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Initially, graphene oxide attracted substantial interest as a possible intermediate for the manufacture of graphene. The graphene obtained by reduction of graphene oxide still has many chemical and structural defects which is a problem for some applications but an advantage for some others. [5] [6]
Graphene oxide is usually produced through chemical exfoliation of graphite. A particularly popular technique is the improved Hummers' method . [ 219 ] Using paper-making techniques on dispersed, oxidized and chemically processed graphite in water, the monolayer flakes form a single sheet and create strong bonds.
Graphene is the only form of carbon (or solid material) in which every atom is available for chemical reaction from two sides (due to the 2D structure). Atoms at the edges of a graphene sheet have special chemical reactivity. Graphene has the highest ratio of edge atoms of any allotrope. Defects within a sheet increase its chemical reactivity. [1]
Hummers' method is a chemical process that can be used to generate graphite oxide through the addition of potassium permanganate to a solution of graphite, sodium nitrate, and sulfuric acid. It is commonly used by engineering and lab technicians as a reliable method of producing quantities of graphite oxide.
The electronic properties of graphene are significantly influenced by the supporting substrate. [59] [60] The Si(100)/H surface does not perturb graphene's electronic properties, whereas the interaction between it and the clean Si(100) surface changes its electronic states significantly. This effect results from the covalent bonding between C ...
Graphene aerogel morphologies have also been demonstrated to be controllable through 3D printing methods. Graphene oxide ink composed of graphene oxide gelled in a viscous solution with the addition of silica to lower viscosity and enable printability of the graphene oxide ink. The ink is then extruded from a nozzle into isooctane, which ...
GraPhage13 is the first graphene-based aerogel assembled using graphene oxide and the M13 bacteriophage. [70] Chalcogel is an aerogel made of chalcogens (the column of elements on the periodic table beginning with oxygen) such as sulfur, selenium, and other elements. [71] Metals less expensive than platinum have been used in its creation.
Neither of the earlier observations was sufficient to launch the "graphene gold rush" that awaited macroscopic samples of extracted atomic planes. One of the first patents pertaining to the production of graphene was filed in October 2002 and granted in 2006. [24] It detailed one of the first large scale graphene production processes.