Graphene nanoribbons (GNRs) were successfully produced by using a laser to transform the tubular structure of multiwalled carbon nanotubes (CNTs).

A laser scanning method was developed to heal the graphitic defects of carbon nanotubes (CNTs). The laser beam was controlled to longitudinally scan CNTs aligned in the freestanding CNT sheets. The localized heating zone generated by the laser beam moved along the CNT axes and exhibited the extreme thermal conditions of fast-heating and fast-cooling. This unique laser-CNT interaction was beneficial to quickly heal the CNT defects and limited the undesired structural transformation of CNTs. The effectiveness of the introduced laser method in healing CNTs was confirmed by comparing with the conventional furnace annealing method and also verified by treating the plasma-bombarded CNTs. The generated localized heating zone and the scanning pattern controllability of the laser irradiation method are favorable to thermally treat the 1D-structured nanomaterials having the dominant longitudinal thermal conductivities such as CNTs or nanowires.

Laser is used to produce graphene nanoribbons (GNRs) by unzipping carbon nanotubes (CNTs). It is found that laser can not only unzip CNTs, but also join GNRs through covalent reconnections. Because the CNTs are aligned in a freestanding CNT sheet, the laser irradiation process results in a freestanding GNR network. Experimental results show that the expected results can be achieved by controlling the delivery of laser beam energy to the sheet. Moreover, this process is a solid-state process and a scalable manufacturing process.