Sakaguchi Hiroshi, Kojima Takahiro, Cheng Yingbo, Nobusue Shunpei, Fukami Kazuhiro
Institute of Advanced Energy, Kyoto University, Uji, 611-0011, Japan.
Department of Materials Science and Engineering, Kyoto University, Kyoto, 606-8501, Japan.
Nat Commun. 2024 Jul 29;15(1):5972. doi: 10.1038/s41467-024-50086-6.
On-surface synthesis of edge-functionalized graphene nanoribbons (GNRs) has attracted much attention. However, producing such GNRs on a large scale through on-surface synthesis under ultra-high vacuum on thermally activated metal surfaces has been challenging. This is mainly due to the decomposition of functional groups at temperatures of 300 to 500 °C and limited monolayer GNR growth based on the metal catalysis. To overcome these obstacles, we developed an on-surface electrochemical technique that utilizes redox reactions of asymmetric precursors at an electric double layer where a strong electric field is confined to the liquid-solid interface. We successfully demonstrate layer-by-layer growth of strong electron-donating GNRs on electrodes at temperatures <80 °C without decomposing functional groups. We show that high-voltage facilitates previously unknown heterochiral di-cationic polymerization. Electrochemically produced GNRs exhibiting one of the strongest electron-donating properties known, enable extraordinary silicon-etching catalytic activity, exceeding those of noble metals, with superior photoconductive properties. Our technique advances the possibility of producing various edge-functional GNRs.
边缘功能化石墨烯纳米带（GNRs）的表面合成备受关注。然而，在超高真空条件下，通过热激活金属表面的表面合成大规模制备此类GNRs一直具有挑战性。这主要是由于官能团在300至500°C的温度下会分解，以及基于金属催化的单层GNR生长受限。为克服这些障碍，我们开发了一种表面电化学技术，该技术利用不对称前驱体在双电层处的氧化还原反应，在双电层中强电场局限于液 - 固界面。我们成功地证明了在温度低于80°C的电极上，强供电子GNRs的逐层生长，且官能团不会分解。我们表明高压促进了此前未知的异手性双阳离子聚合。电化学制备的GNRs展现出已知最强的供电子性质之一，具有非凡的硅蚀刻催化活性，超过贵金属，且具有优异的光电导性能。我们的技术提升了制备各种边缘功能化GNRs的可能性。
