JP4716162B2 - Metal oxide nanotube and method for producing the same - Google Patents

Description

  The present invention relates to a metal oxide nanotube and a method for producing the same, and more particularly to an energy conversion material, an electronic material, a nonlinear optical material, a catalyst for various chemical reactions, an adsorbent and the like, and a method for producing the metal oxide nanotube. .

  “Nanotube” refers to particles having a hollow tubular shape having an outer diameter of several nm to several hundred nm and an inner diameter of several nanometers to several tens of nanometers. Nanotubes include single-walled nanotubes composed of one cylinder and multi-walled nanotubes in which a plurality of cylinders are concentrically overlapped at equal intervals. Although nanotubes exist in nature, carbon nanotubes, BN nanotubes, metal oxide nanotubes, and the like are known as artificially synthesized nanotubes. Among these, metal oxide nanotubes have a unique tube structure on the nanoscale. Therefore, various kinds of high-order functional materials that combine the characteristics of the nanosurface and internal nanospace and various physical properties of the material are various. Expected to have potential.

  Since various characteristics of the nanotube depend not only on the material but also on the structure, it is necessary to selectively synthesize nanotubes having a desired composition and structure in order to apply the nanotube to various uses. For this reason, various proposals have conventionally been made regarding nanotube synthesis methods. Among these, the following methods are known as methods for synthesizing nanotubes mainly composed of metal oxides.

For example, in Non-Patent Document 1,
(1) Stir an ethanol solution of vanadium triisopropoxide and hexadecylamine (surfactant) under an inert atmosphere for 1 hour,
(2) Next, the mixture was hydrolyzed with water with vigorous stirring, and then aged for several hours to one day to produce a curved layered composite composed of a surfactant and hydrolyzed vanadium oxide. ,
(3) Further, the layered composite is hydrothermally treated at 180 ° C. in an autoclave.
A method for producing vanadium oxide nanotubes is disclosed.
In this document, a nanotube having an apparent composition of VO _2.40 (C ₁₆ H ₃₃ NH ₂ ) _0.34 and a diameter of 15 to 100 nm can be obtained by such a method, and Further, it is described that the template (surfactant) could not be removed by calcination due to thermal instability of nanotubes at 250 ° C. or higher.

  Patent Document 1 discloses that a mixture of erbium nitrate, sodium dodecyl sulfate, urea and water (molar ratio 1: 2: 30: 60) is put in a heating vessel, and stirred at 40 ° C. for 1 hour, and further 80 A method for producing nanotubes to react at 100 ° C. for 100 hours is disclosed. This document describes that a tube-shaped composition containing a rare earth oxide as a main component, an outer diameter of 6 nm, an inner diameter of 3 nm, and containing a dodecyl sulfate group can be obtained by such a method.

  Further, Patent Document 2 discloses a method for producing crystalline titania, in which anatase-type titania powder is treated with sodium hydroxide having a concentration of 20 wt% (outer coating) at 110 ° C. for 20 hours in an airtight container. This document describes that titania nanotubes can be obtained by alkali treatment of titania powder under predetermined conditions.

E. Spahr et al., Angew. Chem. Int. Ed., 37, p1263-1265 (1998) JP 2003-246619 A Japanese Patent Laid-Open No. 10-152323

However, there has never been an example in which a nanotube made of Mn oxide or Fe oxide has been synthesized. Various conventionally known synthesis methods can be applied only to metal oxides having a specific composition, and are not applicable to metal oxides having any composition. Actually, according to the study by the inventors of the present application, nanotubes made of Mn and / or Fe oxides were not obtained by any of the methods described above.
Furthermore, the methods described in Non-Patent Document 1 and Patent Document 2 are expensive because hydrothermal treatment is required to synthesize nanotubes. Further, according to the method described in Patent Document 1, a nanotube that contains an organic sulfur acid group such as a dodecyl sulfate group as a subcomponent and is made of only a rare earth oxide cannot be obtained.

The problem to be solved by the present invention is to provide a metal oxide nanotube comprising an oxide of Fe and a method for producing the same. Another object of the present invention is to provide, such that use of hydrothermal treatment Ku, the method which can manufacture a metal oxide nanotube consisting oxides of Fe, i.e., using a soft chemical approach It is providing the manufacturing method of a metal oxide nanotube.

In order to solve the above problems, a metal oxide nanotube according to the present invention is made of an oxide of Fe, has a length of 100 nm to 500 nm, an outer diameter of 10 nm to 30 nm, and an inner diameter of 2 nm. The gist is that the thickness is less than 10 nm .
The method for producing metal oxide nanotubes according to the present invention includes a first step of forming a micelle by adding a block copolymer type surfactant to a non-aqueous solvent , and dissolving an Fe salt in the non-aqueous solvent. The second step of forming a layered organic / inorganic composite sheet by aging it at a temperature of 30 ° C. or higher and 60 ° C. or lower for 72 hours or more, and the organic / inorganic composite sheet at 100 ° C. or higher and 180 ° C. ℃ was heated for 1 hour or more at temperatures below, a third step of forming a nanotube precursor, wherein removing the detergent from the nanotube precursor, and a fourth step of obtaining a metallic oxide nanotubes according to the present invention The gist is to have.

When adding a salt of Fe to a non-aqueous solvent containing a surfactant and aging and heating it, conversion and growth from a layered organic / inorganic composite sheet to a nanotube precursor is achieved by optimizing the aging and heating conditions. Happens. Furthermore, if the surfactant is removed from the obtained nanotube precursor, metal oxide nanotubes made of Fe oxide can be obtained.

Hereinafter, an embodiment of the present invention will be described in detail. The metal oxide nanotube according to the present invention is made of an oxide of Mn and / or Fe.
The ratio of Mn and Fe contained in the metal oxide nanotube is not particularly limited, and can be arbitrarily selected from the composition of Mn oxide alone to the composition of Fe oxide alone.

The shape of the metal oxide nanotube can be controlled by optimizing the synthesis conditions described later.
Specifically, a metal oxide nanotube having a length of 100 nm to 500 nm can be obtained by optimizing the synthesis conditions.
Further, by optimizing the synthesis conditions, a metal oxide nanotube having an outer diameter of 10 nm to 30 nm can be obtained.
Further, by optimizing the synthesis conditions, metal oxide nanotubes having an inner diameter of 3 nm to 10 nm can be obtained.
Furthermore, by optimizing the synthesis conditions, metal oxide nanotubes having a multilayer structure with an interlayer between 1 nm and 2 nm can be obtained.

  Next, the manufacturing method of the metal oxide nanotube which concerns on this invention is demonstrated. The method for producing a metal oxide nanotube according to the present invention includes a first step, a second step, a third step, and a fourth step.

The first step is a step of forming a micelle by adding a block copolymer type surfactant to a non-aqueous solvent.
As the non-aqueous solvent, a surfactant which can be described later, and one capable of dissolving Mn salt and / or Fe salt is used. Further, since it is necessary to form micelles, the non-aqueous solvent needs to be a polar solvent. Furthermore, the non-aqueous solvent preferably has a water content of 1% by weight or less. This is because the reaction proceeds very slowly in the process of hydrolyzing the Mn salt and / or Fe salt and promoting crystallization.
The non-aqueous solvent may be a single solvent composed of only one kind of compound or a mixed solvent containing two or more kinds of compounds. Moreover, when using the mixed solvent which consists of 2 or more types of compounds as a non-aqueous solvent, all satisfy | fill the conditions mentioned above. As the non-aqueous solvent used for the synthesis, an optimum one is selected in consideration of handling properties, cost, types of other raw materials, and the like.

  Specific examples of non-aqueous solvents that can be used for the synthesis include alcohols such as methanol, ethanol, and propanol, mixed solvents of propanol and ethylene glycol, mixed solvents of ethanol and ethylene glycol, mixed solvents of methanol and ethylene glycol, There is a mixed solvent of 1-propanol and propylene glycol. In particular, propanol or a mixed solvent of propanol and ethylene glycol is particularly suitable as a non-aqueous solvent for synthesizing metal oxide nanotubes because crystallization can proceed slowly and a good material can be obtained.

  When the non-aqueous solvent is a mixed solvent composed of two or more compounds, the mixing ratio is selected in consideration of the type of non-aqueous solvent, the type of other raw materials, and the like. For example, when a mixed solvent of alcohol (for example, propanol) and diol (for example, ethylene glycol) is used as the non-aqueous solvent, the mixing ratio is preferably 1: 4 to 1: 0, more preferably , 1: 1 to 1: 0. When the mixing ratio is within this range, crystallization proceeds slowly and a good material is obtained.

  In the present invention, the “block copolymer type surfactant” is a surfactant having a hydrophilic group that is not ionized when dissolved in water (so-called “nonionic surfactant”), and includes ethylene oxide / What consists of block copolymers, such as a propylene oxide / ethylene oxide (EO-PO-EO) triblock copolymer, ethylene oxide / propylene oxide (EO-PO) diblock copolymer, ethylene oxide / butylene oxide (EO-BO), etc. Say. When a block copolymer type surfactant is used as a starting material, a lamellar structure indispensable for nanotube formation can be formed in the process of self-organization and aging.

In particular, the EO-PO-EO triblock copolymer represented by the following formula (1), the EO-PO diblock copolymer represented by the following formula (2), and the following formula (3) are represented. The EO-BO diblock copolymer is suitable as a surfactant used as a starting material.
(HO (CH ₂ CH ₂ O) _x (CH ₂ CH (CH ₃ ) O) _y (CH ₂ CH ₂ O) _x H (1)
(However, x = 20 to 150, y = 20 to 100)
(HO (CH ₂ CH ₂ O) _x (CH ₂ CH (CH ₃ ) O) _y H (2)
(However, x = 30-60, y = 20-150)
(HO (CH ₂ CH ₂ O) _x (CH ₂ CHCH (CH ₃ ) O) _y H (3)
(However, x = 30-60, y = 50-150)
Specifically, as the surfactant represented by the formulas (1) to (3),
HO (CH ₂ CH ₂ O) ₁₀₆ (CH ₂ CH (CH ₃ ) O) ₇₀ (CH ₂ CH ₂ O) ₁₀₆ H,
HO (CH ₂ CH ₂ O) ₂₀ (CH ₂ CH (CH ₃ ) O) ₇₀ (CH ₂ CH ₂ O) ₂₀ H,
HO (CH ₂ CH ₂ O) ₃₀ (CH ₂ CH (CH ₃ ) O) ₂₀ H,
and so on. These surfactants can be used in combination of two or more, but preferably each is used alone.

  The concentration of the surfactant added to the non-aqueous solvent may be at least the concentration at which micelles are formed (critical micelle concentration).

  A predetermined amount of surfactant is added to a predetermined non-aqueous solvent and mixed to form micelles. At this time, the temperature of the surfactant solution is preferably 10 ° C. or higher and 80 ° C. or lower. If the temperature of the solution is less than 10 ° C., the surfactant is difficult to dissolve, which is not preferable. On the other hand, if the temperature of the solution exceeds 80 ° C., the solvent tends to volatilize, which is not preferable. The temperature of the solution is more preferably about room temperature to 35 ° C.

In the second step, a salt of Mn and / or Fe is dissolved in a non-aqueous solvent containing a block copolymer type surfactant, and this is maintained at a temperature of 30 ° C. to 60 ° C. for 72 hours (3 days) or more. And aging to form a layered organic / inorganic composite sheet.
Here, the “organic / inorganic composite sheet” has a lamellar structure in which the surfactant molecules are stacked in layers so that the hydrophilic groups and the hydrophobic groups of the surfactant are associated with each other, and A sheet-like composite in which a layered metal oxide precursor formed by hydrolysis of a metal salt is inserted between associated hydrophilic groups.
Further, the “metal oxide precursor” refers to a metal salt in which all or part of the anion of the metal salt is replaced with a hydroxyl group, or all or part of the hydroxyl group is condensed.

The type of Mn and / or Fe salt is not particularly limited, but nitrate is particularly preferred. In addition, each of the Mn salt and the Fe salt may be used alone or in combination. When both are used in combination, a nanotube composed of a composite oxide containing both Mn and Fe can be obtained. In this case, the ratio of the Mn salt and the Fe salt is not particularly limited, and can be mixed at an arbitrary ratio.
The optimum addition amount of the salt to the non-aqueous solvent varies depending on the type of the surfactant and the type of the metal salt, but in general, 1: 1 to 20 is preferable as the weight ratio of the surfactant to the metal salt. 2-10 are particularly preferred.

When a sol obtained by adding a salt to a non-aqueous solvent containing a surfactant is allowed to stand at a predetermined temperature and aged, a metal salt or a metal oxide precursor is collected between the hydrophilic groups of the surfactant, and organic / An inorganic composite gel is formed. When this is further ripened, the hydrolysis of the metal salt or metal oxide precursor further proceeds to form a layered organic / inorganic composite sheet.
In this case, the water required for hydrolysis is supplied from the metal salt used, the trace amount of water contained in the non-aqueous solvent used, and the like. In addition, when an anhydrous salt is used, water corresponding to the hydrated salt may be added.

The aging temperature is preferably 30 ° C. or higher and 60 ° C. or lower. If the aging temperature is less than 30 ° C., hydrolysis tends not to be sufficiently promoted. On the other hand, when the aging temperature exceeds 60 ° C., a layered organic / inorganic composite sheet that is a precursor of the nanotube structure cannot be obtained. The aging temperature is more preferably 45 ° C. ± 5 ° C.
The aging time is preferably 72 hours (3 days) or longer. If the aging time is less than 72 hours, hydrolysis tends not to be sufficiently promoted. The aging time is more preferably 168 hours (7 days) or longer. On the other hand, when it is aged for a predetermined time, the hydrolysis reaches saturation. Therefore, the aging time is preferably 336 hours (14 days) or less.

The third step is a step of heating the organic / inorganic composite sheet at a temperature of 100 ° C. or higher and 180 ° C. or lower for 1 hour or longer to form a nanotube precursor.
Here, the “nanotube precursor” is a nanotube-like structure formed by rolling an organic / inorganic composite sheet, and an organic substance (surfactant) is taken into the nanotube made of an inorganic material. It is what is in the state.

  The heating temperature is preferably 100 ° C. or higher and 180 ° C. or lower. When the heating temperature is less than 100 ° C., when the organic / inorganic composite sheet rolls to become a nanotube precursor, the bond between the metal oxides at the meeting point of the sheet end tends not to be sufficiently promoted. On the other hand, when the heating temperature exceeds 180 ° C., the nanotube structure tends to be broken. The heating temperature is more preferably 120 ° C. or higher and 160 ° C. or lower.

  The heating time is preferably 1 hour or longer. When the heating time is less than 1 hour, the bond between the metal oxides tends not to be sufficiently promoted. The heating time is more preferably 2 hours or more. On the other hand, when the heating is performed for a predetermined time, the bonding reaction between the metal oxides reaches saturation, so that heating more than necessary is not very beneficial. Therefore, the heating time is preferably 10 hours or less, more preferably 5 hours or less.

Moreover, the one where the temperature increase rate to heating temperature is slow is preferable. In general, the higher the rate of temperature rise, the more easily the nanotube structure tends to break. Specifically, the heating rate is preferably 2 ° C./min or less, more preferably 1 ° C./min or less.
Furthermore, the heating atmosphere during rolling is not particularly limited, and may be in an oxidizing atmosphere (for example, in the air) or in an inert atmosphere. In particular, when heating is performed in an oxidizing atmosphere, there is an advantage that the oxidation of the metal oxide precursor further proceeds and at the same time a part of the surfactant can be removed by combustion.

The fourth step is a step of obtaining a metal oxide nanotube by removing the surfactant from the nanotube precursor.
As a method of removing the surfactant from the nanotube precursor,
(1) A method of immersing a nanotube precursor in a solvent having high solubility in a surfactant (for example, ethanol, propanol, water, etc.) to dissolve the surfactant,
(2) A method in which a nanotube precursor is baked at 400 ° C. to 700 ° C. for 4 to 6 hours in the air or in an inert gas to burn and decompose the surfactant,
(3) these combinations,
and so on.
By such a process, pores are formed at the site where the surfactant was present in the nanotube precursor, and a tubular porous body (that is, a nanotube) is obtained.

Next, the operation of the metal oxide nanotube according to the present invention and the manufacturing method thereof will be described. When aging and heating an organic / inorganic composite sheet using a Mn and / or Fe oxide as a skeleton component and a block copolymer type surfactant as a template, and aging and heating under certain conditions The organic / inorganic composite sheet can be changed to a nanotube precursor during heating.
Although the details of the mechanism of conversion growth from the layered organic / inorganic composite sheet to the nanotube precursor are not clear, the inventors of the present application have described synthesis conditions (especially the aging step (second step) and the heating step (third step)). )) And temperature) are critical factors determining the structure of the complex. The production mechanism of the estimated metal oxide nanotube is as follows.

FIG. 1 shows a schematic diagram of material changes that occur during the synthesis reaction. The block copolymer type surfactant functions as a “template” when the metal oxide nanotubes are synthesized. When a predetermined amount of such a surfactant is dissolved in a non-aqueous solvent, surfactant micelles are formed in the non-aqueous solvent.
Next, when a metal salt is added to a non-aqueous solvent in which a surfactant is dissolved and stirred, a sol is generated. When this is left under a predetermined temperature, a metal salt or a metal oxide precursor generated by hydrolysis of the metal salt collects in the hydrophilic group of the surfactant (self-organization). As a result, a gel (lamella structure) of an organic / inorganic composite in which surfactant molecules are regularly stacked in layers and metal salts or metal oxide precursors are aggregated between associated hydrophilic groups is obtained.

  When such an organic / inorganic composite gel is aged, as shown in the following formula 1, a metal salt (for example, nitrate) between hydrophilic groups is slightly contained by water slightly contained in the non-aqueous solvent. The hydrolysis proceeds slowly, or the condensation reaction of the metal oxide precursor further proceeds. As a result, an organic / inorganic composite sheet (lamella structure) in which the surfactant molecules are regularly stacked in layers and the layered metal oxide precursor is inserted between the associated hydrophilic groups is obtained.

  Next, when the obtained layered organic / inorganic composite sheet is heated under predetermined conditions, in addition to rolling of the organic / inorganic composite sheet, both ends of the sheet are bonded to obtain a nanotube precursor. . In addition, the nonaqueous solvent contained in the organic / inorganic composite sheet is almost completely removed by heating, and at the same time, the condensation reaction further proceeds and the metal oxide precursor becomes a metal oxide. Furthermore, the metal oxide nanotube according to the present invention can be obtained by removing the surfactant from the nanotube precursor.

  When the method according to the present invention is used, a metal oxide nanotube composed of Mn oxide and / or Fe oxide which cannot be obtained by a conventional method can be synthesized. In addition, the method according to the present invention is a simple method (soft chemical method) and does not require the use of hydrothermal treatment, so that it is possible to synthesize metal oxide nanotubes at a lower cost than conventional methods. .

(Reference Example 1)
1 g of a block copolymer type surfactant (HO (CH ₂ CH ₂ O) ₁₀₆ (CH ₂ CH (CH ₃ ) O) ₇₀ (CH ₂ CH ₂ O) ₁₀₆ H, “F-127” manufactured by Aldrich) The surfactant was dissolved in a mixed solvent of 5 g of propanol + 5 g of ethylene glycol and stirred. To this solution, 0.01 mol of manganese (II) nitrate hexahydrate (Mn (NO ₃ ) ₂ .6H ₂ O) was added and stirred vigorously for 1 hour.
The obtained sol was aged at 45 ° C. for 7 days, and then heated under conditions of a heating rate of 1 ° C./min and 150 ° C. × 4 hours to obtain a precursor. After cooling the obtained precursor to room temperature, this was immersed in ethanol and F-127 was extracted from the precursor. Further, this was fired in air at 400 ° C. for 4 hours to obtain a powder made of manganese oxide.

FIG. 2 shows a transmission electron micrograph of the obtained manganese oxide powder. From FIG. 2, manganese oxide obtained in the present reference example, that see that exhibits a hollow nanotube structure. The outer diameter of the manganese oxide nanotubes obtained in this reference example was 15.2 nm, and the average tube length was 250 nm.
2 shows that the tip of the nanotube is open (scale: 15 nm). Also, in the inset 2 in FIG. 2, a straight channel (pore in the tube) can be observed inside each of the two nanotubes (scale: 20 nm). Further, in the inset 3 of FIG. 2, fringes are observed on the nanotube walls. From this, it can be seen that the nanotubes obtained in this reference example have a multilayer tube structure with an interlayer of 1 to 2 nm.

FIG. 3 shows nitrogen adsorption isotherms of manganese oxide nanotubes. The inset in FIG. 3 shows a pore distribution curve obtained from this adsorption isotherm by the SJK method. FIG. 3 shows that the pore center diameter of the manganese oxide nanotube is 7.0 nm.
FIG. 4 shows an X-ray diffraction pattern of the manganese oxide nanotube. FIG. 4 shows that a sharp peak corresponding to the _d001 diffraction line of the tube structure is observed. The d value was 15.2 nm, which almost coincided with the outer diameter of the nanotube measured from the electron micrograph. Further, it was found from wide-angle X-ray diffraction that manganese oxide is composed of MnO.

(Example 2)
1 g of F-127 block copolymer type surfactant was added to 10 g of propanol and stirred to dissolve the surfactant. The solution of iron nitrate (III) 9 hydrate _{(Fe (NO 3) 3 ·} 9H 2 O) was added to 0.01 mol, stirred vigorously for 1 h.
The obtained sol was aged at 50 ° C. for 10 days, and then heated under conditions of a heating rate of 1 ° C./min and 120 ° C. × 4 hours to obtain a precursor. After cooling the obtained precursor to room temperature, this was immersed in ethanol and F-127 was extracted from the precursor, and the powder which consists of iron oxides was obtained.

FIG. 5 shows a transmission electron micrograph of the obtained iron oxide powder. FIG. 5 shows that the iron oxide obtained in the present example has a hollow tube structure. The outer diameter of the iron oxide nanotubes obtained in this example was 17.0 nm, and the average tube length was 200 nm.
Moreover, although not shown in figure, from the nitrogen adsorption isotherm of an iron oxide nanotube and the pore distribution curve calculated | required by this from the SJK method, it turned out that the pore center diameter of an iron oxide nanotube is 7.0 nm.
FIG. 6 shows an X-ray diffraction pattern of the iron oxide nanotube. FIG. 6 shows that a sharp peak corresponding to the _d001 diffraction line of the tube structure is observed. The d value was 17.0 nm, which almost coincided with the outer diameter of the tube measured from the electron micrograph. Furthermore, it was found from wide-angle X-ray diffraction that iron oxide is composed of Fe ₂ O ₃ .

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

The metal oxide nanotubes according to the present invention can be used for energy conversion materials, electronic materials, nonlinear optical materials, catalysts for various chemical reactions, adsorbents, and the like.
The metal oxide nanotubes according to the present invention can be used for VOC removal materials, FC electrode materials, cold start exhaust purification catalysts, solid electrolytes, thermoelectric materials, and the like.

It is a schematic diagram which shows the change of the material at the time of manufacture of a metal oxide nanotube. 2 is a transmission electron micrograph of a manganese oxide nanotube obtained in Reference Example 1 . Inset 1 is an enlarged view near the tip, Inset 2 is an enlarged view showing a channel in the tube, and Inset 3 is a high-resolution photograph showing that the tube has a multilayer structure. It is. 2 is an adsorption isotherm of nitrogen of the manganese oxide nanotubes obtained in Reference Example 1 . The inset is a pore distribution curve obtained from this adsorption isotherm by the SJK method. 2 is an X-ray diffraction pattern of a manganese oxide nanotube obtained in Reference Example 1. FIG. 2 is a transmission electron micrograph of iron oxide nanotubes obtained in Example 2. FIG. 2 is an X-ray diffraction pattern of iron oxide nanotubes obtained in Example 2. FIG.

Claims (7)

Ri Do from the oxide of F e,
The length is 100 nm or more and 500 nm or less,
The outer diameter is 10 nm or more and 30 nm or less,
A metal oxide nanotube having an inner diameter of 2 nm or more and less than 10 nm . Metal oxide nanotube according to claim 1 layers that have a multilayer structure is 1 to 2 nm. A first step of forming a micelle by adding a block copolymer type surfactant to a non-aqueous solvent;
A second step of dissolving a salt of Fe in the non-aqueous solvent and aging it at a temperature of 30 ° C. or higher and 60 ° C. or lower for 72 hours or more to form a layered organic / inorganic composite sheet;
A third step of heating the organic / inorganic composite sheet at a temperature of 100 ° C. or higher and 180 ° C. or lower for 1 hour or longer to form a nanotube precursor;
The surfactant was removed from the nanotube precursor, a fourth step in the method of manufacturing the metal oxide nanotubes having a obtaining metallic oxide nanotube according to claim 1 or 2. The non-aqueous solvent, the production method of the metal oxide nanotube according to moisture content less than 1% by weight of a polar solvent der Ru claim 3. The non-aqueous solvent, Ru methanol, ethanol, propanol, a mixed solvent of propanol and ethylene glycol, a mixed solvent of ethanol and ethylene glycol, a mixed solvent of methanol and ethylene glycol, or a mixed solvent der of 1-propanol and propylene glycol The manufacturing method of the metal oxide nanotube of Claim 3 or 4 . The surfactant, manufacturing method of the metal oxide nanotube according to any one of claims 3 Ru der least one to 5 represented by the following (1) to (3).
(HO (CH ₂ CH ₂ O) _x (CH ₂ CH (CH ₃ ) O) _y (CH ₂ CH ₂ O) _x H (1)
(However, x = 20 to 150, y = 20 to 100)
(HO (CH ₂ CH ₂ O) _x (CH ₂ CH (CH ₃ ) O) _y H (2)
(However, x = 30-60, y = 20-150)
(HO (CH ₂ CH ₂ O) _x (CH ₂ CHCH (CH ₃ ) O) _y H (3)
(However, x = 30-60, y = 50-150) The salts, method for producing a metal oxide nanotube according to any of nitrates Der Ru claim 3 to 6.

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