阅读说明：本技术 高比表面积二氧化铈的制备方法 (Preparation method of high specific surface area cerium dioxide ) 是由 赵朴素 殷竟洲 朱凤霞 宋洁 李小荣 安礼涛 于 2020-05-29 设计创作，主要内容包括：本发明公开了高比表面积二氧化铈的制备方法,运用水热合成法,在N-N-二甲基甲酰胺水溶液中,以硝酸铈六水合物和新制甲酸溶液为原料,加入聚乙烯吡咯烷酮作为表面活性剂,引入铜离子作为诱导,从而生成偏细形棒状的甲酸铈,对偏细形棒状的甲酸铈进行煅烧得到偏细形的棒状二氧化铈；制备的二氧化铈具有高比表面积的特性,比表面积达151.1961m<Sup>2</Sup>/g,孔径大小主要分布在2-10nm之间；通过紫外-可见光吸收光谱分析,表明了制备的高比表面积的偏细形棒状二氧化铈对罗丹明B具有很好的降解效果,光照140min降解率为94.5％,更一步证实了高比表面积二氧化铈良好的光催化降解性能。(The invention discloses a preparation method of high specific surface area cerium dioxide, which comprises the steps of using a hydrothermal synthesis method, taking cerium nitrate hexahydrate and a newly prepared formic acid solution as raw materials in an N-N-dimethylformamide aqueous solution, adding polyvinylpyrrolidone as a surfactant, introducing copper ions as induction to generate superfine rod-shaped cerium formate, and calcining the superfine rod-shaped cerium formate to obtain superfine rod-shaped cerium dioxide; the prepared cerium dioxide has the characteristic of high specific surface area which reaches 151.1961m 2 The pore size is mainly distributed between 2 nm and 10 nm; by UV-visible absorptionSpectral analysis shows that the prepared superfine rod-shaped cerium dioxide with high specific surface area has a good degradation effect on rhodamine B, the degradation rate is 94.5% after illumination for 140min, and the good photocatalytic degradation performance of the cerium dioxide with high specific surface area is further proved.)

1. The preparation method of the high specific surface area cerium dioxide is characterized by comprising the following steps:

preparation of S1 precursor cerium formate

A1 preparing a fresh formic acid solution from 1mL of 85% formic acid solution and 9mL of distilled water;

a2 is prepared by mixing 10mL of distilled water and 5mL of N-N-dimethylformamide uniformly, adding 0.2426g of cerous nitrate hexahydrate, and stirring with a magnetic stirrer at normal temperature until the cerous nitrate hexahydrate is completely dissolved;

a3, firstly weighing 0.1007g of polyvinylpyrrolidone, adding the polyvinylpyrrolidone, stirring the polyvinylpyrrolidone until the polyvinylpyrrolidone is completely dissolved, then weighing 0.81mL of newly prepared formic acid solution, stirring the solution until the solution is uniformly mixed, finally adding a proper amount of copper ions, stirring the solution until the solution is uniformly mixed, transferring the solution to a 30mL reaction kettle, and carrying out hydrothermal treatment for 1 to 5 days at a constant temperature of between 80 and 100 ℃;

a4 is taken out and cooled, and is centrifugally washed by absolute ethyl alcohol solution for 1-5 times, and then is washed by distilled water for 1-5 times to obtain precipitate, and the precipitate is dried in a drying oven at the constant temperature of 50-70 ℃ for 20-40 min to obtain white powdery solid, namely cerium formate;

s2 preparation of cerium oxide

And putting the precursor cerium formate into a muffle furnace for calcining to obtain light yellow cerium dioxide powder.

2. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: in A3, the polyvinylpyrrolidone is K90 polyvinylpyrrolidone.

3. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: in A3, copper sulfate pentahydrate was added.

4. The method for preparing cerium oxide with high specific surface area according to claim 3, wherein: in A3, the mass of copper sulfate pentahydrate is 0.0270g-0.0280 g.

5. The method for preparing cerium oxide with high specific surface area according to claim 4, wherein: in S3, the mass of copper sulfate pentahydrate was 0.0275 g.

6. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: a3, the mixture was transferred to a 30mL reaction vessel and hydrothermally treated at 90 ℃ for 3 days.

7. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: in A4, the precipitate was obtained by washing with an absolute ethanol solution by centrifugation for 3 times and then with distilled water for 2 times.

8. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: in A4, the drying temperature is constant at 60 ℃ and the drying time is 30 min.

9. The method for preparing cerium oxide with high specific surface area according to claim 1, wherein: and in S2, calcining for 3-5 hours in a muffle furnace at constant temperature of 350-450 ℃.

10. The method for preparing cerium oxide with high specific surface area according to claim 9, wherein: in S2, the mixture was calcined in a muffle furnace at a constant temperature of 400 ℃ for 4 hours.

Technical Field

The invention relates to the field of new materials, in particular to a preparation method of high-specific-surface-area cerium dioxide.

Background

Cerium dioxide is a rare earth material and is a novel material emerging in the field of photocatalysis. The nano-structured cerium dioxide has wide application in the aspects of adsorption, catalysis, electrochemistry, solid oxide fuel cells, air purification catalytic materials, ultraviolet absorption materials and the like. Previously, titanium dioxide is a photocatalyst with the highest utilization rate, but because the solar energy utilization rate of titanium dioxide is low, cerium dioxide is selected as a photocatalyst in a new photocatalytic field, and the cerium dioxide has higher catalytic activity and better stability than the titanium dioxide and is more suitable for treating low-concentration pollution sources.

In the development of modern society science and technology, environmental pollution is increasingly serious, and people have more and more demands on materials, wherein semiconductor materials are artificially manufactured, and have the advantages of longer de broglie wave, higher electronic kinetic energy and the like compared with other naturally existing materials, and the materials are indispensable to the treatment of environmental pollution. Ceria has contributed to this aspect as a good transition metal oxide semiconductor material. In recent years, we have found many methods for synthesizing cerium oxide, of which precipitation methods, sol-gel methods, and hydrothermal synthesis methods are well known. However, the ceria prepared by the conventional method is still insufficient in photocatalytic efficiency as a photocatalyst, and research is required to be continued.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing cerium dioxide with high specific surface area, which comprises controlling the type of surfactant, introducing a proper amount of transition metal ions for induction to prepare a precursor cerium formate metal complex in a shape of a slender rod, and further preparing cerium dioxide, wherein the prepared cerium dioxide has a characteristic of high specific surface area and has higher photocatalytic efficiency.

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

the preparation method of the high specific surface area cerium dioxide comprises the following steps:

preparation of S1 precursor cerium formate

A1 preparing a fresh formic acid solution from 1mL of 85% formic acid solution and 9mL of distilled water;

a2 is prepared by mixing 10mL distilled water and 5mL N-N-dimethylformazane, adding 0.2426g cerous nitrate hexahydrate, and stirring with a magnetic stirrer at room temperature until they are completely dissolved;

a3, firstly weighing 0.1007g of polyvinylpyrrolidone, adding the polyvinylpyrrolidone, stirring the polyvinylpyrrolidone until the polyvinylpyrrolidone is completely dissolved, then weighing 0.81mL of newly prepared formic acid solution, stirring the solution until the solution is uniformly mixed, finally adding a proper amount of copper ions, stirring the solution until the solution is uniformly mixed, transferring the solution to a 30mL reaction kettle, and carrying out hydrothermal treatment for 1 to 5 days at a constant temperature of between 80 and 100 ℃;

a4 is taken out and cooled, and is centrifugally washed by absolute ethyl alcohol solution for 1-5 times, and then is washed by distilled water for 1-5 times to obtain precipitate, and the precipitate is dried in a drying oven at the constant temperature of 50-70 ℃ for 20-40 min to obtain white powdery solid, namely cerium formate;

s2 preparation of cerium oxide

And putting the precursor cerium formate into a muffle furnace for calcining to obtain light yellow cerium dioxide powder.

Preferably, in a3, the polyvinylpyrrolidone is K90 polyvinylpyrrolidone.

Preferably, copper sulfate pentahydrate is added to a 3.

Preferably, in A3, the mass of copper sulfate pentahydrate is 0.0270g-0.0280 g.

Preferably, in A3, the mass of copper sulfate pentahydrate is 0.0275 g.

Preferably, in A3, the mixture is transferred to a 30mL reaction kettle and is hydrothermally treated at a constant temperature of 90 ℃ for 3 days.

Preferably, in A4, the precipitate is obtained after centrifugal washing 3 times with anhydrous ethanol solution and washing 2 times with distilled water.

Preferably, in A4, the drying temperature is constant at 60 ℃ and the drying time is 30 min.

Preferably, in S2, calcining is carried out in a muffle furnace at a constant temperature of 350-450 ℃ for 3-5 hours.

Preferably, in S2, calcination is carried out in a muffle furnace at a constant temperature of 400 ℃ for 4 hours.

Compared with the prior art, the principle and the beneficial effects of the invention are embodied in that:

1. the method comprises the steps of using a hydrothermal synthesis method, adding polyvinylpyrrolidone as a surfactant into an N-N-dimethylformamide aqueous solution by using cerium nitrate hexahydrate and a newly prepared formic acid solution as raw materials, introducing copper ions as an induction agent to generate superfine rod-shaped cerium formate, and calcining the superfine rod-shaped cerium formate to obtain superfine rod-shaped cerium dioxide;

2. the prepared cerium dioxide has the characteristic of high specific surface area which reaches 151.1961m²The pore size is mainly distributed between 2 nm and 10 nm;

3. ultraviolet-visible light absorption spectrum analysis shows that the prepared superfine rod-shaped cerium dioxide with the high specific surface area has a good degradation effect on rhodamine B, the degradation rate is 94.5% in 140min of illumination, and the good photocatalytic degradation performance of the cerium dioxide with the high specific surface area is further proved.

Drawings

FIG. 1 is an XRD spectrum of a precursor cerium formate prepared in example 2;

FIG. 2 is a scanning electron micrograph of a precursor cerium formate prepared in example 2;

FIG. 3 is an XRD spectrum of cerium oxide prepared in example 2;

FIG. 4 is a scanning electron micrograph of cerium oxide prepared in example 2;

FIG. 5 is a BET spectrum of the cerium oxide prepared in example 2;

FIG. 6 is an absorbance-time diagram of photocatalytic degradation of rhodamine B;

FIG. 7 is a reaction rate-time diagram of photocatalytic degradation of rhodamine B;

FIG. 8 is a UV spectrum of cerium formate and cerium oxide prepared in example 2.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings and embodiments, and it is to be understood 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.