阅读说明：本技术 一种水辅助快速制备BiOBr纳米花的方法及其应用 (Method for rapidly preparing BiOBr nanoflower in water-assisted manner and application of BiOBr nanoflower ) 是由 张显龙 冯德鑫 咸漠 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种水辅助快速制备BiOBr纳米花的方法及其应用,属于纳米材料合成领域。本发明要解决现有制备BiOBr的方法工艺复杂,成本高,后处理繁琐,不利于扩大化生产的技术问题。本发明采用两步法水辅助快速制备BiOBr的。本发明方法如下：将五水硝酸铋加入到有机醇中,充分搅拌,加入溴源,继续充分搅拌,溶剂热反应后冷却得到澄清透明溶液,然后加入水,迅速出现白色固体,所得白色固体过滤后清洗,干燥,即可得到BiOBr纳米花。本发明具有制备方法简单,反应时间短,无需添加表面活性剂,易于工业化生产等优点。(The invention discloses a method for rapidly preparing BiOBr nanoflower with assistance of water and application of the BiOBr nanoflower, and belongs to the field of synthesis of nanomaterials. The invention aims to solve the technical problems that the existing method for preparing BiOBr is complex in process, high in cost, complex in post-treatment and not beneficial to expanded production. The invention adopts a two-step method to prepare BiOBr rapidly with water assistance. The method comprises the following steps: adding bismuth nitrate pentahydrate into organic alcohol, fully stirring, adding a bromine source, continuously fully stirring, carrying out thermal reaction on a solvent, cooling to obtain a clear and transparent solution, then adding water, quickly generating a white solid, filtering the obtained white solid, washing, and drying to obtain the BiOBr nanoflower. The invention has the advantages of simple preparation method, short reaction time, no need of adding a surfactant, easy industrial production and the like.)

1. A method for rapidly preparing BiOBr nanoflower with the assistance of water is characterized in that the method for preparing the BiOBr nanoflower is carried out through the following steps:

Dissolving bismuth nitrate pentahydrate in organic alcohol, fully stirring, adding a bromine source with the same molar amount as the bismuth nitrate pentahydrate, continuously fully stirring, and then carrying out a dissolution thermal reaction to obtain a clear solution;

And step two, adding water into the clear solution obtained in the step one, quickly generating white solid precipitate, then carrying out suction filtration to separate out solid, sequentially washing the solid for at least 3 times by using water and absolute ethyl alcohol, and drying to obtain the BiOBr nanoflower.

2. The method for rapidly preparing BiOBr nanoflowers with assistance of water according to claim 1, wherein the organic alcohol in step one is one or a combination of methanol, ethanol, propanol and ethylene glycol.

3. the method for rapidly preparing BiOBr nanoflowers with the assistance of water according to claim 1, wherein the ratio of the moles of bismuth nitrate pentahydrate to the volume of organic alcohol in the step is as follows: 1mmol (4-32) mL.

4. The method for water-assisted rapid preparation of BiOBr nanoflowers according to claim 1, wherein the bromine source in step one is one or a combination of HBr, NaBr and KBr.

5. the method for water-assisted rapid preparation of BiOBr nanoflowers according to claim 1, wherein the volume ratio of the water added in step two to the organic alcohol added in step one is (0.5-5): 1.

6. The method for rapidly preparing BiOBr nanoflowers with assistance of water according to claim 1, wherein the dissolution heat reaction in the second step is carried out at 120-200 ℃ for 0.5-2 h.

7. The method for rapidly preparing BiOBr nanoflowers through water assistance according to claim 1, wherein the reaction of heat of solution in the second step is performed in a high-pressure reaction kettle with a polytetrafluoroethylene lining.

8. The method for water-assisted rapid preparation of BiOBr nanoflowers according to claim 1, wherein the drying in the oven at 50-80 ℃ is performed in the second step.

9. BiOBr nanoflower synthesized according to any one of claims 1 to 8 for use as a photocatalyst.

10. Use of a BiOBr nanoflower according to claim 9, characterized in that the BiOBr nanoflower photocatalysts industrial dyes or antibiotics.

Technical Field

The invention belongs to the technical field of nano materials; in particular to a method for rapidly preparing BiOBr nanoflower with the assistance of water.

Background

The human society of the 21 st century develops rapidly, and has great progress in science and technology and humanity, but simultaneously, the conflict between modern resources and ecological environment is increased day by day, and the sustainable development becomes a road which must be selected by modern society. The photocatalysis technology is a green technology which can effectively solve the energy crisis and the environmental pollution, takes solar energy as power, and has the advantages of low price, cleanness, rich resources and the like. How to effectively utilize solar energy is an important subject of scientific research in the 21 st century, and development of a high-efficiency, stable and low-cost photocatalyst is always a research hotspot in the field of photocatalyst research.

BiOBr is a novel layered semiconductor compound having a tetragonal crystal structure consisting of [ Bi ]₂O₂]The layered structure formed by alternately stacking the double-layer Br atoms enables an internal electric field to exist between layers of the layered structure, so that separation of photogenerated electrons and holes is facilitated, and BiOBr has the advantages of being chemically stable, easily available in raw materials, non-toxic, low in cost and the like, and is considered to be a high-efficiency photocatalyst with inherent commercial prospect. In the past decades, researchers have synthesized BiOBr with different morphologies, such as nanospheres, nanosheets, nanorods, nanodiscs, and 3D nanospheres formed by stacking nanosheets, by changing the composition of the reaction system.

However, the currently developed method for synthesizing BiOBr is complex in process, high in cost, complex in post-treatment and not beneficial to expanded production.

Disclosure of Invention

the invention aims to solve the technical problems that the existing method for preparing BiOBr is complex in process, high in cost, complex in post-treatment and not beneficial to expanded production; the method for preparing the BiOBr nanoflower is simple and rapid to operate, low in manufacturing cost and mild in reaction conditions. The 3D nanoflower formed by stacking the nanosheets has a large specific surface area, provides more catalytic active sites, and shows excellent catalytic performance.

The method for water-assisted rapid preparation of BiOBr nanoflowers does not solve the technical problems and is carried out by the following steps:

dissolving bismuth nitrate pentahydrate in organic alcohol, fully stirring, adding a bromine source with the same molar amount as the bismuth nitrate pentahydrate, continuously fully stirring, and then carrying out a dissolution thermal reaction to obtain a clear solution;

And step two, adding water into the clear solution obtained in the step one, quickly generating white solid precipitate, then carrying out suction filtration to separate out solid, sequentially washing the solid for at least 3 times by using water and absolute ethyl alcohol, and drying to obtain the BiOBr nanoflower.

Further, the organic alcohol in the step one is one of methanol, ethanol, propanol and ethylene glycol or any combination of several of them in any ratio.

further defined, the ratio of moles of bismuth nitrate pentahydrate to the volume of organic alcohol in step one is: 1mmol (4-32) mL.

further, in the first step, the bromine source is one of HBr, NaBr, KBr or a combination of some of them.

further limit, the volume ratio of the water added in the second step to the organic alcohol in the first step is (0.5-5):1

further limiting, in the second step, the solution heat reaction is carried out for 0.5h-2h at the temperature of 120-200 ℃.

further, the solution heat reaction in the second step is carried out in a high-pressure reaction kettle with a polytetrafluoroethylene lining.

Further limiting, drying in an oven at 50-80 ℃ in the second step.

The BiOBr synthesized by the method is used as a photocatalyst and can be used for photocatalysis of industrial dyes and antibiotics.

According to the invention, a clear and transparent precursor is synthesized by a solvothermal method, and then the BiOBr nanoflower is prepared by adding water and quickly hydrolyzing, wherein the hydrolysis process only needs a few seconds to be completed.

The invention does not need to add a surfactant, reduces the reaction cost and simplifies the preparation process.

The invention firstly provides a two-step method for preparing the photocatalyst BiOBr nanoflower, firstly prepares a precursor through solvothermal preparation, and then prepares the BiOBr nanoflower through normal-temperature hydrolysis. Compared with the prior art, the method has the advantages that the preparation processes of the precursor and the final product are separated, the high-temperature heating time is short, the energy consumption is low, the precursor is colorless, clear and transparent solution, the next reaction can be carried out without cleaning the high-temperature reaction kettle after the reaction, the cleaning processes are reduced, the production period is shortened, and the production efficiency is improved.

The BiOBr nanoflower prepared by the method is small in size, large in specific surface area and excellent in performance of visible light catalytic degradation of industrial dyes and antibiotics.

Drawings

FIG. 1 is an X-ray powder diffraction test pattern of BiOBr nanoflower;

FIG. 2 is a scanning electron micrograph of BiOBr nanoflower;

FIG. 3 is a transmission electron micrograph of BiOBr nanoflower;

FIG. 4 shows the performance characterization of photocatalytic degradation of rhodamine B by BiOBr nanoflower;

FIG. 5 is a representation of the performance of BiOBr nanoflower photocatalytic degradation of tetracycline.

Detailed Description