3D reduced graphene oxide foams embedded with nanocatalysts, synthesizing methods and applications of same

Patent metadata

Field	Value
Publication number	US-10815580-B2
Application number	US-201816058587-A
Country	US
Kind code	B2
Filing date	Aug 8, 2018
Priority date	Aug 10, 2017
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method of synthesizing three-dimensional (3D) reduced graphene oxide (RGO) foams embedded with water splitting nanocatalysts includes providing a first solution containing nickel (II) nitrate, a second solution containing iron (III) nitrate, and a graphene oxide (GO) aqueous suspension; mixing the GO aqueous suspension with the first solution and the second solution to form a GO-Ni—Fe mixture; adjusting a pH value of the GO-Ni—Fe mixture to be about 3.5; and performing hydrothermal reaction in the GO-Ni—Fe mixture to form RGO-Ni—Fe foams, wherein nanocatalysts containing Ni-Fi oxide particles are embedded in porous structures of the 3D RGO foams.

First claim

What is claimed is:

1. A method of synthesizing a three-dimensional (3D) reduced graphene oxide (RGO) foam embedded with nanocatalysts, comprising:
providing a first solution containing nickel (II) nitrate, a second solution containing iron (III) nitrate, and a graphene oxide (GO) aqueous suspension;
mixing the GO aqueous suspension with the first solution and the second solution to form a GO-Ni—Fe mixture suspension;
adjusting a pH value of the GO-Ni—Fe mixture suspension to be about 3.5; and
performing hydrothermal reaction in the GO-Ni—Fe mixture suspension to form a RGO-Ni—Fe foam, wherein nanocatalysts containing Ni-Fi oxide particles are embedded in a porous structure of the 3D RGO foam.

2. The method of claim 1 , wherein the GO-Ni—Fe mixture suspension is characterized with a molar ratio of C:Ni:Fe=14:1:0.33.

3. The method of claim 1 , wherein the first and second solutions are provided by dissolving Ni(NO 3 ) 2 .6H 2 O and Fe(NO 3 ) 3 .9H 2 O into deionized water, respectfully.

4. The method of claim 1 , wherein the pH value of the GO-Ni—Fe mixture suspension is adjusted by adding a NaOH solution therein.

5. The method of claim 1 , wherein the hydrothermal reaction in the GO-Ni—Fe mixture suspension is performed in a sealed autoclave for hydrothermal reaction at a predetermined temperature for a period of time.

6. The method of claim 5 , wherein the predetermined temperature is in a ranges of about 160-200° C., and the period of time is in a range of about 7-11 h.

7. The method of claim 1 , further comprising washing the RGO-Ni—Fe foam with deionized water.

8. The method of claim 7 , further comprising freeze-drying the RGO-Ni—Fe foam under about 0.05 mbar vacuum at about 50° C. to obtain the RGO-Ni—Fe solid foam.

9. The method of claim 1 , further comprising, prior to performing hydrothermal reaction in the GO-Ni—Fe mixture suspension, ultrasonicateing the GO-Ni—Fe mixture suspension to remove air bubbles that are trapped in the GO-Ni—Fe mixture suspension.

Assignees

• Univ Arkansas

Inventors

• Zhao Wei
• Wang Daoyuan

Classifications

• C25B11/031

  Porous electrodes · CPC title

• C25B1/04

  by electrolysis of water · CPC title

• C25B11/044 Primary

  Impregnation of carbon · CPC title

• C25B11/077

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

• B01J23/883

  and nickel · CPC title