Preparation method for easily preparing cerium dioxide nanorod with controllable size

Abstract

The invention relates to a preparation method for easily preparing a cerium dioxide nanorod with a controllable size, in particular to a preparation method for regulating and controlling the size of the cerium dioxide nanorod by adding an organic solvent which is mutually soluble with water. The method comprises the following steps: firstly, mixing an organic solvent which is mutually soluble with water with deionized water in a proper proportion to obtain a mixed solution; a proper amount of cerium nitrate hexahydrate is weighed and dissolved in the mixed solution, and a cerium nitrate solution A is obtained; a proper amount of potassium hydroxide is weighed and dissolved in the mixed solution, and a potassium hydroxide solution B is obtained; and adding the solution B into the solution A, uniformly mixing, transferring into a reaction kettle, and carrying out hydrothermal reaction at set temperature for set time. And after the reaction is finished, centrifugally washing with deionized water and ethanol, and drying to finally obtain the cerium dioxide nanorod with the controllable size. The size of the cerium dioxide nanorod can be effectively adjusted by adjusting the variety and the mixing ratio of the organic solvent which is mutually soluble with water. The method is easy and convenient to operate, mild in reaction condition, high in controllability and suitable for large-scale production. The prepared cerium dioxide nanorod has a wide application prospect in the fields of catalysis, optics and electronics.

Description

Technical Field

[0001] The invention relates to the field of nano material preparation, and in particular to a preparation method for regulating the shape and size of cerium dioxide nanorods by adding an organic solvent miscible with water. Background Art

[0002] Nanomaterials have been widely used in many fields, such as catalysis, energy storage and conversion, environmental management, electronic devices, biomedicine, etc., due to their unique physical, chemical and mechanical properties. As an important rare earth oxide material, cerium dioxide (CeO2) has excellent redox properties, oxygen storage capacity and high temperature stability, so it has broad application prospects in catalysts, fuel cells, electrode materials, ultraviolet shielding materials, etc.

[0003] Among the various morphological structures of ceria, nanorods show excellent performance and wide application potential due to their high specific surface area, specific crystal face exposure and good electronic conductivity. However, the existing preparation methods of ceria nanorods often face problems such as complex synthesis process, harsh conditions and uneven product morphology, which limits their large-scale preparation and practical application.

[0004] At present, the main methods for preparing cerium dioxide nanorods include hydrothermal method, solvothermal method, precipitation method, sol-gel method, etc. Among them, the hydrothermal method is widely used in the preparation of nanomaterials due to its advantages such as simple operation, mild conditions, and easy control of product morphology and size. However, when preparing cerium dioxide nanorods by traditional hydrothermal method, it is difficult to effectively control the length and diameter of nanorods, and the synthesis process often requires high temperature and high pressure reaction conditions, which increases the complexity and cost of the process. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing cerium dioxide nanorods with controllable size, which adjusts the size of the cerium dioxide nanorods by controlling the proportion of an organic solvent miscible with water. The method has the advantages of simple operation, mild conditions and strong controllability.

[0006] In order to achieve the purpose of this invention, the present invention adopts the following technical solutions Technical Problem One of the purposes of the present invention is to provide a method for preparing cerium dioxide nanorods that are easy to prepare and have controllable size. The preparation method comprises the following steps: First, an organic solvent miscible with water and deionized water in an appropriate proportion are mixed to obtain a mixed solution.

[0007] An appropriate amount of cerium nitrate hexahydrate is weighed and dissolved in the mixed solution to obtain cerium nitrate solution A.

[0008] Then weigh an appropriate amount of potassium hydroxide and dissolve it in the mixed solution to obtain potassium hydroxide solution B.

[0009] The reaction system was constructed by adding solution B into solution A and mixing well, then transferring the mixture to a reactor for hydrothermal reaction at a set temperature and time.

[0010] After the reaction was completed, the samples were washed with deionized water and ethanol by centrifugation.

[0011] After drying at a specific temperature, cerium dioxide nanorods are obtained.

[0012] The length of the cerium dioxide nanorods can be effectively controlled by adjusting the type and amount of the organic solvent miscible with water.

[0013] In the method for preparing the cerium dioxide catalyst, the synthesis temperature is 60-220°C.

[0014] In the method for preparing the cerium dioxide catalyst, the reaction time for the hydrothermal reaction is 6-72 hours.

[0015] In the cerium dioxide catalyst preparation method, the number of washing with deionized water and ethanol is 3-5 times.

[0016] In the cerium dioxide catalyst preparation method, the rotation speed of the centrifuge is 1000-6000 revolutions.

[0017] In the cerium dioxide catalyst preparation method, the oven drying temperature is 40-140°C.

[0018] In the method for preparing the cerium dioxide catalyst, the ratio of water to the water-miscible organic solvent can be 1:1, 2:1, 1:2, 1:3, 3:1, 5:1, 9:1, 11:1, 15:1; (0.1-20): (1-20). However, it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0019] Compared with the prior art, the present invention has the following beneficial effects: By adjusting the ratio of organic solvents that are miscible with water, the size of cerium dioxide nanorods can be effectively controlled to meet the needs of different application scenarios.

[0020] Morphology controllability: Existing methods make it difficult to uniformly control the length and diameter of cerium dioxide nanorods, affecting their performance and applications.

[0021] Ease of operation: Traditional preparation methods have complex steps and harsh conditions, which are not conducive to large-scale production.

[0022] Product uniformity: It is difficult to obtain cerium dioxide nanorods with uniform morphology and consistent size, which affects their performance in practical applications.

[0023] The preparation method of the invention is simple to operate, the conditions are mild, the obtained nanorods have uniform morphology, and have excellent physical and chemical properties, and have broad application prospects in the fields of catalysis, energy, and environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Through the detailed description of the preferred specific implementation methods, the many advantages and technical effects of the present invention will be clearly presented to ordinary technicians in this field. It should be noted that the drawings in the specification are only used to show the preferred embodiments and do not constitute a limitation on the scope of protection of the present invention. Obviously, the drawings described below are only part of the specific implementation methods of the present invention. For ordinary technicians in this field, other feasible design schemes can still be derived based on these drawings without the need for creative work. In addition, in the drawings, in order to facilitate understanding and unified identification, all identical parts are represented by consistent figure marks.

[0025] In the attached picture: Figure 1 This is a scanning electron microscope (SEM) image of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0026] Figure 2 This is a scanning electron microscope (SEM) image of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0027] Figure 3 This is a scanning electron microscope (SEM) image of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0028] Figure 4 X-ray photoelectron spectroscopy XPS of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0029] Figure 5 Raman spectrum of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0030] Figure 6 This is the XRD spectrum of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0031] Figure 7 The specific surface area adsorption BET spectrum of the cerium dioxide (CeO2) catalyst provided in Example 1.

[0032] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. Specific implementation methods

[0033] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Embodiment 1

[0034] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 180 ml of deionized water and 20 ml of ethylene glycol were measured and stirred to obtain a water-ethylene glycol mixed solution in a ratio of 9:1.

[0035] A 0.11 mol / L cerium nitrate solution was prepared, and 5 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 9:1 water-ethylene glycol mixed solution to obtain cerium nitrate solution A.

[0036] Prepare a 17.86 mol / L potassium hydroxide solution, dissolve 100 g of potassium hydroxide in 100 ml of a 9:1 water-ethylene glycol mixed solution to obtain potassium hydroxide solution B.

[0037] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0038] 2. Reaction system construction: The milky white precursor slurry solution of step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 150°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by centrifuge. It was washed with deionized water for 3 times. It was dried at 60°C for 8 hours to obtain cerium dioxide nanorods with a length of 150-200 nm.

[0039] The XRD pattern of CeO2 nanorods prepared in this example is as follows: Figure 6 As shown in FIG. 1 , the obtained nano-CeO2 is a pure CeO2 phase. The SEM image of the CeO2 nanorods prepared in this embodiment is as follows: Figure 1 , 2 , 3, through Figure 1 , 2 It can be seen that the CeO2 nanorods are uniform in length and well dispersed. Embodiment 2

[0040] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 100 ml of deionized water and 100 ml of glycerol were measured and stirred to obtain a water-glycerol 1:1 mixed solution.

[0041] A 0.23 mol / L cerium nitrate solution was prepared, and 10 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 1:1 water-propylene glycol mixed solution to obtain cerium nitrate solution A.

[0042] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of a 1:1 water-propylene glycol mixed solution to obtain potassium hydroxide solution B.

[0043] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0044] 2. Reaction system construction: The milky white precursor slurry solution in step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 150°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 60°C for 8 hours to obtain cerium dioxide hydroxide nanorods with a length of 30-60 nm. Embodiment 3

[0045] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 150 ml of deionized water and 50 ml of ethylene glycol were measured and stirred to obtain a water-ethylene glycol 3:1 mixed solution.

[0046] A 0.23 mol / L cerium nitrate solution was prepared, and 10 g of cerium nitrate hexahydrate was dissolved in 100 ml of a water-ethylene glycol 3:1 mixed solution to obtain cerium nitrate solution A.

[0047] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of a 3:1 water-ethylene glycol mixed solution to obtain potassium hydroxide solution B.

[0048] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0049] 2. Reaction system construction: The milky white precursor slurry solution in step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 150°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 80°C for 6 hours to obtain cerium dioxide nanorods with a length of 70-120 nm. Embodiment 4

[0050] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: Measure 200 ml of deionized water.

[0051] A 0.11 mol / L cerium nitrate solution was prepared by dissolving 5 g of cerium nitrate hexahydrate in 100 ml of deionized water to obtain cerium nitrate solution A.

[0052] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of deionized water to obtain potassium hydroxide solution B.

[0053] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0054] 2. Reaction system construction: The milky white precursor slurry solution in step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 120°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 60°C for 6 hours to obtain cerium dioxide nanorods with a length of 130-180 nm. Embodiment 5

[0055] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 180 ml of deionized water and 20 ml of glycerol were measured and stirred to obtain a water-glycerol 9:1 mixed solution.

[0056] A 0.11 mol / L cerium nitrate solution was prepared, and 5 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 9:1 water-propylene glycol mixed solution to obtain cerium nitrate solution A.

[0057] Prepare a 17.86 mol / L potassium hydroxide solution, dissolve 100 g of potassium hydroxide in 100 ml of a 9:1 water-propylene glycol mixed solution to obtain potassium hydroxide solution B.

[0058] Add potassium hydroxide solution B into cerium nitrate solution A and stir thoroughly to obtain a milky white precursor slurry. 2. Reaction system construction: The milky white precursor slurry solution in step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 150°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 60°C for 8 hours to obtain cerium dioxide nanorods with a length of 20-50 nm. Embodiment 6

[0059] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 180 ml of deionized water and 20 ml of ethanol were measured and stirred to obtain a water-ethanol mixed solution with a ratio of 9:1.

[0060] A 0.23 mol / L cerium nitrate solution was prepared, and 10 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 9:1 water-ethanol mixed solution to obtain cerium nitrate solution A.

[0061] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of a 9:1 water-ethanol mixed solution to obtain potassium hydroxide solution B.

[0062] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0063] 2. Reaction system construction: The milky white precursor slurry solution in step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 110°C for 21 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 80°C for 8 hours to obtain cerium dioxide nanorods with a length of 60-180 nm. Embodiment 7

[0064] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: Measure 100 ml of deionized water and 100 ml of ethylene glycol, and stir to obtain a water-ethylene glycol 1:1 mixed solution.

[0065] A 0.11 mol / L cerium nitrate solution was prepared, and 5 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 1:1 water-ethylene glycol mixed solution to obtain cerium nitrate solution A.

[0066] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of a 1:1 water-ethylene glycol mixed solution to obtain potassium hydroxide solution B.

[0067] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0068] 2. Reaction system construction: The milky white precursor slurry solution of step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 150°C for 18 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 60°C for 8 hours to obtain cerium dioxide nanorods with a length of 30-70 nm. Embodiment 8

[0069] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: 150 ml of deionized water and 50 ml of glycerol were measured and stirred to obtain a water-glycerol 3:1 mixed solution.

[0070] A 0.11 mol / L cerium nitrate solution was prepared, and 5 g of cerium nitrate hexahydrate was dissolved in 100 ml of a water-propylene glycol 3:1 mixed solution to obtain cerium nitrate solution A.

[0071] Prepare a 17.86 mol / L potassium hydroxide solution, dissolve 100 g of potassium hydroxide in 100 ml of a 3:1 water-propylene glycol mixed solution to obtain potassium hydroxide solution B.

[0072] Potassium hydroxide solution B is added into cerium nitrate solution A and stirred thoroughly to obtain a milky white precursor slurry.

[0073] 2. Reaction system construction: The milky white precursor slurry solution of step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 160°C for 16 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 80°C for 6 hours to obtain cerium dioxide nanorods with a length of 60-100 nm. Embodiment 9

[0074] This embodiment provides a method for preparing cerium dioxide nanorods, the preparation method comprising the following steps: 1. Preparation of precursor solution: Measure 100 ml of deionized water and 100 ml of ethanol, and stir to obtain a water-ethanol 1:1 mixed solution.

[0075] A 0.11 mol / L cerium nitrate solution was prepared, and 5 g of cerium nitrate hexahydrate was dissolved in 100 ml of a 1:1 water-ethanol mixed solution to obtain cerium nitrate solution A.

[0076] Prepare a 17.86 mol / L potassium hydroxide solution by dissolving 100 g of potassium hydroxide in 100 ml of a 1:1 water-ethanol mixed solution to obtain potassium hydroxide solution B.

[0077] Add potassium hydroxide solution B into cerium nitrate solution A and stir thoroughly to obtain a milky white precursor slurry. 2. Reaction system construction: The milky white precursor slurry solution of step (1) was transferred to a hydrothermal reactor, the reactor was sealed, and the reaction was carried out at 110°C for 20 hours. After cooling naturally to room temperature, the hydrothermal product was centrifuged, cooled to room temperature, and the precipitate was separated by a centrifuge. It was washed with deionized water for 3 times. It was dried at 70°C for 6 hours to obtain cerium dioxide nanorods with a length of 120-170 nm.

[0078] Through the above nine embodiments, the present invention demonstrates the preparation method of cerium dioxide nanorods, and can effectively control the length and diameter of cerium dioxide nanorods in different water-miscible organic solvents to meet various application requirements. These methods are simple to operate, have mild reaction conditions, are suitable for large-scale production, and have significant industrial application prospects.

[0079] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and instructive, rather than restrictive. A person of ordinary skill in the art can also make many forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, all of which belong to the protection of the present invention.

Claims

1. A method for preparing size-controllable cerium dioxide nanorods, characterized in that: The following steps are involved: 1.1 Mix an organic solvent miscible with water and deionized water in a certain proportion to form a mixed solution; 1.2 Dissolve cerium nitrate hexahydrate in the mixed solution and stir until completely dissolved to form cerium nitrate solution A; 1.3 Dissolve potassium hydroxide in the mixed solution and stir until completely dissolved to form potassium hydroxide solution B; 1.4 Add the potassium hydroxide solution B in step 1.3 to the cerium nitrate solution A in step 1.2 and mix well, then transfer to a reactor and perform a hydrothermal reaction at a set temperature and time; 1.5 After the reaction is completed, centrifuge and wash with deionized water and ethanol; 1.6 Dry the washed precipitate at a specific temperature to obtain cerium dioxide nanorods.

2. The method according to claim 1, characterized in that The concentration of the cerium nitrate solution is 0.01-5 mol / L.

3. The method according to claim 1 or 2, characterized in that: The water-miscible organic solvents are methanol, ethanol, ethylene glycol, glycerol, acetone, ethylamine, and ethylenediamine, but are not limited to the types listed.

4. The method according to any one of claims 1 to 3, characterized in that: The ratio of water to the water-miscible organic solvent may be 1:1, 2:1, 1:2, 3:1, 1:3, 1:5, 1:9, 1:11, 1:15; (0.1-20): (1-20). However, it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

5. The method according to any one of claims 1 to 4, characterized in that: The temperature of the hydrothermal reaction is 60-220°C.

6. The method according to any one of claims 1 to 5, characterized in that: The hydrothermal reaction time is 6-72 hours.

7. The method according to any one of claims 1 to 6, characterized in that: The drying temperature is 40-140°C.

8. The method according to any one of claims 1 to 7, characterized in that: The washing times include 3-5 times of washing with deionized water.

9. The method according to any one of claims 1 to 8, characterized in that: By adjusting the ratio of the organic solvent miscible with water, the length of the cerium dioxide nanorods can be controlled between 10-300 nm.

10. The present invention regulates the shape and size of cerium dioxide nanorods by regulating the addition of water-miscible organic solvents. The method is simple and easy to operate, the conditions are mild, and it has high controllability and broad application prospects.

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