An example method includes providing coal and extracting the graphene from the coal. The graphene may be extracted using any suitable technique, such as the Hummers method, a modified Hummers method, or exfoliation of graphite. The graphene may include impurities or other electrical properties that depend at least partially on the composition of the coal. The method may further include forming a life science device from the graphene. The life science device may include, for example, a biosensor or a drug delivery system.

The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor and a preparation method thereof, belonging to the technical field of biosensors. The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor, including a substrate, an electrode layer, a graphene film, and a three-dimensional hydrogel material layer that are stacked in sequence; where the three-dimensional hydrogel material layer is formed of a hydrogel material having a three-dimensional network structure; the hydrogel material is obtained by polymerization of raw materials including an acrylamide monomer and a modified probe molecule; and the modified probe molecule is a probe molecule modified with an acrylamide group. The three-dimensional hydrogel-graphene-based biosensor has a desirable stability and a high sensitivity.

A composition suitable for coating a metallic substrate that is susceptible to corrosion is disclosed. The composition comprises a carrier medium and graphene platelets in which the graphene platelets comprise between 0.002 wt % and 0.09 wt % of the coating, and the graphene platelets comprise one of or a mixture of two or more of graphene nanoplates, bilayer graphene nanoplates, few-layer graphene nanoplates, and/or graphite flakes in which the graphite flakes have one nanoscale dimension and 25 or less layers.

A conductive composite material of graphene contains graphene nano-sheets and conjugated copolymers. The conjugated copolymers has alkynyl groups and are in a linear structure and grafted to the graphene nano-sheets. The preparation of conductive composite material includes the steps of: pretreating the graphene nano-sheets with 4-bromobenzenediazonium tetrafluoroborate, and forming the conjugated copolymers in the presence of the pretreated graphene nano-sheets. The conductive composite material of graphene can be uniformly dispersed in an electrode slurry, reduce the internal resistance of an electrode, and improve the electrical conductivity of an electrode. At the same time, the flexible structure associated with the graphene nano-sheets can buffer the volume expansion of the silicon-containing negative materials during charge-discharge cycling. Such a composite material can be in a lithium-ion battery.

Provided are a carbon-silicon three-dimensional structural composite material and a preparation method thereof. The preparation method includes: dissolving graphene quantum dots in ultrapure water, dropwise adding a CuCl.sub.2 or ZnCl.sub.2 solution, and performing oscillation to generate a mixed emulsifier; mixing the mixed emulsifier with a graphite oxide aqueous solution and a cyclohexane solution containing nanosilicon spheres, and performing homogenization to form a uniform oil-in-water emulsion; adding hydrazine hydrate into the obtained emulsion for reduction, and performing a hydrothermal reaction to obtain a reduced emulsion; and freeze-drying the reduced emulsion, performing washing with a washing liquid, and performing vacuum drying to obtain a carbon-silicon three-dimensional structural composite material.

The present invention is related to a production method of a photoluminescence material by micro-plasma treatment for degrading plastic piece into multiple smaller molecular, a graphene quantum dot and the composite thereof. By using micro-plasma treatment, the production method provided by the present invention consumes very little energy and the processing steps is simple and efficiency without the existence of any organic solvent. The products obtained by the said treatment is high valued graphene quantum dot and graphene quantum dot composite with excellent photoluminescence ability for at least white, blue, green, cyan or yellow colors.

Alloys, emf attenuation materials or emf reception materials, materials for biotechnology or biomedical materials, and materials for toxin and heavy metal removal, each containing a newly discovered allotrope of carbon having a multilayered nanocarbon array, and which exhibits, among other properties, exceptional stability, electrical conductivity and electromagnetic frequency (emf) attenuation characteristics. Members of this new allotrope include nanocarbon structures possessing vast electron delocalization in multiple directions, unavailable to known fullerene-characterized materials like carbon nano-onions (CNOs), multiwalled carbon nano-tubes (MWNTs), graphene, carbon nano-horns, and carbon nano-ellipsoids. Such stabilizing electron delocalization crosses or proceeds between layers, as well as along layers, in multiple directions within a continuous cyclic structure having an advanced interlayer connectivity bonding system involving the whole carbon array, apart from incidental defects.

Disclosed are a silicon-doped graphene composite material and a preparation method and application thereof. The silicon-doped graphene composite material comprises silicon and graphene; the silicon is doped in the graphene. The silicon-doped graphene composite material of the present disclosure has excellent charge and discharge capacity and structural stability; the silicon-doped graphene composite material is based on the graphene structure, with silicon atoms replacing the carbon atoms in a two-dimensional network structure of the graphene. The silicon-doped graphene composite material of the present disclosure has a layered structure similar to graphite materials, but is superior to other graphene materials in charge and discharge capacity, which is due to the fact that lithium intercalation sites are constructed by the silicon doped sites.

The invention discloses a method for preparing graphene by mechanical exfoliation and application thereof. The method includes the following steps of: (1) dispersing graphite raw material in a foaming agent aqueous solution to obtain a graphite pre-dispersing solution; and (2) subjecting the graphite pre-dispersing solution to milling, washing with water, and centrifugal classification, to obtain the graphene; wherein the foaming agent aqueous solution includes the following components: sodium alpha-olefin sulfonate, sodium alcohol ether sulphate, diethanolamine coconut fatty acid, polyethylene glycol, and water. In the invention, the foaming agent produce a large amount of stable and fine foam in a closed milling cavity, which can produce jostle effect, support the graphite, and increase the contact area between the graphite and the milling medium, so as to achieve good exfoliation effect.

A negative electrode active material capable of suppressing expansion of a negative electrode is provided. The negative electrode active material disclosed herein includes artificial graphite particles having a plurality of internal voids. The artificial graphite particles have a porosity of 0.7 to 15%. When binarization is performed on a cross-sectional electron microscopic image of 10 or more of the artificial graphite particles arbitrarily selected, circular approximation is then performed on internal voids having cross-sectional areas of 1000 nm.sup.2 or more, and circularities of 20 or more of the internal voids arbitrarily selected in each particle are determined, the internal voids have an average circularity of 0.1 to 0.6.