Methods for synthesizing carbon nanocages

Patent metadata

Field	Value
Publication number	US-10584033-B2
Application number	US-201615760083-A
Country	US
Kind code	B2
Filing date	Sep 14, 2016
Priority date	Sep 14, 2015
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A method for synthesizing carbon nanocages, including N-doped carbon nanocages, includes a first step of forming a solution including a metal salt and an organic carbon source; a second step of drying the solution to obtain a precursor powder; and a third step of annealing the precursor powder to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell. The metal nanoparticle is then removed from the carbon shell by applying an acid solution.

First claim

What is claimed is:

1. A method for synthesizing a carbon nanocage, comprising:
forming a solution including a metal salt and an organic carbon source;
drying the solution to obtain a precursor powder;
annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the nanocage has a size of about 2 nm to about 100 nm.

2. The method of claim 1 , further comprising the step of removing the metal nanoparticle from the carbon shell.

3. The method of claim 2 , wherein the step of removing the metal nanoparticle from the carbon shell comprises applying an inorganic acid solution to the nanocage.

4. The method of claim 3 , wherein the inorganic acid solution comprises a nitric acid solution.

5. The method of claim 1 , wherein the metal salt is a transition metal salt.

6. The method of claim 5 , wherein the transition metal is selected from the group consisting of iron, copper, cobalt, molybdenum, manganese, and nickel.

7. The method of claim 6 , wherein the transition metal is nickel.

8. The method of claim 1 , wherein the solution is an aqueous solution.

9. The method of claim 1 , wherein the solution comprises an equal weight ratio of the metal salt and the organic carbon source.

10. The method of claim 1 , wherein the step of drying the solution comprises drying the solution at a temperature of between about 60° C. to about 120° C.

11. The method of claim 1 , wherein the organic carbon source is citric acid.

12. The method of claim 1 , wherein the step of annealing the precursor powder comprises placing the precursor powder in a furnace.

13. The method of claim 1 , wherein the carrier gas is oxygen-free.

14. The method of claim 13 , wherein the carrier gas is selected from Are, H 2 , helium, neon, xenon, N 2 , or a combination thereof.

15. The method of claim 1 , wherein the nanocage is spherical.

16. The method of claim 1 , wherein the organic carbon source comprises a nitrogen-containing alkaloid, an amide, or a nitrogen-containing heterocycle.

17. The method of claim 16 , wherein the amide is selected from urea and acetaminophen.

18. The method of claim 16 , wherein the nitrogen-containing alkaloid is a purine.

19. The method of claim 18 , wherein the purine is caffeine or theophylline.

20. The method of claim 16 , wherein the nitrogen-containing heterocycle is selected from the group consisting of a diazine, a triazine, and hydrolyzed acids thereof.

21. The method of claim 16 , wherein the nanocage is a N-doped carbon nanocage.

22. The method of claim 1 , wherein the solution comprises a weight ratio of organic carbon source to metal salt of about 10:1 to about 1:10.

23. The method of claim 1 , wherein the step of annealing the precursor powder is performed at a temperature of about 500° C. to about 600° C.

24. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the step of annealing the precursor powder comprises annealing the precursor powder at a temperature of 600° C. for about 10 minutes.

25. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the nanocage has a diameter of about 3 nm.

26. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the nanocage has a wall thickness of about 2 or about 3 layers.

27. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the nanocage has a Brunauer-Emmett-Teller (BET) surface area of about 980 to about 1150 m 2 g −1 .

28. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the carbon shell has a shell thickness of about 1 nm.

29. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum at a temperature of about 450° C. to about 700° C. for a time period of about 1 minute to about 20 minutes to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the nanocage has a mono-modal pore distribution of about 2.5 nm.

30. A method for synthesizing a carbon nanocage, comprising: forming a solution including a metal salt and an organic carbon source; drying the solution to obtain a precursor powder; annealing the precursor powder in a carrier gas or a vacuum to obtain a nanocage including a metal nanoparticle surrounded by a carbon shell, wherein the organic carbon source comprises a nitrogen-containing alkaloid, an amide, or a nitrogen-containing heterocycle, wherein the nanocage is a N-doped carbon nanocage, and wherein the N-doped nanocage has an average size of about 7 nm.

31. The method of claim 21 , wherein the nanocage further comprises one or more co-dopants.

32. The method of claim 31 , wherein the one or more co-dopants are selected from sulfur, phosphorus, and boron.

Assignees

• Univ Louisville Res Found Inc
• Univ Warszawski

Inventors

• Jasinski Jacek B
• Ziolkowska Dominika A
• Sumanasekera Gamini U
• Dilip Jangam John Samuel
• Kumar Bijandra

Classifications

• C01P2006/17

  Pore diameter distribution · CPC title

• B01J13/02

  Making microcapsules or microballoons {(for medical preparations A61K9/50)} · CPC title

• C01B32/15 Primary

  Nano-sized carbon materials · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2004/34

  hollow · CPC title