Design and synthesis of graphene nanoribbons from organic precursors

Abstract

Abstract The strategies of synthesis of graphene nanoribbons (GNRs) with different geometries and edge structures have been investigated by various researchers but their bulk production with structural uniformity maintaining appreciable length is still a great challenge for everyone. In terms of chemistry, preparation of GNR is actually the synthesis of a conjugated polymer which may be possible via rational assembly of small organic blocks using covalent or non-covalent bonding. In this work, two organic precursors viz., p-amino benzoic acid and o-amino phenol were selected for their transformation to graphene nanoribbons. The synthesis process was designed in such a way that functional groups attached at different positions of the aromatic moieties can produce graphenic ribbon like structures. Interestingly, the FE-SEM and TEM images confirmed that intermolecular condensation might have taken place between -NH2 and -COOH groups of p-amino benzoic acid and due to simultaneous dehydration and dehydrogenation, ribbon like structures was formed. Similarly, intermolecular condensation between -NH2 and -OH groups in o-amino phenol was found to be responsible for production of ribbons like structures within the graphenic lattice. The chemistry and mechanism concluded that designing the organic precursors with functional groups at suitable positions, optimization of time and temperature can lead to the formation graphene nanoribbons even at low temperatures.