μm or less.

The diameter of the pores may be 80 μm to 95 μm.

The hole may have a regular polygonal shape, and the regular polygonal shape may have the same area as the circular hole.

The at least one hole formed in a corresponding one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode may include two or more holes.

The hole may be formed such that a center thereof is aligned with a center of a width of a corresponding one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode.

When the holes have the same diameter as each other, the shortest distance from the center of one hole to the other hole may be equal to a length equivalent to half the width of a corresponding one of the first external electrode, the first internal electrode, the second external electrode, and the second internal electrode.

The shortest distance may be 50 μm or less.

At least one of the hydrogen generating electrode and the oxygen generating electrode may include a substrate, an electrode layer formed on the substrate, and a catalyst layer electrodeposited on the electrode layer.

The substrate may be made of at least one selected from the group consisting of: polyethylene terephthalate, polyethylene naphthalate, and polydimethylsiloxane.

The electrode layer may be made of at least one selected from the group consisting of: nickel, titanium, copper, iron, aluminum, stainless steel, Indium Tin Oxide (ITO), and Fluorinated Tin Oxide (FTO).

The thickness of the electrode layer may be less than a skin depth (skin depth) with respect to a visible light frequency range.

The catalyst layer may be made of at least one selected from the group consisting of: nickel, nickel oxide, nickel sulfide, nickel copper phosphide (nickel-copper phosphide), platinum, iridium, and rubidium.

The catalyst layer may have a thickness greater than 150nm and less than 5 μm.

According to another aspect of the present invention, there is provided a method of manufacturing a water decomposition device, the method including: forming a predetermined pattern on at least one of the first and second substrates using any one of a photoresist lithography technique and a nanoimprint lithography technique, forming a metal layer on at least one of the first and second substrates having the pattern thereon, and electrodepositing a catalyst layer on the metal layer.

The predetermined pattern may include: a first outer line and at least one first inner line integrally formed with the first outer line, the first outer line and the first inner line being formed on a first substrate; and a second outer wire and at least one second inner wire integrally formed with the second outer wire, the second outer wire and the second inner wire being formed on the second substrate, wherein the first outer wire and the second outer wire face each other, and the first inner wire and the second inner wire are alternately arranged in a direction perpendicular to a longitudinal direction thereof.

The first internal wire and the second internal wire are spaced apart from each other by a pitch of 10 μm to 500 μm.

At least one of the first outer wire, the first inner wire, the second outer wire, and the second inner wire may have at least one hole formed therein.

The holes may have a circular shape.

The diameter of the hole may be 80% to 95% of the width of a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

The hole may have a regular polygonal shape, and the regular polygonal shape may have the same area as the circular hole.

The at least one hole formed in a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line may include two or more holes.

The hole may be formed such that a center thereof is aligned with a center of a width of a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

When the holes have the same diameter as each other, the shortest distance from the center of one hole to the other hole is equal to a length equivalent to half the width of a corresponding one of the first outer line, the first inner line, the second outer line, and the second inner line.

The thickness of the metal layer may be less than a skin depth with respect to a visible frequency range.

The catalyst layer may have a thickness greater than 150nm and less than 5 μm.

The method and apparatus of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following detailed description, which together serve to explain certain principles of the invention.

Drawings

Fig. 1 is a view showing the configuration of a water splitting apparatus according to an exemplary embodiment of the present invention;

fig. 2 is a view illustrating a circular hole formed in an electrode according to an exemplary embodiment of the present invention;

FIG. 3 is a cross-sectional view of the first outer electrode taken along line A-A' in FIG. 1;

FIG. 4 is a view showing a method of manufacturing the water-splitting apparatus of the present invention;

fig. 5 is a graph showing current density measured over time after immersing the water-splitting device of example 1 of the present invention in a neutral solution (pH 7) and applying a voltage of 10V thereto;

fig. 6 is a graph showing current densities measured over time after the water-splitting device of comparative example 1 of the present invention was immersed in a neutral solution (pH 7) and a voltage of 10V was applied thereto;

fig. 7 is an SEM picture of the water-splitting device of comparative example 2 of the present invention, taken by a Scanning Electron Microscope (SEM), after being attached to and then separated from the curved surface of the headlight;

fig. 8A shows a state in which the interior of a lamp is wet before the device of example 1 is operated, fig. 8B shows a dehumidifying area after 5 minutes of starting the operation of the device of example 1 using the electric power of the vehicle, and fig. 8C shows a dehumidifying area after 10 minutes of starting the operation of the device of example 1 using the electric power of the vehicle;

fig. 9 is a graph showing current densities measured when power of a vehicle is applied to the apparatus of example 1; and

fig. 10 is a graph showing the transmittance in the visible light range of example 1 of the present invention.

It is to be understood that the drawings are not necessarily to scale, presenting a simplified representation of various features illustrative of the basic principles of the invention. Specific design features of the invention disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, may be determined in part by the particular intended application and use environment.

In the drawings, like numerals refer to like or equivalent parts of the invention throughout the several views.

Detailed Description

Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with the exemplary embodiments of the invention, it will be understood that the description is not intended to limit the invention to these exemplary embodiments. On the other hand, the present invention is intended to cover not only exemplary embodiments of the present invention but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the present invention as defined by the appended claims.

Fig. 1 is a view showing the configuration of a water splitting apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 1, in an exemplary embodiment of the present invention, the water-splitting device 10 may include a hydrogen-generating electrode 100 and an oxygen-generating electrode 110. The hydrogen generating electrode 100 may include a first outer electrode 101 and at least one first inner electrode 102 integrally formed with the first outer electrode 101. The oxygen generating electrode 110 may include a second external electrode 111 and at least one second internal electrode 112 formed integrally with the second external electrode 111. The first and second external electrodes 101 and 111 may be disposed to face each other, and the first and second internal electrodes 102 and 112 may be alternately disposed in a direction perpendicular to a longitudinal direction thereof.

The shape of the first or second external electrode 101, 111 may differ depending on where the first or second external electrode 101, 111 is attached within the headlamp. The attachment position may be located in an area in which moisture may remain after being generated in the headlight, and may be different depending on the type of vehicle. For example, the first external electrode 101 or the second external electrode 111 may have a semicircular shape or a U-shape, or may have the same shape as a lateral end portion (lateral end) of the front lamp.

The alternating arrangement of the first and second internal electrodes 102 and 112 means that the hydrogen generating electrodes 100 and the oxygen generating electrodes 110 are alternately disposed, and more particularly, means that the water-splitting device 10 has a repetitive structure in which the first and second internal electrodes 102 and 112 are grouped into a single repetitive device.

The inner electrode located at the uppermost position of the water-splitting device 10 may be the first inner electrode 102 or the second inner electrode 112. For example, the first internal electrode 102 integrally formed with the first external electrode 101 and located at the uppermost position of the first external electrode 101 may be located at a higher position than the second internal electrode 112 integrally formed with the second external electrode 111 and located at the uppermost position of the second external electrode 111. The first and second internal electrodes 102 and 112 form a repeating unit (hereinafter, referred to as a "first repeating unit") in which the first internal electrode 102 is located at an upper position and the second internal electrode 112 is located below the first internal electrode 102.

On the other hand, the second internal electrode 112 integrally formed with the second external electrode 111 and located at the uppermost position of the second external electrode 111 may be located at a higher position than the first internal electrode 102 integrally formed with the first external electrode 101 and located at the uppermost position of the first external electrode 101. The second internal electrodes 112 and the first internal electrodes 102 form a repeating unit (hereinafter referred to as a "second repeating unit") in which the second internal electrodes 112 are located at an upper position and the first internal electrodes 102 are located below the second internal electrodes 112.

The number of repetitions of the repeating unit may be set in consideration of the transmittance and water-splitting ability of the water-splitting device. The number of repetitions may be n (n is a natural number) or may be n + 0.5. The configuration in which the number of repetitions is n +0.5 means that the internal electrode located at the bottom portion of the water-splitting device is the internal electrode located at the top portion of the repeating unit.

For example, in the case where the repeating unit is the first repeating unit, the internal electrode located at the bottom portion of the water-splitting device 10 is the first internal electrode 102. In the case where the repeating unit is the second repeating unit, the internal electrode located at the bottom portion of the water-splitting device 10 is the second internal electrode 112.

The pitch between the first and second internal electrodes 102 and 112 is 10 to 500 μm. In the case where the spacing between the first and second internal electrodes 102 and 112 exceeds 500 μm, it is difficult to decompose water to simultaneously contact the first and second internal electrodes 102 and 112 at the same time, with the result that decomposition of water can be achieved only in a specific region, for example, a region where the size or diameter of a water droplet exceeds 500 μm. In the case where the pitch is less than 10 μm, bubbles generated during the decomposition of water may block the gap between the electrodes and thus may cause malfunction of the water-decomposing device.

The decomposition of water may also occur between the first external electrode 101 and the second internal electrode 112 or between the second external electrode 111 and the first internal electrode 102. As described above, the interval between the electrodes may be set in consideration of uniform water decomposition and prevention of bubble generation, and may preferably be 10 μm to 500 μm.

Fig. 2 is a view illustrating a circular hole formed in an electrode according to an exemplary embodiment of the present invention. Referring to fig. 2, at least one hole 201 may be formed in the electrode 200. Here, the electrode 200 refers to at least one of the first external electrode 101, the first internal electrode 102, the second external electrode 111, and the second internal electrode 112. The hole 201 may preferably have a circular shape. However, the present invention is not limited thereto. The hole 201 may have a regular polygonal shape which is symmetrical even when rotated by 90 °, for example a square shape.

Diameter L of the hole₂May be the width L of the electrode ₁80% to 95%. Following the diameter L of the hole₂As it increases, the transmittance of light emitted from the front lamp increases, but the region of water decomposition in the electrode 200 decreases. Diameter L of the hole therein₂Less than the width L of the electrode₁In the case of 80%, the light transmittance may be reduced to less than 70%. Diameter L of the hole therein₂Over the width L of the electrode₁In 95% of cases, the water-splitting ability and durability of the water-splitting apparatus may be reduced. Here, the durability of the device means the ability to be used without detaching from the headlight or damaging at high voltages

Therefore, the diameter L of the hole takes into consideration the light transmittance and the water-splitting ability of the water-splitting device₂Will be the width L of the electrode ₁80% to 95%. For example, when the width L of the electrode₁At 100 μm, the diameter L of the pores₂May be 80 μm to 95 μm. On the other hand, in the case where the holes have a regular polygonal shape instead of a circular shape, the regular polygonal holes may be formed to have the same area as the circular holes.

At least two holes may be formed in a single electrode 200, and the center of the hole may be aligned with the center of the width of the electrode. Center C of hole_h1、C_h2And C_h3May be located on a line 202 (hereinafter referred to as a center line) to be spaced from one side of the electrode in its width direction by a length L corresponding to half the width of the electrode₃Are connected.

Diameter L of the hole therein₂Identical to each other, from the center C of one hole 203_h2To anotherShortest distance L of one hole 204₄I.e. from the centre C located on the centre line 202_h2And C_h3The distance between the straight line distance minus the radius of the hole 204 may be equal to the length L corresponding to half the width of the electrode₃. For example, in the case where two holes each having a diameter of 80 μm are formed in the center of an electrode having a width of 100 μm, the shortest distance from the center of one hole to the other hole may be 50 μm. From the center C of the hole 201_h1The shortest distance to the aperture 203 may also be equal to the length L corresponding to half the width of the electrode₃As described above.

The position of the center of the holes, the number of holes, the diameter of the holes, the interval between the holes, and the like may be preferably determined in consideration of the water-splitting ability and the light transmittance of the water-splitting device. However, the present invention is not limited thereto.

Fig. 3 is a cross-sectional view of the first external electrode 101 taken along line a-a' in fig. 1. Referring to fig. 3, the first external electrode 101 may include a substrate 301, an electrode layer 302 formed on the substrate 301, and a catalyst layer 303 electrodeposited on the electrode layer 302. The current cross-sectional structure of the first external electrode 101 may be the same as the cross-sectional structure of the first internal electrode 102, the second external electrode 111, or the second internal electrode 112.

The substrate 301 may be made of at least one selected from the group consisting of: polyethylene terephthalate, polyethylene naphthalate, and polydimethylsiloxane. However, the present invention is not limited thereto. The substrate 301 may be formed to be transparent and flexible, and particularly, may include a transparent and flexible polymer film.

The electrode layer 302 may be made of at least one selected from the group consisting of: nickel, titanium, copper, iron, aluminum, stainless steel, Indium Tin Oxide (ITO), and Fluorinated Tin Oxide (FTO). The thickness of the electrode layer 302 may be less than the skin depth with respect to the visible light frequency range.

Skin depth is a measure of how closely current flows along a surface to which an electromagnetic wave is applied. Skin depth is included herein in the same sense as skin depth is well known in the art. In the case where the catalyst layer 303 is attached to the inside of the vehicle lamp to face the light source, if the thickness of the electrode layer 302 is larger than the skin depth, the region of the electrode layer 302 that does not contribute to visible light increases, and thus the transmittance decreases.

The catalyst layer 303 may be made of at least one selected from the group consisting of: nickel, nickel oxide, nickel sulfide, nickel copper phosphide, platinum, iridium, and rubidium. However, the present invention is not limited thereto. The catalyst layer 303 can be formed to have an excellent hydrogen generating effect or oxygen generating effect.

The thickness of the catalyst layer 303 may be more than 150nm and less than 5 μm. In the case where the thickness of the catalyst layer 303 is 150nm or less, the durability of the water-splitting device is reduced. In the case where the thickness of the catalyst layer 303 is 5 μm or more, the flexibility of the water-splitting device is reduced, and thus cracking may occur when the water-splitting device is attached to a curved surface of a vehicle lamp.

Fig. 4 is a view showing a method of manufacturing the water splitting apparatus of the present invention. Referring to fig. 4, the method of manufacturing the water splitting apparatus includes: a step of forming a predetermined pattern on at least one of the first and second substrates using a photoresist lithography technique or a nanoimprint lithography technique (S101), a step of forming a metal layer (electrode layer) on at least one of the first and second substrates having the pattern thereon (S102), and a step of electrodepositing a catalyst layer on the metal layer (S103).

At the same time, the photoresist lithography technique may be performed using one method selected from a positive photoresist lithography technique and a negative photoresist lithography technique, without being limited to any one specific method. The deposition of the metal layer may be performed using sputtering or electron beam evaporation.

The manufacturing method may further include the step of subjecting the metal layer to a hydrophilic surface treatment before electrodepositing the catalyst layer to the metal layer. The hydrophilic surface treatment may be an ultraviolet-ozone purification treatment. The hydrophilic surface treatment may increase the bonding force between the surface of the substrate and the deposition aqueous solution containing the precursor, and may prevent the generation of bubbles on the surface of the substrate during electrodeposition by performing surface modification, i.e., formation of hydroxyl groups (-OH). However, the hydrophilic surface treatment is not limited thereto. Surface treatment with plasma may also be performed.

The manufacturing method may further include the step of subjecting the water-splitting device to ultraviolet-ozone purification treatment after the electrodeposition of the catalyst layer.

The predetermined pattern may be the same as the pattern shown in fig. 1. That is, the first outer wire and at least one first inner wire integrally formed with the first outer wire are formed on the first substrate, and the second outer wire and at least one second inner wire integrally formed with the second outer wire are formed on the second substrate. The first and second outer lines face each other, and the first and second inner lines are alternately arranged in a direction perpendicular to a longitudinal direction thereof.

The spacing between the first internal wire and the second internal wire may be 10 μm to 500 μm. A predetermined interval may be formed between the first outer line and the second inner line or between the second outer line and the first inner line, and the interval may preferably be 10 μm to 500 μm.

At least one hole may be formed in the first outer line, the first inner line, the second outer line, and the second inner line at the time of patterning, and the hole may have a circular shape. The diameter of the hole may be 80% to 95% of the width of the wire. In the case where the holes have a regular polygonal shape, the regular polygonal holes may be formed to have the same area as the circular holes. At least two holes may be formed in a single line, and the center of the hole may be aligned with the center of the width of the line. In the case where the diameters of the holes are the same as each other, the shortest distance from the center of one hole to the other hole may be equal to a length equivalent to half the width of the line.

The metal layer may have a thickness less than a skin depth with respect to a visible light frequency range, and the catalyst layer may have a thickness greater than 150nm and less than 5 μm.

Hereinafter, a method of manufacturing the water-splitting device of the present invention and a water-splitting device manufactured by the method will be described in more detail with reference to specific examples. However, it should be understood that these examples described below are intended only to illustrate or describe the present invention in more detail, and thus the present invention is not limited thereto.

Example 1

Polyethylene naphthalate is used to form the substrate. The first substrate is formed to have a "U" -shaped first outer line and a first inner line, and the second substrate is formed to have a "U" -shaped second outer line and a second inner line. Each of the first outer line, the first inner line, the second outer line, and the second inner line is formed to have a width of 100 μm, and a pitch between the first inner line and the second inner line is set to 100 μm. A plurality of circular holes each having a diameter of 80 μm are formed in each of the first outer wire, the second outer wire, the first inner wire, and the second inner wire. The circular hole is formed such that the center thereof is aligned with the center of the width of each line, i.e., a point spaced apart by 50 μm from one side of each line in the width direction thereof. The shortest distance from the center of one hole to the other hole was set to 50 μm.

Subsequently, a nickel layer was formed on each of the first and second substrates using an electron beam evaporation apparatus. Since the skin depth of nickel in the visible light frequency range is 25nm, the nickel layer is formed to have a thickness of 20 nm.

Subsequently, using an ultraviolet-ozone purifier (AC-6) at 15 to 20mW/cm²Next, the nickel layer formed on each of the substrates was subjected to hydrophilic surface treatment for 10 minutes. A nitrogen gas was purged into the deposition aqueous solution containing the nickel precursor and the phosphorus precursor for 20 minutes, and a nickel phosphide catalyst layer having a thickness of 200nm was formed on the nickel layer using the electroplating apparatus.

Accordingly, the first outer wire and the first inner wire become the first outer electrode and the first inner electrode of the hydrogen generating electrode, respectively. The second outer wire and the second inner wire become a second outer electrode and a second inner electrode of the oxygen generating electrode, respectively.

Comparative example 1

A water splitting device was fabricated in the same manner as in example 1 above, except that the nickel phosphide catalyst layer was formed to have a thickness of 150 nm.

Comparative example 2

A water splitting device was fabricated in the same manner as in example 1 above, except that the nickel phosphide catalyst layer was formed to have a thickness of 5 μm.

Fig. 5 is a graph showing current density measured over time after immersing the water-splitting device of example 1 of the present invention in a neutral solution (pH 7) and applying a voltage of 10V thereto. Referring to FIG. 5, example 1 has a constant current density over time, and the current density is about 1.27A/cm². When converted to the amount of water removed per hour, it means that 0.1 to 0.2 ml of water can be removed per hour.

Fig. 6 is a graph showing current densities measured over time after the water-splitting device of comparative example 1 of the present invention was immersed in a neutral solution (pH 7) and a voltage of 10V was applied thereto. Referring to FIG. 6, it can be seen that the current density reached about 1.25A/cm after about 80 seconds of application of the potential²And then the current density decreases. That is, it can be seen that the device of comparative example 1 is deteriorated in characteristics or durability as compared to example 1.

Fig. 7 is an SEM picture of the device of comparative example 2 of the present invention taken by a Scanning Electron Microscope (SEM) after being attached to and then separated from the curved surface of the headlight. Referring to fig. 7, it can be seen that the flexibility of the device is reduced and thus a rupture occurs.

Fig. 8A shows a state in which the interior of a lamp is wet before the device of example 1 is operated, fig. 8B shows a dehumidifying area after 5 minutes of starting the operation of the device of example 1 using the electric power of the vehicle, and fig. 8C shows a dehumidifying area after 10 minutes of starting the operation of the device of example 1 using the electric power of the vehicle. Fig. 9 is a graph showing current densities measured when power of a vehicle is supplied to the apparatus of example 1.

Referring to fig. 8A to 9, when the device 801 of example 1 was operated for 5 minutes, moisture was removed from the area 802 near the device 801 of example 1, and when the device 801 of example 1 was operated for 10 minutes, moisture was removed from the larger area 803. It can be seen that following the examplesThe operation time of the device 801 of example 1 elapsed, and the dehumidification region expanded from a point corresponding to the center of the device 801 of example 1 toward the rear end portion and the front end portion of the headlight. Further, the current density of example 1 was about 3.57mA/cm²And thus it can be understood that moisture is effectively removed at room temperature.

Fig. 10 is a graph showing the transmittance in the visible light range of example 1 of the present invention. The transmittance was measured by irradiating light in the visible light range to the device of example 1 with an ultraviolet-visible-near infrared spectrometer, detecting light that has passed through the device with a detector located on the opposite side, and comparing the light intensity before and after the light was passed.

Referring to fig. 10, the device of example 1 has an average transmittance of about 79% with respect to the entire visible light range, and has a minimum transmittance of about 75% with respect to a wavelength range of about 400nm to about 450 nm. When the water-splitting device is attached to a headlamp, the desired transmission of the device is about 70%. Therefore, it can be seen that example 1 exhibits excellent transmittance.

As apparent from the above description, various aspects of the present invention are directed to providing a water-splitting device that can simultaneously secure transparency and durability even when an opaque material is used therefor.

For convenience in explanation and accurate definition in the appended claims, the terms "upper", "lower", "inner", "outer", "upper", "lower", "upward", "downward", "front", "rear", "back", "inner", "outer", "inward", "outward", "inner", "outer", "forward", "rearward" are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing description of the exemplary embodiments of the invention has been presented for the purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical applications to enable others skilled in the art to make and utilize various exemplary embodiments of the invention and various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.