Nanostructured titania semiconductor material and its production process

Patent metadata

Field	Value
Publication number	US-10017397-B2
Application number	US-201715399052-A
Country	US
Kind code	B2
Filing date	Jan 5, 2017
Priority date	Jun 21, 2012
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A semiconductor material basically consists of titanium oxide, with the special feature of being like nanostructures, which gives special physicochemical properties, with ability to disperse and stabilize metal particles with high activity and selectivity in catalytic processes mainly. The process of producing the semiconductor material includes adding a titanium alkoxide to an alcoholic solution, adding an acid to the alcoholic solution, controlling the pH from 1 to 5; subjecting the acidic solution to agitation and reflux conditions at 70 to 80° C.; stabilizing the medium and adding bidistilled water in a water/alkoxide molar ratio of 1-2/0.100-0.150, continuing with reflux until gelation; aging the gel for 1 to 24 hours for complete formation of the titania; drying the titania nanostructured at of 50 to 80° C. for about 1 to 24 hours, and subjecting the dried titania to a calcination step at 200 to 600° C. for 1 to 12 hours.

First claim

The invention claimed is:

1. A process for producing a nanostructured titania semiconductor material comprising the steps of:
forming a titanium alkoxides solution at a pH or 1 to 5;
subjecting the solution to hydrolysis under reflux conditions and adding an amount of water to form a gel;
aging the gel;
drying the gel; and
calcining the aged gel to form said nanostructured titania semiconductor material having crystalline amorphous phases of anatase, brookite and rutile, in the following proportions:

Activation Temperature
Crystalline Amorphous phase (%)

(° C.)
Anatase
Brookite
Rutile

200-300
60-70
30-40

350-550
75-80
12-17
5-12.

2. The process for producing the nanostructured titania semiconductor material according to claim 1 , wherein the nanostructured titania semiconductor material shows the following crystal sizes for crystalline amorphous phase:

Activation Temperature
Crystalline Amorphous Phase (nm)

(° C.)
Anatase
Brookite
Rutile

200-300
 6-20
 6-20

350-550
20-23
12-17
31-37.

3. The process for producing the nanostructured titania semiconductor material TSG-IMP according to claim 1 having the following crystal dimension:

Crystal Dimension

Activation Temperature
(nm)

(° C.)
General

200-300
 6-12

350-550
 15-30.

4. The process for producing the nanostructured titania semiconductor material according to claim 1 having the following textural properties:

Activation
Surface Area
Average Pore

Temperature
(m 2 /g)
Diameter (Å)

(° C.)
General
General

200-300
180-250
30-50

350-550
 60-100
  70-110.

5. The process for producing the nanostructured titania semiconductor material according to claim 1 having the following band gap energy (Eg) values:

Band gap Energy

Activation
(Eg) (eV)

Temperature (° C.)
General

200-300
3.30-3.90

350-550
 3.00-3.20.

6. The process for producing the nanostructured titania semiconductor material according to claim 1 having the following hydroxylation degrees:

Activation Temperature
Hydroxylation

(° C.)
Degree*

300
5.67706-12.88881

500
1.50975-3.92518 

*Deconvolutions determined at 300° C.

7. The process of claim 1 , wherein said titanium alkoxides solution is an alcoholic solution.

8. The process of claim 1 , wherein said water is added to titanium alkoxide solution in a water/alkoxide molar ratio of 1-2/0.100-0.150.

9. The process of claim 1 , wherein said aging is under agitation and reflux conditions.

10. The p

Assignees

• Mexicano Inst Petrol

Inventors

• Castillo Cervantes Salvador
• Mejia Centeno Isidro
• Camposeco Solis Roberto
• Moran Pineda Florencia Marina
• Navarrete Bolanos Juan
• Montoya De La Fuente J Ascension
• Vargas Escudero Alfredo

Classifications

• B01J37/036

  to form a gel or a cogel · CPC title

• C01G23/08

  Drying; Calcining {; After treatment of titanium oxide} · CPC title

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2006/16

  Pore diameter · CPC title