Incorporating Metals, Metal Oxides and Compounds on the Inner and Outer Surfaces of Nanotubes and Between the Walls of the Nanotubes and Preparation Thereof

• US 20150050494A1
• Filed: 03/19/2013
• Published: 02/19/2015
• Est. Priority Date: 03/19/2012
• Status: Active Grant

• Current Assignee: Hong Kong University of Science and Technology
• Original Assignee: Hong Kong University of Science and Technology
• Inventors: Yeung, King Lun, Ferdousi, Shammi Akter, Han, Wei
• Granted Patent: US 10,238,762 B2
• Time in Patent Office: Days
• US Class Current: 428/376
• CPC Class Codes: A61L 2/238 Metals or alloys, e.g. oligodynamic metals
• CPC Class Codes: B01D 15/22 relating to the construction of the column
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/06 of zinc, cadmium or mercury
• CPC Class Codes: B01J 23/22 Vanadium
• CPC Class Codes: B01J 23/42 Platinum
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 23/50 Silver
• CPC Class Codes: B01J 23/52 Gold
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 23/75 Cobalt
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/615 100-500 m2/g
• CPC Class Codes: B01J 37/0201 Impregnation
• CPC Class Codes: B01J 37/06 Washing B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: B01J 37/10 in the presence of water, e.g. steam
• CPC Class Codes: B01J 37/346 : of microwave energy
• 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: B82Y 99/00 : Subject matter not provided for in other groups of this subclass
• CPC Class Codes: C01G 23/005 : Alkali titanates
• CPC Class Codes: C01G 23/053 : Producing by wet processes, e.g. hydrolysing titanium salts
• CPC Class Codes: C01P 2002/82 : by IR- or Raman-data
• CPC Class Codes: C01P 2002/84 : by UV- or VIS- data
• CPC Class Codes: C01P 2002/85 : by XPS, EDX or EDAX data
• 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: C01P 2004/20 : extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/51 : Particles with a specific particle size distribution
• CPC Class Codes: C01P 2004/53 : bimodal size distribution
• CPC Class Codes: C01P 2006/12 : Surface area
• CPC Class Codes: C30B 29/02 : Elements
• CPC Class Codes: C30B 29/602 : Nanotubes
• CPC Class Codes: C30B 7/10 : by application of pressure, e.g. hydrothermal processes
• CPC Class Codes: Y10S 977/734 : Fullerenes, i.e. graphene-based structures, such as nanohorns, nanococoons, nanoscrolls or fullerene-like structures, e.g. WS2 or MoS2 chalcogenide nanotubes, planar C3N4, etc.
• CPC Class Codes: Y10S 977/811 : Of specified metal oxide composition, e.g. conducting or semiconducting compositions such as ITO, ZnOx
• CPC Class Codes: Y10S 977/845 : Purification or separation of fullerenes or nanotubes
• CPC Class Codes: Y10S 977/846 : internal modifications, e.g. filling, endohedral modifications
• CPC Class Codes: Y10S 977/847 : Surface modifications, e.g. functionalization, coating
• CPC Class Codes: Y10S 977/902 : Specified use of nanostructure
• CPC Class Codes: Y10T 428/2935 : Discontinuous or tubular or cellular core

Abstract

A multi-walled titanium-based nanotube array containing metal or non-metal dopants is formed, in which the dopants are in the form of ions, compounds, clusters and particles located on at least one of a surface, inter-wall space and core of the nanotube. The structure can include multiple dopants, in the form of metal or non-metal ions, compounds, clusters or particles. The dopants can be located on one or more of on the surface of the nanotube, the inter-wall space (interlayer) of the nanotube and the core of the nanotube. The nanotubes may be formed by providing a titanium precursor, converting the titanium precursor into titanium-based layered materials to form titanium-based nanosheets, and transforming the titanium-based nanosheets to multi-walled titanium-based nanotubes.

Claims

1. A multi-walled titanium-based nanotube array containing one or more metal or non-metal dopants wherein said dopants comprise ions, compounds, clusters and particles located on at least one of a surface, inter-wall space and core of the nanotube.

2. The multi-walled titanium-based nanotube array as described in claim 1, further comprising:

at least first and second dopants, in the form of metal or non-metal ions, compounds, clusters or particles, wherein the first and second dopants have a configuration selected from the group consisting of;

the first dopant located on the surface and the second dopant located in the inter-wall space (interlayer) of the nanotube;

the first dopant located on the surface and the second dopant located in the core of the nanotube; and

the first dopant located on the core and the second dopant located on the inter-wall space (interlayer) of the nanotube.

3. The multi-walled titanium-based nanotube array as described in claim 1, further comprising:

a third dopant in the form of metal or non-metal ions, compounds, clusters or particles, wherein the first, second and third dopants have a configuration of the first dopant located on the surface, the second dopant located in the inter-wall space and the third dopant located in the core of the nanotube.

4. The multi-walled titanium-based nanotube array as described in claim 1, further comprising:

the dopants comprise inorganic dopant materials selected from the group consisting of Group IB, IIB, IVB, V and VIII elements, or

the dopants comprise materials selected from the group consisting of V, Co, Cu, Zn, Pd, Ag, Pt and Au are used as metal or nonmetal dopants, or.

the dopants comprise a non-metallic organic compound.

5. The multi-walled titanium-based nanotube array as described in claim 1 wherein the dopants comprise a non-metallic dye.

6. The multi-walled titanium-based nanotube array as described in claim 5 wherein said dye comprises at least one material selected from the group consisting of acid Blue, methyl orange, acid yellow, copper phthalocyanine-3,4′

,4″

,4′

″

-tetrasulfonic acid tetrasodium salt and reactive Black 5.

7. A method of preparation of multi-walled titanium-based nanotubes containing a metal and/or non-metal dopants located on a core of the nanotube, the method comprising:

providing a titanium precursor;

converting the titanium precursor into titanium-based layered materials to form titanium-based nanosheets; and

transforming the titanium-based nanosheets to multi-walled titanium-based nanotubes.

8. The method as described in claim 7, further comprising:

in an ex situ process, forming titanium nanostructure from the titanium precursor by using microwave (MW) assisted alkaline hydrothermal synthesis by preparing a homogeneous mixture of titanium followed by microwave hydrothermal irradiation to produce titanate nanosheets in an intermediate stage;

mixing a transition metal in an aqueous acid solution or water, resulting in a transformation mechanism; and

doping the formed titanium nanostructures using a microwave hydrothermal irradiation process.

9. The method as described in claim 7, further comprising:

converting the titanium precursor into titanium-based nanosheets by hydrothermal or solvothermal treatment in a solution containing an inorganic of 2 M to 15 M or organic base of 2 M to 5 M,

wherein said inorganic and organic base comprises a material selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), and tetrapropylammonium hydroxide (TPAOH); and

applying continuous or pulsating microwave irradiation during said converting.

10. The method as described in claim 9, further comprising providing the titanium precursor for the dopant for rinsing at a concentration of the titanium precursor of 10 mM to 100 mM.

11. The method as described in claim 7, further comprising:

for transforming the negatively-charged titanium-based nanosheets into multi-walled titanium-based nanotubes containing metal and/or non-metal dopants by single, sequential or combination by;

a. rinsing the titanium-based nanosheets in a solution of a concentrated anionic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants on the surface;

b. rinsing the titanium-based nanosheets in a solution of a cationic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants in the inter-wall spaces (interlayer);

c. rinsing the titanium-based nanosheets in a solution of the dilute anionic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants in the core,

or by

a. rinsing with water or acid solution to obtain multi-walled titanium-based nanotubes containing metal and/or nonmetal dopants;

b. rinsing with a concentrated anionic solution of a precursor for a dopant to introduce additional dopant on surface;

c. rinsing with a cationic solution of a precursor for a dopant to introduce additional dopant in the inter-wall space (interlayer);

d. rinsing with a dilute anionic solution of a precursor for a dopant to introduce additional dopant in the core; and

for transforming the positively-charged titanium-based nanosheets into multi-walled titanium-based nanotubes containing a metal and/or non-metal dopants by single, sequential or combination;

a. rinsing the titanium-based nanosheets in a solution of the concentrated cationic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants on the surface;

b. rinsing the titanium-based nanosheets in a solution of the anionic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants in the inter-wall spaces (i.e., interlayer);

c. rinsing the titanium-based nanosheets in a solution of the dilute cationic precursor for the dopant to obtain multi-walled titanium-based nanotubes with dopants in the core,

or by

a. rinsing with water or acid solution to obtain multi-walled titanium-based nanotubes containing metal and/or nonmetal dopants;

b. rinsing with a concentrated cationic solution of a precursor for a dopant to introduce additional dopant on surface;

c. rinsing with a anionic solution of a precursor for a dopant to introduce additional dopant in the inter-wall space (interlayer);

d. rinsing with a dilute cationic solution of a precursor for a dopant to introduce additional dopant in the core.

12. The method as described in claim 7, wherein said titanium precursor comprises a material selected from the group consisting of titanium, titanium chloride, titanium alkoxides, titanium oxides in the form of solutions and powder, anatase, rutile and mix phase), titanium nitride, titanium carbide and titanium-containing ceramics and composites.

13. The method as described in claim 7, further comprising selecting, as a dopant for the doping of the formed titanium nanostructures, a transition metal.

14. A method as described in claim 7, further comprising selecting, as a dopant for the doping of the formed titanium nanostructures, a material selected from the group consisting of Au, Ag, Pt, Pd, Co, Cu, V, Zn.

15. A method as described in claim 7, further comprising selecting, as a dopant for the doping of the formed titanium nanostructures, a material selected from the group consisting of Au³⁺, Ag⁺, Pt²⁺, Pd²⁺, Co²⁺, Cu²⁺, V⁵⁺, Zn²⁺.

16. The method as described in claim 7, further comprising heat treating multi-walled titanium-based nanotubes containing dopants in inter-wall space (interlayer) at 50°

C. to 400°

C.

17. The method as described in claim 7, further comprising applying hydrothermal treatment at temperatures of 180°

C. to 200°

C.

18. The method as described in claim 7, further comprising applying microwave hydrothermal irradiation from 180°

C. to 200°

C. for 30 to 360 minutes.

19. The method as described in claim 7, further comprising carrying out a solvothermal treatment in an alcohol compound, glycerol, propylene glycol and ethylene glycol at temperatures of 50 to 250°

C.

20. The method as described in claim 7, further comprising rinsing the nanotubes with an acid, wherein said acid comprises a material selected from the group consisting of hydrochloric acid, nitric acid, sulphuric acid and acetic acid, in a concentration of 1 mM to 700 mM.

21. The method as described in claim 7, further comprising preparing doped 1D titanium-containing nanomaterial including nanofiber and nanorods by heat treatment of multi-walled titanium-based nanotubes containing metal or non-metal dopants at temperatures above 400°

C.

22. The method as described in claim 7, further comprising:

extracting doped titanate nanotubes by using centrifugation; and

drying the titanate nanotubes.

23. A doped titanium nanostructure formed in accordance with the process of claim 7.