title: Selective chemical modification of graphene surfaces: distinction between single- and bilayer graphene.
abstract: Graphene modifications with oxygen or hydrogen are well known in contrast to carbon attachment to the graphene lattice. The chemical modification of graphene sheets with aromatic diazonium ions (carbon attachment) is analyzed by confocal Raman spectroscopy. The temporal and spatial evolution of surface-adsorbed species allows accurate tracking of the chemical reaction and identification of intermediates. The controlled transformation of sp(2) to sp(3) carbon proceeds in two separate steps. The presented derivatization is faster for single-layer graphene and allows controlled transformation of adsorbed diazonium reagents into covalently bound surface derivatives with enhanced reactivity at the edge of single-layer graphene. On bilayer graphene the derivatization proceeds to an adsorbed intermediate, which reacts slower to a covalently attached species on the carbon surface.
authors.affiliation: Institute for Chemical and Bioengineering ETH Zurich, CH-8093 Zurich, Switzerland.
authors.forename: Fabian M
authors.initials: FM
authors.lastname: Koehler
authors.forename: Arnhild
authors.initials: A
authors.lastname: Jacobsen
authors.forename: Klaus
authors.initials: K
authors.lastname: Ensslin
authors.forename: Christoph
authors.initials: C
authors.lastname: Stampfer
authors.forename: Wendelin J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D006108:Graphite / Q000737:chemistry*; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D013059:Spectrum Analysis, Raman
chemical_list: D006108:Graphite