FRESH Lecture: Playing Lego with 2D crystals
- Prof. Petra Rudolf (University of Groningen)
- Thursday 26 April 2018
- Gorlaeus Building
2333 CC Leiden
Even since the Mayans first used clays to make dyes, mankind has made use of layered materials. Over the past two centuries this effort is mirrored in scientific research leading to experiments to exfoliate into one- or few-atom thick sheets or to intercalate them with atoms and (macro)molecules, as well as to an elucidation of their laminar structure and peculiar properties. Currently we live in an era of enormous interest in the manipulation of two-dimensional materials following the discovery of graphene.
In this presentation I shall start by illustrating various aspects of the exfoliation of pure and oxidized graphite. Then I shall pass on to pillared structures achieved by intercalation and in particular report on experimental and theoretical studies of the intercalation mechanism of polycyclic aromatic molecules into graphite oxide. Two representative molecules of this family, aniline and naphthalene amine behave very differently after intercalation, namely aniline molecules prefer to covalently bind to the graphene oxide matrix via chemical grafting, while naphthalene amine molecules bind with the graphene oxide surface through π-πinteractions.
This new understanding opens the way to build pillared materials for gas storage, catalytic and biomedical applications through “intercalation chemistry”. For applications in electronics, germanane and MoS2 are interesting candidates: I shall report on their synthesis and stability as well as on the first realisation of germanane field-effect transistors fabricated from multilayer single crystal flakes. Our germanane devices show transport in both electron and hole doped regimes.