Graphene synthesis

Patent metadata

Field	Value
Publication number	US-2019003042-A1
Application number	US-201615752387-A
Country	US
Kind code	A1
Filing date	Aug 12, 2016
Priority date	Aug 14, 2015
Publication date	Jan 3, 2019
Grant date	—

Abstract

The invention relates to methods for the production of high quality graphene. In particular, the invention relates to single-step thermal methods which can be carried out in an ambient-air or vacuum environment using renewable biomass as a carbon source. Specifically, the invention comprises heating a metal substrate and carbon source in a sealed ambient environment to a temperature which produces carbon vapour from the carbon source such that the vapour comes into contact with the metal substrate, maintaining the temperature for a time sufficient to form a graphene lattice and then cooling the substrate at a controlled rate to form a deposited graphene.

First claim

1 . A method of preparing a deposited graphene comprising the steps of heating a metal substrate and carbon source in a sealed ambient environment to a temperature which produces carbon vapour from the carbon source such that the vapour comes into contact with the metal substrate, maintaining the temperature for a time sufficient to form a graphene lattice and then cooling the substrate at a controlled rate to form a deposited graphene.

2 . A method according to claim 1 wherein the deposited graphene is a film.

3 . A method according to claim 2 wherein the deposited graphene is a continuous film.

4 . A method according to any one of the preceding claims wherein the ambient environment is air at atmospheric pressure or a vacuum.

5 . The method according to any one of the preceding claims wherein the metal substrate is a transition metal substrate.

6 . The method according to any one of the preceding claims wherein the metal substrate is nickel or copper.

7 . The method according to claim 6 wherein the metal substrate is nickel and the ambient environment is air at atmospheric pressure.

8 . The method according to claim 7 wherein the metal substrate is nickel of purity 99% and above.

9 . The method according claims 6 to 8 wherein the metal substrate is polycrystalline nickel.

10 . The method according to claim 6 wherein the metal substrate is copper and the ambient environment is vacuum.

11 . The method according to any one of the preceding claims wherein the carbon source is biomass or is derived from biomass.

12 . The method according to any one of the preceding claims wherein the carbon source is a liquid.

13 . The method according to any one of the preceding claims wherein the carbon source is soybean oil.

14 . The method according to any one of the present claims wherein the method is free from feedstock gases.

15 . The method according to any one of the preceding claims wherein the ratio of carbon source to surface area of the metal substrate is 0.01-0.03 mL/cm 2 .

16 . The method according to claim 15 wherein the ratio of carbon source to surface area of the metal substrate is 0.01-0.025 ml/cm 2 .

17 . The method according to claim 15 wherein the ratio of carbon source to surface area of the metal substrate is 0.025-0.03 ml/cm 2 .

18 . The method according to any one of the preceding claims wherein the metal substrate and carbon source are both located in the one heating zone.

19 . The method according to any one of the preceding claims wherein the sealed environment is contained in an inert container.

20 . The method according to any one of the preceding claims wherein the sealed environment is a quartz, glass or other dielectric heat resistant container.

21 . The method according to any one of the preceding claims wherein the sealed environment is contained in a quartz tube.

22 . The method according to any one of the preceding claims wherein the temperature sufficient to form a graphene lattice is maintained for 3-15 minutes.

23 . The method according to any one of the preceding claims wherein the metal substrate and carbon source are heated to a temperature sufficient to form a graphene lattice in the range 650° C.-900° C.

24 . The method according to claims 22 and 23 wherein the temperature sufficient to form a graphene lattice is maintained at 800° C.

25 . A method according to claim 24 wherein the deposited graphene is in the form of a single layer.

26 . A method according to claim 24 wherein the deposited graphene is in the form of 1-3 layers.

27 . A method according to claim 24 wherein the deposited graphene is in the form of 1-19 layers.

28 . The method according to claims 22 and 23 wherein the temperature sufficient to form a graphene lattice is maintained at 900° C.

29 . A method according to claim 28 wherein the deposited graphene is in the form of 20-40 layers.

30 . A method according to claim 28 wherein the deposited graphene is in the form >40 layers.

31 . The method according to any one of the preceding claims wherein the substrate is cooled at a controlled rate to segregate the graphene lattice from the metal substrate.

32 . The method according to any one of the preceding claims wherein the substrate is cooled to ambient temperature at a rate of 10-100° C./minute.

33 . The method according to claim 32 wherein the substrate is cooled to ambient temperature at a rate of up to 18° C./minute.

34 . The method according to claim 32 wherein the substrate is cooled to ambient temperature at a rate of up to 25° C./minute.

35 . The method according to claim 32 wherein the substrate is cooled to ambient temperature at a rate of 50-100° C./minute.

36 . The method according to any one of the preceding claims further comprising the step of decoupling graphene from the substrate.

37 . An as-grown graphene film prepared by the method of any one of claims 1 to 36 .

38 . A free-standing graphene film prepared by the method of claim 36 .

Assignees

• Commw Scient Ind Res Org

Inventors

• Seo Dong Han
• Pineda Shafique
• Han Zhao Jun
• Ostrikov Kostyantyn

Classifications

• C23C16/4409

  characterised by sealing means · CPC title

• C23C16/4485

  by evaporation without using carrier gas in contact with the source material (C23C16/4486 takes precedence) · CPC title

• C23C16/463

  Cooling of the substrate · CPC title

• C01B32/186

  by chemical vapour deposition [CVD] · CPC title

• G01N27/308

  at least partially made of carbon · CPC title