TITANIUM OXIDE NANO TUBE MATERIAL AND METHOD FOR MANUFACTURING THE SAME

• US 20120171112A1
• Filed: 08/04/2011
• Published: 07/05/2012
• Est. Priority Date: 12/29/2010
• Status: Active Grant

• Current Assignee: SNU R&DB Foundation (Seoul National University)
• Original Assignee: SNU R&DB Foundation (Seoul National University)
• Inventors: Lee, Sang-Wook, Hong, Kug-Sun, Jung, Hyun-Suk, Park, Ik-Jae, Kim, Dong-Hoe, Han, Gil-Sang
• Granted Patent: US 8,613,901 B2
• Time in Patent Office: Days
• US Class Current: 423/608
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01G 23/047 Titanium dioxide
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/13 Nanotubes
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/82 water content
• CPC Class Codes: C30B 29/16 Oxides
• CPC Class Codes: C30B 29/602 Nanotubes
• CPC Class Codes: C30B 7/12 by electrolysis
• CPC Class Codes: Y02E 10/542 Dye sensitized solar cells

Abstract

A titanium oxide nano tube material is configured so that crystal grains of a nano tube has a crystal structure oriented with the [001] direction of a tetragonal crystal system as a preferred direction. FWHM (Full Width at Half Maximum) of a rocking curve with respect to the (004) plane peak is 11.1 degrees to 20.3 degrees. The titanium oxide nano tube material has excellent photoelectric characteristics since the crystal grains of the nano tube are oriented with the (004) plane or the [001] direction of a tetragonal crystal system as a preferred direction.

Claims

1. A titanium oxide nano tube material, characterized in that crystal grains of a nano tube has a crystal structure oriented with the [001] direction of a tetragonal crystal system as a preferred direction,

wherein FWHM (Full Width at Half Maximum) of a rocking curve with respect to the (004) plane peak is 11.1 degrees to 20.3 degrees.

2. The titanium oxide nano tube material according to claim 1, wherein the FWHM of the rocking curve is 11.1 degrees to 16.5 degrees.

3. The titanium oxide nano tube material according to claim 1, wherein a I₍₀₀₄₎/I₍₂₀₀₎ value of the titanium oxide nano tube material, which is a relative ratio of peak intensities of (004) plane and (200) plane of XRD (X-ray Diffraction) data, is 5 or above.

4. The titanium oxide nano tube material according to claim 1, wherein the titanium oxide nano tube material includes nano tube arrays of anatase titanium oxide vertically grown by anodizing on a titanium substrate.

5. The titanium oxide nano tube material according to claim 1, wherein an electron diffusion length of an electron carrier of the titanium oxide nano tube material is 20 μ

m to 50 μ

m.

13. A photoelectric conversion device comprising the titanium oxide nano tube material defined in claim 1 as an electrode material.

14. A product comprising the titanium oxide nano tube material defined in claim 1.

6. A method for manufacturing a titanium oxide nano tube material, comprising:

(a) preparing an electrolyte with a moisture content of 1.5 to 2.5 wt %;

(b) growing a titanium oxide nano tube on a titanium substrate by anodizing in a state in which the titanium substrate is immersed in a container containing the electrolyte;

(c) cleaning and drying the titanium substrate on which the titanium oxide nano tube is grown; and

(d) annealing the dried titanium substrate to crystallize the grown titanium oxide nano tube so that crystal grains of the titanium oxide nano tube are oriented with the [001] direction of a tetragonal crystal system as a preferred direction.

7. The method for manufacturing a titanium oxide nano tube material according to claim 6, wherein the moisture content in the electrolyte is controlled in the range from 2.0 to 2.4 wt %.

8. The method for manufacturing a titanium oxide nano tube material according to claim 6, wherein said preparing the electrolyte includes:

removing residual moisture from the electrolyte; and

adding 1.5 to 2.5 wt % of moisture to the electrolyte free from the residual moisture.

9. The method for manufacturing a titanium oxide nano tube material according to claim 8, wherein the residual moisture in the electrolyte is removed by evaporation.

10. The method for manufacturing a titanium oxide nano tube material according to claim 6, wherein the titanium oxide nano tube is grown under an inert gas circumstance.

11. The method for manufacturing a titanium oxide nano tube material according to claim 10, wherein the inert gas circumstance is a nitrogen gas circumstance.

12. The method for manufacturing a titanium oxide nano tube material according to claim 6, wherein said annealing the titanium substrate is performed in a temperature range from 300°

C. to 600°

C. for 10 minutes or more.