CN102020306A - Microwave rapid synthetic method of nanometer cerium oxide - Google Patents

Abstract

Translated fromChinese

本发明提供了纳米二氧化铈的微波快速合成方法。其特征是：以功率连续可调的家用微波炉为热源，采用简单的微波辅助回流的方法，以水为溶剂，有机胺为碱源：三乙烯四胺、四乙烯五胺、二乙醇胺和乙醇胺，无需高温高压，无需添加表面活性剂，10-30min快速合成了纳米二氧化铈。采用微波加热，不仅缩短了二氧化铈的合成时间，还使合成的产物粒度更为均匀。本方法所制备得到的二氧化铈粒径约为5nm，具有分散性好、不易团聚、合成路径简单和操作便捷等优点。

The invention provides a microwave rapid synthesis method of nanometer ceria. Its characteristics are: using a domestic microwave oven with continuously adjustable power as the heat source, adopting a simple microwave-assisted reflux method, using water as a solvent, and organic amines as alkali sources: triethylenetetramine, tetraethylenepentamine, diethanolamine and ethanolamine, Nano ceria was quickly synthesized in 10-30 minutes without high temperature and high pressure, without adding surfactant. Microwave heating not only shortens the synthesis time of ceria, but also makes the particle size of the synthesized product more uniform. The particle size of the cerium oxide prepared by the method is about 5nm, and has the advantages of good dispersibility, difficulty in agglomeration, simple synthesis path, convenient operation and the like.

Description

Translated fromChinese

纳米二氧化铈的微波快速合成方法Rapid Microwave Synthesis of Nano-Cerium Oxide

技术领域technical field

本发明涉及制备纳米二氧化铈的方法。The invention relates to a method for preparing nanometer ceria.

背景技术Background technique

纳米稀土材料是稀土产业革命的主力军，是未来稀土产品研发的一个重要方向，对其研究引起越来越多研究作者的关注，许多国家都在这方面投入巨资，以其占领其研发的制高点或一席之地。CeO₂是一种廉价、用途极广的轻稀土氧化物，并且享有“二十一世纪的工业味精”之美誉。广泛用作发光材料、电子陶瓷、玻璃的抛光剂、玻璃脱色澄清剂；也是超导体、陶瓷、气体传感器、石油裂解催化剂和均相催化剂中的重要组成成分。CeO₂的物理化学性质可以直接影响材料的性能，如：加入超细CeO₂不但可以降低陶瓷的烧结温度，还可以增加陶瓷的密度；大比表面积可以提高催化剂的催化活性；并且铈具有变价，对发光材料也具有重要意义。纳米二氧化铈表现出许多体状二氧化铈不具有的优异特性而成为当前二氧化铈未来研发的一个主要方向，也是当前研究的热点。纳米CeO₂优异性能的发挥很大程度上取决于颗粒的大小，粒径小、分布均匀的纳米CeO₂颗粒材料的制备成为一个迫切需要解决的课题。纳米二氧化铈的制备方法主要有沉淀法、溶胶一凝胶法，水热法、微乳液法、喷雾反应法等。其中沉淀法是液相化学合成高纯度纳米粒子广泛采用的方法。它是把沉淀剂(OH^一，CO₃^2一，SO4^2-，C₂O₄^2-等)加入金属盐溶液中进行沉淀处理，再将沉淀物过滤、干燥、焙烧、就制得纳米级氧化物粉末，是典型的液相法。沉淀法主要用于制备纳米级金属氧化物粉末。常用的沉淀法有直接沉淀法、共沉淀法、水解沉淀法、均相沉淀法、鳌合物分解法等。沉淀反应过程中，由于颗粒间的直接接触或是受“接触再结晶”支配，粒子会不可逆地粘在一起发生凝聚。实验过程可采用双电层、凝胶网络以及保护试剂来抑制。文献[中国稀土学报，2001，l9 (1): 24]利用采用乙醇为分散剂和保护剂，以氨水为沉淀剂将Ce³⁺沉淀，反应过程中还用H₂O₂为氧化剂来促进Ce(OH)₃向Ce(OH)₄的转化，最后将得到的棕色沉淀离心分离，在不同的温度下进行焙烧，得到纳米CeO₂。实验结果表明采用有机溶剂为溶剂，团聚问题有所改善，同时乙醇的包覆作用也抑制了粒子的生长，获得的纳米CeO₂粒子小。文献[Materials Letters，2002，56: 610] 在制备纳米CeO₂的过程中将Ce(OH)₄过滤、乙醇洗涤，然后再用乙二酸乙二醇脂和乙醇循环过滤再分散，经焙烧制的了平均粒径为10-50 nm的CeO₂粒子。Nano-rare earth materials are the main force of the rare earth industry revolution and an important direction for the research and development of rare earth products in the future. Their research has attracted more and more research authors' attention. commanding heights or place. CeO₂ is a cheap and widely used light rare earth oxide, and enjoys the reputation of "industrial monosodium glutamate in the 21st century". It is widely used as luminescent material, electronic ceramics, glass polishing agent, glass decolorization clarifier; it is also an important component in superconductors, ceramics, gas sensors, petroleum cracking catalysts and homogeneous catalysts. The physical and chemical properties of CeO₂ can directly affect the performance of materials, such as: adding ultra-fine CeO₂ can not only reduce the sintering temperature of ceramics, but also increase the density of ceramics; large specific surface area can improve the catalytic activity of catalysts; and cerium has a variable price, It is also of great significance to luminescent materials. Nano ceria exhibits many excellent properties that bulk ceria does not have, so it has become a main direction of future research and development of ceria, and it is also a hot spot of current research. The excellent performance of nano-CeO₂ largely depends on the size of the particles. The preparation of nano-CeO₂ particles with small particle size and uniform distribution has become an urgent problem to be solved. The preparation methods of nano ceria mainly include precipitation method, sol-gel method, hydrothermal method, microemulsion method, spray reaction method and so on. Among them, the precipitation method is a widely used method for liquid-phase chemical synthesis of high-purity nanoparticles. It is to add a precipitant (^OH- , CO₃^2- , SO4^2- , C₂ O₄^2- , etc.) Oxide powder is a typical liquid phase method. The precipitation method is mainly used to prepare nanoscale metal oxide powders. Commonly used precipitation methods include direct precipitation, co-precipitation, hydrolysis precipitation, homogeneous precipitation, and chelate decomposition. During the precipitation reaction, due to direct contact between particles or dominated by "contact recrystallization", particles will irreversibly stick together and agglomerate. Experimental processes can be inhibited using electric double layers, gel networks, and protective reagents. The literature [Chinese Journal of Rare Earth, 2001, l9 (1): 24] uses ethanol as a dispersant and protective agent, ammonia water as a precipitant to precipitate Ce 3+, and H₂ O₂ is used as an oxidant to promote Ce³⁺ during the reaction process. Transformation of (OH)₃ to Ce(OH)₄ , and finally the obtained brown precipitate was centrifuged and roasted at different temperatures to obtain nano CeO₂ . The experimental results show that the problem of agglomeration is improved by using an organic solvent as the solvent, and the coating effect of ethanol also inhibits the growth of the particles, and the obtained nano-CeO₂ particles are small. Literature [Materials Letters, 2002, 56: 610] in the process of preparing nano-_CeO2 , Ce(OH)₄ is filtered, washed with ethanol, and then redispersed with ethylene glycol oxalate and ethanol circulation filtration, and roasted._CeO2 particles with an average particle size of 10-50 nm were obtained.

文献[化学通报，1998，12: 51] 成功地利用W/O微乳液法制备了粒径小于40 nm的CeO₂超细粒子。该方法制备过程中，粒子间不易聚结，粒子的大小可通过选择不同的表面活性剂分子进行控制。但该方法在制备过程中所消耗表面活性剂及溶剂量多，很难从最后获得的粒子表面除去这些有机物，且成本较高。因此在反应过程中，提倡介质的循环利用。目前此种方法正处在研究热点时期，还需研究微乳液性质，寻求成本低，易回收的表面活性剂，建立适合工业化的生产体系。The literature [Chemical Bulletin, 1998, 12: 51] successfully prepared CeO₂ ultrafine particles with a particle size of less than 40 nm by using the W/O microemulsion method. During the preparation process of the method, the particles are not easy to coalesce, and the size of the particles can be controlled by selecting different surfactant molecules. However, this method consumes a lot of surfactants and solvents during the preparation process, and it is difficult to remove these organic substances from the surface of the finally obtained particles, and the cost is relatively high. Therefore, in the reaction process, the recycling of the medium is advocated. At present, this method is in the research hotspot period, and it is necessary to study the properties of microemulsions, find low-cost, easy-to-recycle surfactants, and establish a production system suitable for industrialization.

制备超细及纳米CeO₂的方法还有熔融法，喷雾反应法、燃烧法、电化学合成法等，这些制备超细及纳米CeO₂的方法，目前均处于试验研究阶段。各种制备方法从实验原料、反应条件、所用仪器设备、最后所得粒子的大小等方面都有其不同的特点。Methods for preparing ultrafine and nanometer_CeO2 include melting method, spray reaction method, combustion method, electrochemical synthesis method, etc. These methods for preparing ultrafine and nanometer_CeO2 are currently in the stage of experimental research. Various preparation methods have different characteristics in terms of experimental raw materials, reaction conditions, instruments and equipment used, and the size of the finally obtained particles.

20世纪80年代新兴发展起来的微波是一种新型的加热技术，具有快速高效(比传统高温固相法快15～20倍) ，反应温度也相对较低(比传统高温固相低300～500 ℃)、省电节能(50 %～80 %)、环保、产物纯度高和操作方便等优点。此外，微波合成的产物粒度均匀且细小，是合成纳米材料的一种有效手段。特别是在微波炉的技术已日臻完善的今天，有望在不久的将来实现工业化生产。我们曾用成功用半工业微波炉[02149755]合成4A分子筛，量产可达5公斤。结果表明用微波合成的产物粒度均匀，粒度要比常规法小，合成周期短，具有快速节能等优点。The microwave developed in the 1980s is a new type of heating technology, which is fast and efficient (15-20 times faster than the traditional high-temperature solid-phase method), and the reaction temperature is relatively low (300-500 times lower than the traditional high-temperature solid-phase method). ℃), energy saving (50% to 80%), environmental protection, high product purity and convenient operation. In addition, the particle size of microwave synthesis products is uniform and small, which is an effective means of synthesizing nanomaterials. Especially today, as the technology of microwave ovens has been perfected day by day, it is expected to realize industrialized production in the near future. We have successfully used semi-industrial microwave [02149755] to synthesize 4A molecular sieve, and the mass production can reach 5 kg. The results show that the particle size of the product synthesized by microwave is uniform, the particle size is smaller than that of the conventional method, the synthesis period is short, and it has the advantages of rapid energy saving and so on.

专利[200710118268]将铈离子溶液与碱液混合，然后放入微波高压反应罐中，经微波辅助反应得到氧化铈纳米粒子。此法的优点在于，制备工艺简单，反应时间短，节省能源，所得氧化铈纳米粒子粒径小，分散性好，形貌规整。文献[无机盐工业，2007, 39: 21]以四水硫酸高铈和氢氧化钠为反应物, 表面活性剂聚乙二醇起到分散产物的作用, 在微波作用下制备纳米二氧化铈，在最优工艺条件下制备的产物颗粒粒径为24. 9 nm。但上述反应均在密闭容器中进行，安全性不好，仪器设备要求较高，不易进行工业放大量合成。The patent [200710118268] mixes cerium ion solution with lye, and then puts it into a microwave high-pressure reaction tank, and obtains cerium oxide nanoparticles through microwave-assisted reaction. The method has the advantages of simple preparation process, short reaction time and energy saving, and the obtained cerium oxide nanoparticles have small particle size, good dispersibility and regular shape. The literature [Inorganic Salt Industry, 2007, 39: 21] uses cerium sulfate tetrahydrate and sodium hydroxide as reactants, and the surfactant polyethylene glycol plays the role of dispersing the product, and prepares nano-cerium dioxide under the action of microwaves. The particle size of the product prepared under the optimal process conditions was 24.9 nm. However, the above-mentioned reactions are all carried out in airtight containers, and the safety is not good, and the requirements for instruments and equipment are relatively high, and it is difficult to carry out industrial scale-up synthesis.

发明内容Contents of the invention

CeO₂ 作为一种重要的催化剂(或助剂)和催化剂载体，均具有独特的性质。由于纳米粒子的比表面积大、化学活性高，和体状CeO₂ 相比，表现出许多优异的性能。本发明的目的就在于提供了一种简便的纳米CeO₂粒子的方法。As an important catalyst (or additive) and catalyst carrier, CeO₂ has unique properties. Due to the large specific surface area and high chemical activity of nanoparticles, they exhibit many excellent properties compared with bulk CeO₂ . The purpose of the present invention is to provide a kind of easy nano-_CeO2 particle method.

本发明（第一发明）提供了一种简易合成纳米CeO₂粒子的制备方法，其特征是：采用微波法合成超细纳米CeO₂粒子，产物具有很好的分散性，颗粒尺寸小且均匀。通过利用微波加热，大大缩短了CeO₂的合成时间，减少了能耗，降低了合成的成本。The present invention (the first invention) provides a simple method for preparing nano-CeO₂ particles, which is characterized in that ultra-fine nano-CeO₂ particles are synthesized by a microwave method, and the product has good dispersibility, and the particle size is small and uniform. By using microwave heating, the synthesis time of_CeO2 is greatly shortened, the energy consumption is reduced, and the cost of synthesis is reduced.

本发明制备超细纳米CeO₂粒子的方法按如下步骤进行：The present invention prepares_superfine nanometer CeO The method for particle is carried out as follows:

a.      以硝酸亚铈或硝酸铈铵或氯化亚铈为铈源，三乙烯四胺或四乙烯五胺或二乙醇胺或乙醇胺为碱源，溶剂为水；a. Use cerous nitrate or cerous ammonium nitrate or cerous chloride as the cerium source, triethylenetetramine or tetraethylenepentamine or diethanolamine or ethanolamine as the alkali source, and the solvent is water;

b.     将铈源和水加入到烧瓶中，搅拌15 min，然后加入有机碱至上述溶液，继续搅拌30min，微波电流在20～80 mA，40 mA；功率45～150 W，反应时间15 min。b. Add cerium source and water into the flask, stir for 15 minutes, then add organic base to the above solution, continue stirring for 30 minutes, microwave current at 20-80 mA, 40 mA; power 45-150 W, reaction time 15 minutes.

c.     待反应完成后取出，离心分离沉淀物，用水和乙醇分别洗涤三次，洗去表面碱液和杂质，烘干。c. After the reaction is completed, take it out, centrifuge the precipitate, wash it with water and ethanol three times respectively, wash away the surface lye and impurities, and dry it.

本发明制备超细纳米CeO₂粒子的更优方法按如下步骤进行：The present invention prepares_ultrafine nanometer CeO The better method of particle is carried out as follows:

  将硝酸亚铈（Ce(NO₃)₃??6H₂O）和30 mL水加入到100 mL的圆底烧瓶中，电磁搅拌15 min，然后加入150 μL三乙烯四胺至上述溶液，继续搅拌30min，搭好反应装置，将微波炉功率调到90 W，电流40 mA，反应时间设置为15 min。Add cerous nitrate (Ce(NO₃ )₃ ??6H₂ O) and 30 mL of water into a 100 mL round-bottomed flask, stir for 15 min, then add 150 μL of triethylenetetramine to the above solution, and continue stirring After 30 minutes, set up the reaction device, adjust the power of the microwave oven to 90 W, the current to 40 mA, and the reaction time to 15 minutes.

本发明采用经改装的微波炉合成纳米二氧化铈，无需高压密闭合成，合成装置简单，重复性好，利于工业放大量合成。本发明反应为敞开体系，以水为介质，且不用添加表面活性剂，易于进行放大量合成，相比于现有方法有具有很好的优越性。The invention adopts a refitted microwave oven to synthesize nano cerium dioxide, does not need high-pressure airtight synthesis, has a simple synthesis device, good repeatability, and is beneficial to industrial large-scale synthesis. The reaction of the present invention is an open system, uses water as the medium, and does not need to add surfactants, and is easy to carry out large-scale synthesis, and has great advantages compared with the existing methods.

本发明采用微波加热，由于加热速度快，可在较短的时间内形成大量的CeO₂晶核，合成的CeO₂晶粒小且均匀，且在微波场中合成的产物不易团聚。The present invention adopts microwave heating. Due to the fast heating speed, a large number of_CeO2 crystal nuclei can be formed in a relatively short time, and the synthesized_CeO2 crystal grains are small and uniform, and the products synthesized in the microwave field are not easy to agglomerate.

本发明通过对原料配方的选择，以有机胺为碱源，既可起到碱的作用，又可起到表面活性剂的作用，降低了CeO₂的粒径，还使合成的产物不易团聚，分散性好。In the present invention, through the selection of the raw material formula, organic amines are used as the alkali source, which can not only play the role of alkali, but also play the role of surfactant, reduce the particle size of_CeO , and make the synthesized products difficult to agglomerate, Good dispersion.

本发明采用的微波加热功率90~150 W，电流40~80 mA。最佳条件为功率90 W，电流40 mA下反应，最佳的反应时间为15 min。The microwave heating power adopted in the present invention is 90-150 W, and the electric current is 40-80 mA. The best conditions are 90 W power, 40 mA current, and the best reaction time is 15 min.

所述的纳米二氧化铈的制备方法，在水溶液中进行，具有溶剂易得、环保和价廉的特点。The preparation method of nanometer cerium dioxide is carried out in aqueous solution, and has the characteristics of easy-to-obtain solvent, environmental protection and low price.

本发明中各种原料对原料纯度要求低，操作弹性增大；合成出的超细纳米CeO₂粒子平均粒径2～5 nm，分布均匀。完全适用于催化剂、抛光粉、电极材料等领域。Various raw materials in the invention have low requirements on raw material purity, and the operating flexibility is increased; the average particle diameter of the synthesized ultrafine nanometer_CeO2 particles is 2-5 nm, and the distribution is uniform. It is completely suitable for catalysts, polishing powders, electrode materials and other fields.

附图说明Description of drawings

图1超细纳米CeO₂的XRD图。Figure 1 XRD pattern of ultrafine nano-CeO₂ .

图2三乙烯四胺为碱源合成纳米CeO₂的透射电镜图。Fig. 2 is the transmission electron micrograph of nano-CeO₂ synthesized by triethylenetetramine as alkali source.

图3四乙烯五胺为碱源合成纳米CeO₂的透射电镜图。Fig. 3 is the transmission electron micrograph of nanometer CeO₂ synthesized by tetraethylenepentamine as alkali source.

图4乙醇胺为碱源合成纳米CeO₂的透射电镜图。Fig. 4 ethanolamine is the transmission electron micrograph of nano-CeO₂ synthesized by alkali source.

图5二乙醇胺为碱源合成纳米CeO₂的透射电镜图。Fig. 5 is the transmission electron micrograph of nanometer CeO₂ synthesized by diethanolamine as alkali source.

为了进一步描述本发明，下面给出了几个具体实施案例，但专利权利并不局限于这些例子。In order to further describe the present invention, several specific implementation cases are given below, but patent rights are not limited to these examples.

具体实施例specific embodiment

实施例1Example 1

在连续搅拌下，将0.5 mmol 的Ce(NO₃)₃·6H₂O溶解在30 ml去离子水中；然后，将150 ??l的三乙烯四胺在搅拌的条件下滴加到上述反应液中；继续搅拌30 min，最终形成紫色悬浊液；然后悬浊液转移至100 mL圆底烧瓶中，置于微波炉(改装的家用微波炉，带回流装置，微波功率可调)，控制微波功率为90 W，反应时间为15 min；反应结束后自然冷却到室温。将产物离心分离，用去离子水和乙醇循环洗涤沉淀三次。最后将所得产物置于烘箱中，在80 ℃下烘4 h，即得到最终产物。Under continuous stirring, dissolve 0.5 mmol of Ce(NO₃ )₃ 6H₂ O in 30 ml of deionized water; then, add 150??l of triethylenetetramine dropwise to the above reaction solution under stirring Continue to stir for 30 min to form a purple suspension; then transfer the suspension to a 100 mL round-bottomed flask and place it in a microwave oven (a modified household microwave oven with a reflux device and adjustable microwave power), and control the microwave power to 90 W, the reaction time is 15 min; naturally cool to room temperature after the reaction. The product was separated by centrifugation, and the precipitate was washed three times with deionized water and ethanol cycles. Finally, the obtained product was placed in an oven and baked at 80 °C for 4 h to obtain the final product.

XRD衍射图用Philips X’ Pert Pro Super X-ray衍射仪测定(λ = 1.541 78 ??)。透射照片用Hitachi H-800透射电镜拍摄。The XRD diffraction pattern was measured with a Philips X' Pert Pro Super X-ray diffractometer (λ = 1.541 78 ??). Transmission pictures were taken with a Hitachi H-800 transmission electron microscope.

图1为合成样品的XRD图，从图中可知，样品的峰完全和CeO₂的标准谱图吻合(JCPDS No. 81-0792)，并且没有杂峰，说明可用微波快速合成纯度较高的二氧化铈。此外，样品的XRD衍射峰较宽，进一步说明合成产物的粒度较小。Figure 1 is the XRD pattern of the synthesized sample. It can be seen from the figure that the peak of the sample is completely consistent with the standard spectrum of_CeO2 (JCPDS No. 81-0792), and there are no miscellaneous peaks, indicating that microwaves can be used to quickly synthesize the higher purity CeO2. Ceria. In addition, the XRD diffraction peaks of the samples are broad, which further indicates that the synthesized products have a smaller particle size.

图2是样品的TEM图，从图可知合成的二氧化铈的颗粒分布很均匀，且具有较好的分散性，粒径在3-5 nm之间。Figure 2 is the TEM image of the sample. It can be seen from the figure that the particle distribution of the synthesized ceria is very uniform, and has good dispersion, and the particle size is between 3-5 nm.

实施例2Example 2

在连续搅拌下，将0.5 mmol 的Ce(NO₃)₃·6H₂O溶解在30 ml去离子水中；然后，将150 ??l的四乙烯五胺在搅拌的条件下滴加到上述反应液中；继续搅拌30 min，最终形成紫色悬浊液；然后悬浊液转移至100 mL圆底烧瓶中，置于微波炉(改装的家用微波炉，带回流装置，微波功率可调)，控制微波功率为90 W，反应时间为15 min；反应结束后自然冷却到室温。将产物离心分离，用去离子水和乙醇循环洗涤沉淀三次。最后将所得产物置于烘箱中，在80 ℃下烘4 h，即得到最终产物。图3是合成样品的TEM图，从图可知，样品的结晶性不是很好，为很细小的颗粒，产物粒径小于5 nm。Under continuous stirring, dissolve 0.5 mmol of Ce(NO₃ )₃ 6H₂ O in 30 ml of deionized water; then, add 150??l of tetraethylenepentamine dropwise to the above reaction solution under stirring Continue to stir for 30 min to form a purple suspension; then transfer the suspension to a 100 mL round-bottomed flask and place it in a microwave oven (a modified household microwave oven with a reflux device and adjustable microwave power), and control the microwave power to 90 W, the reaction time is 15 min; naturally cool to room temperature after the reaction. The product was separated by centrifugation, and the precipitate was washed three times with deionized water and ethanol cycles. Finally, the obtained product was placed in an oven and baked at 80 °C for 4 h to obtain the final product. Figure 3 is the TEM image of the synthesized sample. It can be seen from the figure that the crystallinity of the sample is not very good, and it is a very fine particle, and the particle size of the product is less than 5 nm.

实施例3Example 3

在连续搅拌下，将0.5 mmol 的Ce(NO₃)₃·6H₂O溶解在30 ml去离子水中；然后，将150 ??l的乙醇胺在搅拌的条件下滴加到上述反应液中；继续搅拌30 min，最终形成紫色悬浊液；然后悬浊液转移至100 mL圆底烧瓶中，置于微波炉(改装的家用微波炉，带回流装置，微波功率可调)，控制微波功率为90 W，反应时间为15 min；反应结束后自然冷却到室温。将产物离心分离，用去离子水和乙醇循环洗涤沉淀三次。最后将所得产物置于烘箱中，在80 ℃下烘4 h，即得到最终产物。图4是样品的TEM图，从图可知产物粒度较为均匀，为5 nm左右的颗粒。Under continuous stirring, dissolve 0.5 mmol of Ce(NO₃ )₃ ·6H₂ O in 30 ml of deionized water; then, add 150??l of ethanolamine dropwise to the above reaction solution while stirring; continue After stirring for 30 min, a purple suspension was finally formed; then the suspension was transferred to a 100 mL round-bottomed flask, placed in a microwave oven (a modified household microwave oven with a reflux device, and the microwave power is adjustable), and the microwave power was controlled at 90 W. The reaction time was 15 min; after the reaction was completed, it was naturally cooled to room temperature. The product was separated by centrifugation, and the precipitate was washed three times with deionized water and ethanol cycles. Finally, the obtained product was placed in an oven and baked at 80 °C for 4 h to obtain the final product. Figure 4 is the TEM image of the sample. It can be seen from the figure that the particle size of the product is relatively uniform, which is about 5 nm.

实施例4Example 4

在连续搅拌下，将0.5 mmol 的Ce(NO₃)₃·6H₂O溶解在30 ml去离子水中；然后，将150 ??l的二乙醇胺在搅拌的条件下滴加到上述反应液中；继续搅拌30 min，最终形成紫色悬浊液；然后悬浊液转移至100 mL圆底烧瓶中，置于微波炉(改装的家用微波炉，带回流装置，微波功率可调)，控制微波功率为90 W，反应时间为15 min；反应结束后自然冷却到室温。将产物离心分离，用去离子水和乙醇循环洗涤沉淀三次。最后将所得产物置于烘箱中，在80 ℃下烘4 h，即得到最终产物。图5是样品的TEM图，从图可知产物粒度较为均匀，为5 nm左右的颗粒。Under continuous stirring, 0.5 mmol of Ce(NO₃ )₃ 6H₂ O was dissolved in 30 ml of deionized water; then, 150??l of diethanolamine was added dropwise to the above reaction solution under stirring; Stirring was continued for 30 min, and finally a purple suspension was formed; then the suspension was transferred to a 100 mL round bottom flask, placed in a microwave oven (modified household microwave oven, equipped with a reflux device, and the microwave power is adjustable), and the microwave power was controlled at 90 W , the reaction time was 15 min; after the reaction was completed, it was naturally cooled to room temperature. The product was separated by centrifugation, and the precipitate was washed three times with deionized water and ethanol cycles. Finally, the obtained product was placed in an oven and baked at 80 °C for 4 h to obtain the final product. Figure 5 is the TEM image of the sample. It can be seen from the figure that the particle size of the product is relatively uniform, which is about 5 nm.

Claims (4)

Translated fromChinese

1.纳米二氧化铈的微波快速合成方法，其特征是在微波辅助回流条件下，其制备步骤如下：1. The microwave rapid synthesis method of nanometer cerium oxide is characterized in that under microwave-assisted reflux conditions, its preparation steps are as follows:以硝酸亚铈或硝酸铈铵或氯化亚铈为铈源，三乙烯四胺或四乙烯五胺或二乙醇胺或乙醇胺为碱源，溶剂为水；Use cerous nitrate or cerous ammonium nitrate or cerous chloride as the cerium source, triethylenetetramine or tetraethylenepentamine or diethanolamine or ethanolamine as the alkali source, and the solvent is water;将铈源和水加入到烧瓶中，搅拌15 min，然后加入有机碱至上述溶液，继续搅拌30min，微波电流在20～80 mA，40 mA；功率45～150 W，反应时间15 min；Add cerium source and water into the flask, stir for 15 min, then add organic base to the above solution, continue stirring for 30 min, microwave current at 20-80 mA, 40 mA; power 45-150 W, reaction time 15 min;待反应完成后取出，离心分离沉淀物，用水和乙醇分别洗涤三次，洗去表面碱液和杂质，烘干。After the reaction is completed, take it out, centrifuge the precipitate, wash it with water and ethanol three times respectively, wash away the surface lye and impurities, and dry it.2.根据权利要求1所述的纳米二氧化铈的制备方法，其特征是将铈源和30 mL水加入到100 mL的圆底烧瓶中，电磁搅拌15 min，然后加入150 μL三乙烯四胺至上述溶液，继续搅拌30min，搭好反应装置，将微波炉功率调到90 W，电流40 mA，反应时间设置为15 min。2. the preparation method of nano-cerium dioxide according to claim 1 is characterized in that cerium source and 30 mL water are joined in the round bottom flask of 100 mL, electromagnetic stirring 15 min, then add 150 μ L triethylenetetramine To the above solution, continue to stir for 30 minutes, set up the reaction device, adjust the power of the microwave oven to 90 W, the current to 40 mA, and the reaction time to 15 minutes.3.根据权利要求1所述的纳米二氧化铈的制备方法，其特征是铈源选用硝酸亚铈（Ce(NO₃)₃??6H₂O）。3. The method for preparing nano ceria according to claim 1, characterized in that cerium nitrate (Ce(NO₃ )₃ ??6H₂ O) is selected as the cerium source.4.根据权利要求1所述的纳米二氧化铈的制备方法，其特征是碱源为三乙烯四胺。4. the preparation method of nanometer ceria according to claim 1 is characterized in that alkali source is triethylenetetramine.

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