Title：A Future for Carbon Nanostructures

Invited Speaker: Prof. Xinliang Feng

        Center for Advancing Electronics Dresden and Department of Chemistry and Food Chemistry,
        Dresden University of Technology, Germany.

Venue: Chemistry Building,A717

Time: 4:00 pm,May 10,2018

Abstract：
Carbon is intimately connected to almost everything we deal with in a daily basis. Scientists have realized two allotropes of carbon two hundred years ago, which are the most well-known diamond and graphite. These allotropes, with their vastly different structures, reveal that the structure and alignment of carbon atoms have profound effects on the material properties. In the past four decades, nanometre-sized allotropes of carbons, such as fullerenes, carbon nanotubes and graphene have emerged that have completely changed the landscape of carbon-based materials, and their discoveries have opened doors to enable the development of new physical sciences and technologies.
Nowadays, many carbon nanostructures have been theoretically predicted but are yet to be developed experimentally. Strategies like “top-down” and “bottom-up” approaches are established towards their syntheses. In general, “top-down” approach starting from graphitic precursors often leads to a mixture of molecules/polymers with a broad range of carbon nanostructures and thus a variety of properties. “Bottom-up” step-wise synthesis represents a promising approach to achieve structurally defined carbon nanostructures with molecular-level design. In this presentation, I will firstly introduce the rationale for using bottom-up chemistry for the precise synthesis of various graphene nanostructures ranging from arm-chair to zig-zag edge structures. In addition to the planar nanocarbons, curved carbon nanostructures as promising next-generation carbon materials will be next discussed. The curvature has important ramifications on the inherent physical behavior of carbon materials. Third, the implementation of combinations of heteroatoms, such as nitrogen and boron, for example substituting a C=C unit with an isoelectronic B-N moiety or the NBN-fragment at the zig-zag edges which can be selectively oxidized into the radical cation, will be presented. Finally, to bridge the molecules and devices, structurally well-defined graphene nanoribbons will be particularly introduced. Over the past few years, a variety of GNRs with different width and edge structures have been accessed by solution-phase and on-surface syntheses, as well as CVD-based method, which are essential for the development of future graphene-based nanoelectronics and spintronics.