Nanostructured titanium oxide material and its synthesis procedure

• US 8,658,126 B2
• Filed: 06/19/2012
• Issued: 02/25/2014
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Instituto Mexicano Del Petrã³Leo (Gobierno Federal De Los Estados Unidos Mexicanos)
• Original Assignee: Instituto Mexicano Del Petrã³Leo (Gobierno Federal De Los Estados Unidos Mexicanos)
• Inventors: Toledo Antonio, Jose Antonio, Angeles Chavez, Carlos, Alvarez Ramirez, Fernando, Ruiz Morales, Yosadara, Ferrat Torres, Gerardo, Flores Ortiz, Luis Francisco, Lopez Salinas, Esteban, Lozada y Cassou, Marcelo, Cortes Jacome, Maria Antonia
• Primary Examiner(s): Zimmer, Anthony J
• Application Number:
  US13/527,245
• Publication Number:
  US 20120301526A1
• Time in Patent Office: 616 Days
• Field of Search: 423/608, 423/609, 423/610, 423/611, 423/612, 423/613, 423/614, 423/598, 423/594.15, 423/644, 977/734, 977/762, 977/765, 977/811, 977/823
• US Class Current: 423/608
• 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 23/043 Titanium sub-oxides
• CPC Class Codes: C01G 23/047 Titanium dioxide
• CPC Class Codes: C01P 2002/76 by a space-group or by other symmetry indications
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• 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 2004/16 Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer
• CPC Class Codes: Y10S 977/811 Of specified metal oxide composition, e.g. conducting or semiconducting compositions such as ITO, ZnOx
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• 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

Nanomaterials of the JT phase of the titanium oxide TiO_2-x, where 0≦x≦1 having as a building block a crystalline structure with an orthorhombic symmetry and described by at least one of the space groups 59 Pmmn, 63 Amma, 71 Immm or 63 Bmmb. The nanomaterials are in the form of nanofibers, nanowires, nanorods, nanoscrolls and/or nanotubes and are obtained from a hydrogen titanate and/or a mixed sodium and hydrogen titanate precursor compound that is isostructural to the JT crystalline structure. The titanates are the hydrogenated, the protonated, the hydrated and/or the alkalinized phases of the JT crystalline phase that are obtained from titanium compounds such as titanium oxide with an anatase crystalline structure, amorphous titanium oxide, and titanium oxide with a rutile crystalline structure, and/or directly from the rutile mineral and/or from ilmenite.

Claims

1. Nanomaterial of hydrogen titanate and/or mixed sodium and hydrogen titanate, having the formula HTiO₂ and/or Na_xH_1-xTiO₂, wherein x is from 0 to less than 1, the hydrogen and sodium atoms are in the interlayer regions of the orthorhombic structure and said nanomaterial has a nanotubular morphology constituted of piled structural layers that are folded or rolled inwards into themselves, or formed by overlapped semitubes.

2. The nanomaterial of claim 1, wherein said nanomaterial has an orthorhombic structure, which is isostructural with TiO_2-x, where 0≦

x≦

1 and whose unit cell is described by at least one of the space groups 59 Pmmn, 63 Amma, 71 Immm or 63 Bmmb.

3. The nanomaterial of claim 1, wherein the cell parameters for the space groups of said orthorhombic crystalline lattice are, respectively:

a from 0.263 nm to 0.331 nm;

b from 0.332 nm to 0.448 nm, and c from 0.635 nm to 0.902 nm, for the space group 59 Pmmn, and a from 0.263 nm to 0.331 nm;

b from 0.332 nm to 0.448 nm, and c from 1.368 nm to 1.905, for the space groups 63 Amma, 71 Immm, and 63 Bmmb;

with α

=β

=90°

.

4. The nanomaterial of claim 1, wherein said nanomaterial has a disordered mesoporosity with an average pore diameter between 3 and 25 nm and a specific area between 100 and 600 m²/g.

5. The nanomaterial of claim 1, wherein said nanomaterial has a nanotubular morphology with dimensions of 3 to 50 nm in diameter and lengths from 0.1 to 100 μ

m.

6. The nanomaterial of claim 1, wherein said nanomaterial has a nanotubular morphology constituted by 1 to 50 structural layers with an inter-layer spacing in the range of 0.635 nm to 0.902 nm for the 59 Pmmn space group, and from 0.684 nm to 0.953 for the 63 Amma, 71 Immm, and 63 Bmmb space groups.

7. The nanomaterial of claim 1, wherein said nanomaterial is hydrogen titanate and a mixed sodium and hydrogen titanate in which the hydrogen and sodium atoms are in the interlayer regions of the orthorhombic structure.

8. The nanomaterial of claim 7, wherein said nanomaterial has an orthorhombic structure, which is isostructural with TiO_2-x where 0≦

x≦

1 and whose unit cell is described by at least one of the space groups 59 Pmmn, 63 Amma, 71 Immm or 63 Bmmb.

9. The nanomaterial of claim 1, wherein said nanomaterial has the X-ray diffraction pattern of FIG. 4 curve (b).

10. The nanomaterial of claim 1, wherein the nanomaterial has a nanotubular morphology with an internal diameter between 3 and 10 nm and a specific surface area between 380 and 470 m²/g and an average pore diameter between 5 and 8 nm.

11. A method for the production of nanotubes of hydrogen titanate and/or mixed sodium and hydrogen titanate comprising contacting a titanium oxide of the anatase phase, said anatase phase titanium dioxide having a crystal size between 5 and 10 nm with sodium hydroxide to form a suspension, subjecting said suspension to a synthesis procedure with reflux in a closed system with continuous stifling between 100-500 rpm under autogenous pressure at a temperature in the range of 80°

to 120°

C. to form a hydrogen titanate and/or a mixed sodium and hydrogen titanate with orthorhombic structure.

12. Nanotubes of hydrogen titanate and/or mixed sodium and hydrogen titanate, having the formula HTiO₂ and/or Na_xH_1-xTiO₂, wherein x is from 0 to less than 1 made according to the process of claim 11.