阅读说明：本技术 一种二氧化钛纳米材料及制备方法与应用 (Titanium dioxide nano material, preparation method and application ) 是由 柴金岭 王娇 于 2019-10-29 设计创作，主要内容包括：本公开提供了一种二氧化钛纳米材料及制备方法与应用,其制备方法为：钛酸四正丁酯在微乳液的油相中水解获得二氧化钛前驱体,将二氧化钛前驱体进行水热处理或煅烧处理获得,其中,微乳液为由水、异丙醇、乙酸乙烯酯组成油包水体系,水、异丙醇、乙酸乙烯酯的质量比为0.01～3.75:6.25～9.99:0.01～3.75。采用本公开制备的二氧化钛纳米材料具有更好的光催化性能。(The invention provides a titanium dioxide nano material and a preparation method and application thereof, wherein the preparation method comprises the following steps: hydrolyzing tetra-n-butyl titanate in an oil phase of the microemulsion to obtain a titanium dioxide precursor, and carrying out hydrothermal treatment or calcination treatment on the titanium dioxide precursor to obtain the titanium dioxide, wherein the microemulsion is a water-in-oil system consisting of water, isopropanol and vinyl acetate, and the mass ratio of the water to the isopropanol to the vinyl acetate is 0.01-3.75: 6.25-9.99: 0.01-3.75. The titanium dioxide nano material prepared by the method has better photocatalytic performance.)

1. The microemulsion is characterized in that a water-in-oil (O/W) system is composed of water, isopropanol and vinyl acetate, and the mass ratio of the water, the isopropanol and the vinyl acetate is 0.01-3.75: 6.25-9.99: 0.01-3.75.

2. The microemulsion according to claim 1, wherein the mass ratio of water, isopropanol and vinyl acetate is 1: 3.9-4.1: 0.87-0.89.

3. Use of a microemulsion according to claim 1 or 2 for the preparation of titanium dioxide nanomaterials.

4. A preparation method of titanium dioxide nano-materials is characterized in that tetrabutyl titanate is hydrolyzed in the oil phase of the microemulsion as claimed in claim 1 or 2 to obtain a titanium dioxide precursor, and the titanium dioxide precursor is subjected to hydrothermal treatment or calcination treatment to obtain the titanium dioxide nano-materials.

5. The method for preparing titanium dioxide nanomaterial according to claim 4, wherein the hydrolysis to obtain the titanium dioxide precursor comprises: adding tetra-n-butyl titanate into the microemulsion, stirring for a set time, adding ammonia water for reaction, and obtaining a precipitate after the reaction, namely a titanium dioxide precursor;

preferably, the stirring time is 3.5-4.5 h;

preferably, the method for separating the precipitate is centrifugation followed by washing with ethanol and water.

6. The method for preparing titanium dioxide nanomaterial according to claim 4, wherein the temperature of the hydrothermal treatment is 100-200 ℃;

or, carrying out hydrothermal treatment and centrifugal separation, and drying the separated precipitate to obtain the titanium dioxide nano material.

7. The method for producing a titanium dioxide nanomaterial according to claim 4, wherein a titanium dioxide precursor is dried and then calcined;

or the temperature of the calcination treatment is 500-700 ℃.

8. A titanium dioxide nanomaterial characterized by being obtained by the production method according to any one of claims 4 to 7.

9. Use of the titanium dioxide nanomaterial of claim 8 in photocatalysis.

10. A method for photodegradation of methylene blue, comprising subjecting a methylene blue solution to photodegradation using the titanium dioxide nanomaterial of claim 8 as a photocatalyst.

Technical Field

The disclosure belongs to the technical field of photocatalysts, and relates to a titanium dioxide nano material, and a preparation method and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the disclosure and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

Titanium dioxide (TiO)₂) The white pigment is a white inorganic pigment, has the characteristics of no toxicity, optimal opacity, optimal whiteness and brightness and the like, is considered to be the white pigment with the best performance in the world nowadays, and is widely applied to the fields of coatings, chemical fibers, rubber, sensor devices and the like. Nanostructured titanium dioxide (Nano-TiO)₂) And the photocatalyst also has higher photocatalytic activity and better chemical stability, and can be used as an efficient photocatalyst to be applied to the aspects of atmospheric pollutant degradation, sewage treatment and the like. TiO 2₂In nature, the crystal mainly exists in three crystal forms of anatase, rutile and brookite. TiO 2₂The photocatalytic activity of (A) is related to its crystal phase, crystallinity, crystal grain size, specific surface area, etc.

Preparation of TiO at present₂There are many methods for nanomaterials. The sol-gel method, vapor deposition method, chemical precipitation method, hydrothermal method, etc. can be used for preparing nano TiO₂However, the reaction steps are complicated and the reaction conditions are severe. The microemulsion template method is considered to be a very promising preparation method, and has the advantages of simple required equipment, mild experimental conditions, controllable particle size and the like. The microemulsion liquid drop can be used as a 'micro-reactor', the size of the microemulsion liquid drop has a limit effect on the preparation reaction, and the aim of controlling the particle size of the product is fulfilled. Meanwhile, the method combining the microemulsion method with the hydrothermal method or the calcination method can be adopted to obtain TiO with higher crystallinity₂. The surfactant-free microemulsions (SFMEs) consisting only of two liquids which are immiscible with each other and of a "double solvent", are used for preparing TiO₂The nano material can solve the problems of high production cost, difficult recycling, easy environmental pollution and the like caused by the addition of the surfactant. However, through the research of the inventor of the present disclosure, the TiO prepared by the surfactant-free microemulsion is now available₂The photocatalytic performance of the nano material needs to be improved.

Disclosure of Invention

In order to solve the defects of the prior art, the purpose of the present disclosure is to provide a titanium dioxide nanomaterial, a preparation method and an application thereof, wherein the titanium dioxide nanomaterial prepared by the present disclosure has better photocatalytic performance.

In order to achieve the purpose, the technical scheme of the disclosure is as follows:

on the one hand, the microemulsion consists of a water-in-oil (O/W) system consisting of water, isopropanol and vinyl acetate, wherein the mass ratio of the water to the isopropanol to the vinyl acetate is 0.01-3.75: 6.25-9.99: 0.01-3.75.

On the other hand, the microemulsion is applied to the preparation of titanium dioxide nano materials.

In the third aspect, the preparation method of the titanium dioxide nano material is that tetrabutyl titanate is hydrolyzed in the oil phase of the microemulsion to obtain a titanium dioxide precursor, and the titanium dioxide precursor is subjected to hydrothermal treatment or calcination treatment to obtain the titanium dioxide nano material.

In a fourth aspect, a titanium dioxide nanomaterial obtained by the above-described production method.

In a fifth aspect, the titanium dioxide nano material is applied to photocatalysis.

In a sixth aspect, a photodegradation method of methylene blue is to perform photodegradation on a methylene blue solution by using the titanium dioxide nano-material as a photocatalyst.

Firstly, water, isopropanol and vinyl acetate are utilized to construct an O/W type surfactant-free microemulsion template system, then lipophilic tetra-n-butyl titanate is added into the system, the lipophilic tetra-n-butyl titanate can enter oil cores of O/W liquid drops and is hydrolyzed in the oil cores to form TiO₂The precursor is added with ammonia water, so that the hydrolysis speed is accelerated, and TiO is promoted₂Nucleation and growth of and then separately on room temperature synthesized TiO₂Carrying out low-temperature hydrothermal treatment or high-temperature calcination treatment on the precursor to obtain TiO with different morphologies and different crystal forms₂Nanoparticles, TiO prepared by the method₂The nano particles have better photocatalytic performance.

The beneficial effect of this disclosure does:

(1) the reaction conditions are mild, the operation is simple and feasible, and the water/isopropanol/vinyl acetate surfactant-free agent is constructed in the methodMicroemulsion system as TiO₂The synthesized soft template has simple components, can be recycled, does not use a surfactant, greatly saves the production cost and simultaneously reduces the pollution to the environment.

(2) Synthetic TiO of the disclosure₂The shape of the nano material is better, and the shape can be regulated and controlled by changing reaction conditions.

(3) Synthetic TiO of the disclosure₂The surface of the nano material is not loaded with a surfactant, so that the nano material has higher purity and more excellent photocatalytic performance.

(4) The method has the advantages of simple required equipment, high synthesis efficiency, strong practicability, easy popularization, universality and large-scale production value.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.

FIG. 1 is a ternary phase diagram at 25 ℃ for the water/isopropanol/vinyl acetate system of example 1 of the present disclosure, wherein the contents of the components are expressed in mass fractions. Wherein the blank area is a clear and transparent single-phase microemulsion area, the shadow area is a multi-phase area, in the single-phase area, I represents O/W type microemulsion, II represents W/O type microemulsion, III represents B.C. type microemulsion, and the point a of the O/W area is selected as nano TiO in other embodiments of the disclosure₂The synthetic template of (2);

FIG. 2 shows spindle, spherical and diamond TiO synthesized at 100 deg.C (a), 150 deg.C (b) and 200 deg.C (c) in accordance with embodiments 3-5 of the present disclosure₂TEM images of the nanomaterials;

FIG. 3 shows TiO synthesized in embodiments 3 to 5 of the present disclosure at hydrothermal synthesis temperatures of 100 ℃ (a), 150 ℃ (b), and 200 ℃ (c), respectively₂XRD pattern of the nanomaterial;

FIG. 4 shows TiO granules, spheres, and networks synthesized in examples 6 to 8 of the present disclosure at calcination temperatures of 500 ℃ (a), 600 ℃ (b), and 700 ℃ (c), respectively₂SEM images of nanomaterials;

FIG. 5 is E, 6E, an embodiment of the disclosure8 TiO synthesized at the calcining temperatures of 500 ℃ (a), 600 ℃ (b) and 700 ℃ (c) respectively₂XRD pattern of the nanomaterial;

FIG. 6 shows TiO compounds obtained by photocatalytic experiments in example 9 of the present disclosure₂Comparative graph of photocatalytic degradation rate of sample to methylene blue solution.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Aiming at solving the problem that the existing method adopts microemulsion without surfactant to prepare TiO₂The present disclosure provides a titanium dioxide nanomaterial, a preparation method and an application thereof.

The typical embodiment of the disclosure provides a microemulsion, which comprises a water-in-oil (O/W) system composed of water, isopropanol and vinyl acetate, wherein the mass ratio of the water, the isopropanol and the vinyl acetate is 0.01-3.75: 6.25-9.99: 0.01-3.75.

In one or more embodiments of the present disclosure, the mass ratio of water, isopropanol, and vinyl acetate is 1:3.9 to 4.1:0.87 to 0.89.

In another embodiment of the disclosure, the application of the microemulsion in preparing titanium dioxide nano materials is provided.

In a third embodiment of the present disclosure, a preparation method of a titanium dioxide nanomaterial is provided, wherein tetra-n-butyl titanate is hydrolyzed in an oil phase of the microemulsion to obtain a titanium dioxide precursor, and the titanium dioxide precursor is subjected to hydrothermal treatment or calcination treatment to obtain the titanium dioxide nanomaterial.

Experiments show that the titanium dioxide nano material obtained by adopting microemulsion and hydrothermal treatment has more excellent photocatalytic performance.

The hydrothermal treatment in the disclosure is a treatment by heating water as a solvent to a temperature of not less than 100 ℃ under a closed condition.

The calcination treatment in the present disclosure refers to a treatment method at a temperature of not less than 500 ℃.

In one or more embodiments of this embodiment, the hydrolysis to obtain the titanium dioxide precursor comprises: adding tetrabutyl titanate into the microemulsion, stirring for a set time, adding ammonia water for reaction, and obtaining a precipitate after the reaction, namely a titanium dioxide precursor.

In the series of embodiments, the stirring time is 3.5-4.5 h.

In this series of examples, the method of separating the precipitate was centrifugation followed by washing with ethanol and water.

In one or more embodiments of this embodiment, the temperature of the hydrothermal treatment is 100 to 200 ℃.

In one or more embodiments of this embodiment, the hydrothermal treatment is followed by centrifugal separation, and the separated precipitate is dried to obtain the titanium dioxide nanomaterial.

In one or more embodiments of this embodiment, the titanium dioxide precursor is dried and then subjected to a calcination process. The method prevents the moisture in the titanium dioxide precursor from influencing the result of the titanium dioxide nano material in the calcining process, thereby influencing the photocatalytic performance.

In one or more embodiments of this embodiment, the temperature of the calcination treatment is 500 to 700 ℃.

In a fourth embodiment of the present disclosure, a titanium dioxide nanomaterial obtained by the above preparation method is provided.

In a fifth embodiment of the present disclosure, an application of the titanium dioxide nanomaterial in photocatalysis is provided.

In a sixth embodiment of the present disclosure, a method for photodegradation of methylene blue is provided, in which the titanium dioxide nanomaterial is used as a photocatalyst to photodegrade a methylene blue solution.

In order to make the technical solutions of the present disclosure more clearly understood by those skilled in the art, the technical solutions of the present disclosure will be described in detail below with reference to specific embodiments.