Bottom-up synthesis of nitrogen-doped graphene nanoribbons (original) (raw)
Related papers
Monodisperse N-Doped Graphene Nanoribbons Reaching 7.7 Nanometers in Length
Angewandte Chemie (International ed. in English), 2018
The properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N-doped graphene nanoribbons with different lengths. To showcase this approach, the synthesis and characterisation of a series of nanoribbons constituted of 10, 20 and 30 conjugated linearly-fused rings (2.9, 5.3, and 7.7 nm in length, respectively) is presented.
Electronic, structural, and transport properties of Ni-doped graphene nanoribbons
Physical Review B, 2009
... Lett. 98, 196803 [?]2007[?]. 13 TB Martins, RH Miwa, AJR da Silva, and A. Fazzio, 1 K. Nano Lett. 8, 2293 [?]2008[?]. Banhart, JC Charlier, and PM Ajayan, Phys. ... 16 Y. Yagi, TM Briere, MHF Sluiter, V. Kumar, AA Farajian, and Y. Kawazoe, Phys. Rev. B 69, 075414 [?]2004[?]. ...
Chemical synthesis of graphene nanoribbons
Arkivoc, 2015
Graphene is a two-dimensional atom-thick sheet of graphite composed of an sp 2-hybridized carbon atom network. Its isolation in 2004 and the extensive research that followed have led, amongst others, to graphene nanoribbons (GNRs), a graphene-based structure having nano-scale dimensions and semiconducting or metallic electronic properties that depend on its geometry and dimensions. These characteristics of GNRs are in stark contrast to those of graphene, which is a carbon sheet with semimetal, zero band gap characteristics. In the present article, we discuss the progress that has been reported towards producing GNRs with predefined dimensions, by using bottom-up chemical synthesis approaches.
Nitrogen doping has been an effective way to tailor the properties of graphene and render its potential use for various applications. Three common boding configurations are normally obtained when doing nitrogen into the graphene, i.e. pyridinic N, pyrrolic N and graphitic N. This paper reviews the nitrogen doped graphene, including various synthesis methods to introduce the N doping and various characterization techniques for the examination of various N bonding configuration. Potential applications of N-graphene are also reviewed based on the experimental and theoretical studies.
Versatile and scalable synthesis of graphene nanoribbons
Materials Letters, 2014
The inability to readily upscale nanofabrication of carbon nanomaterials often restricts their application, despite outstanding performances reported in both the research laboratory and prototype stages. Here we report the direct chemical synthesis of graphene nanoribbons by a bottom-up approach based on the common laboratory reagents sodium and propanol; these are solvothermally reacted to give an intermediate precursor that is then rapidly pyrolized yielding single-and few-layer graphene nanoribbons. Our results show that confinement of the lateral dimensions of graphene can be achieved simply by varying the alcohol feedstock. The ability to produce bulk quantities of graphene nanoribbons by a low cost and scalable approach is anticipated to enable a wider range of affordable real-world graphene applications.
New Approaches to Edge-Doping Graphene Nanoribbons
Bulletin of the American Physical Society, 2016
TEAM 1 , FISCHER TEAM 2 , LOUIE TEAM 3-Graphene nanoribbons (GNRs) are narrow semiconducting strips of graphene that exhibit novel electronic and magnetic properties. New bottom-up fabrication techniques enable atomic-scale precision in GNR synthesis. The use of these techniques to reliably tune the position and size of GNR band gaps is an important challenge that also has relevance for the question of whether GNRs are viable for future nanotechnologies. We have used scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) to investigate how the geometry of heteroatom incorporation alters the electronic structure of bottom-up fabricated chevron-type GNRs. We find that the addition of nitrogen into the GNR edge via a five-membered ring yields a reduced band gap compared to the behavior of pristine, undoped chevron GNRs.
Atomically precise bottom-up fabrication of graphene nanoribbons
Nature, 2010
Graphene nanoribbons-narrow and straight-edged stripes of graphene, or single-layer graphite-are predicted to exhibit electronic properties that make them attractive for the fabrication of nanoscale electronic devices 1-3 . In particular, although the twodimensional parent material graphene 4,5 exhibits semimetallic behaviour, quantum confinement and edge effects 2,6 should render all graphene nanoribbons with widths smaller than 10 nm semiconducting. But exploring the potential of graphene nanoribbons is hampered by their limited availability: although they have been made using chemical 7-9 , sonochemical 10 and lithographic 11,12 methods as well as through the unzipping of carbon nanotubes 13-16 , the reliable production of graphene nanoribbons smaller than 10 nm with chemical precision remains a significant challenge. Here we report a simple method for the production of atomically precise graphene nanoribbons of different topologies and widths, which uses surface-assisted coupling 17,18 of molecular precursors into linear polyphenylenes and their subsequent cyclodehydrogenation 19,20 . The topology, width and edge periphery of the graphene nanoribbon products are defined by the structure of the precursor monomers, which can be designed to give access to a wide range of different graphene nanoribbons. We expect that our bottom-up approach to the atomically precise fabrication of graphene nanoribbons will finally enable detailed experimental investigations of the properties of this exciting class of materials. It should even provide a route to graphene nanoribbon structures with engineered chemical and electronic properties, including the theoretically predicted intraribbon quantum dots 21 , superlattice structures 22 and magnetic devices based on specific graphene nanoribbon edge states 3 . sketches the basic graphene nanoribbon (GNR) fabrication steps for the prototypical armchair ribbon 6 of width N 5 7 obtained from 10,109-dibromo-9,99-bianthryl precursor monomers. Thermal sublimation of the monomers onto a solid surface removes their halogen substituents, yielding the molecular building blocks of the targeted graphene ribbon in the form of surface-stabilized biradical species. During a first thermal activation step, the biradical species diffuse across the surface and undergo radical addition reactions 17 to form linear polymer chains as imprinted by the specific chemical functionality pattern of the monomers. In a second thermal activation step a surface-assisted cyclodehydrogenation establishes an extended fully aromatic system. shows GNRs obtained according to the scheme in , using precursor monomers 1 and a Au(111) surface. The first step to GNR fabrication-intermolecular colligation through radical addition-is thermally activated by annealing at 200 uC, at which temperature the dehalogenated intermediates have enough thermal energy to diffuse along the surface and form single covalent C-C bonds between each monomer to give polymer chains. Scanning tunnelling microscopy (STM) images of the colligated monomers show protrusions that appear alternately on both sides of the chain axis and with a periodicity of 0.86 nm , in excellent agreement with the periodicity of the bianthryl core of 0.85 nm. Steric hindrance between the hydrogen atoms of adjacent anthracene units rotates the latter around the s-bonds connecting them, resulting in opposite tilts of successive anthracene units with respect to the metal surface. This deviation from planarity explains the large apparent height of the polyanthrylenes of about 0.4 nm , with the finite size of the scanning probe tip moreover imaging the polymer with a width much larger (1.5 nm) than expected from the structural 1 Br Br Precursor monomer 'Biradical' intermediate Graphene nanoribbon Linear polymer Figure 1 | Bottom-up fabrication of atomically precise GNRs. Basic steps for