GRAPHENE-BASED COMPOUND, PREPARATION METHOD THEREOF, AND SINGLE-PHASE COMPOSITION FOR PREPARING GRAPHENE-BASED COMPOUND AND GRAPHENE QUANTUM DOT

• US 20190315626A1
• Filed: 11/16/2018
• Published: 10/17/2019
• Est. Priority Date: 04/12/2018
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology, Korea University Research and Business Foundation
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: PARK, O Ok, LEE, Seok Hwan, IM, Sang Hyuk
• Granted Patent: US 11,306,000 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2204/22 Electronic properties
• CPC Class Codes: C01B 32/184 Preparation
• CPC Class Codes: C01B 32/194 After-treatment
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2002/85 by XPS, EDX or EDAX data
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C09K 11/65 containing carbon in organic compounds C09K11/06

Abstract

Provided are a graphene-based compound, a preparation method thereof, a single-phase composition for preparing a graphene-based compound, and a graphene quantum dot. Specifically, provided are a graphene-based compound prepared from a single-phase composition for preparing a graphene-based compound including hydrocarbyl amine, a hydroxyl group-containing carbon source, and an acid, a preparation method thereof, a single-phase composition for preparing a graphene-based compound, and a graphene quantum dot.

Claims

1. A single-phase composition for preparing a graphene-based compound comprising:

hydrocarbyl amine, a hydroxyl group-containing carbon source, and an acid.

2. The single-phase composition for preparing a graphene-based compound of claim 1, wherein the hydroxyl group-containing carbon source includes a saccharide-based compound.

3. The single-phase composition for preparing a graphene-based compound of claim 2, wherein the saccharide-based compound includes a monosaccharide compound.

4. The single-phase composition for preparing a graphene-based compound of claim 1, wherein the acid includes an organic acid.

5. The single-phase composition for preparing a graphene-based compound of claim 1, further comprising:

a hydrocarbyl alcohol-based solvent.

6. The single-phase composition for preparing a graphene-based compound of claim 1, wherein the pH of the composition ranges from 4 to 7.

7. The single-phase composition for preparing a graphene-based compound of claim 1, wherein the graphene-based compound includes a graphene quantum dot.

8. A method for preparing a graphene-based compound comprising:

(a) preparing a reaction mixture including hydrocarbyl amine, a hydroxyl group-containing carbon source, and an acid; and

(b) heating the reaction mixture.

9. The method of claim 8, wherein the reaction mixture further includes a hydrocarbyl alcohol-based solvent.

10. The method of claim 8, wherein a reaction temperature in the (b) heating ranges from 60 to 300°

C.

11. The method of claim 9, further comprising:

mixing a reaction product obtained after the (b) heating with a (C1-C3) alcohol-based solvent.

12. The method of claim 8, further comprising:

cooling the reaction product obtained after the (b) heating to a melting point or less of the hydrocarbyl amine.

13. The method of claim 8, wherein the reaction mixture of the (a) preparing has a single phase.

14. A graphene-based compound prepared by the method of claim 8.

15. The graphene-based compound of claim 14, wherein the graphene-based compound includes a graphene quantum dot.

16. A graphene quantum dot in which an average particle diameter is 2 nm to 10 μ

m and a ratio of I(D)/I(G) is 1.0 or less.

17. The graphene quantum dot of claim 16, wherein the graphene quantum dot includes a carbonyl group or a —

C—

O group at an edge region of the graphene, and

a nitrogen atom of the hydrocarbyl amine is covalently bonded to a carbon atom of the edge region.

18. The graphene quantum dot of claim 16, wherein the graphene quantum dot has a maximum luminescence characteristic at 380 to 480 nm at 300K on a methanol solvent.

19. The graphene quantum dot of claim 16, wherein the graphene quantum dot has monocrystalline characteristics.

20. The graphene quantum dot of claim 16, wherein an exciton lifetime of the graphene quantum dot in a 5 mg/mL solution at 300K on a methanol solvent is 4 ns or less.

21. The graphene quantum dot of claim 16, wherein an emission maximum wavelength (λ

_em) and an excitation wavelength (λ

_ex) of PL on the methanol solvent at 300K of the graphene quantum dot satisfy Relational Expression 1 below;

λ

_em=A×

λ

_ex+B 

 

[Relational Expression 1]

in Relational Expression 1, A is 0.59 and B ranges from 208.81 to 238.81.

22. The graphene quantum dot of claim 16, wherein the graphene quantum dot has a full width at half maximum (FWHM) of PL emission spectrum at 300K of 100 nm or less.

23. The graphene quantum dot of claim 16, wherein a diameter (Dp) and a carbon/oxygen atomic ratio (C/O ratio) of a graphene quantum dot molecule satisfy Relational Expression 2 below:

C/O ratio=−

0.221×

Dp+C 

 

[Relational Expression 2]

in Relational Expression 2, the diameter (Dp) has a unit of nm, and the constant C ranges from 20.48 to 30.48.

24. The graphene quantum dot of claim 16, wherein the graphene quantum dot has a hexagonal array.