A graphene layer, a method of forming the graphene layer, a device including the graphene layer, and a method of manufacturing the device are provided. The method of forming the graphene layer may include forming a first graphene at a first temperature using a first source gas and forming a second graphene at a second temperature using a second source gas. One of the first and second graphenes may be a P-type graphene, and the other one of the first and second graphenes may be an N-type graphene. The first graphene and the second graphene together form a PN junction.

Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 and method of preparing the same.

Provided herein are high throughput continuous or semi-continuous reactors and processes for manufacturing graphenic materials, such as graphene. Such processes are suitable for manufacturing graphenic materials at rates that are up to hundreds of times faster than conventional techniques, and have little batch-to-batch variation. Also provided herein are graphenic compositions of matter, including large, high quality and/or highly uniform graphene.

Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 and method of preparing the same.

A method for producing colloidal graphene dispersions comprises the steps of: (i) stirring graphite oxide in an aqueous dispersion medium to form a dispersion; (ii) determining if the dispersion is optically clear in a light microscope at 1000 fold magnification after 1 to 5 hours of stirring, and, if not clear, removing any undissolved impurities in the dispersion, in order to form a colloidal graphene oxide dispersion, or a multi-graphene oxide dispersion, that is optically clear in a light microscope at 1000 fold magnification; and (iii) thermally reducing the graphene oxide, or multi-graphene oxide, in dispersion in the aqueous dispersion medium at a temperature between 120 C. and 170 C. under pressure in order to ensure that the dispersion medium is not evaporated to form a stable colloidal graphene dispersion or a stable multi-graphene dispersion. Using the method used for the preparation of the starting dispersion a graphene or a multi-graphene dispersion is obtained that can be further processed to multi-graphene with larger inter-planar distances than graphite. Such dispersions and multi-graphenes are suitable materials in the manufacturing of rechargeable lithium ion batteries.

This invention relates generally to systems and methods for the production of high-quality graphene from solid carbon sources.

A graphene powder, its preparation method and application are provided. The graphene powder is a stack of graphene sheets. The graphene powder involves in its Raman spectrum a D peak and a G peak with peak heights of I.sub.D and I.sub.G respectively, where I.sub.D/I.sub.G is 0.10 or less. The graphene powder can be applied in conductive composite materials, anti-corrosion coatings, heat dissipation composite materials. In particular, when used in lithium-ion batteries, it can significantly reduce electrode internal resistance and improve battery stability at any current rates.

In one aspect, the disclosure relates to methods for hydrogen storage and a composition comprising hydrogenated graphene formed by the disclosed methods. In one aspect, the method comprises: irradiating a graphene sample with electrons at energies of about 1 keV to about 40 keV at about 1 atm of pressure, thereby forming hydrogenated graphene. Also disclosed herein is a method for releasing stored hydrogen, comprising heating a hydrogenated graphene sample formed by a method disclosed herein at a temperature of about 240 C. to about 300 C. Also disclosed herein is a system for hydrogenating graphene, comprising a graphene sample and an electron accelerator configured to irradiate the graphene sample with electrons in ambient air at about 1 atm of pressure. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

The present disclosure provides a dispersible graphene platelet and a method of making same. The structure of the graphene platelet 10 comprises a base layer 1 of graphene on which at least one discontinuous layer 2, 3, 4 of graphene is stacked, with each layer of graphene above the base layer having a smaller surface area than the layer it is stacked upon. The edges of the base layer and the discontinuous layers stacked upon it are all at least partially functionalised 5, providing a structure with graphene-like properties owing to the base layer and relatively high dispersibility owing to the increased amount of functionalised groups on each platelet. The platelets may be used for a number of applications, for example in the production of electrodes or composite materials.

A method for the manufacture of reduced graphene oxide from kish graphite including: A. The provision of kish graphite, B. Optionally, a pre-treatment of kish graphite, C. The intercalation of kish graphite with a persulfate salt and an acid at room temperature to obtain intercalated kish graphite, D. The expansion of the intercalated kish graphite to obtain expanded kish graphite and E. An oxidation step of the expanded kish graphite to obtain graphene oxide and F. A reduction of graphene oxide into reduced graphene oxide.