Preparation method of fluorine-doped lamellar black titanium dioxide nano material

Abstract

The method for preparing fluorine-doped lamellar black TiO.sub.2 nanomaterials includes mixing a solution of tetra-n-butyl titanate, n-propanol and hydrofluoric acid together, and then stir the solutions for a period of time. The solution is transferred into an autoclave and reacts at a certain temperature for a period of time. The sample obtained by the reaction is washed and dried. Then, the sample is heated in a protective atmosphere for a period of time so as to produce the fluorine-doped lamellar black TiO.sub.2 nanomaterials. This fluorine-doped lamellar black TiO.sub.2 owns superior optical absorption and electron transport performances.

Claims

1. A method for preparing a fluorine-doped lamellar black TiO.sub.2 nanomaterials, the method comprising the steps of: adding 2030 mL of n-propanol into a beaker; adding 13 mL of tetrabutyl titanate to said n-propanol so as to form a solution; stirring said solution; adding 0.20.8 mL of hydrofluoric acid into said solution so as to form another solution; stirring said another solution for 1 to 3 hours; transferring said another solution to an autoclave at 160200 C. for 1224 hours so as to form a precipitate by a hydrothermal reaction; washing said precipitate with deionized water and ethanol so as to form a washed precipitate and a filtrate, until the filtrate is neutral; drying said washed precipitate so as to form a sample; and calcining said sample at 400450 C. in a protective atmosphere for a period of time so as to form the fluorine-doped lamellar black TiO.sub.2 nanomaterials with light absorption determined by both Ti.sup.3+.sub.surf and Ti.sup.3+.sub.sub-surf defects.

2. The method for preparing a fluorine-doped lamellar black TiO.sub.2 nanomaterials as claimed in claim 1, wherein the step of drying said washed precipitate is at 5060 C. for 1220 hours.

3. The method for preparing a fluorine-doped lamellar black TiO.sub.2 nanomaterials as claimed in claim 1, wherein the step of calcining said sample is 2-4 hours, said protective atmosphere being comprised of a gas mixture of argon and hydrogen.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a contrast diagram of the absorption spectra between a fluorine-doped lamellar black TiO.sub.2 nanomaterials prepared in Embodiment 1 of the present invention and the commercial P25 nanoparticles.

(2) FIG. 2 is a scanning electron microscope (SEM) image of the fluorine-doped lamellar black TiO.sub.2 nanomaterials prepared in Embodiment 1 of the present invention.

(3) FIG. 3 is a contrast diagram of F1s signal in x-ray photo electron spectroscopy (XPS) between the fluorine-doped lamellar black TiO.sub.2 nanomaterials prepared in Embodiment 1 of the present invention and the commercial P25 nanoparticles.

DETAILED DESCRIPTION OF THE INVENTION

(4) A method for preparing a pinecone-shaped TiO.sub.2 nanomaterial provided by the present invention can be implemented as below, and the specific preparing method includes the following steps:

Embodiment 1

(5) (1) add 25 mL of n-propanol into a beaker, then add 2 mL of tetrabutyl titanate, and stir it well;

(6) (2) add 0.4 mL of hydrofluoric acid into the solution, and then stir it for 2 hours;

(7) (3) transfer the solution prepared to an autoclave, and leave it to have hydrothermal reaction at 180 C. for 18 hours;

(8) (4) wash the precipitate obtained after reaction with deionized water and ethanol, until the filtrate is neutral, and then dry it;

(9) (5) calcine the sample obtained at 430 C. in a protective atmosphere to obtain the fluorine-doped lamellar black TiO.sub.2 nanomaterials.

Embodiment 2

(10) (1) add 20 mL of n-propanol into a beaker, then add 1 mL of tetrabutyl titanate, and stir it well;

(11) (2) add 0.15 mL of hydrofluoric acid into the solution, and then stir it for 1 hour;

(12) (3) transfer the solution prepared to an autoclave, and leave it to have hydrothermal reaction at 180 C. for 15 hours;

(13) (4) wash the precipitate obtained after reaction with deionized water and ethanol, until the filtrate is neutral, and then dry it;

(14) (5) calcine the sample obtained at 450 C. in a protective atmosphere to obtain the fluorine-doped lamellar black TiO.sub.2 nanomaterials.