阅读说明：本技术 一种β-FeOOH纳米棒及其制备方法 (beta-FeOOH nano rod and preparation method thereof ) 是由 杨冬 *** 高可奕 王雪 王丽霞 贾彤彤 于 2020-06-04 设计创作，主要内容包括：本发明公开了一种β-FeOOH纳米棒及其制备方法,以三氯化铁、聚乙烯亚胺和去离子水为原料,将三氯化铁均匀分散在聚乙烯亚胺水溶液中,油浴加热进行水解反应,产物冷却至室温后经过多次离心水洗,并将沉淀分散于去离子水中,制备的β-FeOOH纳米棒在去离子水中分散性良好,直径约为10-15nm,长度约为35-185nm。本发明制备的β-FeOOH纳米棒在水溶液中可稳定存在,制备工艺简单,原料来源广泛,成本低廉,反应在常压下进行,对反应设备要求较低,操作安全,无毒无害,绿色环保,工艺流程可控性强,产率高,适用于大规模工业化生产。(The invention discloses a beta-FeOOH nano rod and a preparation method thereof, ferric trichloride, polyethyleneimine and deionized water are taken as raw materials, the ferric trichloride is uniformly dispersed in a polyethyleneimine aqueous solution, the mixture is heated in an oil bath for hydrolysis reaction, products are cooled to room temperature and then are subjected to multiple times of centrifugal washing, and precipitates are dispersed in the deionized water, so that the prepared beta-FeOOH nano rod has good dispersibility in the deionized water, the diameter is about 10-15nm, and the length is about 35-185 nm. The beta-FeOOH nano rod prepared by the invention can stably exist in aqueous solution, the preparation process is simple, the raw material source is wide, the cost is low, the reaction is carried out under normal pressure, the requirement on reaction equipment is lower, the operation is safe, the beta-FeOOH nano rod is nontoxic and harmless, the preparation method is green and environment-friendly, the controllability of the process flow is strong, the yield is high, and the preparation method is suitable for large-scale industrial production.)

1. A preparation method of a beta-FeOOH nano rod is characterized by comprising the following steps:

step (1), mixing a PEI solution and a ferric trichloride solid according to a ratio of 100 mL: 5.4g of the raw materials are mixed according to a feed ratio to obtain a mixed solution; the volume percentage of the PEI solution is 0.1-2%;

step (2), carrying out hydrolysis reaction on the mixed solution in the step (1);

and (3) carrying out centrifugal washing treatment on the solution after the hydrolysis reaction, collecting the precipitate after the centrifugal washing, and dissolving the precipitate in deionized water to obtain the beta-FeOOH nano rod.

2. The method for preparing beta-FeOOH nanorods according to claim 1, characterized in that the ferric trichloride of step 1) is ferric trichloride containing six crystal water.

3. The method of preparing β -FeOOH nanorods according to claim 1, wherein the molecular weight of PEI is 750000.

4. The method for preparing beta-FeOOH nanorods according to claim 3, characterized in that the PEI solution in step 1) uses deionized water as solvent.

5. The method for preparing β -FeOOH nanorods according to claim 1, characterized in that the hydrolysis reaction temperature in step 2) is 80-90 ℃.

6. The preparation method of the beta-FeOOH nanorod according to claim 1, wherein the hydrolysis reaction time in the step 2) is 1-2.5 h.

7. The method for preparing beta-FeOOH nanorods according to claim 1, characterized in that the mixing of step 1) and the hydrolysis reaction of step 2) are performed under magnetic stirring; the hydrolysis reaction in the step 2) is carried out in a constant-temperature oil bath reactor.

8. The preparation method of the beta-FeOOH nanorod according to claim 1, characterized in that in the step 3), washing is performed for 3-5 times by using deionized water to the centrifuged precipitate; the washed precipitate is dissolved in deionized water by ultrasonic decomposition.

9. The beta-FeOOH nanorod prepared by the preparation method of the beta-FeOOH nanorod according to any one of claims 1-8.

10. The beta-FeOOH nanorod according to claim 9, wherein the beta-FeOOH nanorod has a length of 35-185nm and a diameter of 10-15 nm.

Technical Field

The invention belongs to the technical field of inorganic nano materials, and relates to a beta-FeOOH nanorod and a preparation method thereof.

Background

beta-FeOOH as a natural mineral widely exists in soil water and sediments, and is widely concerned due to the special tunnel structure, stable physicochemical property, huge specific surface area and nano structure. As a common yellow inorganic dye, the yellow inorganic dye has been applied to water-based coatings and oil-based coatings, and simultaneously has a special tunnel structure, and is an important raw material for preparing electrode materials and flame-retardant materials. Due to the high specific surface area, high stability and abundant hydroxyl groups of beta-FeOOH, the beta-FeOOH is often used for oxidation adsorption and photocatalyst of metal ions and organic dyes in wastewater treatment. Besides, the beta-FeOOH is one of the important precursors for preparing the magnetic material.

The currently reported beta-FeOOH preparation methods are many, such as a hydrothermal method, a thermal decomposition method, a precipitation method, a ferrous oxidation method, a microemulsion method, a microwave hydrolysis method and the like, most of the methods need to use complex and expensive instruments, the preparation conditions are strict, the preparation process needs to be carried out at a high temperature, the production period is relatively long, the efficiency is low, and the influence factors of the material morphology are complex, so that the method is not beneficial to industrial production. And the prepared beta-FeOOH has poor dispersibility and large particle size, and cannot reach the nano level, so that the further research on the aspect of biomedicine is limited.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a beta-FeOOH nanorod and a preparation method thereof, so as to solve the technical problems that the existing beta-FeOOH preparation method is harsh in conditions and complex in operation, and the prepared product is difficult to reach the nano level.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a preparation method of a beta-FeOOH nano rod comprises the following steps:

step (1), mixing a PEI solution and a ferric trichloride solid according to a ratio of 100 mL: 5.4g of the raw materials are mixed according to a feed ratio to obtain a mixed solution; the volume percentage of the PEI solution is 0.1-2%;

step (2), carrying out hydrolysis reaction on the mixed solution in the step (1);

and (3) carrying out centrifugal washing treatment on the solution after the hydrolysis reaction, collecting the precipitate after the centrifugal washing, and dispersing the precipitate in a deionized water solution to obtain the beta-FeOOH nano rod.

Preferably, the ferric trichloride in the step 1) is ferric trichloride containing six crystal water.

Preferably, the molecular weight of the PEI is 750000.

Further preferably, the PEI solution uses deionized water as a solvent.

Preferably, the hydrolysis reaction temperature in step 2) is 80-90 ℃.

Preferably, the hydrolysis reaction time in the step 2) is 1-2.5 h.

Preferably, the mixing of step 1) and the hydrolysis reaction of step 2) are both carried out under magnetic stirring;

further preferably, the hydrolysis reaction described in step 2) is carried out in a thermostatted oil bath reactor.

Preferably, in the step 3), washing is carried out on the centrifuged precipitate for 3-5 times by using deionized water; the washed precipitate is dissolved in deionized water by ultrasonic decomposition.

The invention also discloses a beta-FeOOH nano rod.

Preferably, the length of the beta-FeOOH nanorod is 35-185nm, and the diameter of the beta-FeOOH nanorod is 10-15 nm.

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

the invention discloses a preparation method of a beta-FeOOH nanorod, which adopts ferric trichloride and Polyethyleneimine (PEI) as raw materials to prepare the beta-FeOOH nanorod by a simple low-temperature hydrolysis method, and the beta-FeOOH nanorod has good dispersibility in water, stable property, uniform appearance and adjustable length-diameter ratio. The preparation method adopts a one-step synthesis method, has the advantages of simple process, convenient operation, wide raw material source, low cost, low requirement on equipment, mild reaction condition, environmental protection and contribution to large-scale industrial production.

In the preparation method, the beta-FeOOH nano rod with good dispersibility is prepared by adopting a simple heating hydrolysis method, and only ferric trichloride, PEI and deionized water are used as raw materials, so that the preparation method is low in cost, non-toxic, harmless, green and environment-friendly. The appearance of the product beta-FeOOH nano rod in the system is mainly influenced by the dosage of PEI, and the controllability of the preparation process is strong. The temperature of dissolution and reaction in the reaction process is relatively low and the reaction is carried out under normal pressure, so the method has low requirement on equipment, is safe and reliable, and is beneficial to large-scale production. The separation process of the product adopts a centrifugal method, the yield is high, the process is simple, no complex instrument is needed, and the preparation cost is effectively reduced. In addition, the prepared beta-FeOOH nano rod has higher specific surface area and has greater advantages in the aspects of adsorption, catalysis and the like.

Further, a PEI aqueous solution with the volume concentration of 0.1% -2% is prepared by using deionized water, PEI plays a role of a soft template in the reaction process, PEI can be preferentially adsorbed on the high-energy surface of the beta-FeOOH seed, in order to ensure thermodynamic stability, the particle tends to grow along a certain direction so as to reduce the surface free energy, the adsorption chances of PEI on all surfaces of the beta-FeOOH seed are increased along with the increase of the dosage of PEI, the directional growth tendency of the particle is weakened, the length of the beta-FeOOH nanorod is gradually shortened, and the length-diameter ratio is reduced.

Furthermore, the temperature of the hydrolysis reaction is 80-90 ℃, the reaction time is 1-2.5 h, the purpose of the hydrolysis reaction can be realized through a simple experimental device, the preparation process is simple, the cost is low, the practicability is high, and the large-scale industrial production is facilitated.

The invention discloses a beta-FeOOH nanorod which is obtained based on the preparation method, and the length of the beta-FeOOH nanorod is 35-185nm, and the diameter of the beta-FeOOH nanorod is 10-15 nm. Compared with the existing FeOOH particles, the beta-FeOOH nano rod prepared by the preparation method has better dispersibility and shape adjustability, and the nano-scale size of the beta-FeOOH nano rod is more favorable for application and research in the aspect of biomedicine.

Drawings

FIG. 1 is a transmission electron microscope image of the β -FeOOH nanorods prepared in example 1;

FIG. 2 is a transmission electron microscope image of the β -FeOOH nanorods prepared in example 2, with the scale size of 200 nm;

FIG. 3 is a transmission electron microscope image of the β -FeOOH nanorods prepared in example 2, in which the size of the scale is 100 nm;

FIG. 4 is a distribution diagram of hydrated particle size of the β -FeOOH nanorods prepared in example 4;

FIG. 5 is a hydrated particle size distribution diagram of the β -FeOOH nanorods prepared in example 5.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings: