CN109133144B - Preparation method of monodisperse ultra-small particle size cerium dioxide nanocrystal - Google Patents

Abstract

A preparation method of monodisperse ultra-small particle size cerium dioxide nano-crystal comprises the following steps: dissolving cerous nitrate hexahydrate in deionized water to prepare a cerous nitrate solution, adding N, N-dimethylformamide and triethanolamine, mixing, and magnetically stirring to obtain a uniform mixed solution; and transferring the mixed solution into a reaction kettle with a polytetrafluoroethylene lining, sealing, heating in an oven, heating and preserving heat, cooling the product to room temperature after the reaction is finished, and centrifugally separating and washing the precipitate to obtain the cerium dioxide nanocrystalline material. The particle size of the obtained cerium dioxide nano-crystal is about 4-8 nm, the morphology is approximately spherical, and the dispersibility is good. The method has the advantages of simple process, low preparation cost, mild reaction conditions, high yield and short production period, and is beneficial to industrial production.

Description

Preparation method of monodisperse ultra-small particle size cerium dioxide nanocrystal

Technical Field

The invention relates to a preparation method of monodisperse cerium dioxide nano-crystals with ultra-small particle sizes.

Background

Ceria is an important rare earth metal oxide, and is widely used in the fields of catalysts, ultraviolet absorbing materials, fuel cells, and the like due to its excellent oxygen storage capacity, oxygen release capacity, and good redox capacity.

The morphology, particle size, surface structure, dispersibility and the like of the nano cerium dioxide material have obvious influence on the performance of the nano cerium dioxide material, and the cerium dioxide nano crystal which is monodisperse, ultra-small in particle size, large in specific surface area and high in activity is obtained by improving the preparation process and the preparation method, and is a research hotspot which is continuously concerned internationally. In recent years, the preparation technology of nano-ceria has been rapidly developed, and methods such as precipitation method, sol-gel method, hydrothermal method, peptization method, microemulsion method, hydrolysis method, solvent thermal decomposition method and the like are successfully applied, and the particle size, morphology and agglomeration state of the prepared nano-ceria are different. However, because the cerium dioxide is in a face-centered cubic structure, the crystallization trend is not easy to control in the preparation process, and the difficulty in obtaining monodisperse cerium dioxide nano-crystals with ultra-small particle sizes is very high. From the current research situation, the prepared cerium dioxide nanocrystalline is large in particle size (about 20-100 nm), poor in dispersity, or high in cost due to the adoption of an expensive oily solvent. Therefore, it is necessary to develop a new preparation method for obtaining cerium dioxide nanocrystalline material with good dispersibility and small particle size, which is simple and feasible, high in yield, low in cost.

Disclosure of Invention

The invention aims to provide a preparation method of monodisperse cerium dioxide nanocrystals with ultra-small particle sizes, which solves the problems that the cerium dioxide nanocrystals prepared by the prior art are large in particle size, poor in dispersibility, or high in cost due to the adoption of expensive oily solvents.

The technical scheme adopted for realizing the aim is that the preparation method of the monodisperse ultra-small particle size cerium dioxide nanocrystal comprises the following steps:

(1) dissolving cerous nitrate hexahydrate in deionized water to prepare a cerous nitrate solution, adding N, N-dimethylformamide and triethanolamine, mixing, and magnetically stirring to obtain a uniform mixed solution;

(2) and (2) transferring the mixed solution obtained in the step (1) into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, sealing, placing in an oven, heating and preserving heat, cooling the product to room temperature after the reaction is finished, and performing centrifugal separation and washing on the precipitate to obtain the cerium dioxide nanocrystalline material.

The concentration of the cerium nitrate solution in the step (1) is 0.02-0.08 mol/L; the volume ratio of the triethanolamine to the cerium nitrate solution to the N, N-dimethylformamide is 1: 6-16: 54-64.

The heating temperature of the oven in the step (2) is 150-170 ℃, and the heat preservation time is 5-10 h.

Advantageous effects

Compared with the prior art, the invention has the following advantages.

The method has the advantages that cerous nitrate hexahydrate and triethanolamine are used as raw materials, water and N, N-dimethylformamide are used as solvents, cerous nitrate hexahydrate is dissolved in deionized water to obtain a cerous nitrate solution, then N, N-dimethylformamide is added, and magnetic stirring is carried out; and adding triethanolamine, wherein the triethanolamine is soluble in water and N, N-dimethylformamide and alkaline, the triethanolamine and the solution are mixed and then heated in a reaction kettle to release alkali root ions, the alkali root ions react with cerium ions ionized by cerium nitrate to generate cerium hydroxide, and the cerium hydroxide is thermally decomposed to obtain cerium dioxide nano-crystals.

Drawings

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

FIG. 1 is a TEM image of cerium oxide nanocrystals prepared in example 1 of the present invention;

FIG. 2 is a TEM image of cerium oxide nanocrystals prepared in example 2 of the present invention.

Detailed Description

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

A preparation method of monodisperse ultra-small particle size cerium dioxide nano-crystal comprises the following steps:

(1) dissolving cerous nitrate hexahydrate in deionized water to prepare a cerous nitrate solution, adding N, N-dimethylformamide and triethanolamine, mixing, and magnetically stirring to obtain a uniform mixed solution;

(2) and (2) transferring the mixed solution obtained in the step (1) into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, sealing, placing in an oven, heating and preserving heat, cooling the product to room temperature after the reaction is finished, and performing centrifugal separation and washing on the precipitate to obtain the cerium dioxide nanocrystalline material.

The concentration of the cerium nitrate solution in the step (1) is 0.02-0.08 mol/L; the volume ratio of the triethanolamine to the cerium nitrate solution to the N, N-dimethylformamide is 1: 6-16: 54-64.

The heating temperature of the oven in the step (2) is 150-170 ℃, and the heat preservation time is 5-10 h.

Example 1

(1) Dissolving 0.40 g of cerous nitrate hexahydrate in 20 mL of deionized water, and magnetically stirring to obtain a cerous nitrate solution; then adding 120 mL of N, N-dimethylformamide, and magnetically stirring for 15 min; adding 2 mL of triethanolamine, and magnetically stirring for 30 min to obtain a uniform mixed solution;

(2) and (2) transferring 35mL of the mixed solution obtained in the step (1) into a reaction kettle with a polytetrafluoroethylene lining, sealing, heating in an oven at 150 ℃, preserving heat for 7 h, cooling the product to room temperature after the reaction is finished, centrifugally separating the precipitate, and washing with deionized water and absolute ethyl alcohol for 3 times to obtain the cerium dioxide nanocrystalline material, wherein the formula is shown in figure 1.

Example 2

(1) Dissolving 0.40 g of cerous nitrate hexahydrate in 20 mL of deionized water, and magnetically stirring to obtain a cerous nitrate solution; then adding 120 mL of N, N-dimethylformamide, and magnetically stirring for 15 min; adding 2 mL of triethanolamine, and magnetically stirring for 30 min to obtain a uniform mixed solution;

(2) and (2) transferring 35mL of the mixed solution obtained in the step (1) into a reaction kettle with a polytetrafluoroethylene lining, sealing, heating in a drying oven at 160 ℃, preserving heat for 6 h, cooling the product to room temperature after the reaction is finished, centrifugally separating the precipitate, and washing with deionized water and absolute ethyl alcohol for 3 times to obtain the cerium dioxide nanocrystalline material, wherein the formula is shown in figure 2.

Claims (1)

1. A preparation method of monodisperse cerium dioxide nano-crystal with ultra-small grain diameter is characterized by comprising the following steps:

(1) dissolving cerous nitrate hexahydrate in deionized water to prepare a cerous nitrate solution, adding N, N-dimethylformamide and triethanolamine, mixing, and magnetically stirring to obtain a uniform mixed solution;

(2) transferring the mixed solution obtained in the step (1) into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, sealing, placing in an oven, heating and preserving heat, cooling a product to room temperature after the reaction is finished, and performing centrifugal separation and washing on a precipitate to obtain a cerium dioxide nanocrystalline material;

the concentration of the cerium nitrate solution in the step (1) is 0.02-0.08 mol/L, and the volume ratio of triethanolamine to the cerium nitrate solution to N, N-dimethylformamide is 1: 6-16: 54-64;

the heating temperature of the oven in the step (2) is 150-170 ℃, and the heat preservation time is 5-10 h.

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