KR20120021647A - Three dimensional porous structure and producing method of the same - Google Patents

Abstract

PURPOSE: A three-dimensional porous structure and a method for manufacturing the same are provided to improve the photo-electric transformation efficiency of a photo-catalyst by increasing the absorbing efficiency of the structure. CONSTITUTION: A method for manufacturing a three-dimensional porous structure includes the following: a three-dimensional porous photoresist patterns using interference lithography; metals are coated on the pore surface of the three-dimensional porous photoresist patterns to form a metal/photoresist composite; and the photoresist is eliminated from the metal/photoresist composite to form the three-dimensional porous structure. The photoresist eliminating process is implemented based on an organic solvent-based dissolving process or a calcinating process.

Description

THREE DIMENSIONAL POROUS STRUCTURE AND PRODUCING METHOD OF THE SAME

The present application relates to a three-dimensional porous structure prepared by using a three-dimensional photoresist photonic crystal structure prepared using optical interference lithography as a template and a method of manufacturing the same.

Pores of the porous material can be classified into three types according to their diameter size: micropores (<2 nm), mesopores (2 to 50 nm), and macropores (> 50 nm). In addition, through the control of the pore size, the porous material may be used in many fields, including a catalyst, a separation system, a low dielectric material, a hydrogen storage material, a photonic crystal, an electrode, and the like, and is a material that has recently attracted attention.

Such porous materials include inorganic materials such as metal oxides and semiconductors, and materials including metals, polymers, and carbon. In particular, porous structures including semiconducting metal oxides have air and water quality through photocatalytic reaction and photoelectrochemical conversion characteristics. A wide range of applications are possible, including self-purification of pollution and hydrolysis hydrogen production for hydrogen fuel cells. Conventionally, porous structures including such semiconducting metal oxides have been prepared using colloidal solutions of semiconductor nanocrystal oxides, but irregular structures due to low solubility and agglomeration of oxide particles control the size and distribution of porous structures in electrodes. There are many limitations. In addition, a titanium precursor (n-butoxide or iso-butyl butoxide) was previously filled with a photonic crystal structure, and then a sol-gel reaction was induced to prepare a titanium oxide inverse opal structure (PR Somani, C. Dionigi, M. Murgia, D. Palles, P. Nozar, G. Ruani, Sol.Energy Mater.Sol. Cells, 87, 2005, 513-19). However, the titanium oxide particles formed from this sol-gel reaction have a problem that it is difficult to control the desired crystal structure (inverse opal structure). That is, the titanium oxide particles prepared according to the conventional method have low dispersibility and thus the titanium oxide particles cannot be uniformly dispersed or filled in the photonic crystal structure. Accordingly, the titanium oxide inverse opal structure is not manufactured as desired, and there is a problem in that the optical amplification effect is insufficient when applied as a photoelectrode or the like.

Thus, in forming porous structures having three-dimensionally interconnected and regularly aligned uniform pores, the size of the pores can be precisely controlled, and the three-dimensional porous can quickly form the porous structure. There is an increasing demand for structure development.

The present inventors completed the present application by studying a porous structure and a method of manufacturing the porous structure having a uniformly aligned uniform pores and capable of precisely controlling the size of the pores. Accordingly, the present application is to provide a three-dimensional porous structure and a method of manufacturing the same by using a three-dimensional photoresist photonic crystal structure prepared by using optical interference lithography as a template coating the metal.

However, the problem to be solved by the present application is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, one aspect of the present invention, forming a three-dimensional porous photoresist pattern using optical interference lithography; Forming a metal / photoresist composite by coating a metal on the pore surface of the three-dimensional porous photoresist pattern; And removing the photoresist from the metal / photoresist composite to form a three-dimensional porous structure.

Another aspect of the present application provides a three-dimensional porous metal or metal oxide structure including a metal or metal oxide structure and having three-dimensional pores connected to each other and manufactured by the above method.

Provided herein is a three-dimensional porous structure and a method of manufacturing the same, which are prepared by coating a metal using a three-dimensional photoresist photonic crystal structure prepared by a light interference etching process as a template. The three-dimensional porous structure according to an embodiment of the present application, including a metal or metal oxide and has three-dimensional pores connected to each other, the pores are arranged in a regular three-dimensional structure, such that the light by the periodic structure of the pores In addition to having a bandgap, it can contain P-type semiconductor metal oxides that cause electron-hole pairs in light in the visible wavelength range, allowing for self-purification of air and water pollution through photocatalytic reactions and photoelectrochemical conversion characteristics, hydrogen fuel cells A wide range of applications are possible, including the production of hydrolyzed hydrogen for petroleum. The three-dimensional porous structure according to the embodiment of the present application may have pores arranged in various three-dimensional periodic structures such as a three-dimensional face centered cubic structure to provide an efficient passage for electron transfer passage and electrolyte movement by such pores. Photoelectrochemical properties.

1 is a three-dimensional schematic diagram showing an embodiment of a method of manufacturing a three-dimensional porous structure of the present application.
FIG. 2 is an example of computer simulation of the surface of a levelsurface or photoresist pattern representing the boundary of constructive light cancellation interference in an interference pattern used to form a three-dimensional porous photoresist pattern using optical interference lithography. Is a schematic showing the result.
3 is an electron micrograph of a three-dimensional porous photoresist pattern formed using optical interference lithography in an embodiment of the present disclosure.
Figure 4 is an electron micrograph of a three-dimensional porous copper oxide structure prepared according to an embodiment of the present application.
5 is an XRD diffraction graph of a three-dimensional porous copper oxide structure prepared according to an embodiment of the present application.
Figure 6 is a graph comparing the photoelectrode test between the electrode and the electrode including a three-dimensional porous copper oxide structure prepared according to an embodiment of the present application.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments and embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout this specification, when an element is referred to as &quot; including &quot; an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

Throughout this specification, when a layer or member is located “on” with another layer or member, it is not only when one layer or member is in contact with another layer or member, but also between two layers or another member between the two members. Or when another member is present. In addition, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless otherwise stated.

As used throughout this specification, the terms “about”, “substantially”, and the like, are used at, or in the vicinity of, numerical values when manufacturing and material tolerances inherent in the meanings indicated are given, and an understanding of the invention Accurate or absolute figures are used to help prevent unfair use by unscrupulous infringers. As used throughout this specification, the term "step of" or "step of" or "step for" does not mean.

One aspect of the present invention, forming a three-dimensional porous photoresist pattern using optical interference lithography; Forming a metal / photoresist composite by coating a metal on the pore surface of the three-dimensional porous photoresist pattern; And removing the photoresist from the metal / photoresist composite to form a three-dimensional porous structure. The three-dimensional porous structure manufactured by the method includes metals or metal oxides, and also has pores arranged regularly in three dimensions, and the pores may be connected to each other to form three-dimensional pores. In addition, the metal or metal oxide forming the manufactured three-dimensional porous structure forms a framework of the porous structure and forms a structure connected through pores arranged regularly in three dimensions.

In an exemplary embodiment, removing the photoresist from the metal / photoresist composite may be performed by dissolution treatment or calcinations treatment with an organic solvent, but is not limited thereto.

In an exemplary embodiment, the calcination process may be performed in an oxidizing atmosphere or a reducing atmosphere, but is not limited thereto. The oxidizing atmosphere may include a gas containing air or oxygen. An oxide of the metal may be formed by firing in the oxidizing atmosphere to form a three-dimensional porous metal oxide structure. In addition, when using the firing treatment under the reducing atmosphere it can form a three-dimensional porous metal structure.

 In an exemplary embodiment, the forming of the three-dimensional porous photoresist pattern using the optical interference lithography may include irradiating the three-dimensional optical interference pattern on the photoresist layer formed on the substrate and performing post-exposure baking. It may be performed using three-dimensional optical interference lithography including baking and developing, but is not limited thereto.

In an exemplary embodiment, the shape or size of the formed three-dimensional porous photoresist pattern or the pores of the pattern is dependent on the irradiation angle, irradiation direction, irradiation time, irradiation intensity, or a combination thereof of the coherent parallel light. It may be adjusted by, but is not limited thereto.

In an exemplary embodiment, the shape or size of the formed three-dimensional porous photoresist pattern or the pores of the pattern may be controlled by the post-exposure baking time, but is not limited thereto.

In an exemplary embodiment, the pore size of the three-dimensional porous photoresist pattern may have a nanometer to micrometer unit, for example, may be 100 nm to 10 ㎛, but is not limited thereto. .

In an exemplary embodiment, the metal may be coated by a chemical wet deposition method, but is not limited thereto.

In an exemplary embodiment, the metal to be coated is Ti, Cu, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and It may include those selected from the group consisting of a combination thereof, but is not limited thereto.

In an exemplary embodiment, the manufacturing method may further include coating the catalyst before coating the metal on the pore surface of the three-dimensional porous photoresist pattern, but is not limited thereto. The catalyst is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), iron (Fe), ruthenium (Ru), rhodium (Rh), cobalt ( Co), zinc (Zn) and combinations thereof may be selected from, but is not limited thereto.

An embodiment of the method of manufacturing the three-dimensional porous structure is schematically shown in FIG.

First, referring to FIG. 1, in one embodiment, the three-dimensional porous structure comprises: forming a three-dimensional porous photoresist pattern using photointerference lithography on a photoresist layer formed on a substrate (a); Coating a catalyst on the pore surface of the three-dimensional porous photoresist pattern to activate the surface thereof (b); (C) forming a metal / photoresist composite by coating a metal on the pore surface of the catalyst-coated three-dimensional porous photoresist pattern; (D) forming the three-dimensional porous structure by removing the photoresist from the metal / photoresist composite.

The catalyst may be coated in the form of fine particles on the surface of the three-dimensional porous photoresist pattern, and may be coated at least a portion of the surface. The catalyst serves to activate the surface of the three-dimensional porous photoresist pattern in order to be easily coated with the metal.

The metal may be coated on the pore surface of the three-dimensional porous photoresist pattern and the metal may be coated to fill a part or all of the pores of the three-dimensional porous photoresist pattern by appropriately adjusting the coating thickness of the metal.

For example, removing the photoresist from the metal / photoresist composite may be removed by dissolution treatment or calcinations treatment with an organic solvent. Any organic compound liquid capable of dissolving and removing the photoresist as the organic solvent can be used without particular limitation. For example, the organic solvent may include, but is not limited to, an aliphatic hydrocarbon solvent such as hexane, cyclohexane, an aromatic solvent such as benzene, toluene, or a combination thereof. Those skilled in the art may readily select and use an appropriate organic solvent in addition to those exemplified above as the organic solvent.

The calcination treatment may be performed in an oxidizing atmosphere or a reducing atmosphere. An oxide of the metal may be formed by firing in the oxidizing atmosphere to form a three-dimensional porous metal oxide structure. In addition, when using the firing treatment under the reducing atmosphere it can form a three-dimensional porous metal structure. The oxidizing atmosphere may include a gas containing air or oxygen. The reducing atmosphere may include a gas containing argon, helium, nitrogen, hydrogen, or a combination thereof.

The baking treatment temperature can be determined by appropriately selecting a temperature sufficient to remove the photoresist. For example, the firing treatment temperature may be appropriately selected in the range of 400 ° C or higher or 500 ° C or higher. The firing treatment temperature may be, for example, 400 ° C to 1000 ° C, or 400 ° C to 800 ° C, or 400 ° C to 600 ° C, or 500 ° C to 1000 ° C, or 500 ° C to 800 ° C, but is not limited thereto. It is not. In addition, the three-dimensional porous structure formed by controlling the firing temperature can be controlled to the crystallinity of the metal or metal oxide.

By removing the photoresist pattern by the firing process, it is possible to obtain a three-dimensional porous structure having a structure inverted with respect to the three-dimensional porous photoresist pattern used as a template.

The metal may be coated on the pore surface of the three-dimensional porous photoresist pattern and the metal may be coated to fill a part or all of the pores of the three-dimensional porous photoresist pattern by appropriately adjusting the coating thickness of the metal. For example, when the metal is coated to fill a part of the pores of the three-dimensional porous photoresist pattern, the metal or metal oxide forming the three-dimensional porous structure may be empty so that the metal or metal oxide May also have pores therein.

The optical interference lithography used to form the three-dimensional porous photoresist pattern is a patterning technique using interference of light, which is similar to conventional photolithography, but uses an interference fringe instead of using a mask to form a pattern. You can theoretically form all Bravais gratings by adjusting the wave vector. By using the interference fringe, for example, various photonic crystal structures such as simple cubic (SC), face-centered cubic (FCC), body-centered cubic (BCC), etc. are formed. The spatial movement of the interference fringe by phase can be applied to form various grids. In addition, by controlling the properties of the light it is possible to form a three-dimensional pattern having a variety of connection structure and pore size, it is possible to form a pattern of defects basically.

Such optical interference lithography is a patterning technique that uses interference of light. The coherent multi-beam interference fringes can be represented by the following equation (1):

(식 1)

(Equation 1)

를 조절하는 경우 간섭무늬의 위치를 조절할 수 있다. N is the number of lights forming the interference fringes, and four or more lights are required to create a three-dimensional lattice structure. E _i is a polarization vector and can control the shape of the unit atoms forming the lattice, k _i is a wave vector to determine the shape of the lattice.

If you adjust the position of the interference fringe can be adjusted.

For example, among the various three-dimensional patterns that can be formed by optical interference lithography as described above, for forming a simple cubic (SC), face-centered cubic structure and body-centered cubic (BCC) The conditions are shown in Table 1. 2 is a result of computer simulation of the surface of the level surface or photoresist pattern indicating the boundary of constructive light cancellation interference in the interference pattern formed under the conditions of Table 1 below.

[Table 1] Wave and Polarization Vector Conditions for Forming Simple Cubic, Face-centered Cubic, and Body-Cubic Structures

The interference pattern formed by the optical interference lithography can be used as a mask to form a three-dimensional porous photoresist pattern having various connection structures and pores.

The photoresist may be used without particular limitation those known in the art. In an exemplary embodiment, the photoresist may include, but is not limited to, a negative type or a positive type photoresist. In the case of using the negative photoresist, the photoresist sheet is crosslinked in the reinforcement interference region, and crosslinking is not performed in the destructive interference region. Thus, a three-dimensional pattern may be formed after a development process through a solvent. Non-limiting examples of the photoresist, SU-8, PGMA (poly (glycidylmethacrylate)), PHEMNA, Sol-gel composities (POS), polyhedral oligomeric silsesquioxanes (POSS), Poly (2-hydroxyethyl methacrylate) (PHEMA) ), And the like. Among them, SU-8 has a high pattern resolution as a negative photoresist, and patterns are formed through photo-crosslinking of epoxy groups, and three-dimensional patterns of face-centered cubic structures are formed through three-dimensional holography lithography. Can be. In particular, in the case of SU-8, various applications are possible through various surface modifications through hydroxyl groups formed by crosslinking with epoxy groups.

In one embodiment, forming a three-dimensional porous photoresist pattern using the optical interference lithography comprises: forming a photoresist layer on the substrate; Forming a three-dimensional porous photoresist pattern by using optical interference lithography comprising irradiating a three-dimensional optical interference pattern to the photoresist layer, post-exposure baking and developing: May be, but is not limited thereto. In another embodiment, the forming of the three-dimensional porous photoresist pattern, the photoresist layer is a multi-scale grating on the photoresist layer by overlapping the two or more three-dimensional optical interference pattern having a different period from each other It may be to include forming a pattern, but is not limited thereto.

As the substrate, for example, a metal, an oxide, silicon, glass, or the like may be used, but is not limited thereto. When the 3D porous structure is to be applied to the production of an electrode, the substrate may be a conductive substrate or a conductive transparent substrate, but is not limited thereto.

The photoresist layer can be used without particular limitation coating methods known in the art. For example, the photoresist layer may be formed by applying a solution including the photoresist on a substrate by spin coating, dip coating, or the like, but is not limited thereto. The thickness of the photoresist layer can be easily controlled by appropriately adjusting the concentration of the solution containing the photoresist, or the performance conditions of coating methods generally known in the art. In one embodiment, the thickness of the photoresist layer may be appropriately adjusted by those skilled in the art, for example, may be formed to a thickness of about 10 ㎛ to 30 ㎛, but is not limited thereto.

In one embodiment, the three-dimensional optical interference pattern may be formed using four coherent parallel light, but is not limited thereto. For example, the three-dimensional optical interference pattern is formed using four coherent parallel light, and the three-dimensional optical interference pattern may be irradiated onto the photoresist layer to form a three-dimensional porous pattern. In this case, the four lights may be generated by dividing one coherent parallel light into a plurality of lights or by applying a method of irradiating one coherent parallel light to a prism of a polyhedron. For example, after fixing the polyhedral prism on the substrate on which the photoresist is coated, the 3D optical interference pattern may be formed by using a plurality of parallel lights formed by irradiating a 300-400 nm UV light source.

In one embodiment, the shape or size of the formed three-dimensional porous photoresist pattern or the pores of the pattern is controlled by the irradiation angle, irradiation direction, irradiation time, irradiation intensity or combination thereof of the coherent parallel light It may be, but is not limited thereto.

In one embodiment, the shape or size of the three-dimensional porous photoresist pattern formed or the pores of the pattern may be controlled by the post-exposure baking time, but is not limited thereto.

In one embodiment, the pattern formed on the photoresist layer is a variety of photonic crystals such as simple cubic (SC), face-centered cubic (FCC), body-centered cubic (BCC), etc. The structure may be formed, but is not limited thereto. Accordingly, the pores of the pattern formed in the photoresist layer also include a variety of simple cubic (SC), face-centered cubic (FCC), body-centered cubic (BCC), etc. The photonic crystal structure can be formed. For example, it is possible to form a variety of grid structure by adjusting the angle and direction of the light to be irradiated. Furthermore, by controlling the exposure time and the post-exposure baking time of the interference light to be irradiated, it is possible to effectively control the size of the pores included in the pattern. It is possible to overcome the limitations of pore control by arranging existing self-assembly or array of uniform nanoparticles.

For example, the size, shape, etc. of the pores of the three-dimensional porous structure can be easily and variously controlled by variously changing the size, shape, etc. of the three-dimensional porous photoresist pattern.

For example, by adjusting the size of the pores formed in the three-dimensional porous photoresist pattern it is possible to control the coating area of the metal or metal oxide forming the three-dimensional porous structure, and also the size of the pores of the three-dimensional porous structure, The structure and the like can also be adjusted. The pores of the 3D porous structure are formed by removing the photoresist pattern, and the pores may be connected to each other.

For example, the size of the pores formed in the three-dimensional porous photoresist pattern and the spacing between the pores can be adjusted in the range of about several hundred nm to several micrometers, respectively, accordingly, the three-dimensional porous photoresist pattern as a template The size of the pores included in the three-dimensional porous structure formed using and the spacing between the pores can also be adjusted in the range of about several hundred nm to several μm. That is, the shape and / or size of the three-dimensional porous photoresist pattern can be adjusted, for example, the size of pores formed in the three-dimensional porous photoresist pattern and the spacing between the pores are about 100 nm to 10 μm, respectively. The size of the pores included in the three-dimensional porous structure formed by using the three-dimensional porous photoresist pattern as a template and the spacing between the pores may be in the range of about 100 nm to 10 μm, respectively. It is not limited to this.

For example, the pores of the three-dimensional porous structure can be formed up to about a few hundred nm to several ㎛ range, the advantage that the electrolyte can smoothly fill the pores when using the three-dimensional porous structure as a photocatalyst electrode This can provide efficient pores for the penetration of a highly viscous polymer electrolyte or a solid electrolyte.

In one embodiment, the catalyst may be coated by a coating method known in the art, for example, may be formed by a nanoparticle coating method, or a reduction method, but is not limited thereto. The photoresist and the metal are heterogeneous with each other, so coating the metal directly on the surface of the photoresist may not generally be easy. Thus, the catalyst serves to activate the coating by promoting the coating of the metal. The catalyst is formed on the surface of the pores of the photoresist pattern and the catalyst may be formed on a portion of the pore surface. That is, the catalyst does not coat the entire surface of the pores of the photoresist pattern, the catalyst component or fine particles thereof may be scattered on the surface of the pores of the photoresist pattern. For example, the coating of the catalyst by the nanoparticle coating method using a solution in which the catalyst particles are dispersed may be easily performed by coating using a catalyst metal nanoparticle dispersion. Alternatively, the catalyst coating by the reduction method may be carried out by coating the metal oxide solution and then reducing the metal with an appropriate reducing agent, or by coating the metal oxide solution with a suitable reducing agent first and then reducing the coating. Can be. Such nanoparticle coating, or reduction may be easily performed by those skilled in the art by selecting appropriate reagents and conditions, etc.

In one embodiment, the catalyst is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), iron (Fe), ruthenium (Ru), rhodium (Rh), cobalt (Co), zinc (Zn) and combinations thereof may be selected from the group consisting of, but is not limited thereto.

For example, the coating of the catalyst by the reduction method as described above uses a solution containing a salt of the metal for forming the catalyst (eg, a halogen salt, nitrate, sulfate, carbonate, etc.) of the metal and SnCl as a reducing agent. ₂ , NaBH ₄ or LiAlH ₄ .

The metal coated on the pore surface of the three-dimensional porous photoresist pattern coated with the catalyst metal may be formed by a coating method known in the art. In one embodiment, the metal may be coated by a chemical wet deposition method, but is not limited thereto. For example, the chemical wet deposition method may include, but is not limited to, an electroless plating method or an electrodeposiion method. Such chemical wet deposition may be easily carried out by those skilled in the art by selecting appropriate reagents and conditions and the like. The metal may be coated on the surface of the pores of the photoresist pattern to fill or partially fill the pores, but is not limited thereto. Accordingly, the metal oxide region formed by the metal or the oxidation of the metal formed in the pores of the photoresist pattern by the metal coating may have pores or pores therein.

The metal coated on the pore surface of the three-dimensional porous photoresist pattern coated with the catalytic metal is Ti, Cu, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al , Y, Sc, Sm, Ga and may be selected from the group consisting of a combination thereof, but is not limited thereto.

Another aspect of the present application provides a three-dimensional porous structure comprising a metal or metal oxide structure and having three-dimensional pores connected to each other, which is produced by the method according to the present application. That is, the three-dimensional porous structure may have its pores arranged in a three-dimensional structure. Also, pores or pores may be formed in the metal or metal oxide region forming the 3D porous structure.

In an exemplary embodiment, the pore size of the 3D porous structure may be 100 nm to 10 μm, but is not limited thereto.

In an exemplary embodiment, the pores in the three-dimensional porous structure are simple cubic (SC), face-centered cubic (FCC), or body-centered cubic (BCC) It may be arranged regularly, but is not limited thereto. In one embodiment, the pores of the three-dimensional porous structure is arranged in a face-centered cubic structure and the pores may be connected to each other, but is not limited thereto. For example, the three-dimensional porous structure has an array of pores are spherical or cylindrical pores are arranged in a face-centered cubic structure and the pores may be connected by six pipe-shaped pores, but It is not limited.

In an exemplary embodiment, the three-dimensional porous structure, Ti, Cu, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, It may include a metal selected from the group consisting of Ga and combinations thereof, or an oxide of the metal, but is not limited thereto.

The three-dimensional porous structure of the pores are arranged in a three-dimensional regular structure to form an effective electron transfer path by this pore structure can improve the photoelectric conversion efficiency of the photocatalyst, and also through the pores By providing an efficient passageway for penetration, the electrical stability of the photoelectrochemical performance can be improved.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[ Example ]

Optical interference Lithography  3D porosity using Photoresist  Formation of patterns

As the photoresist, a negative type epoxy-based SU-8 photoresist was used. The SU-8 photoresist was dissolved in g-butyrolactone (GBL) to prepare a photoresist solution and applied onto a conductive transparent glass substrate to form a photoresist layer. The coating was used a spin coating method to be able to adjust the thickness according to the RPM. Specifically, SU-8 was applied to have a thickness of 7 μm by applying 2000 RPM. The thickness of the coated photoresist layer may vary depending on the size of the photocatalyst to be prepared, for example, may be formed to a thickness of about 10 ㎛ to 30 ㎛.

Subsequently, the photoresist was heat-treated on a hot plate at 95 ° C. for 10 minutes, and then a dimensional optical interference pattern composed of a plurality of coherent parallel lights provided with optical path difference was examined. Specifically, after fixing the polyhedral prism on the substrate on which the photoresist layer is formed, a three-dimensional photointerference pattern formed by irradiating a 300-400 nm UV light source is irradiated onto the photoresist layer to obtain a three-dimensional photoresist pattern. Formed. In this case, three-dimensional photointerference lithography was applied to form a three-dimensional photoresist pattern, and a three-dimensional porous photoresist pattern was formed by examining three-dimensional optical interference patterns formed by superposing four or more matching laser lights. .

Subsequently, a post-exposure baking process was performed on a hot plate at 60 ° C., followed by etching by dissolving an uncrosslinked portion of the SU-8 photoresist using an organic solvent. Impurities were washed off with propanol to develop a three-dimensional porous photoresist pattern.

The photograph taken by the electron microscope of the three-dimensional porous photoresist pattern formed as described above is shown in FIG.

3D porosity Photoresist  Catalyst coating on the pore surface of the pattern

The 3D porous photoresist pattern sample was immersed in dilute SnCl ₂ / HCl aqueous solution for 10 minutes and then sufficiently washed with distilled water, and then immersed in PdCl ₂ / HCl aqueous solution for 10 minutes and sufficiently washed with distilled water. The Pd ^{2 +} was reduced to Pd by the SnCl ₂ layer to form a Pd catalyst layer. The process was repeated three times to form a Pd catalyst layer on the surface of the three-dimensional porous photoresist pattern.

3D porous coated catalyst Photoresist  Metal coating on the pores of the pattern

Copper (II) sulfate pentahydrate (Copper (II) sulfate pentahydrate), ethylene diaminetetraacetic acid (EDTA), 2,2-dipyridyl (2,2-dipyridyl), and sodium hydroxide A solution mixed at a molar ratio of 3: 3: 0.04: 0.02 was prepared. Formaldehyde, a reducing agent, was added at a volume ratio of 4: 1 to the solution to prepare a Cu metal coating solution. The photoresist pattern sample was placed on a hotplate at 65 ° C. and the copper precursor solution was added to sufficiently immerse the pattern. The solution was repeatedly injected so as not to dry and the Cu metal was coated for 20 minutes.

3D porous structure formation

The copper metal was grown into pores of the formed three-dimensional porous photoresist pattern and then calcined at 500 ° C. for 2 hours to form a three-dimensional porous copper oxide structure. Electron micrographs and XRD diffraction graphs of the three-dimensional porous copper oxide structure formed are shown in FIGS. 4 and 5, respectively.

[ Test Example ]

Photoelectrode  Performance testing

Photoelectrochemical properties of the formed three-dimensional porous copper oxide structure were analyzed using a three-electrode electrochemical cell. In the three-electrode method, Ag / AgCl (3 M NaCl / saturated AgCl) was used as the reference electrode, Pt wire was used as the counter electrode, and the three-dimensional porous copper oxide structure formed on the FTO glass substrate was used as the working electrode. In addition, 0.5 M Na ₂ SO ₄ was used as the electrolyte solution. As a control, a copper oxide in the form of a film rather than a three-dimensional structure was formed by the electroless coating method as described above. The light source is a 0.85 W, 488 nm laser and adopts a 10 second ON / OFF method. The photoelectrode performance test results of the three-dimensional porous copper oxide structure electrode and the general copper electrode are compared and shown in FIG. 6. As shown in FIG. 6, the three-dimensionally arranged 3D copper oxide structure copper oxide structure is improved in the degree of photocurrent with respect to the light source compared to the copper oxide film of the control group. It is showing performance.

Hereinbefore, the present invention has been described in detail with reference to the embodiments and examples, but the present invention is not limited to the above embodiments and embodiments, and may be modified in various forms, and is commonly used in the art within the technical spirit of the present application. It is evident that many variations are possible by those of skill in the art.

Claims (16)

Forming a three-dimensional porous photoresist pattern using optical interference lithography;
Forming a metal / photoresist composite by coating a metal on the pore surface of the three-dimensional porous photoresist pattern; And
Removing the photoresist from the metal / photoresist composite to form a three-dimensional porous structure:
Including,
Method for producing a three-dimensional porous structure.
The method of claim 1,
Removing the photoresist from the metal / photoresist composite is performed by dissolution treatment or calcinations treatment with an organic solvent.
The method of claim 1,
The three-dimensional porous structure, comprising the metal or the oxide of the metal, has a three-dimensionally arranged pores and the pores are connected to each other, the method of producing a three-dimensional porous structure.
The method of claim 2,
The calculation process is performed in an oxidizing atmosphere or a reducing atmosphere, a three-dimensional porous structure manufacturing method.
The method of claim 1,
Forming the three-dimensional porous photoresist pattern using the optical interference lithography includes irradiating the three-dimensional optical interference pattern on the photoresist layer formed on the substrate, post-exposure baking and developing The method of manufacturing a three-dimensional porous structure, which is performed using a three-dimensional optical interference lithography.
The method of claim 5, wherein
The shape or size of the formed three-dimensional porous photoresist pattern or the pores of the pattern is adjusted by the irradiation angle, irradiation direction, irradiation time, irradiation intensity, or a combination thereof of the coherent parallel light. Method for producing a dimensional porous structure.
The method of claim 5, wherein
The shape or size of the formed three-dimensional porous photoresist pattern or the pores of the pattern is controlled by the post-exposure baking time, the manufacturing method of the three-dimensional porous structure.
The method of claim 1,
The pore size of the three-dimensional porous photoresist pattern is 100 nm to 10 ㎛ method of manufacturing a three-dimensional porous structure.
The method of claim 1,
The method of manufacturing a three-dimensional porous structure, further comprising coating a catalyst before coating a metal on the pore surface of the three-dimensional porous photoresist pattern.
The method of claim 1,
The metal is coated by a chemical wet deposition method, a three-dimensional porous structure manufacturing method.
The method of claim 1,
The metal is selected from the group consisting of Ti, Cu, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and combinations thereof That includes, a method for producing a three-dimensional porous structure.
The method of claim 9,
The catalyst is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), iron (Fe), ruthenium (Ru), rhodium (Rh), cobalt ( Co), zinc (Zn) and a method comprising the one selected from the group consisting of a combination thereof.
A three-dimensional porous structure, comprising a metal or metal oxide structure, having three-dimensional pores connected to each other, and manufactured by the method according to any one of claims 1 to 12.
The method of claim 13,
The pore size of the three-dimensional porous structure is 100 nm to 10 ㎛, three-dimensional porous structure.
The method of claim 13,
The pores in the three-dimensional porous structure is arranged in a simple cubic (SC), face-centered cubic (FCC), or body-centered cubic (BCC), 3 Dimensional porous structure.
The method of claim 13,
The metal or metal oxide is a group consisting of Ti, Cu, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and combinations thereof It comprises a metal selected from or an oxide thereof, three-dimensional porous structure.

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