Unzipping Carbon Nanotubes to Sub-5-nm Graphene Nanoribbons on Cu(111) by Surface Catalysis

Graphene nanoribbons (GNRs) are promising in nanoelectronics for their quasi-1D structures with tunable bandgaps. The methods for controllable fabrication of high-quality GNRs are still limited. Here a way to generate sub-5-nm GNRs by annealing single-walled carbon nanotubes (SWCNTs) on Cu(111) is demonstrated. The structural evolution process is characterized by low-temperature scanning tunneling microscopy. Substrate-dependent measurements on Au(111) and Ru(0001) reveal that the intermediate strong SWCNT-surface interaction plays a pivotal role in the formation of GNRs. A novel approach is reported to facilely prepare graphene nanoribbons (GNRs) through the simple annealing of single-walled carbon nanotubes (SWCNTs) on Cu(111). The surface-catalyzed unzipping of SWCNTs occurs along a longitudinal line which directly contacts with Cu(111), affording straight GNRs. The structural evolution process is characterized by low-temperature scanning tunneling microscopy with atom resolution.image