阅读说明：本技术 一种利用动态微波法添加模板剂制备纳米TiO2的方法 (Method for preparing nano TiO by adding template agent by dynamic microwave method2Method (2) ) 是由 郭志超 王丽霞 李济 韩文祥 沈鹏远 于 2020-07-20 设计创作，主要内容包括：一种利用动态微波法添加模板剂制备纳米TiO<Sub>2</Sub>的方法,其特征在于,该方法步骤为：按要求称取所需量的钛酸四丁酯与无水乙醇进行混合；将一定量的季铵盐型表面活性剂溶于定量的去离子水中；最后将两种溶液均匀混合形成反应液。TiO<Sub>2</Sub>微球在微波场中生成,水解过程采用动态法,能量输入为2.5W/mL-3.5W/mL,加热至120℃-140℃,保持在该温度下反应1h-3h,可制得大小均一的TiO<Sub>2</Sub>微球。本发明优势为,在微波场中利用动态法,添加模板剂下,合成粒度可控,表面孔隙率好的TiO<Sub>2</Sub>微球。相较于传统的对TiO<Sub>2</Sub>形貌及粒径调控制备方法,该方法合成过程简单,可对形成的TiO<Sub>2</Sub>粒度和表面孔隙率产生控制效果,进而制备出的TiO<Sub>2</Sub>微球有良好的光催化活性。(Method for preparing nano TiO by adding template agent by dynamic microwave method 2 The method is characterized by comprising the following steps: weighing required amount of tetrabutyl titanate and absolute ethyl alcohol according to requirements, and mixing; dissolving a certain amount of quaternary ammonium salt surfactant in a certain amount of deionized water; and finally, uniformly mixing the two solutions to form a reaction solution. TiO2 2 The microspheres are generated in a microwave field, a dynamic method is adopted in the hydrolysis process, the energy input is 2.5W/mL-3.5W/mL, the mixture is heated to 120-140 ℃, the mixture is kept at the temperature and reacts for 1-3 h, and TiO with uniform size can be prepared 2 And (3) microspheres. The invention has the advantages that TiO with controllable granularity and good surface porosity is synthesized by using a dynamic method in a microwave field and adding a template agent 2 And (3) microspheres. Compared with the conventional TiO 2 The preparation method for regulating and controlling the shape and the particle size has simple synthetic process and can be used for the formed TiO 2 The grain size and the surface porosity generate control effect, and then the prepared TiO 2 The microsphere has good photocatalytic activity.)

1. Method for preparing nano TiO with mesoporous structure by using dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: preparing nano titanium dioxide microspheres by adding stirring in a microwave field, and adjusting nano TiO formed in the microwave field by adding a template₂Particle size.

2. The method of claim 1, wherein the nano TiO with mesoporous structure is prepared by a dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: in a microwave field, a dynamic method is utilized, the nano titanium dioxide microspheres with mesoporous structures are formed by adding and stirring and adding a surfactant template.

3. The method of claim 1, wherein the catalyst with mesoporous structure nano TiO2 is prepared by dynamic microwave method, and the morphology and particle size are adjusted by adjusting the concentration of the template, and the template adopts quaternary ammonium salt surfactant, comprising: cetyl trimethyl ammonium bromide, tetramethyl ammonium acetate tetrabutyl ammonium hydrogen sulfate, dodecyl trimethyl ammonium chloride, benzalkonium chloride, benzyl triethyl ammonium chloride, tetraethyl ammonium bromide, octadecyl trimethyl ammonium chloride, tetrabutyl ammonium perchlorate and tetramethyl ammonium fluoride, and the addition amount is 4-20 g/L.

4. The method of claim 1, wherein the nano TiO with mesoporous structure is prepared by a dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: in the step of hydrolysis reduction, the components are uniformly mixed in a non-stop stirring manner.

5. The method of claim 1, wherein the nano TiO with mesoporous structure is prepared by a dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: in the step of hydrolysis reduction, the reaction temperature is 120-140 ℃.

6. The method of claim 1, wherein the nano TiO with mesoporous structure is prepared by a dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: in the step of hydrolysis reduction, the reaction time is 1h-3 h.

7. The method of claim 1, wherein the nano TiO with mesoporous structure is prepared by a dynamic microwave method₂The method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of the template agent is characterized by comprising the following steps: in the hydrolysis reduction step, the stirring energy input is 2.5W/mL-3.5W/mL.

Technical Field

The invention relates to a method for preparing nano TiO with a mesoporous structure by utilizing a dynamic microwave method₂A catalyst and a method for adjusting the morphology and the granularity of the catalyst by adjusting the concentration of a template agent belong to the technical field of preparation of photocatalyst materials.

Background

Use of TiO at the present time₂The photocatalytic degradation reaction is focused on TiO₂Surface of a photocatalyst, for TiO, due to this property₂The morphology, particle size, structure and number of surface active sites of the catalyst surface have certain requirements. Thus, by reacting with TiO₂The method for improving the performance of the photocatalyst by regulating and controlling the shape, the structure and the like of the photocatalyst is an effective method. To date, researchers have successfully developed titanium dioxide in various structural morphologies, such as spherical (Xiue Liu, Chen Sun, Yundi Yue, TingjiangYan, Yuanchun He, Yang Yu, Wenjua Li, Wenliang Wang, Kunlei Zhu, Zhong hanging Synthesis and characterization of this-dimensional sea urchin-like AgBr/TiO2 plasmas with enhanced reactivity and visible-luminescent properties, chemical Papers, 2019, 73 (8): 1971-]20170510), sheet, wire, etc. Since the prepared sample needs to be completed through multiple steps, the investment cost is increased. Therefore, it is necessary to find a relatively simple synthetic method for regulating the morphology and the particle size of the titanium dioxide.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for preparing nano TiO by utilizing a dynamic microwave method in a microwave field₂The catalyst and the quaternary ammonium salt surfactant are added as a template agent to adjust the surface appearance, granularity and surface porosity of the catalyst, so that the reaction process is fundamentally simplified, the energy consumption and the input cost are reduced, and the nano titanium dioxide microsphere with small granularity and high porosity is synthesizedAnd has high photocatalytic degradation performance. The method has the advantages of simple process, fast heat transfer, energy conservation, short reaction time and convenient operation, and can control the granularity. The quaternary ammonium salt surfactant can be used as a stabilizer and a template agent to control TiO growing in a microwave field₂The grain size and the crystal growth reduce aggregation or agglomeration and regulate the appearance of crystal grains. Addition of quaternary ammonium salt surfactant can make TiO₂The surface tension of the precursor is reduced, so that the precursor is highly dispersed in the solution, and the control effect on the particle size and the surface porosity of the formed catalyst is generated.

The invention prepares nano TiO with mesoporous structure by utilizing a dynamic microwave method₂The catalyst is prepared by adjusting the concentration of a template agent to adjust the morphology and the granularity of the catalyst, and comprises the following steps:

measuring a proper amount of tetrabutyl titanate, and slowly dripping the tetrabutyl titanate into a certain amount of absolute ethyl alcohol under the ultrasonic condition; weighing a certain amount of quaternary ammonium salt surfactant (4-20g/L) and dissolving in deionized water, then mixing the two solutions together under the ultrasonic condition by using a peristaltic pump, and finally carrying out volume metering by using the deionized water to obtain a precursor solution. Putting the precursor solution into a reaction kettle, heating to 120-140 ℃ in an annular microwave field with energy input of 2.5-3.5W/mL, maintaining the temperature for hydrolysis reaction for 1-3 hours, continuously stirring at the speed of 300rpm in the reaction process to obtain milky mixed solution, cooling the milky mixed solution to room temperature, then placing the milky mixed solution into a centrifuge for dehydration separation, cleaning with ethanol, and drying with an oven at a certain temperature to obtain white powder, namely the nano TiO with spherical surface appearance₂。

The simple preparation method in the reaction kettle is used for preparing the nano TiO₂The method of (1).

The stirring is continued in the reaction process, so that the solution is uniformly heated in a short time, and the influence caused by the temperature gradient is eliminated.

The template agent is added into the precursor solution for controlling the particle size and crystal growth and reducing aggregation or agglomeration,regulating and controlling the appearance of the crystal grains; at the same time, TiO can be made₂The surface tension of the precursor is reduced, so that the precursor is highly dispersed in the solution.

The use of certain reaction temperature (120 ℃. — (140 ℃)), reaction time (1-3 hours) and microwave energy (2.5W/mL-3.5W/mL) is to fully hydrolyze the precursor solution, and provide sufficient energy and time for nucleation and growth of crystals, so as to complete crystallization.

In conclusion, the method according to the embodiment of the invention can be used for effectively synthesizing nano TiO with mesoporous structure₂And (3) microspheres. The invention provides nano TiO₂The microsphere has the advantages of good dispersibility, uniform size, good light absorption capacity and the like, and has high catalytic activity and high stability for simulating the photocatalytic degradation reaction of rhodamine b under sunlight. The invention breaks through the traditional process for preparing the nano titanium dioxide microspheres, and the method has the advantages that: (1) the raw materials are cheap and easy to obtain; (2) the preparation process is simple, the quality is high, and the energy consumption is low; (3) the reaction time is short, and the reaction controllability is strong; (4) the impurities are less; (5) the dynamic microwave method is adopted, so that the innovation is realized; (6) the shape and the granularity are adjusted by adjusting the concentration of the template agent.

Drawings

FIG. 1 shows TiO prepared in examples 1 to 5₂X-ray diffraction pattern of the catalyst.

FIG. 2 shows TiO prepared in example 2₂Electron micrograph of catalyst.

FIG. 3 shows TiO prepared in example 2₂And (3) a degradation efficiency diagram of the photocatalytic degradation of rhodamine b by the catalyst.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified.