Electrochemical on-surface synthesis of a strong electron-donating graphene nanoribbon catalyst

<p><span>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</span><span> </span><span>under ultra-high vacuum on thermally activated metal surfaces has been challenging. This is mainly due to decomposition of functional groups at temperatures </span><span>of</span><span> 300 to 500&deg;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. <a name="_Hlk164526696"></a>We successfully demonstrate layer-by-layer growth of strong electron-</span><span><span>donating</span><span> GNRs on electrodes at temperatures </span><span>&lt;</span><span>80&deg;C without decomposing functional groups.</span></span><span> </span><span>We show</span><span> that high-voltage facilitates previously unknown heterochiral di-cationic polymerization. <a name="_Hlk164368440"></a>Electro</span><span><span>chemically produced</span><span> GNRs exhibiting one of the strongest electron-</span><span>donating</span><span> properties known, enable extraordinary silicon-etching catalytic activit</span><span>y,</span><span> </span><span>exceeding those of </span><span>noble metals, with superior photoconductive properties.</span></span><span> </span><span>Our technique advances the possibility of producing various edge-functional GNRs.</span></p>