WO2022211306A1 - Metal oxide/transition metal dichalcogenide heterostructure and method for manufacturing same - Google Patents

Abstract

A metal oxide/transition metal dichalcogenide heterostructure is provided. A method for manufacturing a metal oxide/transition metal dichalcogenide heterostructure may comprise the steps of: preparing metal oxide nanofibers; and heat-treating a transition metal dichalcogenide precursor solution provided with the metal oxide nanofibers to manufacture a transition metal dichalcogenide nanosheet on the surface of the metal oxide nanofibers, and manufacture a transition metal dichalcogenide aggregate between the plurality of metal oxide nanofibers. In addition, in the step of heat-treating the transition metal dichalcogenide precursor solution provided with the metal oxide nanofibers, the transition metal dichalcogenide precursor solution includes a transition metal source, a solvent, and a reducing agent, and the surface area and hydrophobicity of the metal oxide/transition metal dichalcogenide heterostructure can be controlled according to a molar ratio of the transition metal source.

Description

Metal oxide/transition metal dichalcogenide heterostructure and manufacturing method thereof

The present invention relates to a metal oxide/transition metal dichalcogenide heterostructure and a method for manufacturing the same, and more particularly, a metal comprising a metal oxide nanofiber, a transition metal dichalcogenide nanosheet, and a transition metal dichalcogenide aggregate It relates to an oxide/transition metal dichalcogenide heterostructure and a method for manufacturing the same.

A transition metal dichalcogenide is a chemical substance in which at least one chalcogen anion and a chalcogen cation are bound.

The transition metal dichalcogenide may have a triangular 2H and octahedral 1T crystal structure, have electrical conductivity, and have light absorption for absorbing light of an ultraviolet to infrared wavelength.

Accordingly, the transition metal dichalcogenide can be used in various industries such as electrode materials, gas sensors, energy storage materials, and photocatalysts.

As the field of application increases, research related to various optical semiconductor devices is being conducted. For example, in Korean Patent No. 10-1595429, in an optical semiconductor device containing a transition metal dichalcogenide, a scintillator that converts X-rays into visible or infrared rays, a substrate, and a substrate positioned between the substrate and the scintillator , a photosensitive layer comprising a transition metal dichalcogenide having a first surface and a second surface, detecting visible light or infrared radiation emitted from the scintillator, located on the first surface of the photosensitive layer and electrically connected a first electrode, a second electrode positioned on a second surface of the photosensitive layer and electrically connected thereto, and a switch element electrically connected to the first electrode, wherein the photosensitive layer has the first surface Disclosed is an optical semiconductor device comprising a first conductive layer and a second conductive layer having the second surface, wherein the photosensitive layer includes at least two different types of transition metal dichalcogenides. .

One technical problem to be solved by the present invention is to provide a metal oxide/transition metal dichalcogenide heterostructure having an increased surface area and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a metal oxide/transition metal dichalcogenide heterostructure having improved hydrophobicity and a method for manufacturing the same.

Another technical problem to be solved by the present invention is, when used as a photocatalyst, to provide an oxide/transition metal dichalcogenide heterostructure having improved CO ₂ selectivity and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a metal oxide/transition metal dichalcogenide heterostructure and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a metal oxide/transition metal dichalcogenide heterostructure having a reduced manufacturing time and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a metal oxide/transition metal dichalcogenide heterostructure that is easy to mass-produce and a method for manufacturing the same.

The technical problem to be solved by the present invention is not limited to the above.

In order to solve the above technical problem, the present invention provides a method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure.

According to one embodiment, the method for manufacturing the metal oxide / transition metal dichalcogenide heterostructure includes the steps of preparing a metal oxide nanofiber, heat-treating a transition metal dichalcogenide precursor solution provided with the metal oxide nanofiber to the metal It may include preparing a transition metal dichalcogenide nanosheet on the surface of the oxide nanofiber and preparing a transition metal dichalcogenide aggregate between the plurality of metal oxide nanofibers.

According to an embodiment, the transition metal dichalcogenide precursor solution includes a transition metal source, a solvent, and a reducing agent, and according to the molar ratio of the transition metal source, the surface area of the metal oxide / transition metal dichalcogenide heterostructure and controlled hydrophobicity.

According to an embodiment, as the molar ratio of the transition metal source increases, the hydrophobicity of the surface of the metal oxide/transition metal dichalcogenide heterostructure may include increasing.

According to an embodiment, as the molar ratio of the transition metal source increases, the density of the transition metal dichalcogenide nanosheet on the surface of the metal oxide nanofiber increases, and as the molar ratio of the transition metal source increases, the , it may include an increase in the transition metal dichalcogenide aggregates.

According to an embodiment, the preparing of the metal oxide nanofiber may include preparing a metal oxide precursor solution, electrospinning the metal oxide precursor solution to prepare a preliminary metal oxide nanofiber, and the preliminary metal oxide nanofiber. It may include the step of heat-treating the fiber.

According to an embodiment, in the step of heat-treating the preliminary metal oxide nanofiber, the heat treatment temperature may include that of more than 500 ℃ and less than 600 ℃.

According to an embodiment, on the surface of the metal oxide nanofiber, the transition metal dichalcogenide nanosheet is prepared, and between the plurality of metal oxide nanofibers, after the transition metal dichalcogenide aggregate is prepared, The metal oxide nanofiber, the transition metal dichalcogenide nanosheet, and the step of filtering a solution containing the transition metal dichalcogenide aggregate by providing a membrane, and providing a washing solution on the membrane, to control the pH It may further include the step of

In order to solve the above technical problem, the present invention provides a metal oxide / transition metal dichalcogenide heterostructure.

According to an embodiment, the metal oxide / transition metal dichalcogenide heterostructure is a metal oxide nanofiber, a transition metal dichalcogenide nanosheet disposed on the surface of the metal oxide nanofiber, and a plurality of the metal oxide nanofibers It may include those provided with metal dichalcogenide aggregates in between.

According to an embodiment, the metal oxide nanofibers have anatase and rutile crystal structures, and the transition metal dichalcogenide nanosheets have triangular 2H and octahedral 1T crystal structures. may include

According to an embodiment, the metal oxide nanofiber may include titanium oxide, and the transition metal dichalcogenide nanosheet may include molybdenum selenide.

According to one embodiment, the molar ratio of the transition metal dichalcogenide of the transition metal dichalcogenide nanosheet and the metal dichalcogenide aggregate is greater than 0.24 and less than 0.74 compared to the molar ratio of the metal oxide of the metal oxide nanofiber may include

The method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure according to an embodiment of the present invention comprises the steps of preparing a metal oxide nanofiber, heat-treating a transition metal dichalcogenide precursor solution provided with the metal oxide nanofiber to the metal It may include preparing a transition metal dichalcogenide nanosheet on the surface of the oxide nanofiber and preparing a transition metal dichalcogenide aggregate between the plurality of metal oxide nanofibers.

In the step of heat-treating the transition metal dichalcogenide precursor solution provided with the metal oxide nanofiber, the transition metal dichalcogenide precursor solution may include a transition metal source, a solvent, and a reducing agent.

In addition, the surface area and hydrophobicity of the metal oxide/transition metal dichalcogenide heterostructure may be controlled according to the molar ratio of the transition metal source.

More specifically, the molar ratio of the transition metal element is, the molar ratio of the transition metal dichalcogenide in the transition metal dichalcogenide nanosheet and the transition metal dichalcogenide aggregate is the molar ratio of the metal oxide in the metal oxide nanofiber The ratio can be controlled to be 0.48. Accordingly, on the surface of the metal oxide nanofiber, the transition metal dichalcogenide nanosheet may be uniformly and hierarchically generated and grown. Due to this, the surface area of the metal oxide/transition metal dichalcogenide heterostructure may be increased and hydrophobicity may be improved. And, due to the interface formed between the surface of the metal oxide nanofiber and the base surface of the transition metal dichalcogenide nanosheet, a passage through which electrons can easily move may be formed.

Accordingly, by using the metal oxide / transition metal dichalcogenide heterostructure as a photocatalyst, to provide CO ₂ to the metal oxide / transition metal dichalcogenide heterostructure and irradiating ultraviolet to infrared light, the metal oxide / The transition metal dichalcogenide nanosheet in the transition metal dichalcogenide heterostructure, the CO ₂ is easily adsorbed, the CO ₂ is reduced by the light, CO and CH ₄ can be easily generated . Accordingly, the CO ₂ selectivity of the metal oxide/transition metal dichalcogenide heterostructure may be improved.

1 is a flowchart illustrating a method of manufacturing a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention.

2 and 3 are views for explaining a step of preparing a metal oxide nanofiber in the method for manufacturing a metal oxide / transition metal dichalcogenide heterostructure according to an embodiment of the present invention.

FIG. 4 is a view for explaining a method of manufacturing a transition metal dichalcogenide nanosheet and a transition metal dichalcogenide aggregate in a method of manufacturing a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention.

5 is a solution containing a metal oxide nanofiber, a transition metal dichalcogenide nanosheet, and a transition metal dichalcogenide aggregate in the method for manufacturing a metal oxide / transition metal dichalcogenide heterostructure according to an embodiment of the present invention. It is a view for explaining a method of obtaining a metal oxide / transition metal dichalcogenide heterostructure by filtering.

6 is a view for explaining a photocatalytic CO ₂ reduction process of a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention.

7 is an image taken by SEM and TEM of the experimental examples of the present invention.

8 is a graph analyzed by XRD diffraction of experimental examples of the present invention.

9 is a photograph and graph analyzed by TEM and Raman spectroscopy of experimental examples of the present invention.

10 is a graph in which experimental examples of the present invention are analyzed by XPS.

11 is a graph measuring the photocatalytic CO ₂ reduction characteristics of the experimental examples of the present invention.

12 is a graph of measuring light absorption and band gap of experimental examples of the present invention.

13 is a graph measuring the surface structure and adsorption/desorption characteristics of gas in experimental examples of the present invention.

14 is a graph of measuring the surface properties of the experimental examples of the present invention.

15 is an SEM image of TiO ₂ nanofibers according to experimental examples of the present invention.

16 is an XRD diffraction graph of TiO ₂ nanofibers according to experimental examples of the present invention.

FIG. 17 is an SEM image for comparatively explaining a process of obtaining TiO ₂ /MoSe ₂ when manufacturing a TiO ₂ /MoSe ₂ heterostructure according to experimental examples of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In this specification, when a component is referred to as being on another component, it may be directly formed on the other component or a third component may be interposed therebetween. In addition, in the drawings, the thicknesses of the films and regions are exaggerated for effective description of technical contents.

Also, in various embodiments of the present specification, terms such as first, second, third, etc. are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. Accordingly, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes a complementary embodiment thereof. In addition, in this specification, 'and/or' is used in the sense of including at least one of the components listed before and after.

In the specification, the singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to designate that a feature, number, step, element, or a combination thereof described in the specification exists, and one or more other features, numbers, steps, or configurations It should not be construed as excluding the possibility of the presence or addition of elements or combinations thereof.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a flowchart for explaining a method of manufacturing a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention, FIGS. 2 and 3 are metal oxide/transition metal dichalcogen according to an embodiment of the present invention It is a view for explaining the step of preparing a metal oxide nanofiber in the manufacturing method of the nide heterostructure, Figure 4 is a transition metal in the manufacturing method of the metal oxide / transition metal dichalcogenide heterostructure according to an embodiment of the present invention It is a view for explaining a method for manufacturing a dichalcogenide nanosheet and a transition metal dichalcogenide aggregate, and FIG. 5 is a metal oxide in a method for manufacturing a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention It is a view for explaining a method of obtaining a metal oxide / transition metal dichalcogenide heterostructure by filtering a solution containing nanofibers, transition metal dichalcogenide nanosheets, and transition metal dichalcogenide aggregates.

1 to 3 , the metal oxide nanofiber 100 is prepared by electrospinning and heat treating the metal oxide precursor solution 110 ( S110 ).

According to an embodiment, the metal oxide precursor solution 110 may include a metal oxide source, a binder, and a solvent. For example, the metal oxide source may be titanium oxide. As a specific example, the metal oxide source may be titanium butoxide. For example, the binder may be polyvinylpolypyrrolidone. For example, the solvent may be at least one of ethanol and acetylacetone.

According to an embodiment, the preliminary metal oxide nanofiber 120 may be manufactured by providing the metal oxide precursor solution 100 to an electrospinning apparatus and performing electrospinning. In addition, the metal oxide nanofiber 100 may be manufactured by heat-treating the preliminary metal oxide nanofiber 120 at a temperature of more than 500° C. and less than 600° C. Accordingly, the metal oxide nanofiber 100 may have an anatase and rutile crystal structure.

On the other hand, when the preliminary metal oxide nanofiber 120 is heat-treated at 500° C. or less, the metal oxide nanofiber 100 may have an anatase crystal structure.

In addition, when the preliminary metal oxide nanofiber 120 is heat-treated at 600° C. or higher, the metal oxide nanofiber 100 may have a rutile crystal structure.

However, according to an embodiment of the present invention, as described above, the heat treatment temperature of the preliminary metal oxide nanofiber 120 may be controlled to be more than 500 ℃ and less than 600 ℃. Accordingly, the metal oxide nanofiber 100 may have an anatase and rutile crystal structure. Accordingly, CO ₂ selectivity may be improved, and photocatalytic properties may be improved.

According to one modification, the metal oxide nanofiber 100 may be doped with a doping metal. For example, the doping metal may include at least one of Cu, Ni, and Mn.

In the method of manufacturing the metal oxide nanofiber 100 doped with the doping metal according to the above-described modification example, a doping metal precursor including the doping metal is added to the metal oxide precursor solution 110, and the doping It may be prepared by electrospinning and heat-treating the metal oxide precursor solution 110 to which the metal precursor is added. Specifically, the metal oxide source (eg titanium butoxide) and ethanol are mixed, the doping metal precursor is added, the binder (eg polyvinylpyrrolidone) and the solvent (eg acetylacetone) ), the metal oxide precursor solution 110 to which the doped metal precursor is added may be prepared.

In this case, the doped metal precursor may be the doped metal acetate. For example, the doping metal precursor may be copper acetate hydrate or Ni acetate tetrahydrate. As such, the doping metal precursor may include acetate, which may be easily dissolved in alcohol (eg, ethanol, etc.), thereby preventing the formation of crystals.

In addition, electronic and bandgap are provided by the doping of the doping metal, and carbon dioxide light reduction characteristics may be improved. For example, when the doping metal includes Cu, CH ₄ production may be selectively possible.

When light is irradiated to the metal oxide nanofiber 100 , electrons may function as a support. In other words, since the valence band is the most negative in the bandgap structure state of the metal oxide nanofiber 100, electrons and holes are first generated and moved. In addition, the band gap is extended by the metal oxide nao fiber 100 and the transition metal dichalcogenide to be described later, so that more light can be absorbed.

1 and 4, by heat-treating the transition metal dichalcogenide precursor solution 210 provided in the metal oxide nanofiber 100, on the surface of the metal oxide nanofiber 100, transition metal dichalcogenide The nanosheet 200 is manufactured, and between the plurality of metal oxide nanofibers 100 , a transition metal dichalcogenide aggregate 210 is prepared ( S120 ).

According to an embodiment, the transition metal dichalcogenide precursor solution 210 may include a transition metal source, a solvent, and a reducing agent. For example, the transition metal source may be molybdenum selenide. As a specific example, the transition metal source may be at least one of sodium molybdate (Na ₂ MoO ₄ ) and selenium (Se). For example, the solvent may be at least one of distilled water and ethanol. For example, the reducing agent may be sodium borohydride (NaBH ₄ ).

According to one embodiment, the metal oxide nanofiber 100 is provided to the transition metal dichalcogenide precursor solution 210, and heat-treated by a solvothermal method, the metal oxide nanofiber 100 On the surface of the transition metal dichalcogenide nanosheet 200 may be prepared. Accordingly, the transition metal dichalcogenide nanosheet 200 may have a triangular prism 2H and an octahedral 1T crystal structure. For this reason, the transition metal dichalcogenide nanosheet 200 may have electrical conductivity and light absorption in the ultraviolet to infrared region. And, between the plurality of the metal oxide nanofibers 100, the transition metal dichalcogenide aggregate 220 may be prepared. For example, the heat treatment temperature may be 200 ℃. For example, the heat treatment time may be 48 hours.

Accordingly, the transition metal dichalcogenide aggregate 220 between the transition metal dichalcogenide nanosheet 200, and the plurality of metal oxide nanofibers 100 on the surface of the metal oxide nanofiber 100. A solution including a metal oxide/transition metal dichalcogenide double structure 300 having a solution may be prepared.

According to one embodiment, in the transition metal dichalcogenide precursor solution 210, according to the molar ratio of the transition metal source, on the surface of the metal oxide nanofiber 100, the transition metal dichalcogenide sheet ( 200) can be controlled. As the molar ratio of the transition metal source increases, the density of the transition metal dichalcogenide sheet 200 generated on the surface of the metal oxide nanofiber 100 may increase. Due to this, the surface area of the metal oxide/transition metal dichalcogenide double structure 300 may be increased and hydrophobicity may be improved. In other words, the surface area and hydrophobicity of the metal oxide/transition metal dichalcogenide dual structure 300 may be controlled according to the molar ratio of the transition metal source. In contrast, as the molar ratio of the transition metal source decreases, the density of the transition metal dichalcogenide sheet 200 generated on the surface of the metal oxide nanofiber 100 may decrease. Due to this, the surface area of the metal oxide/transition metal dichalcogenide double structure 300 may be reduced and hydrophobicity may be reduced.

And, according to the molar ratio of the transition metal source in the transition metal dichalcogenide precursor solution 210, the amount of the transition metal dichalcogenide aggregate 220 between the plurality of metal oxide nanofibers 100 is controlled can be As the molar ratio of the transition metal source increases, the amount of the transition metal dichalcogenide aggregate 220 generated between the plurality of metal oxide nanofibers 100 may increase. As the molar ratio of the transition metal source decreases, the amount of the transition metal dichalcogenide aggregate 220 generated between the plurality of metal oxide nanofibers 100 may be reduced.

Therefore, by controlling the molar ratio of the transition metal source, the density of the transition metal dichalcogenide sheet 200 generated on the metal oxide nanofiber 100 and the amount of the transition metal dichalcogenide aggregate 220 In addition to this control, the surface area and hydrophobicity of the metal oxide/transition metal dichalcogenide double structure 300 may be controlled.

More specifically, the molar ratio of the transition metal source is, the molar ratio of the transition metal dichalcogenide in the transition metal dichalcogenide nanosheet 200 and the transition metal dichalcogenide aggregate 220 is the metal oxide nano The molar ratio of the metal oxide in the fiber 100 may be controlled to be greater than 0.24 and less than 0.74.

According to an embodiment of the present invention, the molar ratio of the transition metal element is, the molar ratio of the transition metal dichalcogenide in the transition metal dichalcogenide nanosheet 200 and the transition metal dichalcogenide aggregate 220 is , compared to the molar ratio of the metal oxide in the metal oxide nanofiber 100, it may be controlled to be 0.48. Accordingly, on the surface of the metal oxide nanofiber 100, the transition metal dichalcogenide nanosheet 200 may be uniformly and hierarchically generated and grown. Due to this, the surface area of the metal oxide/transition metal dichalcogenide heterostructure 300 may be increased and hydrophobicity may be improved. Accordingly, by providing CO ₂ gas to the metal oxide / transition metal dichalcogenide heterostructure 300 When used as a photocatalyst, the selectivity of the CO ₂ of the metal oxide/transition metal dichalcogenide heterostructure 300 may be improved.

1 and 5, as described above, by filtering the solution containing the metal oxide / transition metal dichalcogenide double structure 300, the metal oxide / transition metal dichalcogenide heterostructure 300 is obtained

According to an embodiment, by providing the solution to the membrane and filtering, the metal oxide nanofiber 100, the transition metal dichalcogenide nanosheet 200, and the transition metal dichalcogenide aggregate 220 are filtered can be And, on the membrane, while controlling the pH by providing a cleaning solution, the metal oxide nanofiber 100, the transition metal dichalcogenide nanosheet 200, and the transition metal dichalcogenide aggregate 220 are can be washed. Specifically, the washing solution may be provided until the pH of the provided washing solution becomes 7. For example, the washing solution may be at least one of distilled water and ethanol.

Then, after controlling the pH of the washing solution, the washing solution and the metal oxide nanofiber 100, the transition metal dichalcogenide nanosheet 200, and the transition metal dichalcogenide aggregate 220 are separated and dried Thus, the metal oxide/transition metal dichalcogenide heterostructure 300 may be obtained.

In contrast, the solution is separated by using a centrifuge to separate the metal oxide / transition metal dichalcogenide heterostructure 300, and by washing with the washing solution to obtain the metal oxide / transition metal dichalcogenide heterostructure 300 In this case, the metal oxide nanofibers 100 in the metal oxide/transition metal dichalcogenide heterostructure 300 may be damaged. In addition, the amount of the transition metal dichalcogenide aggregate 220 in the metal oxide/transition metal dichalcogenide heterostructure 300 may be increased.

However, according to an embodiment of the present invention, as described above, the solution is provided to the membrane and filtered, and the washing solution is provided on the membrane to wash and dry while controlling the pH, so that the metal oxide/transition A metal dichalcogenide heterostructure 300 may be obtained. Accordingly, damage to the metal oxide fiber 100 in the metal oxide/transition metal dichalcogenide heterostructure 300 is prevented, and the amount of the transition metal dichalcogenide aggregate 220 can be prevented from increasing have.

The metal oxide / transition metal dichalcogenide heterostructure 300 according to an embodiment of the present invention, as described above, the molar ratio of the transition metal dichalcogenide in the transition metal dichalcogenide aggregate 220 is, Compared to the molar ratio of the metal oxide in the metal oxide nanofiber 100, the molar ratio of the transition metal element in the transition metal dichalcogenide precursor solution 210 may be controlled to be 0.48. Accordingly, on the surface of the metal oxide nanofiber 100, the transition metal dichalcogenide nanosheet 200 may be produced and grown uniformly and hierarchically. Due to this, the surface area of the metal oxide/transition metal dichalcogenide heterostructure 300 may be increased and hydrophobicity may be improved. And, in the metal oxide / transition metal dichalcogenide heterostructure 300, between the surface of the metal oxide nanofiber 100 and the base surface of the transition metal dichalcogenide nanosheet 200, an interface may be formed have. Accordingly, a path through which electrons can easily move can be formed by reducing the resistance of the interface.

The metal oxide/transition metal dichalcogenide heterostructure according to the embodiment of the present invention described above may be used as a photocatalyst. Hereinafter, a photocatalytic CO ₂ reduction process of the metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention will be described with reference to FIG. 6 .

6 is a view for explaining a photocatalytic CO ₂ reduction process of a metal oxide/transition metal dichalcogenide heterostructure according to an embodiment of the present invention.

Referring to FIG. 6 , the metal oxide/transition metal dichalcogenide heterostructure 300 described in FIGS. 1 to 5 is provided. The metal oxide / transition metal dichalcogenide heterostructure 300, on the surface of the metal oxide nanofiber 100 and the metal oxide nanofiber 100, a transition metal dichalcogenide nanosheet 200. can And, between the surface of the metal oxide nanofiber 100 and the base surface of the transition metal dichalcogenide nanosheet 200, an interface through which electrons can easily move may be included.

As shown in Figure 6, the metal oxide / transition metal dichalcogenide heterostructure (300, hereinafter photocatalyst) is provided with a TEOA solution, CO ₂ , and H ₂ O When light (ultraviolet rays to infrared rays) is irradiated, Due to the surface properties of the photocatalyst, the CO ₂ may be easily adsorbed to the transition metal dichalcogenide nanosheet 200 in the photocatalyst. And, the photocatalyst may easily absorb the light by the transition metal dichalcogenide nanosheet 200 . Accordingly, at the interface in the photocatalyst, some electrons and holes are easily recombined, and the remaining electrons and holes are easily converted into the transition metal dichalcogenide nanosheet 200 and the metal oxide nanofiber 100, respectively. can be moved

More specifically, the electrons may be easily moved to the transition metal dichalcogenide nanosheet 200 through the interface. Due to this, by reacting with the CO ₂ adsorbed on the transition metal dichalcogenide nanosheets, the CO ₂ is reduced, CO and CH ₄ can be easily generated. Accordingly, the CO ₂ selectivity of the photocatalyst may be improved. In addition, the hole may be moved to the metal oxide nanofiber 100 . Due to this, the TEOA solution may be oxidized, and the TEOA solution may be ionized into TEOA ⁺ .

Hereinafter, specific experimental examples and characteristic evaluation of metal oxide nanofibers, and transition metal dichalgokenide nanosheets, and metal oxide/transition metal dichalcogenide heterostructures according to an embodiment of the present invention will be described.

Metal oxide nanofibers according to Experimental Example 1 (TiO ₂ Nanofiber) manufacturing method

TiO ₂ As a precursor, titanium butoxide, polyvinylpolypyrrolidone as a binder, and ethanol and acetylacetone as a solvent were prepared.

The titanium butoxide was provided in the ethanol and stirred to prepare a mixed solution. Then, 8wt% of the polyvinylpyrrolidone was provided in the mixed solution compared to the mixed solution and stirred for 12 hours, and the acetylacetone was provided and stirred for 1 hour to prepare a TiO ₂ precursor solution.

The TiO ₂ precursor solution was provided to a 25 gauge needle of the electrospinning device, and the TiO ₂ precursor solution was electrospun under the process conditions of <Table 1> to prepare a preliminary TiO ₂ nanofiber.

division	process conditions
DC voltage	20kV
Feed rate	10uL/min
Humidity	15%
Distance between syringe needle and collector	110mm
dry conditions	The spun nanofibers are dried in a box oven at 60°C for 2 hours.

The preliminary TiO ₂ nanofibers were provided in a box furnace in an oxygen atmosphere, and heat-treated at 550° C. (temperature increase rate: 5° C./min) for 2 hours to prepare TiO ₂ nanofibers.

Metal oxide / transition metal dichalcogenide heterostructure (TiO) according to Experimental Examples 2 to 4 ₂ /MoSe ₂ heterogeneous structure) manufacturing method

MoSe ₂ Sodium molybdate (Na ₂ MoO ₄ ) and selenium (Se) as a source, distilled water and ethanol as a solvent, sodium borohydride (NaBH ₄ ) as a reducing agent, TiO ₂ nanofiber according to Experimental Example 1 as a metal oxide nanofiber prepared.

In a mixed solvent in which distilled water and ethanol were mixed in a 1:1 ratio, 60 mL of the sodium molybdate was provided, and the selenium was further provided and stirred for 30 minutes. Then, the sodium borohydride was provided and stirred for 30 minutes to prepare a MoSe ₂ precursor solution. (The MoSe ₂ precursor solutions according to Experimental Examples 2 to 4 are, as shown in Table 2 below, the sodium molybdate (Na ₂ MoO ₄ ), the selenium (Se), and the sodium borohydride (NaBH ₄ ) ) differs only in the number of moles.)

division	Sodium Molybdate (Na 2 MoO 4 )	selenium (Se)	Sodium borohydride (NaBH 4 )
Experimental Example 2	1.7 mmol	3.4 mmol	1.7 mmol
Experimental Example 3	2.6 mmol	5.1 mmol	2.6 mmol
Experimental Example 4	5.1 mmol	10.2 mmol	5.1 mmol

And, in the MoSe ₂ precursor solution, the TiO ₂ nanofiber is provided and left for 1 hour without stirring, and then heat-treated at 200° C. for 48 hours by a solvothermal method, on the surface of the TiO ₂ nanofiber , MoSe ₂ nanosheets were produced and grown. Then, the TiO ₂ nanofibers and the MoSe ₂ nanosheet solution were filtered using a membrane filter and washed with distilled water and ethanol until the pH reached 7 and dried in an oven at 60° C. for 2 hours to prepare a TiO ₂ / MoSe ₂ heterostructure. (TiO ₂ /MoSe ₂ heterostructure according to Experimental Examples 2 to 4, except that the MoSe ₂ precursor solution according to Experimental Examples 2 to 4 was used, all were prepared in the same manner.)

Transition metal dichalcogenide nanosheets according to Experimental Example 5 (MoSe ₂ Nanosheet) manufacturing method

In the manufacturing method of the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3, the TiO ₂ nanofiber according to Experimental Example 1 is not provided in the MoSe ₂ precursor solution according to Experimental Example 3, except that the same as in Experimental Example 3 As a method, MoSe ₂ nanosheets according to Experimental Example 5 were prepared.

division	TiO 2 : MoSe 2 molar ratio	MoSe 2 precursor solution			TiO 2 nanofiber
		Sodium Molybdate (Na 2 MoO 4 )	selenium (Se)	Sodium borohydride (NaBH 4 )
Experimental Example 1	1:0	-			60 mg
Experimental Example 2	1:0.25	1.7 mmol	3.4 mmol	1.7 mmol	60 mg
Experimental Example 3	1:0.48	2.6 mmol	5.1 mmol	2.6 mmol	60 mg
Experimental Example 4	1:0.74	5.1 mmol	10.2 mmol	5.1 mmol	60 mg
Experimental Example 5	0:1	2.6 mmol	5.1 mmol	2.6 mmol	-

7 is an image taken by SEM and TEM of the experimental examples of the present invention.

Referring to FIG. 7 , TiO ₂ nanofibers according to Experimental Example 1, TiO ₂ / MoSe ₂ heterostructures according to Experimental Examples 2 to 4, and MoSe ₂ nanosheets according to Experimental Example 5 were photographed by SEM and TEM. The pictures on the left of FIG. 7 are images taken by SEM of the experimental examples, and the pictures on the right are images taken by the TEM of the experimental examples.

As can be seen in FIGS. 7 and <Table 3>, when the TiO ₂ /MoSe ₂ heterostructure was prepared according to Experimental Examples 2 to 4, in the MoSe ₂ precursor solution, MoSe ₂ Source (sodium molybdate, selenium) molar As the ratio increases, it can be seen that the density of the MoSe ₂ nanosheets generated on the surface of the TiO ₂ nanofibers increases. In addition, it can be seen that the MoSe ₂ aggregates generated on the surface of the plurality of TiO ₂ nanofibers are also increased. That is, in the order of Experimental Example 2, Experimental Example 3, and Experimental Example 4 in which the molar ratio of the MoSe ₂ source increases, the density of the MoSe ₂ nanosheet on the surface of the TiO ₂ nanofiber increases, and the TiO ₂ It can be seen that the MoSe ₂ aggregates increase between the nanofibers.

In conclusion, in the manufacturing process of the TiO ₂ /MoSe ₂ heterostructure, by controlling the molar ratio of the MoSe ₂ source in the MoSe ₂ precursor solution, the MoSe ₂ density of the nanosheets generated on the surface of the TiO ₂ nanofibers can be controlled, as well as the amount of the MoSe ₂ aggregates generated between the plurality of TiO ₂ nanofibers can be controlled.

8 is a graph analyzed by XRD diffraction of experimental examples of the present invention.

Referring to FIG. 8 , TiO ₂ nanofibers according to Experimental Example 1, TiO ₂ /MoSe ₂ heterostructures according to Experimental Examples 2 to 4, and MoSe ₂ nanosheets according to Experimental Example 5 were analyzed by XRD diffraction. And, the XRD diffraction peaks of the experimental examples were compared with the reference peaks (TiO ₂ anatase, TiO ₂ rutile, MoSe ₂ ) of the XRD diffraction analysis equipment.

As can be seen from FIGS. 8 and <Table 3>, it can be seen that the TiO ₂ nanofiber according to Experimental Example 1 has a peak in which TiO ₂ anatase and TiO ₂ rutile peaks are combined. Therefore, it can be seen that the TiO ₂ nanofiber has an anatase and rutile crystal structure.

And, it can be seen that the peak of the TiO ₂ /MoSe ₂ heterostructure according to Experimental Examples 3 and 4 is similar to the MoSe ₂ peak distribution than the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 2.

In contrast, the peak of the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 2 is similar to the TiO ₂ anatase and TiO ₂ rutile peaks than the TiO ₂ /MoSe ₂ heterostructure according to Experimental Examples 3 and 4 Able to know.

Therefore, in the order of Experimental Example 2, Experimental Example 3, and Experimental Example 4, in the TiO ₂ /MoSe ₂ heterostructure, on the surface of the TiO ₂ nanofiber, it can be seen that the density of MoSe ₂ nanosheets increases.

9 is a photograph and graph analyzed by TEM and Raman spectroscopy of experimental examples of the present invention, and FIG. 10 is a graph analyzed by XPS of experimental examples of the present invention.

Referring to FIG. 9, (a) of FIG. 9 is a TEM analysis of the crystal structure of the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3 of the present invention, and (b) of FIG. TiO ₂ nanofibers, the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3, and MoSe ₂ nanosheets according to Experimental Example 5 are graphs analyzed by Raman spectroscopy.

Referring to FIG. 10, (a) of FIG. 10 is a graph obtained by analyzing the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3 and the MoSe ₂ nanosheet according to Experimental Example 5 with respect to Mo 3d by XPS, FIG. (b) of 10 is a graph in which the TiO ₂ /MoSe ₂ heterostructure and the MoSe ₂ nanosheet according to Experimental Example 5 were analyzed by XPS for Se 3d, and the analysis results are summarized as shown in Table 4 below.

XPS line					Mo 3d (eV)				Se 3d (eV)
division			Mo 4+ 3d 5/2		Mo 4+ 3d 3/2		Se 2+ 3d 5/2		Se 2+ 3d 3/2
	1T	2H		1T		2H		1T		2H		1T	2H
Experimental Example 3	227.0	228.2	229.4	231.3	53.64	54.38	54.91	55.13
Experimental Example 5	227.8	228.8	230.6	231.9	52.80	54.13	54.91	54.78

As can be seen in FIGS. 9, 10, and <Table 4>, in the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3, the TiO ₂ nanofiber has an anatase and rutile crystal structure. And, it can be seen that the MoSe ₂ nanosheets on the surface of the TiO ₂ nanofibers have 1T and 2H crystal structures.

Accordingly, the TiO ₂ /MoSe ₂ heterostructure may have electrical conductivity and photoreaction properties due to the 1T and 2H crystal structures of the MoSe ₂ nanosheet. Accordingly, the TiO ₂ /MoSe ₂ heterostructure may be used as a photocatalyst for reducing CO ₂ through a photoreaction.

11 is a graph measuring the photocatalytic CO ₂ reduction characteristics of the experimental examples of the present invention.

Referring to FIG. 11 , TiO ₂ nanofibers according to Experimental Example 1, TiO ₂ /MoSe ₂ heterostructures according to Experimental Examples 2 to 4, and MoSe ₂ nanosheets according to Experimental Example 5, 12mW/cm ² intensity of Ultraviolet-visible light was irradiated. When UV-visible light is irradiated, (a) of FIG. 11 is a graph for comparing the amounts of H ₂ , CO, and CH ₄ of the experimental examples, and (b) of FIG. 11 is a comparison of the CO ₂ selectivity of the experimental examples is a graph for, (c) of FIG. 11 is a graph for comparing the amount of H ₂ generation over time of the experimental examples, CO, CH ₄ , and CO ₂ Selectivity of the experimental examples is summarized as in <Table 5> did.

division	Experimental Example 1	Experimental Example 2	Experimental Example 3	Experimental Example 4	Experimental Example 5
CO selectivity	37%	16%	33%	33%	17%
CH 4 selectivity	28%	29%	47%	40%	41%
CO 2 selectivity	65%	45%	80%	73%	59%

11, <Table 3>, and as can be seen from <Table 5>, Experimental Example 1, Experimental Example 2, and Experimental Example 5, the amount of H ₂ gas generated, CO and CH ₄ It can be seen that more than the amount of gas generated can On the other hand, in Experimental Example 2 and Experimental Example 4, it can be seen that the amount of CO and CH ₄ gas generated is greater than the amount of H ₂ gas generated.

And, it can be seen that the CO ₂ selectivity is high in the order of Experimental Example 3, Experimental Example 4, Experimental Example 1, Experimental Example 5, and Experimental Example 2. Accordingly, it can be seen that the greater the amount of CO and CH ₄ gas generated, the higher the CO ₂ selectivity.

Experimental Example 3, a factor with higher CO ₂ selectivity than Experimental Example 4, is that MoSe ₂ nanosheets on the surface of TiO ₂ nanofibers in the TiO ₂ /MoSe ₂ heterostructure according to Experiment 3 were more uniformly generated than in Experiment 4 It can be interpreted as being caused by

And, the factor that generated the highest H ₂ gas in Experimental Example 2 is, in the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 2, on the surface of the TiO ₂ nanofibers, the MoSe ₂ nanosheets, the TiO ₂ nano On the surface of the fiber, it can be interpreted that it is due to being partially generated and grown rather than entirely generated and grown.

In conclusion, in the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3, on the surface of the TiO ₂ nanofibers, the MoSe ₂ nanosheets are more uniformly generated than in other experimental examples, so that the most CO and CH ₄ It can be seen that gas is generated and has the highest CO ₂ selectivity.

12 is a graph of measuring light absorption and band gap of experimental examples of the present invention.

Referring to FIG. 12, (a) of FIG. 12 is a graph in which light absorption in the infrared to ultraviolet region is measured by UV-vis-NIR spectrometry for experimental examples, and (b) of FIG. 12 is the band gap of the experimental examples. This is the measured graph.

As can be seen from FIG. 12 , in Experimental Example 1, it can be seen that light absorption in the infrared to ultraviolet region is significantly lower than that of other experimental examples (Experimental Examples 2 to 5). And, in Experimental Example 1, it can be seen that the light absorbance is rapidly decreased after about 400 nm, and in Experimental Examples 2 to 5, it can be seen that the light absorption is decreased after about 800 nm. And, it can be seen that Experimental Example 2 and Experimental Example 3 have higher light absorption after about 800 nm than Experimental Example 4. The factor in which the light absorption of Experimental Example 2 and Experimental Example 3 is higher than that of Experimental Example 4 is, TiO ₂ /MoSe ₂ According to Experimental Example 2 and Experimental Example 3 In this structure, TiO ₂ nanofibers and It can be interpreted that it is due to the fact that the interface of the MoSe ₂ nanosheets was formed better than that of Experimental Example 4.

And, it can be seen that the band gap is low in the order of Experimental Example 1 (2.92 eV), Experimental Example 2 (1.25 eV), Experimental Example 3 (1.25 eV), Experimental Example 4 (1.24 eV), and Experimental Example 5 (1.23 eV). can

In conclusion, it can be seen that the TiO ₂ /MoSe ₂ heterostructure according to Experimental Examples 2 to 4 absorbs light in the infrared to ultraviolet region.

13 is a graph measuring the surface structure and adsorption/desorption characteristics of gas in experimental examples of the present invention.

13, (a) of FIG. 13 shows that the surface area, pore volume, and average size of pores for the experimental examples were measured by the adsorption/desorption method of N ₂ gas, and FIG. 13 (b) shows the experimental examples. The degree of adsorption/desorption of CO ₂ gas was measured, and the surface area, pore volume, average pore size, micropore area, and CO ₂ adsorption degree of the experimental examples were summarized as shown in Table 6 below.

division	S BET (m 2 /g)	Pore volume (cm 3 /g)	Avg.Pore size (nm)	T-plot micropores (m 2 /g)	CO 2 adsorption (cm 2 /g)
Experimental Example 1	13.5723	0.0649	15.2818	-	0.83
Experimental Example 2	27.2684	0.0795	9.8422	-	1.02
Experimental Example 3	63.1875	0.1041	6.3778	34.2984	2.46
Experimental Example 4	29.0493	0.0998	10.8091	-	1.94
Experimental Example 5	26.0640	0.1298	13.9841	-	1.12

13 and <Table 6>, it can be seen that the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3 has the highest surface area. A factor in which the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3 has the highest surface area may be interpreted as having micropores. Accordingly, the TiO ₂ /MoSe ₂ heterostructure may easily diffuse and absorb CO ₂ gas.

And, it can be seen that the CO ₂ gas adsorption amount of the TiO ₂ /MoSe ₂ heterostructure according to Experimental Example 3 is the highest. The reason that the TiO ₂ /MoSe ₂ heterostructure has the highest amount of CO ₂ gas adsorption may be interpreted as the fact that the TiO ₂ /MoSe ₂ heterostructure has the highest surface area.

14 is a graph of measuring the surface properties of the experimental examples of the present invention.

Referring to FIG. 14 , the contact angles of the experimental examples were measured to compare the hydrophobicity of the surfaces of the experimental examples.

As can be seen in FIGS. 14 and <Table 3>, Experimental Example 4 (116°), Experimental Example 3 (113°), Experimental Example 2 (112°), Experimental Example 5 (99°), Experimental Example 1 (36°) ), it can be seen that the contact angle is high.

Accordingly, in the TiO ₂ /MoSe ₂ heterostructure according to Experimental Examples 2 to 4, on the surface of the TiO ₂ nanofiber, as the density of the MoSe ₂ nanosheet increases, the hydrophobicity is reduced by the MoSe ₂ nanosheet. improvement can be seen.

Due to the hydrophobic properties of the MoSe ₂ nanosheets, the photocatalytic CO ₂ reduction activity of the TiO ₂ /MoSe ₂ heterostructure may be improved.

15 is an SEM image of TiO ₂ nanofibers according to experimental examples of the present invention, and FIG. 16 is an XRD diffraction graph of TiO ₂ nanofibers according to experimental examples of the present invention.

15, (a) of FIG. 15 is an image taken by SEM of the surface of the TiO ₂ nanofiber prepared by heat-treating the preliminary TiO ₂ fiber at 500° C. when manufacturing the TiO ₂ nanofiber. b) is an image taken by SEM of the surface of the TiO ₂ nanofiber prepared by heat-treating the preliminary TiO ₂ nanofiber at 550° C. when manufacturing the TiO ₂ nanofiber, and (c) of FIG. 15 is when the TiO ₂ nanofiber is prepared , Preliminary TiO ₂ It is an image taken by SEM of the surface of the nanofibers prepared by heat treatment at 600 ℃ TiO ₂ nanofibers.

Referring to FIG. 16 , the TiO ₂ nanofibers of FIGS. 15 (a) to (c) were analyzed by XRD diffraction.

As can be seen in FIGS. 15 and 16 , the preliminary TiO ₂ nanofibers are heat-treated at 500° C. and the TiO ₂ nanofibers have an anatase crystal structure. On the contrary, it can be seen that the TiO ₂ nanofiber (Experimental Example 1) prepared by heat-treating the preliminary TiO ₂ nanofiber at 550° C. has anatase and rutile crystal structures. In addition, it can be seen that the preliminary TiO ₂ nanofibers are heat-treated at 600° C. and the TiO ₂ fibers have a rutile crystal structure.

FIG. 17 is an SEM image for comparatively explaining a process of obtaining TiO ₂ /MoSe ₂ when manufacturing a TiO ₂ /MoSe ₂ heterostructure according to experimental examples of the present invention.

Referring to FIG. 17 , after generating MoSe ₂ nanosheets on the surface of TiO ₂ nanofibers, FIG. 17 (a) shows a solution containing the TiO ₂ nanofibers and the MoSe ₂ nanosheets, a centrifugal separator A TiO ₂ /MoSe ₂ heterostructure prepared by centrifugation, washing twice and drying using SEM was photographed. 17 (b) is a TiO 2 /MoSe 2 heterostructure prepared by centrifuging the solution containing the TiO ₂ nanofibers and the MoSe ₂ nanosheet using a centrifuge, washing 6 times, and drying the TiO ₂ /MoSe ₂ heterostructure. Photographed by SEM. Figure 17 (c) shows the TiO ₂ TiO 2 /MoSe 2 prepared by filtering the solution containing the nanofibers and the MoSe ₂ nanosheets using a membrane filter, washing and drying while lowering the pH to 7 TiO ₂ /MoSe ₂ The heterogeneous structures were photographed by SEM.

As can be seen in FIG. 17, the solution containing the TiO ₂ nanofiber and the MoSe ₂ nanosheet is centrifuged, and as the number of washing increases, the TiO ₂ nanofiber is broken in the TiO ₂ /MoSe ₂ heterostructure, It can be seen that the amount of MoSe ₂ aggregates is increased between the plurality of TiO ₂ nanofibers.

Therefore, the method of filtering the solution including the TiO ₂ nanofibers and the MoSe ₂ nanosheets using a membrane filter and washing the solution while lowering the pH to 7 prevents deformation of the TiO ₂ nanofibers, and the MoSe ₂ It can be seen that this is a method of preventing an increase in the amount of aggregates.

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments and should be construed according to the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

The metal oxide / transition metal dichalcogenide heterostructure and the manufacturing method thereof according to an embodiment of the present application are aerospace and automobile industries, energy storage and utilization fields, photoelectrochemical electrode cells, artificial photosynthesis, hydrogen storage capacity and energy efficiency fields, It can be used in various industrial fields such as the field of organic pollutants.

Claims (11)

1. preparing metal oxide nanofibers;

   By heat-treating the transition metal dichalcogenide precursor solution provided with the metal oxide nanofiber, on the surface of the metal oxide nanofiber, to prepare a transition metal dichalcogenide nanosheet, between the plurality of metal oxide nanofibers, transition A method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure comprising the step of preparing a metal dichalcogenide aggregate.
2. The method of claim 1,

   The transition metal dichalcogenide precursor solution includes a transition metal source, a solvent, and a reducing agent,

   According to the molar ratio of the transition metal source, metal oxide / metal oxide / transition metal dichalcogenide heterostructure manufacturing method comprising controlling the surface area and hydrophobicity of the heterostructure.
3. 3. The method of claim 2,

   As the molar ratio of the transition metal source increases, the method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure comprising increasing the hydrophobicity of the surface of the metal oxide / transition metal dichalcogenide heterostructure.
4. 4. The method of claim 3,

   As the molar ratio of the transition metal source increases, the density of the transition metal dichalcogenide nanosheet on the surface of the metal oxide nanofiber increases,

   As the molar ratio of the transition metal source increases, the transition metal dichalcogenide aggregates increase.
5. The method of claim 1,

   The step of preparing the metal oxide nanofiber,

   preparing a metal oxide precursor solution;

   preparing a preliminary metal oxide nanofiber by electrospinning the metal oxide precursor solution; and

   Method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure comprising the step of heat-treating the preliminary metal oxide nanofiber.
6. 6. The method of claim 5,

   In the step of heat-treating the preliminary metal oxide nanofiber,

   The heat treatment temperature, the method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure, including that of more than 500 ℃ less than 600 ℃.
7. The method of claim 1,

   On the surface of the metal oxide nanofiber, the transition metal dichalcogenide nanosheet is prepared, between the plurality of metal oxide nanofibers, after the transition metal dichalcogenide aggregate is prepared, the metal oxide nanofiber, filtering the transition metal dichalcogenide nanosheet, and providing a solution containing the transition metal dichalcogenide aggregate to a membrane; and

   By providing a washing solution on the membrane, the method of manufacturing a metal oxide / transition metal dichalcogenide heterostructure further comprising the step of controlling the pH.
8. metal oxide nanofibers;

   a transition metal dichalcogenide nanosheet disposed on the surface of the metal oxide nanofiber; and

   A metal oxide / transition metal dichalcogenide heterostructure comprising a metal dichalcogenide aggregate provided between the plurality of the metal oxide nanofibers.
9. 9. The method of claim 8,

   The metal oxide nanofiber has an anatase and rutile crystal structure,

   The transition metal dichalcogenide nanosheet is a metal oxide / transition metal dichalcogenide heterostructure, including those having a triangular prism 2H and an octahedral 1T crystal structure.
10. 10. The method of claim 9,

    The metal oxide nanofibers include titanium oxide,

    The transition metal dichalcogenide nanosheet is a metal oxide / transition metal dichalcogenide heterostructure comprising molybdenum selenide.
11. 9. The method of claim 8,

    The molar ratio of the transition metal dichalcogenide of the transition metal dichalcogenide nanosheet and the metal dichalcogenide aggregate is, compared to the molar ratio of the metal oxide of the metal oxide nanofiber, more than 0.24 and less than 0.74 Metal oxide / transition comprising Metal dichalcogenide heterostructure.

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