Dendritic materials with hierarchical porosity

Patent metadata

Field	Value
Publication number	US-11858816-B2
Application number	US-202217883851-A
Country	US
Kind code	B2
Filing date	Aug 9, 2022
Priority date	Mar 8, 2017
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

Disclosed herein are dendritically porous three-dimensional structures, including hierarchical dendritically porous three-dimensional structures. The structures include metal foams and graphite structures, and are useful in energy storage devices as well as chemical catalysis.

First claim

What is claimed is:

1. A method of making a dendritically porous three-dimensional graphite foam comprising:
(a) placing a conductive substrate in an electrolyte solution, wherein the electrolyte solution is in electrical communication with an electrode;
(b) applying an electric current via the electrode sufficient to grow metal dendrites on the surface of the conductive substrate;
(c) annealing the metal dendrites and conductive substrate;
(d) depositing carbon upon the annealed metal dendrites and the conductive substrate;
(e) removing the annealed metal dendrites and conductive substrate to obtain a three-dimensional graphite foam comprising porous graphite dendrites radiating from a porous core.

2. The method of claim 1 , wherein the conductive substrate comprises a conductive metal, silicon, or a conductive polymer.

3. The method of claim 2 , wherein the conductive substrate comprises a metal foam.

4. The method of claim 3 , wherein the conductive substrate comprises a nickel foam, a copper foam, an iron foam, a zinc foam, an aluminum foam, or a tin foam.

5. The method of claim 1 , wherein the electrolyte solution comprises a copper salt, a nickel salt, a cobalt salt, or a mixture thereof.

6. The method of claim 1 , wherein the applied electric current is at least −25 mA.

7. The method of claim 1 , wherein the electric current is applied at an applied voltage from −2.5 V-2.5 V.

8. The method of claim 1 , wherein the electric current is applied to the conductive substrate from 25-500 C/in 2 , relative to the surface area of the conductive substrate.

9. The method of claim 1 , wherein step (b) comprises:
(b1) applying an electric current via the electrode sufficient to grow metal dendrites on the surface of the conductive substrate;
(b3) rotating the metal substrate relative to the electrode; and
(b2) applying an electric current via the electrode sufficient to grow metal dendrites on the surface of the rotated conductive substrate.

10. The method of claim 9 , comprising multiple rotation-dendrite growth sequences.

11. The method of claim 1 , wherein the depositing step comprises chemical vapor deposition or hydrothermal synthesis using a carbon source.

12. The method of claim 11 , wherein the carbon source comprises a C 2-4 hydrocarbon.

13. The method of claim 11 , wherein the depositing step is conducted at a temperature less than about 1,000° C.

14. The method of claim 11 , wherein the depositing step is conducted at a temperature between about 500-1,000° C.

15. The method according to claim 1 , wherein the conductive substrate is removed by chemical etching.

16. The method according to claim 15 , wherein the chemical etching comprises treatment with at least one acid.

17. The method according to claim 15 , wherein the chemical etching comprises a treatment with a mineral acid and a Lewis acid.

18. The method according to claim 17 , wherein the mineral acid comprises HCl, HBr, HI, HF, HNO 3 , H 2 SO 4 , H 3 PO 4 , or a mixture thereof.

19. The method according to claim 17 , wherein the Lewis acid comprises a transition metal salt.

Assignees

• Univ Texas

Inventors

• Li Weigu
• Fan Donglei

Classifications

• C01B32/205 Primary

  Preparation · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C23C16/26

  Deposition of carbon only · CPC title

• C25D1/003

  3D structures, e.g. superposed patterned layers · CPC title