Tantalum oxyiodide having high conductivity and light absorption and manufacturing method therefor

Abstract

One embodiment of the present invention provides tantalum oxyiodide. The tantalum oxyiodide of the present invention provides a tantalum-based material having high electrical conductivity and light absorption, and can be utilized in various fields, such as optoelectronic devices and photocatalysts.

Description

Tantalum oxyiodide having high conductivity and light absorption and method for preparing the same

[0001] The present invention relates to tantalum oxyiodide having the same crystal structure as tantalum oxide (Ta2O5), which is a widegap oxide semiconductor, and a method for manufacturing the same.

[0002] Tantalum oxide (Ta2O5) has been widely used in capacitors and optical lenses due to its excellent dielectric properties, high chemical stability, and heat resistance. Furthermore, it has been utilized in optical coatings and UV-blocking filters due to its high light transmittance and excellent UV resistance.

[0003] However, tantalum oxide exhibits very low electrical conductivity and light absorption, posing difficulties in its application to optoelectronic devices and photocatalysts. To overcome these limitations and enable its application in various optoelectronic devices and photocatalysts, material technology capable of enhancing the electrical conductivity and light absorption of tantalum oxide is required.

[0004] (Patent Document 1) U.S. Registered Patent US 6786951

[0005] The present invention aims to provide tantalum oxyiodide, which can be utilized in various fields, by dramatically improving electrical conductivity and light absorption in tantalum oxide, which has very low electrical conductivity and light absorption, while maintaining the crystal structure, through partial substitution of iodine at oxygen sites, as a method to solve the problems of the aforementioned prior art.

[0006] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0007] To achieve the above technical problem, one embodiment of the present invention provides tantalum oxyiodide.

[0008] Tantalum oxyiodide according to one embodiment of the present invention is characterized by being represented by the following chemical formula.

[0009] <Chemical Formula 1>

[0010] Ta2O 5-x I y

[0011] (In the above chemical formula 1, 0 <x<5이고, 0<y<5이다.)

[0012] In an embodiment of the present invention, the tantalum oxyiodide may be a tantalum oxyiodide characterized in that it is in the form of a pellet or a powder.

[0013] In an embodiment of the present invention, in the above chemical formula 1, 0 <x<3이고, 0<y<2인 것을 특징으로 하는 탄탈럼 옥시아이오다이드일 수 있다.

[0014] In an embodiment of the present invention, the tantalum oxyiodide may be characterized by having a resistivity of 1 MΩ cm or less.

[0015] Another embodiment of the present invention for achieving the above technical problem provides a method for manufacturing tantalum oxyiodide.

[0016] A method for manufacturing tantalum oxyiodide according to one embodiment of the present invention is characterized by comprising: a step of mixing tantalum oxide and tantalum iodide powder to produce a mixed powder; and a heat treatment step of heat-treating the mixed powder.

[0017] In an embodiment of the present invention, the heat treatment step may be a method for manufacturing tantalum oxyiodide characterized by sealing the mixed powder in the form of pellets and then heat treating it.

[0018] In an embodiment of the present invention, the method for producing tantalum oxyiodide may be characterized in that the molar mass of the tantalum oxide (Ta2O5) and tantalum iodide (TaI5) powders is 10 to 0.2:1 (Ta2O5:TaI5).

[0019] In an embodiment of the present invention, the method for manufacturing tantalum oxyiodide may be characterized in that the temperature of the heat treatment is 600 ℃ or higher and 1600 ℃ or lower.

[0020] In an embodiment of the present invention, the method for producing tantalum oxyiodide may be characterized in that the time of the heat treatment is 24 hours or more and 240 hours or less.

[0021] According to an embodiment of the present invention, a tantalum-based material with high electrical conductivity and light absorption can be provided, and it has the characteristic of being usable in various fields such as optoelectronic devices and photocatalysts.

[0022] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0023] FIG. 1 is a conceptual diagram showing a method for manufacturing tantalum oxyiodide according to one embodiment of the present invention.

[0024] FIG. 2 is a diagram showing the crystal structure, local structure, and powder photograph of tantalum oxyiodide according to one embodiment of the present invention.

[0025] FIG. 3 is a diagram comparing the X-ray diffraction patterns of tantalum oxyiodide and tantalum oxide (Ta2O5) according to one embodiment of the present invention.

[0026] Figure 4 is a diagram showing a micrograph and compositional distribution of tantalum oxyiodide according to one embodiment of the present invention.

[0027] FIG. 5 is a diagram showing the iodine 3d core level comparison of tantalum oxyiodide and tantalum oxide according to one embodiment of the present invention (a) and a diagram showing the tantalum cation bonding state inside tantalum oxyiodide (b).

[0028] Figure 6 is a figure showing the resistivity of various tantalum oxyiodide samples according to an embodiment of the present invention.

[0029] FIG. 7 is a diagram comparing the light absorption spectra, Tauc plot, and band gap of tantalum oxyiodide and tantalum oxide according to an embodiment of the present invention.

[0030] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0031] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0032] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0033] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0034]

[0035] A tantalum oxyiodide according to one embodiment of the present invention will be described.

[0036] The present invention relates to tantalum-based materials, and specifically aims to provide tantalum oxyiodide that can be utilized in various fields by dramatically improving electrical conductivity and light absorption through partial substitution of iodine at oxygen sites to solve the problem of existing tantalum oxides, which have very low electrical conductivity and light absorption.

[0037] The above tantalum oxyiodide is characterized by being represented by the following chemical formula 1.

[0038] <Chemical Formula 1>

[0039] Ta2O 5-x I y

[0040] In the above Chemical Formula 1, 0 <x<5이고, 0<y<5일 수 있고, 바람직하게는 0<x<3, 0<y<2일 수 있다.

[0041] The above tantalum oxyiodide may have the same crystal structure as tantalum oxide (Ta2O5), which is a wide-gap oxide semiconductor, and since it has superior properties compared to existing tantalum oxide, it is a material that can replace existing tantalum oxide.

[0042] The iodine of the above chemical formula 1 can exist in an anionic state within the tantalum oxyiodide structure, and the iodine existing in an anionic state can exist in a chemically bonded state with the tantalum cation.

[0043] The above tantalum oxyiodide may be formed in the form of pellets or powder, but there are no special restrictions on the shape or structure, and it may be composed in various forms.

[0044] The above tantalum oxyiodide has a resistivity of about 1 MΩ cm or less, specifically a value of 1 Ω cm to 50 Ω cm, and thus has excellent electrical conductivity.

[0045] In addition, the above tantalum oxyiodide has superior light absorption compared to conventional tantalum oxide.

[0046] Accordingly, the tantalum oxyiodide according to the embodiment of the present invention can be used in various technical fields requiring electrical conductivity or absorbance, and, for example, can be used as a photoelectronic device or a photocatalytic material.

[0047]

[0048] Next, a method for manufacturing tantalum oxyiodide according to one embodiment of the present invention will be described.

[0049] A method for manufacturing tantalum oxyiodide according to one embodiment of the present invention is characterized by comprising: a step (S100) of mixing tantalum oxide and tantalum iodide powder to produce a mixed powder; and a heat treatment step (S200) of heat-treating the mixed powder.

[0050] First, a mixed powder is prepared (S100).

[0051] In the above S100 step, the amount of the mixed powder can be appropriately adjusted according to the stoichiometric ratio of the tantalum oxyiodide to be manufactured, for example, the mixing ratio of the tantalum oxide (Ta2O5) and tantalum iodide (TaI5) powders may be 10 to 0.2:1 (Ta2O5:TaI5) based on the molar ratio.

[0052] At this time, depending on the form of tantalum oxyiodide to be manufactured, the mixed powder may be sealed before heat treatment, for example, the mixed powder may be sealed in the form of pellets.

[0053] Next, the above mixed powder is heat-treated (S200).

[0054] The above heat treatment can be performed at a temperature of about 600 ℃ or higher, and preferably in the range of 600 ℃ or higher and 1600 ℃ or lower.

[0055] In addition, it is suitable for the production of tantalum oxyiodide to perform the heat treatment for 24 hours or more. For example, the heat treatment may be performed for 24 hours or more and 240 hours or less.

[0056] The tantalum oxyiodide produced by the above manufacturing method can be represented by the following chemical formula 1.

[0057] <Chemical Formula 1>

[0058] Ta2O 5-x I y

[0059] (In the above chemical formula 1, 0 <x<5이고, 0<y<5일 수 있고, 바람직하게는 0<x<3, 0<y<2일 수 있다.)

[0060]

[0061] The present invention will be explained in more detail below through manufacturing examples, comparative examples, and experimental examples. However, the present invention is not limited to the following manufacturing examples and experimental examples.

[0062]

[0063] Example 1: Preparation of Tantalum Oxyiodide

[0064] FIG. 1 is a conceptual diagram showing a method for manufacturing tantalum oxyiodide according to one embodiment of the present invention.

[0065] A mixed powder was prepared by mixing Ta2O5 and TaI5 in a molar ratio of 1.5:1.

[0066] The prepared mixed powder was pelletized using a glass tube, sealed, and heat-treated at 800°C for 48 hours to produce tantalum oxyiodide.

[0067]

[0068] Experimental Example 1: Evaluation of Structural Characteristics

[0069] FIG. 2 is a diagram showing the crystal structure, local structure, and powder photograph of tantalum oxyiodide according to one embodiment of the present invention.

[0070] Specifically, FIG. 2a shows the tantalum oxyiodide (Ta2O2) presented in the present invention. 5-x I y Figure 2b shows the crystal structure of ), the local structure showing that iodine (I) is partially substituted at the oxygen (O) position surrounding the tantalum (Ta) cation in tantalum oxyiodide, and Figure 2c shows a photograph of tantalum oxyiodide powder.

[0071] The tantalum oxyiodide prepared in Example 1 has the same crystal structure as the existing tantalum oxide (Ta2O5) as shown in FIG. 2a, and exhibits a local structure in which iodine (I) is partially substituted at the oxygen (O) positions surrounding the tantalum cation (Fig. 2b).

[0072] In addition, it can be seen that the tantalum oxyiodide sample is black, in contrast to the existing tantalum oxide which is white (Fig. 2c).

[0073]

[0074] FIG. 3 is a diagram comparing the X-ray diffraction patterns of tantalum oxyiodide and tantalum oxide (Ta2O5) according to one embodiment of the present invention.

[0075] In Figure 3 above, it can be confirmed that the tantalum oxyiodide of the present invention has the same crystal structure as tantalum oxide.

[0076] FIG. 4 is a diagram showing a micrograph and compositional distribution of tantalum oxyiodide according to one embodiment of the present invention using scanning electron microscopy and energy dispersive X-ray analysis.

[0077] Table 1 below shows various tantalum oxyiodide (Ta2O2) 5-x I y This is a table summarizing the composition of the sample.

[0078] sample No.12345678910x2.272.601.982.282.530.701.572.471.961.86y0.680.740.811.100.710.170.241.341.261.26

[0079] As shown in Figure 4 above, through elemental mapping, it can be confirmed that iodine is evenly distributed throughout the sample, and by analyzing the composition of various tantalum oxyiodide samples as shown in Table 1 above, Ta2O 5-x I y It can be confirmed that x has a value between 0 and 3, and y has a value between 0 and 2. FIG. 5 is a diagram showing the iodine 3d core level comparison of tantalum oxyiodide and tantalum oxide (a) and the tantalum cation bonding state inside tantalum oxyiodide (b) according to one embodiment of the present invention.

[0080] Specifically, Figure 5a above compares the iodine 3d core level spectra of tantalum oxyiodide and conventional tantalum oxide using X-ray photoelectron spectroscopy. While no iodine peak appeared in conventional tantalum oxide, an iodine peak was clearly observed in tantalum oxyiodide, proving that iodine is present within tantalum oxyiodide. Furthermore, the 3d of tantalum oxyiodide 5 / 2 It can be confirmed that iodine exists inside tantalum oxyiodide in an anionic state by showing that the peak position is 618.9 eV, which is lower energy than the peak position of monatomic iodine solid at 619.3 eV.

[0081] Figure 5b shows the analysis of the bonding state of tantalum cations present in tantalum oxyiodide using X-ray absorption fine structure analysis, confirming the presence of Ta-I bonds as well as Ta-O bonds, which indicates that iodine anions present in tantalum oxyiodide are bonded with tantalum cations.

[0082]

[0083] Experimental Example 2: Evaluation of Electrical Conductivity and Light Absorption Performance

[0084] Figure 6 is a figure showing the resistivity of various tantalum oxyiodide samples according to an embodiment of the present invention.

[0085] Referring to Figure 6 above, the resistivity of various tantalum oxyiodide samples was measured, and it can be confirmed that although there is variation depending on the sample, it exhibits very low resistivity between about 1 and 50 Ω cm, which means that tantalum oxyiodide has excellent electrical conductivity.

[0086] FIG. 7 is a diagram comparing the light absorption spectra, Tauc plot, and band gap of tantalum oxyiodide and tantalum oxide according to an embodiment of the present invention.

[0087] Specifically, Figure 7a compares the light absorption spectra of tantalum oxyiodide and conventional tantalum oxide using UV-Visible spectroscopy, and confirms that tantalum oxyiodide has superior absorption over a wide wavelength range compared to tantalum oxide.

[0088] In addition, as shown in Figure 7b, the band gap was analyzed using a Tauc plot, and it was found that the band gap energy decreased significantly from 3.9 eV to 1.3 eV by partially substituting iodine for the oxygen positions of tantalum oxide.

[0089] In other words, the excellent light absorption and low bandgap of tantalum oxyiodide shown in Experimental Example 2 demonstrate the potential for tantalum oxyiodide to be utilized as a photoelectronic device and photocatalytic material.

[0090]

[0091] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0092] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

1. Tantalum oxyiodide characterized by being represented by the following chemical formula 1: <Chemical Formula 1> Ta2O 5-x I y (In the above Chemical Formula 1, 0 <x<5이고, 0<y<5이다.) 2. In Paragraph 1, The above tantalum oxyiodide is characterized by being in the form of pellets or powder.

3. In Paragraph 1, In the above Chemical Formula 1, 0 <x<3이고, 0<y<2인 것을 특징으로 하는 탄탈럼 옥시아이오다이드.

4. In Paragraph 1, Tantalum oxyiodide characterized by having a resistivity of 1 MΩ cm or less.

5. A step of preparing a mixed powder by mixing tantalum oxide and tantalum iodide powder; and A method for manufacturing tantalum oxyiodide characterized by including a heat treatment step of heat-treating the above-mentioned mixed powder.

6. In Paragraph 5, A method for manufacturing tantalum oxyiodide, characterized in that the heat treatment step involves sealing the mixed powder into a pellet form and then heat treating it.

7. In Paragraph 5, The mixing molar ratio of the above tantalum oxide (Ta2O5) and tantalum iodide (TaI5) powders is A method for preparing tantalum oxyiodide characterized by a ratio of 10~0.2:1 (Ta2O5:TaI5).

8. In Paragraph 5, A method for manufacturing tantalum oxyiodide, characterized in that the temperature of the heat treatment is 600 ℃ or higher and 1600 ℃ or lower.

9. In Paragraph 5, A method for manufacturing tantalum oxyiodide, characterized in that the time of the heat treatment is 24 hours or more and 240 hours or less.

10. Tantalum oxyiodide produced by any one of the manufacturing methods of paragraphs 5 to 9.

11. A photoelectronic device comprising the tantalum oxyiodide of claim 1.

12. A catalyst comprising the tantalum oxyiodide of claim 1.

Images