FABRICATION OF CoVOx COMPOSITE THIN FILM ELECTRODE VIA SINGLE STEP AACVD

Patent metadata

Field	Value
Publication number	US-2021115578-A1
Application number	US-201916660160-A
Country	US
Kind code	A1
Filing date	Oct 22, 2019
Priority date	Oct 22, 2019
Publication date	Apr 22, 2021
Grant date	—

Abstract

A CoVO x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO x 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 CoVO x composite electrode is capable of being used in an electrochemical cell for water oxidation.

First claim

1 : 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 substrate is a transparent conducting film.

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

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

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

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

6 : The composite thin film electrode of claim 1 , wherein the transparent conducting film is 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 : A method of making the composite thin film electrode of claim 1 , the method comprising:
contacting an aerosol with the substrate to deposit the CoVO x layer to form the composite thin film electrode, wherein the aerosol comprises a carrier gas, and a cobalt complex and a vanadium complex dissolved in a solvent, and wherein the substrate has a temperature in a range of 450-550° C. during the contacting.

8 : The method of claim 7 , wherein the cobalt complex and the vanadium complex each independently comprise at least one ligand selected from the group consisting of acetylacetonate, acetate ligand, trifluoroacetate, isopropanol, and tetrahydrofuran.

9 : The method of claim 7 , wherein the cobalt complex is Co(II) acetylacetonate, and the vanadium complex is V(III) acetylacetonate.

10 : The method of claim 7 , wherein before the contacting, the aerosol consists essentially of the carrier gas, the cobalt complex, the vanadium complex, and the solvent.

11 : The method of claim 7 , wherein a weight ratio of the cobalt complex to the solvent in the aerosol, and/or a weight ratio of the vanadium complex to the solvent in the aerosol is in a range of 1:1,000-1:5.

12 : The method of claim 7 , wherein the aerosol is contacted with the substrate for a time period of 10-30 min.

13 : The method of claim 7 , wherein during the contacting, the carrier gas has a flow rate in a range of 20-250 cm 3 /min.

14 : An electrochemical cell, comprising:
the composite thin film electrode of claim 1 ; a counter electrode; and an electrolyte solution in contact with both electrodes.

15 : The electrochemical cell of claim 14 , wherein the composite thin film electrode has an overpotential in a range of 270-335 mV at a current density of 9-11 mA/cm 2 .

16 : The electrochemical cell of claim 14 , 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.

17 : The electrochemical cell of claim 14 , wherein the electrolyte solution comprises water and an inorganic base having a concentration of 0.1-1.0 M.

18 : The electrochemical cell of claim 14 , wherein the composite thin film electrode has a mass activity in range of 38-50 A/g at a potential of 350 mV.

19 : A method for decomposing water into H 2 and O 2 , the method comprising:
subjecting the electrodes of the electrochemical cell of claim 14 with a potential of 0.5-2.0 V.

20 : The method of claim 19 , 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

• Y02E60/50

  Fuel cells · CPC title

• H01M4/9016

  Oxides, hydroxides or oxygenated metallic salts · CPC title

• H01M4/8878

  Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body · CPC title

• H01M4/8875

  Methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing, casting without support, extrusion without support · CPC title

• H01M4/886

  Powder spraying, e.g. wet or dry powder spraying, plasma spraying · CPC title