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The onset temperature of reaction between the basal plane of single-layer graphene and oxygen gas is below 260 °C (530 K). [2] Graphene combusts at 350 °C (620 K). [3] Graphene is commonly modified with oxygen- and nitrogen-containing functional groups and analyzed by infrared spectroscopy and X-ray photoelectron spectroscopy.
Graphene has the highest ratio of edge atoms of any allotrope. Defects within a sheet increase its chemical reactivity. [184] The onset temperature of reaction between the basal plane of single-layer graphene and oxygen gas is below 260 °C (530 K). [185] Graphene burns at very low temperatures (e.g., 350 °C (620 K)). [186]
A rapidly increasing list of graphene production techniques have been developed to enable graphene's use in commercial applications. [1]Isolated 2D crystals cannot be grown via chemical synthesis beyond small sizes even in principle, because the rapid growth of phonon density with increasing lateral size forces 2D crystallites to bend into the third dimension. [2]
Graphene spray guns are a kinetic spray system that deposits, through supersonic acceleration, a one atom thick sheet of pure carbon named graphene by means of a de Laval nozzle, [1] which is a pinched tube with an hourglass type shape. The system deposits graphene flakes and a hexagonal graphene lattice is created upon impact of the desired ...
Graphene doped with various gaseous species (both acceptors and donors) can be returned to an undoped state by gentle heating in vacuum. [22] [24] Even for dopant concentrations in excess of 10 12 cm −2 carrier mobility exhibits no observable change. [24] Graphene doped with potassium in ultra-high vacuum at low temperature can reduce ...
Bilayer graphene is a material consisting of two layers of graphene. One of the first reports of bilayer graphene was in the seminal 2004 Science paper by Geim and colleagues, [ 1 ] in which they described devices "which contained just one, two, or three atomic layers"
The basic chemical reaction involved in the Hummers' method is the oxidation of graphite, introducing molecules of oxygen to the pure carbon graphene. The reaction occurs between the graphene and the concentrated sulfuric acid with the potassium permanganate and sodium nitrate acting as catalysts.
The air stability of graphene shows a clear thickness dependence: monolayer graphene is reactive to oxygen at 250 °C, strongly doped at 300 °C, and etched at 450 °C; in contrast, bulk graphite is not oxidized until 800 °C. [71] Atomically thin boron nitride has much better oxidation resistance than graphene.