The embodiments herein provide a facile four-step process for the preparation of binder-free graphene felts that are free standing and mechanically robust. The step of deagglomeration of graphene material leads to a uniform size distribution which when combined/integrated with an appropriate moulding technique allows an easy fine tuning of various attributes of graphene felts including electrical conductivity, porosity, surface area, surface morphology and surface functionalization depending on the desired application. Since graphene felts obtained from this process do not incorporate any binder, to achieve better electrical conductivity, electrochemical activity and catalytic and sensing properties compared to conventional graphene felts while not compromising with their mechanical properties.

Methods of making graphene oxide and reduced graphene oxide are provided. The methods can include a simple one-pot synthesis of graphene oxide from a purified coal powder using a mild oxidizing acid. The methods provide for an improved, more cost-effective, and simpler process than conventional methods such as Hummers methods. In some aspects, placing the purified coal powder in the mild oxidation atmosphere includes contacting the purified coal powder with a mild oxidizing acid such as nitric acid, nitrous acid, sulfuric acid, phosphoric acid, benzoic acid, or a combination thereof. In some aspects, the mild oxidizing acid consists essentially of nitric acid. Graphene oxides and reduced graphene oxides prepared by the methods are also provided.

A lithium ion secondary battery includes at least a positive electrode, a negative electrode, and an electrolyte solution. The negative electrode includes a negative electrode current collector and a negative electrode mixture layer. The negative electrode mixture layer is formed on a surface of the negative electrode current collector. The negative electrode mixture layer includes graphite particles, inorganic filler particles, lithium titanate particles, and a water-based binder. The inorganic filler particles have an average primary particle size that is ½ or less of an average primary particle size of the graphite particles. The lithium titanate particles have an average primary particle size of 1 μm or less. A ratio of an average primary particle size of the lithium titanate particles with respect to an average primary particle size of the inorganic filler particles is one or less.

The present invention provides a paper ball-like graphene microsphere, a composite material thereof, and a preparation method therefor. Such paper ball-like graphene microspheres are obtained by chemically reducing graphene oxide microspheres to slowly remove oxygen-containing functional groups on the surface of the graphene oxide to avoid the volume expansion caused by rapid removal of the groups, thereby maintaining a tight bond between graphene sheets without separation; and removing the remaining small number of oxygen-containing functional groups and repairing defect structures in the graphene oxide sheets by means of high temperature treatment, such that the graphene structure becomes perfect at an ultrahigh temperature (2500 to 3000° C.), thereby further improving the bonding ability between the graphene sheets in the microspheres and achieving a dense structure.

A graphene dispersion liquid containing graphene dispersed in a dispersion medium is described, in which, in the graphene contained in the dispersion liquid, a proportion of graphene with a size in the plane direction of 500 nm or more and 1 μm or less is 30% or more on an area basis, and a proportion of graphene with a size in the plane direction of 10 μm or more and 50 μm or less is 30% or more on an area basis. The graphene dispersion liquid is in a stable dispersion state and forms a strong conductive path.

A method and apparatus produce materials by exfoliation from a bulk material, by disposing bulk material in suspension in a liquid in a chamber; applying superimposed ultrasound fields in the chamber, the superimposed ultrasound fields generating cavitation in the liquid at least at a zone of field superimposition; measuring cavitation in the chamber while applying the superimposed cavitation fields, at least at the zone of field superimposition; and adjusting at least one of the ultrasound fields on the basis of measured cavitation so as to control cavitation energy applied to the material and thereby to control exfoliation of the bulk material and the formation of materials therefrom. Inertial cavitation is controlled, resulting in significantly greater production yields compared to prior art systems and methods. A high intensity focused ultrasound transducer is provided to impart suspension energy to the liquid in the chamber for suspending bulk material in the zone of field superimposition.

Disclosed herein is a system and method for transistor pathogen virus detector in which one embodiment may include a substrate layer, a silicon dioxide layer on the substrate layer, a nanocrystalline diamond layer on the silicon dioxide layer, a graphene oxide layer on the nanocrystalline diamond layer, fluorinated graphene oxide portions; and a linker layer, the linker layer including a plurality of pathogen receptors.

The present invention provides for an ice-nucleating particle for cloud seeding and other applications, which can initiate ice nucleation at a temperature of−8° C. Further, the ice nucleation particle number increased continuously and rapidly with the reducing of temperature. The ice nucleating particle in the present invention is a nanostructured porous composite of 3-dimensional reduced graphene oxide and silica dioxide nanoparticles (PrGO-SN). The present invention also provides for a process for synthesizing the PrGO-SN.

Provided is a carbon material, which can increase the capacitance in an electrical storage device. Provided is a carbon material including a carbon material that has a graphene laminated structure, where the carbon material has a BET specific surface area of 240 m.sup.2/g or more, and has a powder density of 0.5 g/cc or more when 0.1 g of the carbon material is put in a container with a cross-sectional area of 3.14 cm.sup.2 and compressed at a pressure of 16 kN.

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.