KR101122007B1 - Preparation of titanium dioxide with nanowire structure by using natural extracts - Google Patents

Abstract

The present invention relates to a method for producing titanium dioxide using an extract obtained from a natural plant as a template. More specifically, a) dispersing a natural plant in water, followed by heating to prepare a natural plant extract (extract); b) mixing, stirring and reacting the natural plant extract and the titanium dioxide precursor mixed solution; c) removing water after the reaction to obtain a powder; And d) calcining the powder to remove organic matter. It relates to a method for producing titanium dioxide having a nanowire structure using a fiber of a natural product extract comprising a.

Titanium Dioxide, Nanowire Structure, Natural Extract, Kelp Extract, Raisin Extract

Description

Preparation method of titanium dioxide with nanowire structure using natural extracts {Preparation of titanium dioxide with nanowire structure by using natural extracts}

The present invention relates to a method for producing a fibrous nanostructure using a natural extract, and more particularly, a titanium alkoxide solution as a precursor, a natural extract is added as a template, the fibrous form of the natural extract as a template, The present invention relates to a method for obtaining rod-shaped titanium dioxide having a nano size having a one-dimensional structure having a large surface area per unit area having a nanowire structure.

Nanomaterials can be divided into two-dimensional structures, such as nanodots, nanodimensional structures such as nanoparticles, one-dimensional structures of 100 nm or less in diameter, such as nanowires, nanorods, and nanobelts, and nanoplates and nanofilms. Can be classified. Among them, one-dimensional nanowires can be a useful basic unit for realizing nano devices by themselves, and due to new new functions and high functionalities such as quantum limitation effect and high specific surface area, which were not found in conventional bulk materials, It is attracting attention as a potent material that can open various possibilities for nanoelectronic devices.

Currently, semiconductor nanowires have been reported to be applied to various devices such as lasers, field effect transistors (FETs), logic gates, solar cells, and secondary batteries. Research on nano devices using surface phenomena such as optical sensor, gas sensor, and bio sensor using the dimensional characteristics of one-dimensional nanowires is being actively conducted.

Currently, the nanowires are synthesized by vapor phase transport using gaseous precursors such as thermal evaporation, chemical vapor deposition, and pulsed laser deposition (PLD). It is being synthesized through). Recently, various types of metal and metal oxide nanowires have been manufactured using electrospun.

However, controlling the structure of these nanowires is quite difficult and requires complex processes and expensive equipment to synthesize the nanowires we need. Therefore, a method for more easily synthesizing a desired nanowire-type structure was needed.

The present invention relates to a method for synthesizing a nanowire structure that can be easily synthesized, and to prepare a natural extract using a natural plant that can be easily obtained in nature, and to provide a method for producing titanium dioxide using the same as a template.

The present invention is to provide a method for producing a titanium dioxide structure of various forms including nanowires. Accordingly, the present invention is to provide a titanium dioxide structure having a large surface area.

The present invention relates to a method for synthesizing titanium dioxide, a photocatalyst, and more particularly, a method for synthesizing titanium dioxide (TiO ₂ ) having a nanowire structure in a fibrous form.

The present invention is a method for synthesizing a titanium dioxide structure having a nanowire of a one-dimensional form using a natural extract.

By synthesizing nanowire structures using natural extracts, the present inventors can produce titanium dioxide having nanowire structures more easily than currently used methods, and the nanostructures can maximize the surface area per unit area and thus the efficiency of the catalyst. The present invention was completed by discovering that it can be improved.

Specifically, the method for producing titanium dioxide having a nanowire structure using the fiber of the natural product extract of the present invention as a template

a) milling or heating the natural plant to produce a natural plant extract;

b) mixing, stirring and reacting the natural plant extract and the titanium dioxide precursor mixed solution;

c) removing water after the reaction to obtain a powder; And

d) calcining the powder to remove organic matter;

It includes.

The natural plant is not limited, but may be any one or two or more selected from potatoes, bananas, lotus root, sesame leaves, cherry tomatoes, mushrooms, spinach, kelp, dried bananas, raisins, dried persimmons.

As a method of preparing the natural plant extract, it may vary depending on the type and nature of the natural plant used, and a hot water extraction method, which is a method of preparing an extract, may be used.

Specifically, in the case of kelp extract, the dried kelp is washed with 1% NaCl and distilled water, and then the kelp is put in distilled water and stored for 40 to 50 hours. After stor- ing, kelp slime (alginic acid) and water are mixed. It is prepared by the method of separating and extracting sticky mucus. In the case of raisins extract, the dried raisins are washed with distilled water and dried at 100 ° C, and dried raisins are distilled in water and heated at 80-90 ° C for 20-30 hours to extract a dark red solution. do. Other bananas, lotus root, sesame leaves, cherry tomatoes, spinach, etc. are pulverized well using a blender to make juice, and then extract is filtered using GF / C filter paper.

In the present invention, the titanium dioxide precursor is used by dissolving a titanium alkoxide in a solvent, it is preferable to use a solution of 0.1 ~ 0.5 mol to prepare a nanostructure.

The titanium alkoxide may be selected from titanium isopropoxide, titanium methoxide, titanium butoxide, titanium ethoxide and titanium ethyl hexoxide.

The solvent may be one or more selected from alcohols (methanol, ethanol, propanol, etc.), ketones (acetone, methyl ethyl ketone, etc.) and hydrocarbons (hexane, heptane, octane, etc.).

In the present invention, the natural plant extract and the titanium dioxide precursor mixture solution are mixed and stirred to react. Specifically, it is good to make it fully react by stirring for 24 hours or more using a stirrer. In this case, the mixing ratio is preferably 1: 1 to 2 by weight of the natural plant extract and the mixed solution of titanium dioxide precursor to produce a titanium dioxide nanowire having a nanostructure.

After the natural plant extract and the titanium alkoxide is reacted and dried in an oven at 80 ~ 120 ℃ to remove the moisture to prepare a powder. Next, the dried powder is dried at 30 to 80 ° C. for 10 minutes or more and 10 to 60 minutes using an electric furnace, and then heated to 5 ° C./min to 500 to 800 ° C., more preferably at 600 to 700 ° C. Fire for 2-4 hours. When firing, organic matter is removed, and titanium dioxide in a fibrous form of a natural plant extract is produced (see FIGS. 1 and 2). In the case of calcination above 800 ° C., the resulting nanostructure has a rutile structure. When firing in the above temperature range, it is possible to manufacture a nanowire structure having both an anatase structure and a rutile structure.

Nanowire structure produced by the manufacturing method according to the invention has a fibrous form having a diameter of 10 ~ 30nm.

The present invention used a natural extract to provide a simple synthesis method of titanium dioxide (TiO ₂ ) having a nanowire that was possible through a complex process and expensive equipment. According to the present invention it is possible to synthesize a new titanium dioxide structure in the form of nano-sized wire according to the characteristics of the natural extract, the synthesis of a new nanowire-shaped nanostructure by this method is to prepare a nanostructure through a conventional complex process You can simply synthesize it. More largely, the mechanism by which such nanostructures are generated may be a material for making nanostructures more easily.

In particular, the titanium dioxide according to the present invention is formed on the surface of the nanowire, can maximize the surface area per unit area can improve the efficiency when used as a photocatalyst.

The one-dimensional nanostructure of titanium dioxide according to the present invention can be used in various fields such as photocatalyst, dye sensitized solar cell, optical device, gas sensor, etc. The efficiency can be maximized.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1

Preparation of Kelp Extract

Kelp extract is dried kelp with 1% NaCl and distilled water to wash the surface, and 200 g of kelp in 200 mL of distilled water and stored for 48 hours. After 48 hours, a mixture of kelp extract and water was produced, and only the kelp extract was separated and used.

Preparation of Titanium Dioxide

A solution was prepared using titanium butoxide as starting material. First, 2 mL of titanium butoxide was added to 50 mL of ethanol to prepare a titanium butoxide solution at a concentration of 0.1 M (mol / L), and this solution was used as a starting material. The kelp extract was mixed with the prepared 0.1 M titanium butoxide solution in a 1: 1 weight ratio and stirred for 24 hours to react. After fully reacting, the powder was prepared by drying in a 100 ° C. dry oven for 24 hours.

The prepared powder was dried at 50 ° C. for 30 minutes using an electric furnace, and then heated to 5 ° C./min and calcined at 600 ° C. for 3 hours.

The components of the prepared titanium dioxide nanostructures were analyzed using an XRD (X-ray diffraction) apparatus. The X-ray diffraction (XRD) analysis was performed with a High Resolution X-Ray Diffractometer (X'Pert PRO Multi Purpose X-Ray Diffractometer; Cu 2KW (Max. 60kV 55mA)), 2θ range, 10 to 70.

The crystallinity of the titanium dioxide nanostructures prepared according to the method of Example 1 was examined by XRD, and it was confirmed that the formation of titanium dioxide had a crystal structure in which anatase and rutile were mixed.

In addition, as a result of measuring 2,000 times using an optical microscope, as shown in Figure 1, it can be seen that the nanowire-like structure was formed.

[Example 2]

Preparation of Raisin Extract

The raisins extract was prepared by putting 20 g of dried raisins into 100 ml of distilled water and extracting by heating at 80 ° C. for 24 hours. The solution at this time appeared dark red.

Preparation of Titanium Dioxide

A solution was prepared using titanium butoxide as starting material. First, 2 mL of titanium butoxide was added to 50 mL of ethanol to prepare a titanium butoxide solution at a concentration of 0.1 M (mol / L), and this solution was used as a starting material. The raisins extract was mixed in a 1: 1 weight ratio to the prepared 0.1 M titanium butoxide solution, and stirred for 24 hours. After fully reacting, the powder was prepared by drying in a 100 ° C. dry oven for 24 hours.

The prepared powder was dried at 50 ° C. for 30 minutes using an electric furnace, and then heated to 5 ° C./min and calcined at 600 ° C. for 3 hours.

The components of the prepared titanium dioxide nanostructures were analyzed using an XRD (X-ray diffraction) apparatus. The X-ray diffraction (XRD) analysis was performed with a High Resolution X-Ray Diffractometer (X'Pert PRO Multi Purpose X-Ray Diffractometer; Cu 2KW (Max. 60kV 55mA)), 2θ range, 10 to 70.

The crystallinity of the titanium dioxide nanostructures prepared according to the method of Example 2 was examined by XRD, and it was confirmed that the formation of titanium dioxide had a crystal structure in which anatase and rutile were mixed.

In addition, as measured by 1,000 times using an optical microscope, as shown in Figure 2, it can be seen that the nanowire-like structure formed on the surface. In addition, as magnified 20,000 times, as shown in FIG. 3, it was found that nanowires were formed.

Figure 1. Nanowire optical photograph (2,000 times) prepared through sea tangle extract

Figure 2. Nanowire optical photograph (1,000 times) prepared through the raisins extract

Figure 3. Magnified optical photograph of the nanowire structure of the fibrous form prepared through the raisins extract (20,000 times)

Claims (7)

a) milling or heating the natural plant to produce a natural plant extract; b) mixing, stirring and reacting the natural plant extract and the titanium dioxide precursor mixed solution; c) removing water after the reaction to obtain a powder; And d) calcining the powder to remove organic matter; Method for producing titanium dioxide having a nanowire structure having anatase structure and a rutile structure at the same time using a natural extract containing a. The method of claim 1, The natural plant is a method for producing titanium dioxide, any one or two or more selected from potatoes, bananas, lotus root, sesame leaves, cherry tomatoes, mushrooms, spinach, kelp, dried bananas, raisins, dried persimmons. The method of claim 1, The titanium dioxide precursor is a method for producing titanium dioxide is 0.1 to 0.5 mol of titanium alkoxide solution. The method of claim 3, Wherein said titanium alkoxide is selected from titanium isopropoxide, titanium methoxide, titanium butoxide, titanium ethoxide and titanium ethyl hexoxide. The method of claim 1, The firing is a method of producing titanium dioxide is carried out at 500 to 800 ℃. delete The method according to any one of claims 1 to 5, The nanowire structure is a method for producing titanium dioxide in the form of a fiber having a diameter of 10 ~ 30nm.

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