阅读说明：本技术 一种用于光催化的有色二氧化钛的简易制备方法 (Simple preparation method of colored titanium dioxide for photocatalysis ) 是由 崔大祥 王娅楠 林琳 吴晓燕 何丹农 于 2020-12-30 设计创作，主要内容包括：本发明提供一种用于光催化的有色二氧化钛的简易制备方法,本发明采用一步水热和原位还原法相结合,在制备的过程中加入氨基酸作还原剂和表面活性剂,制备了表面含有缺陷的有色二氧化钛材料。该有色二氧化钛表面的缺陷会在能带中形成缺陷能级,从而拓宽了其对可见光的吸收,同时缺陷产生造成的晶格扭曲也能抑制光生电子空穴对的复合,从而提高了其在可见光下的光催化性能。本方法工艺简单,可见光催化活性高。(The invention provides a simple preparation method of colored titanium dioxide for photocatalysis, which combines a one-step hydrothermal method and an in-situ reduction method, and adds amino acid as a reducing agent and a surfactant in the preparation process to prepare a colored titanium dioxide material with a defect on the surface. The defects on the surface of the colored titanium dioxide can form defect energy levels in an energy band, so that the absorption of the colored titanium dioxide to visible light is widened, and meanwhile, the lattice distortion caused by the defects can also inhibit the recombination of photo-generated electron hole pairs, so that the photocatalytic performance of the colored titanium dioxide under the visible light is improved. The method has simple process and high visible light catalytic activity.)

1. A simple preparation method of colored titanium dioxide for photocatalysis is characterized in that a one-step hydrothermal and in-situ reduction method is combined, amino acid is added as a reducing agent and a surfactant in the preparation process, and a colored titanium dioxide material with defects on the surface is prepared, and the method comprises the following steps:

(1) preparing a precursor solution:

3mL of strong acid and 25mL of glycol are taken to be mixed in a beaker at room temperature, and a magnetic stirrer is used for stirring to ensure that the strong acid and the glycol are uniformly mixed; then adding 0.005mol of amino acid into the uniformly mixed solution, and continuously stirring for 1h to completely dissolve the amino acid; after the amino acid is dissolved, stirring continuously, slowly adding 5mL of alkoxy titanate into the mixed solution while stirring, and continuously stirring for 1h until a light yellow transparent solution is obtained;

(2) hydrothermal reaction:

after stirring is finished, transferring the mixed solution into a lining of a 50mL high-pressure reaction kettle, ensuring that the filling degree is between 60 and 80 and the sealing performance of the reaction kettle is good, and placing the reaction kettle in an oven for hydrothermal reaction;

(3) centrifugal filtration and drying:

washing the product obtained by the reaction with water and ethanol for 3 times respectively, performing centrifugal separation at 6500r/min to obtain colored titanium dioxide, putting the sample into an oven, drying for 12h at 80 ℃, and grinding the dried sample by using an agate mortar to obtain colored titanium dioxide powder.

2. The method of claim 1, wherein the strong acid is any one of hydrochloric acid, sulfuric acid or nitric acid.

3. The method of claim 1, wherein the amino acid is any one of aspartic acid, citrulline, glutamic acid, arginine, or cysteine.

4. The method of claim 1, wherein the alkoxy titanate is n-butyl titanate or tetraisopropyl titanate.

5. The simple preparation method of the colored titanium dioxide for photocatalysis according to claim 1, wherein the hydrothermal condition is that the hydrothermal temperature is 140-200 ℃ and the hydrothermal time is 12-20 h.

Technical Field

The invention relates to the technical field of catalysts, in particular to a simple preparation method of colored titanium dioxide for photocatalysis.

Background

The photocatalysis technology is a fast emerging oxidation technology, and has a remarkable application prospect in the field of sewage treatment. The method has the advantages of energy conservation, no treatment by-product, mild reaction condition, greenness, no secondary pollution and the like, is regarded as a green and environment-friendly technology with the most application prospect, and causes wide attention and acceptance of researchers at home and abroad.

Titanium dioxide (TiO)₂) Because of its strong chemical stability, high light transmittance and refractive index, non-toxicity, innocuity, rich reserves, low cost, it has a creditable leading position in the field of photocatalysis research. But because the band gap is wider, the ultraviolet light can only respond to ultraviolet light with short wavelength and high energy, and the ultraviolet light only accounts for 4-6% of the sunlight, so that the use of the ultraviolet light under the sunlight is greatly limited.

In recent years, colored titanium dioxide having defects on the surface thereof exhibits excellent catalytic performance under visible light, and has attracted extensive attention. The surface defects of the titanium dioxide are mainly oxygen vacancies and Ti3+, which form defect energy levels in the energy level of the titanium dioxide, thereby promoting the absorption of visible light and improving the photocatalytic performance.

At present, the preparation method of the colored titanium dioxide is mainly a hydrogenation reduction method, although the colored titanium dioxide with excellent performance can be prepared by the method, the colored titanium dioxide needs to be calcined in a high-temperature closed hydrogen environment, the problems of multiple steps, harsh synthesis conditions, expensive equipment and the like exist, and the large-scale production is not easy to realize.

The invention provides a simple and convenient preparation method of colored titanium dioxide. In the preparation process, amino acid is added as a reducing agent and a surfactant, and the colored titanium dioxide nanoparticles with excellent photocatalytic performance under visible light can be prepared without calcining by using a method combining a one-step hydrothermal method and in-situ reduction.

Disclosure of Invention

In order to solve the problems that the preparation of the prior colored titanium dioxide needs to be calcined in a high-temperature closed hydrogen environment, the steps are multiple, the synthesis conditions are harsh, the equipment is expensive and the like, the invention aims to provide a simple preparation method of the colored titanium dioxide for photocatalysis.

The purpose of the invention is realized by the following scheme:

a simple preparation method of colored titanium dioxide for photocatalysis is characterized in that a one-step hydrothermal and in-situ reduction method is combined, amino acid is added as a reducing agent and a surfactant in the preparation process, and a colored titanium dioxide material with defects on the surface is prepared, and the method comprises the following steps:

(1) preparing a precursor solution:

3mL of strong acid and 25mL of glycol are taken to be mixed in a beaker at room temperature, and a magnetic stirrer is used for stirring to ensure that the strong acid and the glycol are uniformly mixed; then adding 0.005mol of amino acid into the uniformly mixed solution, and continuously stirring for 1h to completely dissolve the amino acid; after the amino acid is dissolved, stirring continuously, slowly adding 5mL of alkoxy titanate into the mixed solution while stirring, and continuously stirring for 1h until a light yellow transparent solution is obtained;

(2) hydrothermal reaction:

after stirring is finished, transferring the mixed solution into a lining of a 50mL high-pressure reaction kettle, ensuring that the filling degree is between 60 and 80 and the sealing performance of the reaction kettle is good, and placing the reaction kettle in an oven for hydrothermal reaction;

(3) centrifugal filtration and drying:

washing the product obtained by the reaction with water and ethanol for 3 times respectively, performing centrifugal separation at 6500r/min to obtain colored titanium dioxide, putting the sample into an oven, drying for 12h at 80 ℃, and grinding the dried sample by using an agate mortar to obtain colored titanium dioxide powder.

The strong acid is any one of hydrochloric acid, sulfuric acid or nitric acid.

The amino acid is any one of aspartic acid, citrulline, glutamic acid, arginine or cysteine.

The alkoxy titanate is n-butyl titanate or tetraisopropyl titanate.

The hydrothermal condition is that the hydrothermal temperature is 140-200 ℃, and the hydrothermal time is 12-20 h.

The defects on the surface of the colored titanium dioxide can form defect energy levels in an energy band, so that the absorption of the colored titanium dioxide to visible light is widened, and meanwhile, the lattice distortion caused by the defects can also inhibit the recombination of photo-generated electron hole pairs, so that the photocatalytic performance of the colored titanium dioxide under the visible light is improved. The method has simple process and high visible light catalytic activity. The green and environment-friendly biological agent amino acid is used as a reducing agent, and the colored titanium dioxide with excellent photocatalytic performance under visible light is prepared by a one-step hydrothermal method.

Compared with the prior art, the invention has the beneficial effects that:

1. the colored titanium dioxide prepared by the method is needle-shaped spherical particles, has excellent dispersibility in aqueous solution, and has excellent visible light photocatalysis performance on dyes such as methyl orange, methylene blue and the like.

2. The method for preparing the colored titanium dioxide by adopting the one-step hydrothermal in-situ reduction method has the advantages of simple and convenient operation, no need of calcination, low energy consumption and capability of being used for industrial production.

Drawings

FIG. 1 is an SEM photograph of the colored titanium dioxide obtained in example 2.

Detailed Description

The present invention is described in detail by the following specific examples, but the scope of the present invention is not limited to these examples.

Example 1

A colored titanium dioxide material for photocatalysis is prepared by combining a one-step hydrothermal method and an in-situ reduction method, adding amino acid as a reducing agent and a surfactant in the preparation process, and preparing the colored titanium dioxide material with defects on the surface according to the following steps:

(1) preparing a precursor solution:

3mL of nitric acid and 25mL of glycol are taken to be mixed in a beaker at room temperature, and a magnetic stirrer is used for stirring to ensure that the nitric acid and the glycol are uniformly mixed; adding 0.005mol of arginine into the uniformly mixed solution, and continuously stirring for 1h to completely dissolve the arginine; after the arginine is dissolved, stirring continuously, slowly adding 5mL of tetraisopropyl titanate into the mixed solution while stirring, and continuously stirring for 1h until a light yellow transparent solution is obtained;

(2) hydrothermal reaction:

after stirring is finished, transferring the mixed solution into a lining of a 50mL high-pressure reaction kettle, ensuring that the filling degree is between 60 and 80 and the sealing performance of the reaction kettle is good, and placing the reaction kettle in an oven for hydrothermal reaction for 16 hours at 160 ℃;

(3) centrifugal filtration and drying:

washing the product obtained by the reaction with water and ethanol for 3 times respectively, and performing centrifugal separation at 6500r/min to obtain the colored titanium dioxide. And (3) putting the sample into an oven to be dried for 12h at the temperature of 80 ℃, and grinding the dried sample by using an agate mortar to obtain colored titanium dioxide powder.

Example 2

A photocatalytic coloured titanium dioxide, prepared as described in example 1, by the following steps:

(1) preparing a precursor solution:

3mL of hydrochloric acid and 25mL of ethylene glycol are taken to be mixed in a beaker at room temperature, and a magnetic stirrer is used for stirring to ensure that the hydrochloric acid and the ethylene glycol are uniformly mixed; adding 0.005mol of aspartic acid into the uniformly mixed solution, and continuously stirring for 1h to completely dissolve the aspartic acid; after the aspartic acid is dissolved, stirring continuously, slowly adding 5mL of tetrabutyl titanate into the mixed solution while stirring, and continuously stirring for 1h until a light yellow transparent solution is obtained;

(2) hydrothermal reaction:

after stirring is finished, transferring the mixed solution into a lining of a 50mL high-pressure reaction kettle, ensuring that the filling degree is between 60 and 80 and the sealing performance of the reaction kettle is good, and placing the reaction kettle in an oven for hydrothermal reaction for 18 hours at 180 ℃;

(3) centrifugal filtration and drying:

washing the product obtained by the reaction with water and ethanol for 3 times respectively, and performing centrifugal separation at 6500r/min to obtain the colored titanium dioxide. And (3) putting the sample into an oven to be dried for 12h at the temperature of 80 ℃, and grinding the dried sample by using an agate mortar to obtain colored titanium dioxide powder. The SEM image of the resulting colored titanium dioxide is shown in FIG. 1.

Example 3

A photocatalytic coloured titanium dioxide, prepared as described in example 1, by the following steps:

(1) preparing a precursor solution:

3mL of sulfuric acid and 25mL of ethylene glycol are mixed in a beaker at room temperature, and are stirred by a magnetic stirrer to be uniformly mixed; then adding 0.005mol of glutamic acid into the uniformly mixed solution, and continuously stirring for 1h to completely dissolve the glutamic acid; after the glutamic acid is dissolved, stirring continuously, slowly adding 5mL of tetrabutyl titanate into the mixed solution while stirring, and continuously stirring for 1h until a light yellow transparent solution is obtained;

(2) hydrothermal reaction: after stirring, transferring the mixed solution into a lining of a 50mL high-pressure reaction kettle, ensuring that the filling degree is between 60 and 80 and the sealing performance of the reaction kettle is good, and placing the reaction kettle in an oven for hydrothermal reaction for 16 hours at 150 ℃;

(3) centrifugal filtration and drying:

washing the product obtained by the reaction with water and ethanol for 3 times respectively, and performing centrifugal separation at 6500r/min to obtain the colored titanium dioxide. And (3) putting the sample into an oven to be dried for 12h at the temperature of 80 ℃, and grinding the dried sample by using an agate mortar to obtain colored titanium dioxide powder.