Graphene is obtained by exfoliating individual atomic layers from bulk graphite
CHEMISTRY · Multi-part · AP · Chemistry · Compound Structure and Properties · Compound Structure and Properties
Problem
Graphene is obtained by exfoliating individual atomic layers from bulk graphite. A single layer of graphene retains the in-plane hexagonal carbon network but is only one atom thick.
Researchers measure the tensile strength of a suspended graphene sheet and find it to be among the highest recorded for any material. They also report an electron mobility of approximately 2×105cm2V−1s−1, far exceeding that of bulk graphite.
(a) Compare the covalent bonding present in a graphene sheet with that in one layer of graphite and explain any similarities or differences.
(b) Using bonding considerations, predict how the tensile strength of a single graphene sheet should compare with the tensile strength measured for bulk graphite parallel to the layers. Provide a clear rationale.
(c) Offer a molecular-level explanation for the exceptionally high electron mobility observed in graphene relative to bulk graphite.
(d) Propose one experimental technique that could be used to confirm that an isolated sheet is truly a single atomic layer thick, and briefly describe the type of data that would support this conclusion.