Electrocatalyst with a NiMoO4 layer with nanoflower morphology

Patent metadata

Field	Value
Publication number	US-12139798-B2
Application number	US-202318336394-A
Country	US
Kind code	B2
Filing date	Jun 16, 2023
Priority date	Jun 29, 2022
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

A rapid method of synthesizing nanoflowers made of nanoflakes of nickel molybdate (NiMoO 4 ) directly on nickel foam (NF) through an aerosol-assisted chemical vapor deposition (AACVD) process is disclosed. The nickel molybdate nanoflowers were grown on NF by varying the deposition time for 60 and 120 min at a fixed temperature of 480° C. and their efficiency was investigated as oxygen evolution reaction (OER) catalysts in 1 M KOH electrolyte. The NiMoO 4 nanoflowers of NF obtained after 60 minutes of AACVD process showed OER performance with lowest overpotential of 320 mV to reach standard current density of 10 mA cm −2 . The catalyst continuously performed the OER for 15 h, signifying its prominent stability under electrochemical conditions.

First claim

The invention claimed is:

1. An electrocatalyst produced by aerosol-assisted chemical vapor depositing a mixture comprising Ni(acac) 2 and MoO 2 (acac) 2 on a substrate to form NiMoO 4 nanoflowers on the substrate,
wherein the electrocatalyst comprises a continuous NiMoO 4 nanoflower coating of the NiMoO 4 nanoflowers directly on a surface of the substrate;
wherein the NiMoO 4 nanoflowers in the continuous NiMoO 4 nanoflower coating are in the form of crosslinked nanosheets consisting of NiMoO 4 ;
wherein the substrate is a nickel foam.

2. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers are crystalline by XRD, wherein the nanoflowers are in a form of irregularly aggregated nanoflakes.

3. The electrocatalyst of claim 1 , wherein the electrocatalyst is produced by carrying out the aerosol-assisted chemical vapor depositing for from 30 to 200 min at a temperature of 400 to 700° C.

4. The electrocatalyst of claim 1 , wherein the electrocatalyst is produced by carrying out the aerosol-assisted chemical vapor depositing for from 60 to 120 min at a temperature from 430 to 540° C.

5. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers of the electrocatalyst produced after 40 to 90 minutes of the aerosol-assisted chemical vapor depositing have a Tafel value of 50 to 100 mV dec −1 .

6. The electrocatalyst of claim 1 , wherein the electrocatalyst has a constant current density after 10 to 20 hours with 7-15 mA cm −2 .

7. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers are crystalline.

8. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers consist of a crystalline single phase NiMoO 4 .

9. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers in the continuous NiMoO 4 nanoflower coating include vertically aligned nanosheets.

10. The electrocatalyst of claim 1 , wherein the NiMoO 4 nanoflowers have a crystalline single phase by XRD and XPS.

11. A method of using the electrocatalyst of claim 1 for water oxidation, comprising:
contacting the electrocatalyst with an aqueous electrolyte solution having a pH of 8 to 14; and
applying a potential of 1.30 to 1.70 V to the electrocatalyst and a counter electrode immersed in the aqueous electrolyte solution.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Ehsan Muhammad Ali
• Khan Abuzar

Classifications

• C25B11/061

  Metal or alloy · CPC title

• C23C16/405

  of refractory metals or yttrium · CPC title

• C23C16/406

  of iron group metals · CPC title

• C25B11/077

  the compound being a non-noble metal oxide · CPC title

• C23C16/4486

  by producing an aerosol and subsequent evaporation of the droplets or particles · CPC title