In-situ control method for form and crystal face of nano cerium oxide

A technology of nano-cerium oxide and control method, which is applied in the field of preparation of rare earth nano-material technology, can solve problems such as difficult removal of new functional groups, performance interference of nano-cerium oxide, and limitation of application fields of nano-cerium oxide, so as to achieve large specific surface area and ease Effect of degree of hard agglomeration

Active Publication Date: 2017-06-30
JIANGXI UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the hydrothermal / solvent method often uses toxic or expensive additives and surfactants to regulate the morphology of nano-cerium oxide, and requires high-temperature, high-pressure and long-term treatment, which cannot meet the green and environment-friendly practical needs of preparing nanomaterials; On the other hand, the new functional groups introduced in the preparation process of this method are not easy to be completely removed, which interferes with the performance of nano-cerium oxide and limits the practical application field of nano-cerium oxide.

Method used

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  • In-situ control method for form and crystal face of nano cerium oxide

Examples

Experimental program
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Effect test

Embodiment 1

[0016] Disperse 5 mg of carbon nanotubes in 100 mL of ethylene glycol by ultrasonic waves, and obtain dispersed and sheared carbon nanotubes after 15 h; in addition, a cerium salt solution with a concentration of 0.5 mol / L was prepared; the dispersed and sheared carbon Nanotubes were added to the cerium salt solution, and an alkaline precipitant was added dropwise to adjust the pH of the system to 9; the above mixed solution was transferred into a polytetrafluoroethylene reactor for solvothermal reaction, the reaction temperature was 160 °C, the reaction time was 12 h, and cooled Afterwards, vacuum freeze-drying was carried out at a drying temperature of -45 °C, a drying time of 15 h, and a vacuum pressure of 40 Pa to obtain a carbon nanotube / cerium precursor composite; the carbon nanotube / cerium precursor composite was placed in a magnetic boat and pushed to In the central area of ​​the corundum reaction tube in a horizontal tube furnace, oxygen was introduced and then heat tr...

Embodiment 2

[0018] Disperse 10 mg of carbon nanotubes in 150 mL of ethanol by ultrasonic waves, and obtain dispersed and sheared carbon nanotubes after 15 h; in addition, a 0.1 mol / L cerium salt solution was prepared; the dispersed and sheared carbon nanotubes were added to In the cerium salt solution, add an alkaline precipitant dropwise at the same time to adjust the pH value of the system to 9.5; move the above mixed solution into a polytetrafluoroethylene reactor for solvothermal reaction, the reaction temperature is 160 °C, the reaction time is 24 h, and vacuum is carried out after cooling. Freeze drying, drying temperature -50 ℃, drying time 20 h, vacuum pressure 45 Pa, to obtain carbon nanotubes / cerium precursor composites; put carbon nanotubes / cerium precursor composites in a magnetic boat and push them to the horizontal tube In the central area of ​​the corundum reaction tube in a type furnace, oxygen was introduced and heat treatment was carried out accordingly. The heating rate ...

Embodiment 3

[0020] Disperse 5 mg of graphene in 100 mL of ethylene glycol by ultrasonic waves, and obtain a uniformly dispersed graphene ethylene glycol suspension after 12 h; prepare a cerium salt solution with a concentration of 0.5 mol / L; The suspension was added to the cerium salt solution, and an alkaline precipitant was added dropwise to adjust the pH of the system to 10; the above mixed solution was transferred into a polytetrafluoroethylene reactor for solvothermal reaction, the reaction temperature was 180 °C, and the reaction time was 24 h. After cooling, carry out vacuum freeze-drying, the drying temperature is -55 ℃, the drying time is 25 h, and the vacuum pressure is 50 Pa to obtain the graphene / cerium precursor composite; the carbon nanotube / cerium precursor composite is placed in a magnetic boat and pushed to In the central area of ​​the corundum reaction tube in a horizontal tube furnace, air was introduced and then heat treated. The heating rate was 10 ℃ / min, the heat trea...

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Abstract

The invention discloses an in- situ control method for the form and the crystal face of nano cerium oxide, and belongs to the technical field of rare earth nano materials. Organic alcohol used as a dispersing agent is combined with a cavitation effect to disperse and shear a nano template. A alkaline matter is used as a cerium source precipitator, the size of the nano template and an aggregation state of the same in a reaction system are controlled by adjusting viscosity and surface tension of the dispersing agent, so that a cerium precursor is adsorbed on the surface of the nano template and grows in a preferred orientation, and thus a growth speed of each crystal face of the cerium oxide is finally controlled, and control on the form and the crystal face of the nano cerium oxide in a nanoscale range is achieved. The method provided by the invention is simple in preparation technology, moderate in reaction condition and easy to acquire reaction material; no surfactant is added, and the added nano template has no residual and consumes a part of oxygen by calcining and oxidation, so that the purified cerium oxide is acquired and meanwhile oxygen vacancy concentration can be increased, and thus the method is wide in application prospect.

Description

technical field [0001] The invention relates to a preparation method in the technical field of rare earth nanomaterials, in particular to a method for controlling the morphology and crystal plane of nano-cerium oxide in situ through solvothermal reaction combined with nano-template. Background technique [0002] Nanostructured cerium oxide has unique redox activity and excellent oxygen storage and release properties, making it widely used in related catalytic technology fields such as automobile exhaust purification, organic wastewater degradation, polishing materials, and reforming of methane and carbon dioxide. The redox ability of nano-cerium oxide is closely related to its microstructure, crystal active surface, dispersion, purity and other factors. Ceria with different geometries usually expose different crystal active faces (such as (111), (110) or (100)), resulting in significantly different catalytic properties. Therefore, it is particularly important to control the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F17/00B82Y30/00C30B29/16C30B1/02
CPCB82Y30/00C01P2004/04C01P2004/64C30B1/02C30B29/16C01F17/206
Inventor 尹艳红袁先应吴子平廖春发黎业生刘先斌梁同祥
Owner JIANGXI UNIV OF SCI & TECH
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