Top > Search of International Patents > Heteroelement-containing graphene

Heteroelement-containing graphene

Foreign code F210010326
File No. AF39-05WO
Posted date Feb 1, 2021
Country EPO
Application number 18860508
Gazette No. 3689819
Date of filing Sep 28, 2018
Gazette Date Aug 5, 2020
International application number JP2018036399
International publication number WO2019066013
Date of international filing Sep 28, 2018
Date of international publication Apr 4, 2019
Priority data
  • P2017-190683 (Sep 29, 2017) JP
  • 2018JP36399 (Sep 28, 2018) WO
Title Heteroelement-containing graphene
Abstract An object of the present invention is to provide a highly crystalline heteroelement-containing graphene. A heteroelement-containing graphene disclosed herein includes carbon (C) and, as a heteroelement (X), at least one element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si). Also, spots belonging to either the orthorhombic system or the hexagonal system and having the symmetry of a single crystal are observed in the selected area electron diffraction.
Outline of related art and contending technology Background Art
Heteroelement-containing graphene in which heterogeneous elements other than carbon are introduced into the carbon six-membered ring structure of graphene has attracted attention. In the heteroelement-containing graphene, for example, when a heterogeneous element such as nitrogen is introduced into the valley portion of the zigzag edge of the graphene, the heterogeneous element acts physically and chemically on the adjacent carbon atoms. It is known that the adjacent carbon atoms develop oxygen reduction properties as a result. Therefore, utilization of heteroelement-containing graphene as a catalyst material has been studied (see, for example, Patent Literatures 1 to 3).
Patent Literature 1 discloses an electrode catalyst support in which nitrogen-containing graphite is formed on a surface of a carbon support. The nitrogen-containing graphite of Patent Literature 1 is formed on a surface of a carbon support which has π electron donor properties. Patent Literature 1 further discloses that when the crystallinity of the nitrogen-containing graphite is evaluated by the ID/IG value based on the Raman spectrum, the ID/IG value is allowed to be 0.8 to 1.2.
Patent Literature 2 discloses a heteroatom-containing graphene containing a heteroatom such as nitrogen, which can be synthesized by a solvothermal reaction. In the Examples of Patent Literature 2, it is described that the heteroatom-containing graphene is doped with nitrogen atoms in a ratio of 14.8 atomic%. However, Patent Literature 2 does not disclose anything about the crystallinity of the heteroatom-containing graphene.
Patent Literature 3 discloses graphite-like carbon nitride (g-C3N4) having a stoichiometric ratio. The graphite-like carbon nitride disclosed in Patent Literature 3 has a structure in which melon ((C6N9H3)X), which has a triangular crystal structure in which three 6-membered rings formed by nitrogen and carbon and sharing C-N bonds with each other, is polymerized through nitrogen atoms at its apexes.
In Patent Literature 4, the present inventors provide a method for producing a heteroatom-containing carbon catalyst containing a large amount of nitrogen of 10 atomic% or more as a heterogeneous element. According to these methods, heteroatom-containing graphene containing no support can be produced.
Furthermore, Patent Literature 5 discloses that a redox-active carbon catalyst is formed on an electrode.
Citation List
Patent Literature
Patent Literature 1: Japanese Patent Laid-Open No. 2013-232409
Patent Literature 2: Japanese Patent Laid-Open No. 2012-153555
Patent Literature 3: International Publication No. WO 2014/098251
Patent Literature 4: Japanese Patent Laid-Open No. 2014-100617
Patent Literature 5: Japanese Patent Laid-Open No. 2016-209798
Scope of claims [claim1]
1. A heteroelement-containing graphene comprising carbon (C) and, as a heteroelement (X), at least one element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si), wherein spots belonging to either an orthorhombic system or a hexagonal system and having a symmetry of a single crystal are observed in selected area electron diffraction.

[claim2]
2. The heteroelement-containing graphene according to claim 1,
wherein the spots form an electron diffraction image belonging to the orthorhombic system with an incident direction of [101], the spots including an array of reciprocal lattice points 11-1, -111, -202, 1-1-1, 20-2, and-1-11.

[claim3]
3. The heteroelement-containing graphene according to claim 1 or 2, wherein a half width of a diffraction peak from (002) planes is 3 degrees or less in X-ray diffraction.

[claim4]
4. The heteroelement-containing graphene according to any one of claims 1 to 3, wherein a ratio (I(101)/I(002)) of a diffraction peak intensity I(101) from (101) planes to a diffraction peak intensity 1(002) from (002) planes is 0.1 or more in X-ray diffraction.

[claim5]
5. The heteroelement-containing graphene according to claim 3 or 4, wherein an interplanar spacing between the (002) planes is 3.5 Å or less in X-ray diffraction.

[claim6]
6. The heteroelement-containing graphene according to any one of claims 1 to 5, wherein an atomic ratio (X/C) of the heteroelement (X) to carbon (C), calculated based on X-ray photoelectron spectroscopy, is 0.1 or more.

[claim7]
7. The heteroelement-containing graphene according to any one of claims 1 to 6, wherein a possibility of a chemical bonding state of nitrogen doped to a basal plane being a chemical bonding state of cationic nitrogen can be indicated based on X-ray photoelectron spectroscopy, and it is determined by Hall effect measurement that a carrier type of the heteroelement-containing graphene is p-type.

[claim8]
8. The heteroelement-containing graphene according to any one of claims 1 to 7, wherein a ratio (I(D)/I(G)) of an intensity I(D) of a D band seen in the vicinity of 1350 cm-1 to an intensity I(G) of a G band appearing in the vicinity of 1580 cm-1 is 1 or less and a half width of the G band is 50 cm-1 or less in Raman spectroscopic analysis with an excitation wavelength of 532 nm.

[claim9]
9. The heteroelement-containing graphene according to any one of claims 1 to 8, wherein a ratio (I(2D)/I(G)) of an intensity I(2D) of a 2D band seen in the vicinity of 2700 cm-1 to the intensity I(G) of the G band is 0.5 or more in the Raman spectroscopic analysis.

[claim10]
10. The heteroelement-containing graphene according to any one of claims 1 to 9, wherein a half width of the 2D band seen in the vicinity of 2700 cm-1 is 80 cm -1 or less in the Raman spectroscopic analysis.

[claim11]
11. The heteroelement-containing graphene according to any one of claims 1 to 10, which does not include a base material that supports the heteroelement-containing graphene.

[claim12]
12. The heteroelement-containing graphene according to any one of claims 1 to 11, comprising a graphene sheet configured such that atoms of the carbon (C) are chemically bonded to atoms of the heteroelement (X) and atoms of the carbon (C) are principally sp2-bonded to each other,
wherein the graphene sheet has a single-layer structure formed by one layer or a stacked structure of two or more and five or less layers.

[claim13]
13. The heteroelement-containing graphene according to any one of claims 1 to 12, which is a powder having an average particle size of 1 nm or more and 10 µm or less.

[claim14]
14. A method for producing a heteroelement-containing graphene comprising carbon (C) and, as a heteroelement (X), at least one element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si), wherein spots belonging to either an orthorhombic system or a hexagonal system and having a symmetry of a single crystal are observed in selected area electron diffraction, the method comprising:
dissolving a hetero 5-membered ring compound having, at least partially, a 5-membered ring structure in a polar aprotic solvent to prepare a raw material-containing liquid, wherein the 5-membered ring is formed by carbon (C) and the heteroelement (X), which is at least one selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si); and
generating plasma in the raw material-containing liquid to polymerize the hetero 5-membered ring compound, thereby obtaining the heteroelement-containing graphene.
  • Applicant
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
  • Inventor
  • SAITO NAGAHIRO
IPC(International Patent Classification)
Specified countries Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Extension States: BA ME
Reference ( R and D project ) CREST Establishment of molecular technology towards the Creation of New Functions AREA
Please contact us by E-mail or facsimile if you have any interests on this patent.

PAGE TOP

close
close
close
close
close
close