阅读说明：本技术 一种水热法合成纳米氧化铈的方法 (Method for synthesizing nano cerium oxide by hydrothermal method ) 是由 侯帅帅 杨景红 吴月 夏义文 于 2021-03-29 设计创作，主要内容包括：本发明公开一种水热法合成纳米氧化铈的方法,水热法合成纳米氧化铈的方法包括以下步骤：称取六水合硝酸铈固体于烧杯加入水溶解中,向烧杯中加入有机胺,边加边搅拌；搅拌过程中加入表面活性剂；将六水合硝酸铈固体溶于A溶液中搅拌；将反应物转移至内衬为聚四氟乙烯的反应釜中；反应结束后,将混合物转移至离心管中,在离心机上离心分离,结束后倒去上层清液,加入水,用玻璃棒搅拌2mi n-5mi n,再次离心,重复离心完成水洗,换成有机溶剂重复清洗；本发明方法工艺条件简单、成本低、对设备的要求低、绿色环保,而且操作程序连续可调,容易控制实验过程,所以易于工业化生产。(The invention discloses a method for synthesizing nano cerium oxide by a hydrothermal method, which comprises the following steps: weighing cerium nitrate hexahydrate solid, adding the solid into a beaker, dissolving the solid in water, adding organic amine into the beaker, and stirring while adding; adding a surfactant in the stirring process; dissolving cerium nitrate hexahydrate solid in the solution A and stirring; transferring the reactant to a reaction kettle with a polytetrafluoroethylene lining; after the reaction is finished, transferring the mixture into a centrifuge tube, performing centrifugal separation on the centrifuge tube, pouring out supernatant after the reaction is finished, adding water, stirring the mixture by using a glass rod for 2min-5min, centrifuging again, performing repeated centrifugation to finish water washing, and changing the mixture into an organic solvent for repeated washing; the method has the advantages of simple process conditions, low cost, low requirement on equipment, environmental protection, continuous and adjustable operation program, and easy control of the experimental process, so the method is easy for industrial production.)

1. A method for synthesizing nano cerium oxide by a hydrothermal method is characterized by comprising the following steps:

s1, weighing cerium nitrate hexahydrate solid, dissolving in water in a beaker, adding organic amine into the beaker, and stirring while adding;

s2, adding a surfactant in the stirring process;

s3, dissolving the cerium nitrate hexahydrate solid in the solution A and stirring;

s4, transferring the reactant into a reaction kettle with a polytetrafluoroethylene lining;

s5: after the reaction is finished, transferring the mixture into a centrifuge tube, performing centrifugal separation on the centrifuge tube, pouring out supernatant after the reaction is finished, adding water, stirring the mixture for 2 to 5 minutes by using a glass rod, centrifuging the mixture again, performing repeated centrifugation to finish water washing, and replacing the mixture with an organic solvent for repeated washing;

s6: and (4) after washing, putting the centrifugal tube into a drying box, and drying at constant temperature to obtain cerium oxide.

2. The hydrothermal synthesis method of nano cerium oxide according to claim 1, wherein the molar ratio of cerium nitrate hexahydrate solid in S1 to organic amine is 3: 1.

3. The hydrothermal synthesis method of nano cerium oxide according to claim 1, wherein the organic amine in S1 is oleylamine.

4. The hydrothermal synthesis method of nano-cerium oxide, according to claim 1, wherein the surfactant in S2 is: the cationic surfactant is cetyl trimethyl ammonium bromide, the anionic surfactant is sodium dodecyl benzene sulfonate, the nonionic surfactant is polyethylene glycol with molecular weight of 10000, and the proportion of the surfactant to the total amount of reactants is 2-6%.

5. The hydrothermal synthesis method of nano-cerium oxide, according to claim 1, wherein a volume ratio of the solution a to the organic amine is 1: (8-10), wherein the solution A is water, and the volume ratio is 1: 4, ethanol and water, and the ratio of ethanol to water is 1: 1, and distilled water, and stirring for 10-20 min.

6. The hydrothermal method for synthesizing nano cerium oxide according to claim 1, wherein the reaction kettle temperature in S4 is 80-110 ℃ for 10-14 h.

7. The hydrothermal method for synthesizing nano cerium oxide according to claim 1, wherein the S4 is washed with water for 3-5 times and with an organic solvent such as ethanol, acetone, and N, N-dimethylformamide for 3-5 times.

8. The hydrothermal synthesis method of nano cerium oxide according to claim 1, wherein the drying temperature in S6 is 80-110 ℃, and the drying time is 3-6 h.

Technical Field

The invention relates to the field of inorganic nonmetal, in particular to a method for synthesizing nano cerium oxide by a hydrothermal method.

Background

Cerium oxide is a rare earth oxide with a unique 4f electron shell composed of rare earthsThe structure of the material makes the material have special optical, electrical and magnetic properties, and the material becomes a new material with great value, such as catalyst, polishing powder, ceramic material, ultraviolet absorbing material, luminescent material and the like, and has been widely applied in a plurality of important chemical processes, such as petrochemical industry, automobile exhaust purification, toxic and harmful gas purification, fuel cells (solid oxide fuel cells) and the like. Nano CeO₂Also has a series of properties of nano material, so that the nano CeO₂The electronic structure of cerium atom is 4f25d06s2, and two common valence states of cerium (III) and cerium (IV) are formed by electron gain and loss.

The most stable form of cerium being CeO₂；CeO₂Is an N-type semiconductor and has a more unique fluorite crystal structure. Each cerium cation being substituted by 8O^2-Surround and each O^2-Is coordinated by 4 cerium cations, and has such a structure that CeO₂After losing a large number of oxygen atoms to form many oxygen vacancies, it can still maintain its fluorite structure, and cerium (IV) is converted to cerium (III) to maintain its charge balance. CeO (CeO)₂Because of its special oxygen storage and release capacity and valence electron configuration, it is naturally paid more attention by researchers, and in addition, because of the lattice oxygen defect caused by doping, its catalytic activity is obviously improved, and the cerium oxide-based composite material is more and more paid more attention by people.

Disclosure of Invention

The invention aims to provide a method for synthesizing nano cerium oxide by a hydrothermal method, which has the advantages of simple process condition, low cost, low requirement on equipment, environmental protection, continuous and adjustable operation program and easy control of the experimental process, and is easy for industrial production; cerium dioxide with different morphologies can be prepared by adjusting experimental parameters (water dosage, surfactant dosage and surfactant category); the preparation environment of the method is obviously different from that of the general liquid phase method by adopting a simpler hydrothermal method, and the cerium dioxide is simply and quickly prepared.

The purpose of the invention can be realized by the following technical scheme:

a method for synthesizing nano cerium oxide by a hydrothermal method comprises the following steps:

s1, weighing cerium nitrate hexahydrate solid, dissolving in water in a beaker, adding organic amine into the beaker, and stirring while adding;

s2, adding a surfactant in the stirring process;

s3, dissolving the cerium nitrate hexahydrate solid in the solution A and stirring;

s4, transferring the reactant into a reaction kettle with a polytetrafluoroethylene lining;

s5: after the reaction is finished, transferring the mixture into a centrifuge tube, performing centrifugal separation on the centrifuge tube, pouring out supernatant after the reaction is finished, adding water, stirring the mixture for 2 to 5 minutes by using a glass rod, centrifuging the mixture again, performing repeated centrifugation to finish water washing, and replacing the mixture with an organic solvent for repeated washing;

s6: and (4) after washing, putting the centrifugal tube into a drying box, and drying at constant temperature to obtain cerium oxide.

Further, the molar ratio of the cerium nitrate hexahydrate solid to the organic amine in the S1 is 3: 1.

Further, the organic amine in S1 is oleylamine.

Further, the surfactant in S2 is: the cationic surfactant is cetyl trimethyl ammonium bromide, the anionic surfactant is sodium dodecyl benzene sulfonate, the nonionic surfactant is polyethylene glycol with molecular weight of 10000, and the proportion of the surfactant to the total amount of reactants is 2-6%.

Further, the volume ratio of the solution A to the organic amine is 1: (8-10), wherein the solution A is water, and the volume ratio is 1: 4, ethanol and water, and the ratio of ethanol to water is 1: 1, and distilled water, and stirring for 10-20 min.

Further, the temperature of the reaction kettle in the S4 is 80-110 ℃ for reaction for 10-14 h.

Further, the S4 is washed by water for 3-5 times, and the organic solvent is washed by ethanol, acetone or N, N-dimethylformamide for 3-5 times.

Further, the drying temperature in the S6 is 80-110 ℃, and the drying time is 3-6 h.

The invention has the beneficial effects that:

1. the method has the advantages of simple process condition, low cost, low requirement on equipment, environmental protection, continuous and adjustable operation program, easy control of experimental process and easy industrial production;

2. the method can prepare cerium dioxide with different morphologies by adjusting the experimental parameters of water dosage, surfactant dosage and surfactant category; the preparation environment of the method is obviously different from that of the general liquid phase method by adopting a simpler hydrothermal method, and the cerium dioxide is simply and quickly prepared.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is an X-ray diffraction (XRD) pattern of cerium oxide produced in the process of the present invention;

FIG. 2 is an X-ray diffraction (XRD) pattern of cerium oxide produced in the process of the present invention;

FIG. 3 is a Scanning Electron Microscope (SEM) spectrum of cerium oxide produced in the process of the present invention;

FIG. 4 is a Scanning Electron Microscope (SEM) spectrum of cerium oxide produced in the process of the present invention.

Detailed Description

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.

Example 1

Adding 4.4g of cerous nitrate hexahydrate and 5ml of oleylamine into a beaker, adding 0.17g of surfactant sodium dodecyl benzene sulfonate, adding 40ml of water, stirring for 10min, transferring into a reaction kettle with a polytetrafluoroethylene lining, placing in a 110 ℃ oven for constant temperature for 10h, centrifuging, pouring out supernatant, washing with ethanol for 4 times, washing with water for 4 times to obtain white powder, stirring with a glass rod for 2min during washing, and drying in a 90 ℃ constant temperature oven for 5h to obtain powdery nano cerium oxide.

Example 2

Adding 4.4g of cerium nitrate hexahydrate and 5ml of oleylamine into a beaker, adding 0.35g of hexadecyl trimethyl ammonium bromide serving as a surfactant, adding 40ml of water, adding 10ml of ethanol solution, stirring for 10min, transferring to a reaction kettle with a polytetrafluoroethylene lining, placing in an oven with the temperature of 80 ℃ for constant 14h, centrifuging, pouring out supernatant, washing with acetone for 3 times, stirring with a glass rod for 3min during washing, washing with water for 5 times to obtain white powder, and drying in the oven with the temperature of 80 ℃ for 6h to obtain powdery nano cerium oxide.

Example 3

4.4g of cerous nitrate hexahydrate and 5ml of oleylamine were added to a beaker, 0.54g of surfactant PEG-10000 (polyethylene glycol having a molecular weight of 10000) was added, and 50ml of an alcohol-water ratio of 1: stirring the mixed solution of 1 for 15min, transferring the mixed solution into a reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle in a drying oven at 90 ℃ for constant temperature for 12h, centrifuging, pouring out supernatant, washing the supernatant with distilled water for 3 times to obtain white powder, stirring the white powder with a glass rod for 5min during cleaning, and drying the white powder in the drying oven at 100 ℃ for 4h to obtain powdery nano cerium oxide.

Example 4

Adding 4.5g of cerous nitrate hexahydrate and 5.5ml of oleylamine into a beaker, adding 0.37g of hexadecyl trimethyl ammonium bromide serving as a surfactant, adding 55ml of distilled water, stirring for 20min, transferring the mixture into a reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle in an oven at 100 ℃ for constant temperature 13h, centrifuging the mixture, pouring out supernatant, washing the supernatant for 5 times by using N, N-Dimethylformamide (DMF) to obtain white powder, and drying the white powder in the oven at 110 ℃ for constant temperature for 3h to obtain the nano cerium oxide.

The cerium oxides obtained in examples 1 and 2 were subjected to X-ray diffraction, and the cerium oxides obtained in examples 3 and 4 were subjected to scanning electron microscope observation, to obtain the following results:

from the XRD of fig. 1, the following conclusions can be drawn: example 1 produced nano-ceria.

From the XRD of fig. 2, the following conclusions can be drawn: the nano cerium oxide prepared in example 2 has good crystallinity.

From the SEM of fig. 3, the following conclusions can be drawn: the morphology of the nano cerium oxide prepared in example 3 is spherical.

From the SEM of fig. 4, the following conclusions can be drawn: the morphology of the nano cerium oxide prepared in example 4 is spherical.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.