Fu Yubin, Yang Huan, Gao Yixuan, Huang Li, Berger Reinhard, Liu Junzhi, Lu Hongliang, Cheng Zhihai, Du Shixuan, Gao Hong-Jun, Feng Xinliang
Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.
Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, China.
Angew Chem Int Ed Engl. 2020 Jun 2;59(23):8873-8879. doi: 10.1002/anie.202000488. Epub 2020 Mar 25.
We report the first bottom-up synthesis of NBN-doped zigzag-edged GNRs (NBN-ZGNR1 and NBN-ZGNR2) through surface-assisted polymerization and cyclodehydrogenation based on two U-shaped molecular precursors with an NBN unit preinstalled at the zigzag edge. The resultant zigzag-edge topologies of GNRs are elucidated by high-resolution scanning tunneling microscopy (STM) in combination with noncontact atomic force microscopy (nc-AFM). Scanning tunneling spectroscopy (STS) measurements and density functional theory (DFT) calculations reveal that the electronic structures of NBN-ZGNR1 and NBN-ZGNR2 are significantly different from those of their corresponding pristine fully-carbon-based ZGNRs. Additionally, DFT calculations predict that the electronic structures of NBN-ZGNRs can be further tailored to be gapless and metallic through one-electron oxidation of each NBN unit into the corresponding radical cations. This work reported herein provides a feasible strategy for the synthesis of GNRs with stable zigzag edges yet tunable electronic properties.
我们报道了通过基于两种在锯齿边缘预先安装了NBN单元的U形分子前体的表面辅助聚合和环脱氢反应，首次自下而上合成了NBN掺杂的锯齿边缘石墨烯纳米带（NBN-ZGNR1和NBN-ZGNR2）。通过高分辨率扫描隧道显微镜（STM）结合非接触原子力显微镜（nc-AFM）阐明了所得石墨烯纳米带的锯齿边缘拓扑结构。扫描隧道谱（STS）测量和密度泛函理论（DFT）计算表明，NBN-ZGNR1和NBN-ZGNR2的电子结构与其相应的原始全碳基锯齿形石墨烯纳米带的电子结构有显著差异。此外，DFT计算预测，通过将每个NBN单元单电子氧化为相应的自由基阳离子，NBN-ZGNRs的电子结构可以进一步调整为无间隙和金属性。本文报道的这项工作为合成具有稳定锯齿边缘但电子性质可调的石墨烯纳米带提供了一种可行的策略。
