Provided is a method of producing multiple isolated hollow graphene balls, comprising: (a) mixing multiple particles of a graphitic material and multiple particles of a solid polymer carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus to peel off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of solid polymer carrier material particles to produce graphene-coated polymer particles; (c) recovering the graphene-coated polymer particles from the impacting chamber; and (d) suspending the graphene-encapsulated polymer particles in a gaseous medium to keep the particles separated from each other while concurrently pyrolyzing the particles to thermally convert polymer into pores and carbon, wherein at least one of the graphene balls comprises a hollow core enclosed by a shell composed of graphene sheets bonded together by carbon.

A method for the production of a graphene layer structure having from 1 to 100 graphene layers, the method comprising providing a substrate having a thermal resistance equal to or greater than that of sapphire, on a heated susceptor in a reaction chamber, the chamber having a plurality of cooled inlets arranged so that, in use, the inlets are distributed across the substrate and have a constant separation from the substrate, supplying a flow comprising a precursor compound through the inlets and into the reaction chamber to thereby decompose the precursor compound and form graphene on the substrate, wherein the inlets are cooled to less than 100° C., preferably 50 to 60° C., and the susceptor is heated to a temperature of at least 50° C. in excess of a decomposition temperature of the precursor, using a laser to selectively ablate graphene from the substrate, wherein the laser has a wavelength in excess of 600 nm and a power of less than 50 Watts.

Provided are a cured product containing a single-layer graphene, a single-layer graphene, a preparation method therefor, and an article containing a single-layer graphene. The method for preparing the cured product containing a single-layer graphene includes (a) mixing graphite with a curable material and optionally a first solvent, and curing and molding same to obtain molded granules; (b) heating a system formed by the molded granules and optionally a second solvent, then introducing a gas for pressurization, and then releasing the pressure to obtain expanded granules; and (c) repeating step (a) and (b) several times, with the graphite and the curable material in step (a) replaced with the expanded granules, to obtain a cured product containing a single-layer graphene. The cured product containing a single-layer graphene is carbonized and separated to obtain a single-layer graphene. The article containing a single-layer graphene contains the cured product or the single-layer graphene.

Proposed are a photocatalyst, including titanium dioxide particles including titanium dioxide (TiO.sub.2), a carbon material located on all or part of the surface of the titanium dioxide particles and including at least one selected from the group consisting of graphene, reduced graphene oxide (rGO), and carbon nanotubes (CNTs), and bimetallic nanoparticles supported on the carbon material and including first metal nanoparticles and second metal nanoparticles, and a water treatment method using the same. In the photocatalyst and the water treatment method using the same, the photocatalyst including bimetallic nanoparticles and graphene oxide is prepared, thereby exhibiting high reduction efficiency and high selectivity to nitrogen gas even without the use of an external electron donor.

A method for manufacturing monocrystalline graphene, includes supplying an aromatic carbon gas onto a single-crystalline metal catalyst to manufacture the monocrystalline graphene.

Systems and method for producing graphene on a substrate are described. Certain types of exemplar systems include lateral arrangements of a substrate gas scavenging environment and an annealing environment. Certain other types of exemplar systems include lateral arrangements of a graphene producing environment and a cooling environment, which cools the graphene produced on the substrate. Yet other types of exemplar systems include lateral arrangements of a localized annealing environment, localized graphene producing environment and a localized cooling environment inside the same enclosure.

Certain type of exemplar methods for producing graphene on a substrate include scavenging a first portion of the substrate and preferably, contemporaneously annealing a second portion of the substrate. Certain other type of exemplar methods for producing graphene include novel annealing techniques and/or implementing temperature profiles and gas flow rate profiles that vary as a function of lateral distance and/or cooling graphene after producing it.

A electronic method, includes receiving, by a graphene structure, a microwave signal. The microwave signal has a driving voltage level. The electronic method includes generating, by the graphene structure, optical photons based on the microvolts. The electronic method includes outputting, by the graphene structure, the optical photons.

A method for preparing large graphene sheets in large scale includes steps of: under a mild condition, processing graphite powders with intercalation through an acid and an oxidant; washing away metal ions and inorganic ions in the graphite powders with dilute hydrochloric acid, then filtering and drying; and, finally processing with a heat treatment. The present invention breaks through a series of bottlenecks restricting an efficient preparation of graphene that result from a traditional method of using large amounts of deionized water to wash graphite oxide to be neutral, and easily realizes a batch production. A radial scale of the prepared graphene sheets is distributed from 20 um to 200 um.

Methods for growing microstructured and nanostructured graphene by growing the microstructured and nanostructured graphene from the bottom-up directly in the desired pattern are provided. The graphene structures can be grown via chemical vapor deposition (CVD) on substrates that are partially covered by a patterned graphene growth barrier which guides the growth of the graphene.

A dispersion of suspended single-layer graphene, multilayer graphene, and graphite is used. A magnetic field is applied to the dispersion to separate the single-layer graphene from the dispersion. By applying the magnetic field, the single-layer graphene, the multilayer graphene, and the graphite are situated at different locations in solvent by the difference in the diamagnetism strengths of the single-layer graphene, the multilayer graphene, and the graphite.