Individualization and Purification of Carbon Nanothreads.

Notwithstanding the synthesis of many types of carbon nanothreads with different structures, compositions, and theoretical property predictions, the experimental verification of thread properties remains challenging due to a paucity of techniques to disperse as-grown solid-state nanothread samples. In this work, we demonstrate that pyridine-derived carbon nitride nanothread samples can be intercalated with potassium to produce reduced carbon nitride nanothreads that can be readily dispersed in polar organic solvents such as dimethyl sulfoxide. Atomic force microscopy of thin films produced from these dispersions reveals thread-like objects as narrow as 0.6 nm in height, suggesting exfoliation and dispersion into individualized threads and small bundles. The individualized nanothreads emit blue/green luminescence, suggesting potential utility in optoelectronic applications. Remarkably, the temperature-dependent conductivity of a thin film of nanothreads shows weakly semiconducting behavior, falling only ∼40% from room temperature to 2 K. The reductive dissolution approach reported in this work greatly improves the processability of as-grown nanothread materials, thus opening opportunities for single-nanothread characterization, post-synthetic functionalization, thin film fabrication, and the production of nanothread composites.