CN111439772A

CN111439772A - Preparation method of thorium dioxide nano material

Info

Publication number: CN111439772A
Application number: CN202010160819.XA
Authority: CN
Inventors: 肖松涛; 赵耀林; 欧阳应根; 王玲钰; 左锋; 叶国安
Original assignee: China Institute of Atomic of Energy
Current assignee: China Institute of Atomic of Energy
Priority date: 2020-03-10
Filing date: 2020-03-10
Publication date: 2020-07-24

Abstract

The invention belongs to the technical field of nano materials, and relates to a preparation method of a thorium dioxide nano material. The preparation method comprises the steps of uniformly mixing a thorium nitrate solution and a sodium hydroxide solution, adding the mixture into a reaction kettle for hydrothermal reaction, cooling a reaction product to room temperature, washing the reaction product with water until the pH value is 7.5-8.5, drying and grinding the reaction product to obtain the thorium dioxide nano material. By using the preparation method of the thorium dioxide nano material, the ThO with controllable appearance, lighter agglomeration, uniform particle size, higher specific surface area and good catalytic activity can be prepared on a large scale₂Ceramic nano-powder.

Description

Preparation method of thorium dioxide nano material

Technical Field

The invention belongs to the technical field of nano materials, and relates to a preparation method of a thorium dioxide nano material.

Background

Thorium dioxide (ThO)₂) Actinide metal oxides are not only important nuclear fuels, but also have been widely used in the fields of adsorption, catalysis, and the like. In order to obtain ThO with better comprehensive performance₂Scientists have tried different preparation methods and raw materials.

Chen et al use oxalic acid precipitation to react thorium nitrate solution with oxalic acid and then calcine to make ThO₂Powders L iu et al were irradiated with a soluble thorium complex (NH)₄)₄Th(C₂O₄)₄Is used as reactant to obtain micron-sized insoluble precursor, and is sintered at 600 ℃ to obtain ThO₂Micron particles. Mishra et al synthesized ThO containing water of crystallization by precipitation₂It was found to be specific for Ba in radioactive waste liquid²⁺And Sr²⁺The cation has better adsorption effect.

The hydrothermal method for preparing the ceramic nano powder does not need high-temperature calcination treatment, and the growth of crystal grains, defect formation and impurity introduction caused in the calcination process are avoided, so that the prepared powder has higher activity.

L iu, etc. by hydrothermal method, using thorium nitrate, urea and glycerol as raw materials to prepare ThO₂Ceramic powder is used for adsorption. Cui and the like are subjected to mixed reaction of thorium nitrate solution and urea solution by using a microwave-assisted hydrothermal method to obtain ThO with a sheet-shaped surface structure₂A ceramic nanomaterial.

Although there are already many ThO' s₂The preparation method, however, prepares ThO with controllable morphology, lighter agglomeration, uniform particle size, higher specific surface area and good catalytic activity on a large scale₂Efforts are still needed for ceramic nanopowders.

Disclosure of Invention

The invention aims to provide a preparation method of thorium dioxide nano material, so as to be large-scaleThe ThO with controllable appearance, lighter agglomeration, uniform particle size, higher specific surface area and good catalytic activity is prepared by a die₂Ceramic nano-powder.

In order to realize the purpose, in a basic embodiment, the invention provides a preparation method of thorium dioxide nano material, which comprises the steps of uniformly mixing a thorium nitrate solution and a sodium hydroxide solution, adding the mixture into a reaction kettle for hydrothermal reaction, cooling a reaction product to room temperature, washing the reaction product to pH7.5-8.5 with water, drying and grinding the reaction product to obtain the thorium dioxide nano material.

In a preferred embodiment, the invention provides a preparation method of thorium dioxide nano-material, wherein the concentration of the thorium nitrate solution is 0.5-1.0 mol/L, the concentration of the sodium hydroxide solution is 5-8 mol/L, and the mixing volume ratio of the thorium nitrate solution and the sodium hydroxide solution is 1:10-1: 20.

In a preferred embodiment, the invention provides a preparation method of thorium dioxide nano-material, wherein the reaction kettle is a stainless steel high-temperature high-pressure reaction kettle taking polytetrafluoroethylene as a lining.

In a preferred embodiment, the invention provides a preparation method of thorium dioxide nano-material, wherein the temperature of the hydrothermal reaction is 80-100 ℃, the pressure is 0.6-0.8MPa, and the time is 18-48 hours.

The method has the beneficial effects that by using the preparation method of the thorium dioxide nano material, the ThO with controllable appearance, lighter agglomeration, uniform particle size, higher specific surface area and good catalytic activity can be prepared on a large scale₂Ceramic nano-powder.

Drawings

FIG. 1 is an XRD detection spectrum of thorium dioxide nano-materials prepared in examples 1-3.

FIG. 2 is a scanning electron microscope detection spectrum of the thorium dioxide nanomaterial prepared in example 1.

FIG. 3 is a scanning electron microscope detection spectrum of the thorium dioxide nanomaterial prepared in example 2.

FIG. 4 is a scanning electron microscope detection spectrum of the thorium dioxide nanomaterial prepared in example 3.

Detailed Description

The following description will further describe embodiments of the present invention with reference to the accompanying drawings.

Example 1:

dropwise adding a thorium nitrate solution of 5m L0.5 mol/L into a sodium hydroxide solution of 75m L5 mol/L, stirring the mixed solution at room temperature for 30min, then transferring the mixed solution into a stainless steel reaction kettle with a 100m L polytetrafluoroethylene lining, placing the stainless steel reaction kettle in an oven at 80 ℃ and 0.6MPa for 48h, cooling to room temperature, washing with ultrapure water to pH7.5, drying and grinding at 60 ℃ to obtain ThO₂White powder.

To obtain ThO₂White powder was measured, XRD pattern and ThO₂Standard PDF cards 65-0291 correspond (see fig. 1); the scanning electron microscope detection result shows that (see figure 2) the particle size is relatively uniform, the average grain size is 8.7nm, and the dispersibility is good.

Example 2:

dropwise adding a thorium nitrate solution of 5m L0.8 mol/L into a sodium hydroxide solution of 75m L6.4.4 mol/L, stirring the mixed solution at room temperature for 30min, then transferring the mixed solution into a stainless steel reaction kettle with a 100m L polytetrafluoroethylene lining, placing the stainless steel reaction kettle in an oven at 90 ℃ and 0.7MPa for 30h, cooling to room temperature, washing with ultrapure water to pH 8.0, drying and grinding at 60 ℃ to obtain ThO₂White powder.

To obtain ThO₂White powder was measured, XRD pattern and ThO₂Standard PDF cards 65-0291 correspond (see fig. 1); the scanning electron microscope detection result shows (see figure 3), the particle size is relatively uniform, the average grain size is 8.9nm, and the dispersibility is good.

Example 3:

dropwise adding a thorium nitrate solution of 5m L1.0 mol/L into a sodium hydroxide solution of 75m L8 mol/L, stirring the mixed solution at room temperature for 30min, then transferring the mixed solution into a stainless steel reaction kettle with 100m L and polytetrafluoroethylene as a lining, placing the stainless steel reaction kettle in an oven at 100 ℃ and 0.8MPa for 18h, cooling to room temperature, washing with ultrapure water to pH 8.5, drying and grinding at 60 ℃ to obtain ThO₂White powder.

To obtain ThO₂White powder was measured, XRD pattern and ThO₂Standard PDF cards 65-0291 correspond (see fig. 1); the scanning electron microscope detection result shows (see figure 4), the particle size is relatively uniform, the average grain size is 9.6nm, and the dispersibility is good.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations. The foregoing examples or embodiments are merely illustrative of the present invention, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the invention should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims should be construed to be included therein.

Claims

1. A preparation method of thorium dioxide nano material is characterized by comprising the following steps: the preparation method comprises the steps of uniformly mixing a thorium nitrate solution and a sodium hydroxide solution, adding the mixture into a reaction kettle for hydrothermal reaction, cooling a reaction product to room temperature, washing the reaction product with water until the pH value is 7.5-8.5, drying and grinding the reaction product to obtain the thorium dioxide nano material.

2. The preparation method of claim 1, wherein the concentration of the thorium nitrate solution is 0.5-1.0 mol/L, the concentration of the sodium hydroxide solution is 5-8 mol/L, and the mixing volume ratio of the thorium nitrate solution to the sodium hydroxide solution is 1:10-1: 20.

3. The method of claim 1, wherein: the reaction kettle is a stainless steel high-temperature high-pressure reaction kettle taking polytetrafluoroethylene as a lining.

4. The method of claim 1, wherein: the temperature of the hydrothermal reaction is 80-100 ℃, the pressure is 0.6-0.8MPa, and the time is 18-48 hours.