High-yield preparation of two-dimensional copper nanosheets

Patent metadata

Field	Value
Publication number	US-11131031-B2
Application number	US-201816006673-A
Country	US
Kind code	B2
Filing date	Jun 12, 2018
Priority date	Jun 12, 2018
Publication date	Sep 28, 2021
Grant date	Sep 28, 2021

Abstract

Cu-based nanostructures have excellent catalytic, electronic, and plasmonic performance due to their unique chemical and physical properties. A range of Cu materials including foil, spherical nanoparticles, nanowires, and nanocubes have been explored for catalyzing CO2 electroreduction. However, practical application of the CO2 electroreduction reaction requires Cu catalysts hold a high percentage of exposed surface atoms for improved product selectivity. The present disclosure describes a high temperature reduction method to prepare Cu nanosheets with size range from about 40 nm to about 13 μm in a hydrophobic system. The purity of trioctyphosphine (TOP) plays an important role for shape-controlled synthesis of Cu nanosheets. The morphology evolution was investigated by adjusting the feeding molar ratio of TOP/Cu-tetradecylamine complex. The Cu nanosheets formed by the methods of the present disclosure have high surface area and stability in solution for more than three months. These Cu nanosheets have applications in reducing CO2 to fuels.

First claim

What is claimed is:

1. A method of making a copper nanosheet, the method comprising:
heating a reactant solution comprising a reducing agent and one or more surfactants to a temperature of about 280° C. to about 330° C., to form a heated solution; and
injecting a hot solution of copper-containing precursor into the heated solution to form the copper nanosheet.

2. The method of claim 1 , wherein the reducing agent is oleylamine, hexadecylamine, or octadecylamine.

3. The method of claim 2 , wherein the reducing agent is oleylamine.

4. The method of claim 1 , wherein the one or more surfactants comprise trioctylphosphine (TOP).

5. The method of claim 4 , wherein the one or more surfactants further comprise tetradecylamine (TDA).

6. The method of claim 4 , wherein the purity of the TOP is at least 97%.

7. The method of claim 6 , wherein the TOP is substantially free of trioctylphosphine oxide (TOPO).

8. The method of claim 4 , wherein the purity of the TOP is at least 90%.

9. The method of claim 4 , wherein the molar ratio of TOP to the copper-containing precursor is about 1.5:1 to about 2.8:1.

10. The method of claim 9 , wherein the molar ratio of TOP to the copper-containing precursor is about 1.8:1 to about 2.8:1.

11. The method of claim 9 , wherein the molar ratio of TOP to the copper-containing precursor is about 2.2:1.

12. The method of claim 1 , wherein the copper-containing precursor is dissolved in octadecene or squalene.

13. The method of claim 1 , wherein the reactant solution is heated to about 300° C.

14. The method of claim 1 , wherein the copper-containing precursor is copper tetradecylamine (Cu-TDA).

15. A method of making a carbon dioxide conversion catalyst comprising a copper nanosheet, the method comprising:
heating a reactant solution comprising oleylamine and trioctylphosphine (TOP) to a temperature of about 280° C. to about 330° C., to form a heated solution; and
injecting a hot solution of copper tetradecylamine (Cu-TDA) into the heated solution to form the copper nanosheet.

16. The method of claim 15 , wherein the molar ratio of TOP to Cu-TDA is about 1.8:1 to about 2.8:1.

17. The method of claim 16 , wherein the molar ratio of TOP to Cu-TDA is about 2.2:1.

18. The method of claim 15 , wherein the purity of the TOP is at least 97%.

19. The method of claim 18 , wherein the TOP is substantially free of trioctylphosphine oxide (TOPO).

20. The method of claim 15 , wherein the purity of the TOP is at least 90%.

Assignees

• Honda Motor Co Ltd

Inventors

• Chen Shutang
• Chen Gugang

Classifications

• H10W20/43

  Layouts of interconnections · CPC title

• B22F1/068

  Flake-like particles · CPC title

• B22F1/056

  Submicron particles having a size above 100 nm up to 300 nm · CPC title

• B22F1/0551

  Flake form nanoparticles · CPC title

• B22F1/054

  Nanosized particles · CPC title