Method for producing metal oxide nanoparticles

Patent metadata

Field	Value
Publication number	US-11591235-B2
Application number	US-202016751075-A
Country	US
Kind code	B2
Filing date	Jan 23, 2020
Priority date	Jul 24, 2017
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

The present disclosure relates to a method for producing metal oxide nanoparticles includes a first step of preparing a reaction solution containing a metal complex, an alcohol, and water; a second step of heating the reaction solution for phase-separation under a hermetically sealed atmosphere where the volumetric expansion ratio of the reaction solution reaches 5 to 15%; a third step of holding the reaction solution heated in the second step for 30 minutes or more for dehydrating the metal complex to precipitate the metal oxide nanoparticles; and a fourth step of collecting the metal oxide nanoparticles after the metal oxide nanoparticles are cooled.

First claim

What is claimed is:

1. A method for producing metal oxide nanoparticles comprising:
a first step of preparing a reaction solution containing a metal complex, an alcohol, and water,
a second step of heating the reaction solution for phase-separation under a hermetically sealed atmosphere where a volumetric expansion ratio of the reaction solution reaches 5 to 15%,
a third step of holding the reaction solution heated in the second step for 12 hours or more for dehydrating the metal complex to precipitate the metal oxide nanoparticles, and
a fourth step of collecting the metal oxide nanoparticles after the metal oxide nanoparticles are cooled,
wherein the phase-separation of the reaction solution proceeds in two stages of clouding of the reaction solution and clarifying of the clouded reaction solution,
a holding temperature under the hermetically sealed atmosphere is 130 to 190° C. in the third step,
the metal complex is prepared by allowing a metal salt containing at least one metal to react with a compound to be a ligand for the metal salt in an aqueous solution,
the at least one metal is selected from copper, nickel, cobalt, zinc, iron, cerium, titanium, silver, palladium, molybdenum, niobium, and zirconium, and
the ligand includes ammonia, urea, thiourea, thiosulfuric acid or cyanides.

2. The method for producing metal oxide nanoparticles according to claim 1 , wherein a pH of the reaction solution is 4.0 to 6.0 in the first step.

3. The method for producing metal oxide nanoparticles according to claim 1 , wherein the first step comprises:
a step of preparing a solution containing the metal complex,
a step of preparing a mixed solution in which the alcohol and water are uniformly mixed, and
a step of mixing the solution containing the metal complex with the mixed solution.

Assignees

• Furukawa Electric Co Ltd
• Nat Inst Materials Science

Inventors

• Tsuzuki Yoshikazu
• Wakae Mariko
• Kurusu Kazuhiko
• Abe Hideki

Classifications

• C01F17/235

  Cerium oxides or hydroxides · CPC title

• C01F17/247 Primary

  Carbonates · CPC title

• C01B13/366

  by hydrothermal processing · CPC title

• C01B13/36

  by precipitation reactions in {aqueous} solutions {(C01B13/328 takes precedence)} · CPC title

• C01G3/02

  Oxides; Hydroxides · CPC title