Systems and methods for making carbon nanostructures

Patent metadata

Field	Value
Publication number	US-2022388847-A1
Application number	US-202017760690-A
Country	US
Kind code	A1
Filing date	Oct 29, 2020
Priority date	Oct 29, 2019
Publication date	Dec 8, 2022
Grant date	—

Abstract

Embodiments of the present disclosure relate to methods and systems for providing an electrolysis reaction in a molten carbonate electrolyte to synthesize helical carbon nanostructures (HCNSs). The electrolyte, electrode composition, current density, temperature and additives all may have important roles in the formation of HCNS. With control of these parameters, a variety of specific, uniform high yield HCNS can be synthesized by molten carbonate electrolysis, according to embodiments of the present disclosure.

First claim

I claim:

1 . A method for synthesizing helical carbon nanostructures (HCNS), the method comprising steps of:
(a) aligning an anode spaced from a cathode for defining an inter-electrode space; (b) introducing a molten carbonate electrolyte into the inter-electrode space; (c) introducing a carbon input into the inter-electrode space; (d) applying a current across the electrodes; and (e) collecting a product that comprises the HCNS from the electrode.

2 . The method of claim 1 , further comprising applying at least two of the following parameters:
(a) applying the current with a high electrolysis current density; (b) heating the inter-electrode space to at least 725° C.; (c) adding into the inter-electrode space an electrolyte additive agent; and (d) adding iron oxide to the inter-electrode space.

3 . The method of claim 2 , wherein the product comprises a helical carbon nanotube (HCNT), a helical carbon nanofiber (HCNF), a double stranded HCNT, a braided HCNT, a helical nano-platelet (HCNP), a sp3 defective CNT, a deformed CNT, a bent CNT, a curved CNT and combinations thereof.

4 . The method of claim 1 , wherein the HCNS comprises a deformed CNT, a bent CNT, a curved CNT and combinations thereof.

5 . The method of claim 4 , wherein the step of applying the current occurs at a high electrolysis current density of about 0.2 A/cm2.

6 . The method of claim 2 , wherein the high electrolysis current density is at least 0.2 A/cm2.

7 . The method of claim 2 , wherein the inter-electrode space is heated to at least 750° C.

8 . The method of claim 2 , wherein the electrolyte additive is an sp3 defect inducing agent.

9 . The method of claim 8 , wherein the sp3 defect inducing agent is an oxide.

10 . The method of claim 9 , wherein the oxide is a metal oxide.

11 . The method of claim 2 , wherein the additive is one or more of a borate, a sulfate, a nitrate, a phosphate and combinations thereof.

12 . The method of claim 2 , wherein the iron oxide is added into the inter-electrode space by adding the iron into the electrolyte, dissolving iron from the anode, an electrolyte precursor, including iron on a surface of the cathode, or combinations thereof.

13 . The method of claim 1 , wherein the molten carbonate electrolyte comprises an alkali carbonate, an alkali earth carbonate or combinations thereof.

14 . A helical carbon nanostructure (HCNS) synthesized by a molten carbonate electrolysis method.

15 . The HCNS of claim 14 , wherein the HCNS comprises one or more of a helical carbon nanotube (HCNT), a helical carbon nanofiber (HCNF), a double stranded HCNT, a braided HCNT, a helical nano-platelet (HCNP), a sp3 defective CNT, a deformed CNT, a bent CNT, a curved CNT and combinations thereof.

16 . A system for making a helical carbon nanostructure (HCNS), the system comprising:
(a) an anode; (b) a cathode; (c) an inter-electrode space that is defined between the anode and the cathode; (d) a source of current for applying a current density is at least 0.2 A/cm 2 across the electrodes; (e) a source of heat for regulating the inter-electrode space at a temperature of at least about 725° C.; and, (f) a source of carbon for introducing a carbon input into the inter-electrode space.

17 . The system of claim 14 , wherein the source of carbon is carbon dioxide gas.

18 . The system of claim 14 , wherein the current density is at least 0.4 A/cm2.

19 . The system of claim 14 , wherein the temperature is at least about 750° C.

20 . The system of claim 14 , further comprising an electrolyte that is received within the inter-electrode space.

21 . The system of claim 14 , wherein the electrolyte is a molten carbonate.

22 . The system of claim 14 , further comprising an additive within the inter-electrode space, wherein the additive is one or more of a metal oxide, a borate, a sulfate, a nitrate, a phosphate or combinations thereof.

Assignees

• C2Cnt Llc

Inventors

• Licht Stuart
• Licht Gad

Classifications

• C01B32/16 Primary

  Preparation · CPC title

• C25B1/135 Primary

  Carbon · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01B32/166

  in liquid phase · CPC title