black phosphorus造句

• Exfoliated black phosphorus sublimes at 400 癈 in vacuum.
• Black phosphorus is obtained by heating white phosphorus under high pressures ( about ).
• Suspensions are then centrifuged for 30 minutes to filter out the unexfoliated black phosphorus.
• Black phosphorus has an cubic crystal lattice structure.
• A recent synthesis of black phosphorus using metal salts as catalysts has been reported.
• It is predicted that crystal structure of black phosphorus can be discriminated under high pressure.
• This is mostly due to the anisotropic compressibility of black phosphorus because of the asymmetrical crystal structures.
• In scotch-tape-based microcleavage, phosphorene is mechanically exfoliated from a bulk of black phosphorus crystal using scotch-tape.
• Heating white phosphorus under high ( GPa ) pressures converts it to black phosphorus which has a layered, graphite-like structure.
• The structural transitions in phosphorus are reversible : upon releasing high pressure, black phosphorus gradually converts into the red allotrope, and by vaporizing red phosphorus at 490 癈 in inert atmosphere and condensing the vapor, covalent red phosphorus can be transformed back into the white molecular solid.
• In the liquid exfoliation method first reported by Brent et al . in 2014 and modified by others, bulk black phosphorus is first ground in a mortar and pestle and then sonicated in deoxygenated, anhydrous organic liquids such as NMP under inert atmosphere using low-power bath sonication.
• The solution is then centrifuged twice, first for 10 minutes to remove any unexfoliated black phosphorus and then for 20 minutes at higher speed to separate thick layers of phosphorene ( 5 12 layers ) from NMP . The supernatant then is centrifuged again at higher speed for another 20 minutes to separate thinner layers of phosphorene ( 1 7 layers ).
• When it is converted to the covalent red phosphorus, the density goes to 2.2 2.4 g / cm 3 and melting point to 590 癈, and when white phosphorus is transformed into the ( also covalent ) black phosphorus, the density becomes 2.69 3.8 g / cm 3 and melting temperature ~ 200 癈 . Both red and black phosphorus forms are significantly harder than white phosphorus, and whereas white phosphorus is an insulator, the black allotrope, which consists of layers extending over the whole crystal, does conduct electricity.
• When it is converted to the covalent red phosphorus, the density goes to 2.2 2.4 g / cm 3 and melting point to 590 癈, and when white phosphorus is transformed into the ( also covalent ) black phosphorus, the density becomes 2.69 3.8 g / cm 3 and melting temperature ~ 200 癈 . Both red and black phosphorus forms are significantly harder than white phosphorus, and whereas white phosphorus is an insulator, the black allotrope, which consists of layers extending over the whole crystal, does conduct electricity.