Method for making iridium oxide nanoparticles

Patent metadata

Field	Value
Publication number	US-11964881-B2
Application number	US-202016939984-A
Country	US
Kind code	B2
Filing date	Jul 27, 2020
Priority date	Mar 18, 2020
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A method for making iridium oxide nanoparticles includes dissolving an iridium salt to obtain a salt-containing solution, mixing a complexing agent with the salt-containing solution to obtain a blend solution, and adding an oxidating agent to the blend solution to obtain a product mixture. A molar ratio of a complexing compound of the complexing agent to the iridium salt is controlled in a predetermined range so as to permit the product mixture to include iridium oxide nanoparticles.

First claim

What is claimed is:

1. A method for making iridium oxide nanoparticles, comprising steps of:
a) dissolving an iridium salt in a salt-dissolving solvent to obtain a salt-containing solution;
b) after step a), mixing a complexing agent with the salt-containing solution to obtain a blend solution, the complexing agent including a complexing compound for complexing iridium ions of the iridium salt, and which has a molar amount larger than that of the iridium salt; and
c) after step b), adding an oxidating agent to the blend solution to permit oxidation of the iridium ions and obtain a product mixture, the oxidating agent including an oxidant compound,
wherein a molar ratio of the complexing compound to the iridium salt is controlled in a predetermined range to permit the product mixture produced in step c) to include iridium oxide nanoparticles,
wherein the salt-dissolving solvent in step a) is water, and
wherein between steps b) and c), the method further comprises a step of b′) adding a stabilizing agent to stabilize the iridium ions at a pH ranging from 3 to 5.

2. The method according to claim 1 , wherein the molar ratio of the complexing compound to the iridium salt is controlled in the predetermined range such that once the oxidating agent is added, the iridium oxide nanoparticles are produced within 10 minutes.

3. The method according to claim 1 , wherein the molar ratio of the complexing compound to the iridium salt is controlled to range from 70000:1 to 6:1.

4. The method according to claim 1 , wherein a molar ratio of the oxidant compound to the iridium salt ranges from 600:1 to 50:1.

5. The method according to claim 1 , wherein the product mixture produced in step c) has a pH ranging from 6 to 8.

6. The method according to claim 1 , wherein step c) is implemented in the absence of heating.

7. The method according to claim 1 , wherein the iridium salt is selected from the group consisting of Na 3 IrCl 6 , K 3 IrCl 6 , IrCl 3 , IrBr 3 , Na 2 IrCl 6 , K 2 IrCl 6 , (NH 4 ) 2 IrCl 6 , and combinations thereof.

8. The method according to claim 1 , wherein
the complexing compound is selected from the group consisting of citric acid, malonic acid, succinic acid, oxalic acid, tartaric acid, EDTA, and combinations thereof.

9. The method according to claim 8 , wherein the stabilizing agent includes a compound selected from the group consisting of NaOH, KOH, tetrabutylammonium hydroxide, and combinations thereof.

10. The method according to claim 1 , wherein the oxidant compound is selected from the group consisting of NaClO, NaClO 2 , KClO, NaBrO 3 , Ca(ClO) 2 , H 2 O 2 , and combinations thereof.

11. The method according to claim 1 , wherein the iridium salt is Na 3 IrCl 6 , the complexing compound is citric acid, the stabilizing agent includes NaOH, and the oxidant compound is NaClO.

12. The method according to claim 1 , further comprising a step of d) after step c), adding a pH adjusting agent to adjust the product mixture to a pH value ranging from 1 to 13.

13. The method according to claim 12 , wherein the pH adjusting agent is selected from the group consisting of NaOH, KOH, tetrabutylammonium hydroxide, HNO 3 , and combinations thereof.

14. The method according to claim 1 , further comprising a step of e) collecting the iridium oxide nanoparticles from the product mixture.

15. The method according to claim 14 , further comprising a step of f) heating the collected iridium oxide nanoparticles so as to increase a particle size of the iridium oxide nanoparticles.

16. The method according to claim 1 , when the complexing compound is selected from the group consisting of citrate, malonate, succinate, oxalate, tartrate, EDTA-2Na, and combinations thereof.

17. The method according to claim 16 , the stabilizing agent includes HNO 3 .

18. A method for making iridium oxide nanoparticles, comprising the steps of:
a) dissolving an iridium salt in a salt-dissolving solvent to obtain a salt-containing solution;
b) after step a), mixing a complexing agent with the salt-containing solution to obtain a blend solution, the complexing agent including a complexing compound which is for complexing iridium ions of the iridium salt, and which has a molar amount larger than that of the iridium salt; and
c) after step b), adding an oxidating agent to the blend solution to permit oxidation of the iridium ions and obtain a product mixture, the oxidating agent including an oxidant compound,
wherein a molar ratio of the complexing compound to the iridium salt is controlled in a predetermined range to permit the product mixture produced in step c) to include iridium oxide nanoparticles, and
wherein the molar ratio of the complexing compound to the iridium salt is controlled in the predetermined range such that once the oxidating agent is added, the iridium oxide nanoparticles are produced within 10 minutes.

19. A method for making iridium oxide nanoparticles, comprising the steps of:
a) dissolving an iridium salt in a salt-dissolving solvent to obtain a salt-containing solution;
b) after step a), mixing a complexing agent with the salt-containing solution to obtain a blend solution, the complexing agent including a complexing compound which is for complexing iridium ions of the iridium salt, and which has a molar amount larger than that of the iridium salt; and
c) after step b), adding an oxidating agent to the blend solution so as to permit oxidation of the iridium ions to obtain a product mixture, the oxidating agent including an oxidant compound,
wherein a molar ratio of the complexing compound to the iridium salt is controlled in a predetermined range to permit the product mixture produced in step c) to include iridium oxide nanoparticles,
wherein the salt-dissolving solvent in step a) is water, and
wherein the product mixture produced in step c) has a pH ranging from 6 to 8.

Assignees

• Univ National Chiao Tung
• National Yang Ming Chiao Tung Univ

Inventors

• Wu Pu-Wei
• Hsieh Yi-Chieh
• Wang Han-Yi
• Tso Kuang-Chih
• Chan Tzu-Ying
• Chang Chung-Kai
• Chen Chi-Shih
• Cheng Yu-Ting

Classifications

• C01G55/004 Primary

  Oxides; Hydroxides · CPC title

• A61L27/025

  Other specific inorganic materials not covered by A61L27/04 - A61L27/12 · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title