Patent
US 10,787,746GRAPHENE OXIDE PREPARED BY ELECTROCHEMICALLY OXIDIZING AND CUTTING END FACE OF CARBON-BASED THREE-DIMENSIONAL MATERIAL AND METHOD THEREFOR
Haibo XU
US
Copyright © 2026 Matter42. All rights reserved.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation, comprising the steps of:-connecting a first piece of a 3-dimensional carbon-based material as a n first electrode and a second piece of a 3-dimensional carbon-based material or inert material as a second electrode to the two electrodes of a DC power supply, respectively, wherein an end face of at least the first electrode serves as a working face and is positioned in contact and parallel with the liquid surface of an electrolyte solution;-then electrifying the first electrode and the second electrode for electrolysis, during which a working zone for the end face serving as the working face is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the end face within the working zone, such that the graphite lamella on the end face of the at least one piece of the 3- dimensional carbon-based material is expansion-exfoliated and cut into graphene oxide by electrochemical oxidation, which is dispersed in the electrolyte solution to obtain a graphene oxide-containing electrolyte solution. Currently amended
The method according to claim 1, wherein when a * the end face of the first electrode serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution, the second electrode is fully or partially immersed in the electrolyte solution. Currently amended
The method according to claim 1, wherein the second electrode is a piece of a 3-dimensional carbon-based material, and wherein an the end face of the first electrode and a * the end face of the second electrode both serve as working faces and are positioned in contact and parallel with the liquid surface of the electrolyte solution, and wherein the first and second electrodes are of the same or different materials. Currently amended
The method according to claim 1, wherein the 3- dimensional carbon-based material includes one of, or a combination of more than one of, graphite sheets, paper, boards, filaments, tubes, and rods made from natural or artificial graphite, carbon fiber bundles, or carpets, cloth, paper, ropes, boards, and tubes woven with carbon fiber bundles. Previously presented
The method according to claim 1, wherein the end face of a the first electrode which serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution is a macroscopic surface at an angle of 60 0 to 90 0 with respect to one of the two-dimensional orientations of a microscopic graphite lamella of the 3- dimensional carbon-based material of the first electrode. Currently amended
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of only one piece of a 3- dimensional carbon-based material either always serves as the anode working face or alternately serves as the anode or cathode working face, the working voltage of the DC power supply during electrolysis is not higher than 80 V, and the working current density with respect to the end face is from +(1 to 300) or ± (1 to 300) A/cm2, wherein the symbol "+" indicates the anode current density, and the symbol " ± " indicates the current density of the alternating anode and cathode, wherein during the alternating cycles of electrolysis, the working current densities of the alternating anode and cathode is the same or different. Previously presented
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of one piece of a 3- dimensional carbon-based material and an end face of the other piece of a 3-dimensional carbon-based material both serve as working faces and the two end faces each alternately serve as an anode or cathode working face, a working voltage of the DC power supply during electrolysis is not higher than 100 V, and a working current density with respect to each end face is ± (1 to 300) A/cm 2, wherein the symbol " ±" indicates the current density of the anode and cathode, wherein during alternating cycles of electrolysis, the working current densities of the anode and cathode i-are the same or different. Currently amended
The method according to claim 1, comprising the steps of:-connecting a bundle-like carbon fiber serving as an anode and an inert electrode serving as a cathode to the positive and negative electrodes of a DC power supply, respectively;-immersing the inert electrode in an electrolyte solution, wherein the working face of the carbon fiber anode consists of an aligned tip face of the carbon fiber, and the tip face of the carbon fiber is positioned in contact and parallel with the liquid surface of the electrolyte solution before electrification;-then starting electrification, during which the working zone for the tip face of the carbon fiber is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the tip face of the carbon fiber within the working zone, such that a microcrystalline graphite lamella on the tip face of the carbon fiber is expansion-exfoliated and cut into graphene quantum dots by electrochemical oxidation, which are dissolved in the electrolyte solution to obtain a solution of graphene quantum dots. Currently amended
Graphene oxide prepared by the method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 1. Withdrawn
Graphene quantum dots prepared by the method of claim 1 for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 8, being 1- to 10-layer thick graphene quantum dots having a particle size of 1 to 100 nm and a carbon/oxygen atomic ratio of 2:1 to 20:1. Withdrawn
The method according to claim 1, wherein the electrolyte solution is a solution having an ion-conducting ability and having conductivity not less than 10 mS/cm. Previously presented
The method according to claim 1, further comprising the step of: separating the graphene oxide-containing electrolyte solution by a physical and/or chemical method to remove the electrolyte(s) and impurities therefrom, so as to obtain a solution containing graphene oxide in water or an organic solvent or graphene oxide in a colloidal or solid form; and/or the step of: subjecting the graphene oxide-containing electrolyte solution to vacuum filtration and/or dialysis treatment to further narrow down the particle-size distribution of the product; and/or the step of: subjecting the graphene oxide to one or more treatments of liquid-phase chemical reduction, electrochemical reduction, thermal reduction, UV-radiation-induced reduction, microwave reduction, active-metal reduction, and gas-phase reduction, to further increase the carbon/oxygen atomic ratio. Previously presented
Claims 14-16. Canceled
Canceled
Materials described outside the worked examples.
3-dimensional carbon-based material
graphene oxide
electrolyte solution
carbon fiber
graphene quantum dots
graphene oxide quantum dots
graphene oxide microplatelets
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene oxide quantum dot particle size (claimed range) | 1–100 nm | graphene oxide quantum dots |
graphene oxide microplatelet particle size (claimed range) | 101–10000 nm | graphene oxide microplatelets |
C to O/N atomic ratio in graphene oxide quantum dots and/or microplatelets (claimed range) | 1–25 C:O ratio (dimensionless) | graphene oxide |
graphene quantum dot particle size (claimed range) | 1–100 nm | graphene quantum dots |
C/O atomic ratio of graphene quantum dots (claimed range) | 2–20 C:O ratio (dimensionless) | graphene quantum dots |
nitrogen atom content in N-doped graphene quantum dots (claimed range) | 1–6 % | graphene quantum dots |
3D size of microcrystalline graphite lamellae in carbon fiber (claimed range) | 10–100 nm | carbon fiber |
electrolyte solution conductivity (claimed minimum) | ≥ 10 mS/cm | electrolyte solution |
Thickness | 3–5 mm | — |
Thickness | 5–5 mm | — |
Thickness | 10–40 nm | — |
Thickness | 3–25 nm | — |
Thickness | 3–10 nm | — |
Thickness | 0.7–10 nm | — |
Thickness | 7–15 nm | — |
Thickness | 1–5 nm | — |
Thickness | 2–100 nm | — |
Thickness | 2–7 nm | — |
Thickness | 10–20 nm | — |
Thickness | 5–10 nm | — |
Thickness | 15–50 nm | — |
Voltage | 30–50 V | — |
Thickness | 30–80 nm | — |
Voltage | 50–80 V | — |
Thickness | 15–25 nm | — |
Voltage | 20–50 V | — |
Thickness | 3–7 nm | — |
Voltage | 10–20 V | — |
Thickness | 30–50 nm | — |
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation, comprising the steps of:-connecting a first piece of a 3-dimensional carbon-based material as a n first electrode and a second piece of a 3-dimensional carbon-based material or inert material as a second electrode to the two electrodes of a DC power supply, respectively, wherein an end face of at least the first electrode serves as a working face and is positioned in contact and parallel with the liquid surface of an electrolyte solution;-then electrifying the first electrode and the second electrode for electrolysis, during which a working zone for the end face serving as the working face is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the end face within the working zone, such that the graphite lamella on the end face of the at least one piece of the 3- dimensional carbon-based material is expansion-exfoliated and cut into graphene oxide by electrochemical oxidation, which is dispersed in the electrolyte solution to obtain a graphene oxide-containing electrolyte solution. Currently amended
The method according to claim 1, wherein when a * the end face of the first electrode serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution, the second electrode is fully or partially immersed in the electrolyte solution. Currently amended
The method according to claim 1, wherein the second electrode is a piece of a 3-dimensional carbon-based material, and wherein an the end face of the first electrode and a * the end face of the second electrode both serve as working faces and are positioned in contact and parallel with the liquid surface of the electrolyte solution, and wherein the first and second electrodes are of the same or different materials. Currently amended
The method according to claim 1, wherein the 3- dimensional carbon-based material includes one of, or a combination of more than one of, graphite sheets, paper, boards, filaments, tubes, and rods made from natural or artificial graphite, carbon fiber bundles, or carpets, cloth, paper, ropes, boards, and tubes woven with carbon fiber bundles. Previously presented
The method according to claim 1, wherein the end face of a the first electrode which serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution is a macroscopic surface at an angle of 60 0 to 90 0 with respect to one of the two-dimensional orientations of a microscopic graphite lamella of the 3- dimensional carbon-based material of the first electrode. Currently amended
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of only one piece of a 3- dimensional carbon-based material either always serves as the anode working face or alternately serves as the anode or cathode working face, the working voltage of the DC power supply during electrolysis is not higher than 80 V, and the working current density with respect to the end face is from +(1 to 300) or ± (1 to 300) A/cm2, wherein the symbol "+" indicates the anode current density, and the symbol " ± " indicates the current density of the alternating anode and cathode, wherein during the alternating cycles of electrolysis, the working current densities of the alternating anode and cathode is the same or different. Previously presented
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of one piece of a 3- dimensional carbon-based material and an end face of the other piece of a 3-dimensional carbon-based material both serve as working faces and the two end faces each alternately serve as an anode or cathode working face, a working voltage of the DC power supply during electrolysis is not higher than 100 V, and a working current density with respect to each end face is ± (1 to 300) A/cm 2, wherein the symbol " ±" indicates the current density of the anode and cathode, wherein during alternating cycles of electrolysis, the working current densities of the anode and cathode i-are the same or different. Currently amended
The method according to claim 1, comprising the steps of:-connecting a bundle-like carbon fiber serving as an anode and an inert electrode serving as a cathode to the positive and negative electrodes of a DC power supply, respectively;-immersing the inert electrode in an electrolyte solution, wherein the working face of the carbon fiber anode consists of an aligned tip face of the carbon fiber, and the tip face of the carbon fiber is positioned in contact and parallel with the liquid surface of the electrolyte solution before electrification;-then starting electrification, during which the working zone for the tip face of the carbon fiber is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the tip face of the carbon fiber within the working zone, such that a microcrystalline graphite lamella on the tip face of the carbon fiber is expansion-exfoliated and cut into graphene quantum dots by electrochemical oxidation, which are dissolved in the electrolyte solution to obtain a solution of graphene quantum dots. Currently amended
Graphene oxide prepared by the method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 1. Withdrawn
Graphene quantum dots prepared by the method of claim 1 for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 8, being 1- to 10-layer thick graphene quantum dots having a particle size of 1 to 100 nm and a carbon/oxygen atomic ratio of 2:1 to 20:1. Withdrawn
The method according to claim 1, wherein the electrolyte solution is a solution having an ion-conducting ability and having conductivity not less than 10 mS/cm. Previously presented
The method according to claim 1, further comprising the step of: separating the graphene oxide-containing electrolyte solution by a physical and/or chemical method to remove the electrolyte(s) and impurities therefrom, so as to obtain a solution containing graphene oxide in water or an organic solvent or graphene oxide in a colloidal or solid form; and/or the step of: subjecting the graphene oxide-containing electrolyte solution to vacuum filtration and/or dialysis treatment to further narrow down the particle-size distribution of the product; and/or the step of: subjecting the graphene oxide to one or more treatments of liquid-phase chemical reduction, electrochemical reduction, thermal reduction, UV-radiation-induced reduction, microwave reduction, active-metal reduction, and gas-phase reduction, to further increase the carbon/oxygen atomic ratio. Previously presented
Claims 14-16. Canceled
Canceled
Materials described outside the worked examples.
3-dimensional carbon-based material
graphene oxide
electrolyte solution
carbon fiber
graphene quantum dots
graphene oxide quantum dots
graphene oxide microplatelets
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene oxide quantum dot particle size (claimed range) | 1–100 nm | graphene oxide quantum dots |
graphene oxide microplatelet particle size (claimed range) | 101–10000 nm | graphene oxide microplatelets |
C to O/N atomic ratio in graphene oxide quantum dots and/or microplatelets (claimed range) | 1–25 C:O ratio (dimensionless) | graphene oxide |
graphene quantum dot particle size (claimed range) | 1–100 nm | graphene quantum dots |
C/O atomic ratio of graphene quantum dots (claimed range) | 2–20 C:O ratio (dimensionless) | graphene quantum dots |
nitrogen atom content in N-doped graphene quantum dots (claimed range) | 1–6 % | graphene quantum dots |
3D size of microcrystalline graphite lamellae in carbon fiber (claimed range) | 10–100 nm | carbon fiber |
electrolyte solution conductivity (claimed minimum) | ≥ 10 mS/cm | electrolyte solution |
Thickness | 3–5 mm | — |
Thickness | 5–5 mm | — |
Thickness | 10–40 nm | — |
Thickness | 3–25 nm | — |
Thickness | 3–10 nm | — |
Thickness | 0.7–10 nm | — |
Thickness | 7–15 nm | — |
Thickness | 1–5 nm | — |
Thickness | 2–100 nm | — |
Thickness | 2–7 nm | — |
Thickness | 10–20 nm | — |
Thickness | 5–10 nm | — |
Thickness | 15–50 nm | — |
Voltage | 30–50 V | — |
Thickness | 30–80 nm | — |
Voltage | 50–80 V | — |
Thickness | 15–25 nm | — |
Voltage | 20–50 V | — |
Thickness | 3–7 nm | — |
Voltage | 10–20 V | — |
Thickness | 30–50 nm | — |
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation, comprising the steps of:-connecting a first piece of a 3-dimensional carbon-based material as a n first electrode and a second piece of a 3-dimensional carbon-based material or inert material as a second electrode to the two electrodes of a DC power supply, respectively, wherein an end face of at least the first electrode serves as a working face and is positioned in contact and parallel with the liquid surface of an electrolyte solution;-then electrifying the first electrode and the second electrode for electrolysis, during which a working zone for the end face serving as the working face is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the end face within the working zone, such that the graphite lamella on the end face of the at least one piece of the 3- dimensional carbon-based material is expansion-exfoliated and cut into graphene oxide by electrochemical oxidation, which is dispersed in the electrolyte solution to obtain a graphene oxide-containing electrolyte solution. Currently amended
The method according to claim 1, wherein when a * the end face of the first electrode serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution, the second electrode is fully or partially immersed in the electrolyte solution. Currently amended
The method according to claim 1, wherein the second electrode is a piece of a 3-dimensional carbon-based material, and wherein an the end face of the first electrode and a * the end face of the second electrode both serve as working faces and are positioned in contact and parallel with the liquid surface of the electrolyte solution, and wherein the first and second electrodes are of the same or different materials. Currently amended
The method according to claim 1, wherein the 3- dimensional carbon-based material includes one of, or a combination of more than one of, graphite sheets, paper, boards, filaments, tubes, and rods made from natural or artificial graphite, carbon fiber bundles, or carpets, cloth, paper, ropes, boards, and tubes woven with carbon fiber bundles. Previously presented
The method according to claim 1, wherein the end face of a the first electrode which serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution is a macroscopic surface at an angle of 60 0 to 90 0 with respect to one of the two-dimensional orientations of a microscopic graphite lamella of the 3- dimensional carbon-based material of the first electrode. Currently amended
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of only one piece of a 3- dimensional carbon-based material either always serves as the anode working face or alternately serves as the anode or cathode working face, the working voltage of the DC power supply during electrolysis is not higher than 80 V, and the working current density with respect to the end face is from +(1 to 300) or ± (1 to 300) A/cm2, wherein the symbol "+" indicates the anode current density, and the symbol " ± " indicates the current density of the alternating anode and cathode, wherein during the alternating cycles of electrolysis, the working current densities of the alternating anode and cathode is the same or different. Previously presented
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of one piece of a 3- dimensional carbon-based material and an end face of the other piece of a 3-dimensional carbon-based material both serve as working faces and the two end faces each alternately serve as an anode or cathode working face, a working voltage of the DC power supply during electrolysis is not higher than 100 V, and a working current density with respect to each end face is ± (1 to 300) A/cm 2, wherein the symbol " ±" indicates the current density of the anode and cathode, wherein during alternating cycles of electrolysis, the working current densities of the anode and cathode i-are the same or different. Currently amended
The method according to claim 1, comprising the steps of:-connecting a bundle-like carbon fiber serving as an anode and an inert electrode serving as a cathode to the positive and negative electrodes of a DC power supply, respectively;-immersing the inert electrode in an electrolyte solution, wherein the working face of the carbon fiber anode consists of an aligned tip face of the carbon fiber, and the tip face of the carbon fiber is positioned in contact and parallel with the liquid surface of the electrolyte solution before electrification;-then starting electrification, during which the working zone for the tip face of the carbon fiber is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the tip face of the carbon fiber within the working zone, such that a microcrystalline graphite lamella on the tip face of the carbon fiber is expansion-exfoliated and cut into graphene quantum dots by electrochemical oxidation, which are dissolved in the electrolyte solution to obtain a solution of graphene quantum dots. Currently amended
Graphene oxide prepared by the method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 1. Withdrawn
Graphene quantum dots prepared by the method of claim 1 for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 8, being 1- to 10-layer thick graphene quantum dots having a particle size of 1 to 100 nm and a carbon/oxygen atomic ratio of 2:1 to 20:1. Withdrawn
The method according to claim 1, wherein the electrolyte solution is a solution having an ion-conducting ability and having conductivity not less than 10 mS/cm. Previously presented
The method according to claim 1, further comprising the step of: separating the graphene oxide-containing electrolyte solution by a physical and/or chemical method to remove the electrolyte(s) and impurities therefrom, so as to obtain a solution containing graphene oxide in water or an organic solvent or graphene oxide in a colloidal or solid form; and/or the step of: subjecting the graphene oxide-containing electrolyte solution to vacuum filtration and/or dialysis treatment to further narrow down the particle-size distribution of the product; and/or the step of: subjecting the graphene oxide to one or more treatments of liquid-phase chemical reduction, electrochemical reduction, thermal reduction, UV-radiation-induced reduction, microwave reduction, active-metal reduction, and gas-phase reduction, to further increase the carbon/oxygen atomic ratio. Previously presented
Claims 14-16. Canceled
Canceled
Materials described outside the worked examples.
3-dimensional carbon-based material
graphene oxide
electrolyte solution
carbon fiber
graphene quantum dots
graphene oxide quantum dots
graphene oxide microplatelets
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene oxide quantum dot particle size (claimed range) | 1–100 nm | graphene oxide quantum dots |
graphene oxide microplatelet particle size (claimed range) | 101–10000 nm | graphene oxide microplatelets |
C to O/N atomic ratio in graphene oxide quantum dots and/or microplatelets (claimed range) | 1–25 C:O ratio (dimensionless) | graphene oxide |
graphene quantum dot particle size (claimed range) | 1–100 nm | graphene quantum dots |
C/O atomic ratio of graphene quantum dots (claimed range) | 2–20 C:O ratio (dimensionless) | graphene quantum dots |
nitrogen atom content in N-doped graphene quantum dots (claimed range) | 1–6 % | graphene quantum dots |
3D size of microcrystalline graphite lamellae in carbon fiber (claimed range) | 10–100 nm | carbon fiber |
electrolyte solution conductivity (claimed minimum) | ≥ 10 mS/cm | electrolyte solution |
Thickness | 3–5 mm | — |
Thickness | 5–5 mm | — |
Thickness | 10–40 nm | — |
Thickness | 3–25 nm | — |
Thickness | 3–10 nm | — |
Thickness | 0.7–10 nm | — |
Thickness | 7–15 nm | — |
Thickness | 1–5 nm | — |
Thickness | 2–100 nm | — |
Thickness | 2–7 nm | — |
Thickness | 10–20 nm | — |
Thickness | 5–10 nm | — |
Thickness | 15–50 nm | — |
Voltage | 30–50 V | — |
Thickness | 30–80 nm | — |
Voltage | 50–80 V | — |
Thickness | 15–25 nm | — |
Voltage | 20–50 V | — |
Thickness | 3–7 nm | — |
Voltage | 10–20 V | — |
Thickness | 30–50 nm | — |
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation, comprising the steps of:-connecting a first piece of a 3-dimensional carbon-based material as a n first electrode and a second piece of a 3-dimensional carbon-based material or inert material as a second electrode to the two electrodes of a DC power supply, respectively, wherein an end face of at least the first electrode serves as a working face and is positioned in contact and parallel with the liquid surface of an electrolyte solution;-then electrifying the first electrode and the second electrode for electrolysis, during which a working zone for the end face serving as the working face is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the end face within the working zone, such that the graphite lamella on the end face of the at least one piece of the 3- dimensional carbon-based material is expansion-exfoliated and cut into graphene oxide by electrochemical oxidation, which is dispersed in the electrolyte solution to obtain a graphene oxide-containing electrolyte solution. Currently amended
The method according to claim 1, wherein when a * the end face of the first electrode serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution, the second electrode is fully or partially immersed in the electrolyte solution. Currently amended
The method according to claim 1, wherein the second electrode is a piece of a 3-dimensional carbon-based material, and wherein an the end face of the first electrode and a * the end face of the second electrode both serve as working faces and are positioned in contact and parallel with the liquid surface of the electrolyte solution, and wherein the first and second electrodes are of the same or different materials. Currently amended
The method according to claim 1, wherein the 3- dimensional carbon-based material includes one of, or a combination of more than one of, graphite sheets, paper, boards, filaments, tubes, and rods made from natural or artificial graphite, carbon fiber bundles, or carpets, cloth, paper, ropes, boards, and tubes woven with carbon fiber bundles. Previously presented
The method according to claim 1, wherein the end face of a the first electrode which serves as the working face and is positioned in contact and parallel with the liquid surface of the electrolyte solution is a macroscopic surface at an angle of 60 0 to 90 0 with respect to one of the two-dimensional orientations of a microscopic graphite lamella of the 3- dimensional carbon-based material of the first electrode. Currently amended
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of only one piece of a 3- dimensional carbon-based material either always serves as the anode working face or alternately serves as the anode or cathode working face, the working voltage of the DC power supply during electrolysis is not higher than 80 V, and the working current density with respect to the end face is from +(1 to 300) or ± (1 to 300) A/cm2, wherein the symbol "+" indicates the anode current density, and the symbol " ± " indicates the current density of the alternating anode and cathode, wherein during the alternating cycles of electrolysis, the working current densities of the alternating anode and cathode is the same or different. Previously presented
The method according to claim 1, wherein the electrochemical oxidation is implemented such that an end face of one piece of a 3- dimensional carbon-based material and an end face of the other piece of a 3-dimensional carbon-based material both serve as working faces and the two end faces each alternately serve as an anode or cathode working face, a working voltage of the DC power supply during electrolysis is not higher than 100 V, and a working current density with respect to each end face is ± (1 to 300) A/cm 2, wherein the symbol " ±" indicates the current density of the anode and cathode, wherein during alternating cycles of electrolysis, the working current densities of the anode and cathode i-are the same or different. Currently amended
The method according to claim 1, comprising the steps of:-connecting a bundle-like carbon fiber serving as an anode and an inert electrode serving as a cathode to the positive and negative electrodes of a DC power supply, respectively;-immersing the inert electrode in an electrolyte solution, wherein the working face of the carbon fiber anode consists of an aligned tip face of the carbon fiber, and the tip face of the carbon fiber is positioned in contact and parallel with the liquid surface of the electrolyte solution before electrification;-then starting electrification, during which the working zone for the tip face of the carbon fiber is located between -5 mm below and 5 mm above the liquid surface of the electrolyte solution; and-intermittently or continuously controlling the tip face of the carbon fiber within the working zone, such that a microcrystalline graphite lamella on the tip face of the carbon fiber is expansion-exfoliated and cut into graphene quantum dots by electrochemical oxidation, which are dissolved in the electrolyte solution to obtain a solution of graphene quantum dots. Currently amended
Graphene oxide prepared by the method for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 1. Withdrawn
Graphene quantum dots prepared by the method of claim 1 for preparing graphene oxide by cutting an end face of a 3-dimensional carbon-based material by electrochemical oxidation according to claim 8, being 1- to 10-layer thick graphene quantum dots having a particle size of 1 to 100 nm and a carbon/oxygen atomic ratio of 2:1 to 20:1. Withdrawn
The method according to claim 1, wherein the electrolyte solution is a solution having an ion-conducting ability and having conductivity not less than 10 mS/cm. Previously presented
The method according to claim 1, further comprising the step of: separating the graphene oxide-containing electrolyte solution by a physical and/or chemical method to remove the electrolyte(s) and impurities therefrom, so as to obtain a solution containing graphene oxide in water or an organic solvent or graphene oxide in a colloidal or solid form; and/or the step of: subjecting the graphene oxide-containing electrolyte solution to vacuum filtration and/or dialysis treatment to further narrow down the particle-size distribution of the product; and/or the step of: subjecting the graphene oxide to one or more treatments of liquid-phase chemical reduction, electrochemical reduction, thermal reduction, UV-radiation-induced reduction, microwave reduction, active-metal reduction, and gas-phase reduction, to further increase the carbon/oxygen atomic ratio. Previously presented
Claims 14-16. Canceled
Canceled
Materials described outside the worked examples.
3-dimensional carbon-based material
graphene oxide
electrolyte solution
carbon fiber
graphene quantum dots
graphene oxide quantum dots
graphene oxide microplatelets
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene oxide quantum dot particle size (claimed range) | 1–100 nm | graphene oxide quantum dots |
graphene oxide microplatelet particle size (claimed range) | 101–10000 nm | graphene oxide microplatelets |
C to O/N atomic ratio in graphene oxide quantum dots and/or microplatelets (claimed range) | 1–25 C:O ratio (dimensionless) | graphene oxide |
graphene quantum dot particle size (claimed range) | 1–100 nm | graphene quantum dots |
C/O atomic ratio of graphene quantum dots (claimed range) | 2–20 C:O ratio (dimensionless) | graphene quantum dots |
nitrogen atom content in N-doped graphene quantum dots (claimed range) | 1–6 % | graphene quantum dots |
3D size of microcrystalline graphite lamellae in carbon fiber (claimed range) | 10–100 nm | carbon fiber |
electrolyte solution conductivity (claimed minimum) | ≥ 10 mS/cm | electrolyte solution |
Thickness | 3–5 mm | — |
Thickness | 5–5 mm | — |
Thickness | 10–40 nm | — |
Thickness | 3–25 nm | — |
Thickness | 3–10 nm | — |
Thickness | 0.7–10 nm | — |
Thickness | 7–15 nm | — |
Thickness | 1–5 nm | — |
Thickness | 2–100 nm | — |
Thickness | 2–7 nm | — |
Thickness | 10–20 nm | — |
Thickness | 5–10 nm | — |
Thickness | 15–50 nm | — |
Voltage | 30–50 V | — |
Thickness | 30–80 nm | — |
Voltage | 50–80 V | — |
Thickness | 15–25 nm | — |
Voltage | 20–50 V | — |
Thickness | 3–7 nm | — |
Voltage | 10–20 V | — |
Thickness | 30–50 nm | — |