Method for splitting water

Patent metadata

Field	Value
Publication number	US-12139799-B2
Application number	US-202418607174-A
Country	US
Kind code	B2
Filing date	Mar 15, 2024
Priority date	Oct 22, 2019
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

A CoVOx composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVOx having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVOx composite electrode is capable of being used in an electrochemical cell for water oxidation.

First claim

The invention claimed is:

1. A method for splitting water into H 2 and O 2 , comprising:
subjecting the electrodes of an electrochemical cell with a potential of 0.5-2.0 V,
wherein the electrochemical cell comprises:
an electrolyte vessel containing an electrolyte solution,
a working electrode, and a spiral wire counter electrode,
wherein the working electrode and the spiral wire counter electrode are disposed at least partially in the electrolyte vessel and are at least partially immersed in the electrolyte solution contained in the electrolyte vessel,
wherein the working electrode is a composite thin film electrode comprising:
a CoVO x layer having an average thickness of 500 nm-5 μm in contact with a substrate,
wherein the CoVO x layer comprises amorphous CoVO x having a Co:V molar ratio in a range of 1.0:1.2-1.5:1.0, and
wherein the CoVO x layer has an O:Co molar ratio and/or an O:V molar ratio in a range of 4:1 to 9:1.

2. The method of claim 1 , wherein the CoVO x layer of the composite thin film electrode is porous with a pore size in a range of 2-10 nm.

3. The method of claim 1 , wherein the composite thin film electrode has an electrochemically active surface area in a range of 12-22 mF/cm 2 .

4. The method of claim 1 , wherein the CoVO x layer of the composite thin film electrode consists essentially of amorphous CoVO x .

5. The method of claim 1 , wherein the CoVO x layer of the composite thin film electrode has an O: Co molar ratio in a range of 4:1 to 9:1.

6. The method of claim 1 , wherein the substrate of the composite thin film electrode is a transparent conducting film selected from the group consisting of fluorine-doped tin oxide, indium tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium zinc oxide, indium zinc tin oxide, indium aluminum zinc oxide, indium gallium zinc oxide, indium gallium tin oxide, and antimony tin oxide.

7. The method of claim 1 , wherein the composite thin film electrode has a current density of 1.0-10.0 mA/cm 2 when the electrodes are subjected to a bias potential of 1.45-1.55 V.

8. The method of claim 1 , wherein the electrolyte solution comprises water and an inorganic base having a concentration of 0.1-1.0 M.

9. The method of claim 1 , wherein the composite thin film electrode has a mass activity in range of 38-50 A/g at a potential of 350 mV.

10. The method of claim 1 , further comprising
separately collecting H 2 -enriched gas and O 2 -enriched gas.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Rehman Abdul
• Saeed Abbas Hakeem
• Ehsan Muhammad Ali

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C01G51/42

  containing alkali metals, e.g. LiCoO2 · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C01G31/006

  Compounds containing vanadium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title