Titanium oxide structure and porous titanium oxide composition

• US 9,409,790 B2
• Filed: 06/19/2009
• Issued: 08/09/2016
• Est. Priority Date: 06/20/2008
• Status: Expired due to Fees

• Current Assignee: Osaka Gas Company Limited
• Original Assignee: Osaka Gas Company Limited
• Inventors: Nishino, Hitoshi, Nishida, Ryoichi, Matsuyoshi, Hiroaki, Sakamoto, Hiroki, Tomita, Haruo, Hayama, Hidekazu, Tabuchi, Minoru, Ichimura, Nobuko, Deguchi, Tomoe
• Primary Examiner(s): MERSHON, JAYNE L
• Application Number:
  US12/996,546
• Publication Number:
  US 20110079276A1
• Time in Patent Office: 2,608 Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01G 23/04 Oxides; Hydroxides
• CPC Class Codes: C01G 23/047 Titanium dioxide
• CPC Class Codes: C01G 23/053 Producing by wet processes, e.g. hydrolysing titanium salts
• 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 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/14 Pore volume
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01G 9/2031 comprising titanium oxide, e.g. TiO2 H01G9/2036 takes precedence
• CPC Class Codes: H01G 9/2059 comprising an organic dye as the active light absorbing material, e.g. adsorbed on an electrode or dissolved in solution
• CPC Class Codes: Y02E 10/542 Dye sensitized solar cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/2927 including structurally defined particulate matter
• CPC Class Codes: Y10T 428/2975 Tubular or cellular
• CPC Class Codes: Y10T 428/298 Physical dimension
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

With a view to realizing a titanium oxide structure that has a large surface area and enables efficient transfer of ions and electrons by virtue of titanium oxide particles connected to one another, an object of the invention is to develop a material useful as an active material for dye-sensitized solar cells, and a process for producing the material; a porous titanium oxide composition and a process for producing the composition; and a photoelectric conversion element comprising the titanium oxide structure or porous titanium oxide composition.

Claims

1. A photoelectric conversion element comprising a dye deposited on a surface of an active material, the active material comprising a titanium oxide structure being rod-shaped, tubular, or fibrous, wherein

the structure comprised titanium oxide particles (1a),

the titanium oxide particles (1a) comprise anatase titanium oxide,

each titanium oxide particle of the titanium oxide particles (1a) are in close contact to each other, and

fine irregularities are present on a surface of the structure.

2. The photoelectric conversion element according to claim 1, wherein the titanium oxide particles (1a) have a mean particle size of 1 to 200 nm.

3. The photoelectric conversion element according to claim 1, wherein the titanium oxide structure has a mean diameter of 5 to 500 nm perpendicular to a long axis, a mean long-axis length of 0.1 to 1,000 and a mean aspect ratio of 3 to 200,000.

4. The photoelectric conversion element according to claim 1, wherein the titanium oxide structure has a powder resistance of 3×

10⁶ Ω

·

m or less at a pressure of 10 MPa.

5. The photoelectric conversion element according to claim 1, wherein the titanium oxide structure is tubular.

6. The photoelectric conversion element according to claim 5, wherein the titanium oxide structure has a thickness of 2 to 500 nm.

7. The photoelectric conversion element according to claim 1, wherein the titanium oxide particles (1a) further comprise at least one member selected from the group consisting of oxide of titanium (II) and oxide of titanium (III).

8. The photoelectric conversion element according to claim 1, wherein the titanium oxide particles (1a) comprise a titanium oxide having a crystalline form of a Magneli-phase structure.

9. The photoelectric conversion element according to claim 1, wherein the titanium oxide structure has a specific surface area of 20 m²/g or more.

10. The photoelectric conversion element according to claim 1, wherein fine irregularities are present on an entire surface of the structure.

11. The photoelectric conversion element according to claim 1, wherein the titanium oxide particles (1a) further comprise rutile titanium oxide, brookite titanium oxide or both.

12. The photoelectric conversion element according to claim 1, wherein the titanium oxide structure has a specific surface area of 80 m²/g to 3,000 m²/g.

13. The photoelectric conversion element according to claim 1, wherein the titanium oxide particles (1a) are in close contact to each other over the entire length of the rod-shaped, tubular or fibrous titanium oxide structure.

14. A process for producing a photoelectric conversion element comprising the steps of:

depositing a dye on a surface of an active material, the active material comprising the titanium oxide structure of claim 1;

wherein forming the titanium oxide structure comprises the steps of;

(A) forming a covering layer comprising titanium oxide particles (1a) connected to one another on a surface of a rod-shaped or fibrous nanoscale carbon by performing a precipitation reaction from a fluorotitanate complex, thereby preparing nanoscale carbon covered with titanium oxide; and

(B) removing the nanoscale carbon present in the nanoscale carbon covered with titanium oxide.

15. The process for producing the photoelectric conversion element according to claim 14, wherein 70 to 100% of the surface of the nanoscale carbon is covered with the titanium oxide particles, as measured by electron microscopic observation.