Scaling up single-wall carbon nanotube laser annealing: Effect on electrical resistance and hydrogen adsorption

Abstract

Carbon nanotube (CNT) performance is highly sensitive to crystallinity and purity. These parameters are generally maximized to capitalise on the outstanding intrinsic properties of these 1-D nanocarbons. This presents challenges from their synthesis, through their manipulation, up to their inclusion in the final product. Many of these challenges can be addressed through fine-tuning the synthesis, yet CNT handling and processing (e.g. dispersion) often incurs unavoidable damage, with consequent drops in crystallinity and purity, and thus in overall performance. Laser annealing stands out as a contactless, fast and localised treatment, capable of drastic healing and purification. We previously demonstrated a near-full recovery of substantial processing-related damage to SWCNTs, applying very local (μm) laser radiation. Here, we scale-up our findings 103-fold to entire as-produced samples (mm), confirming our previous findings of recrystallization and purification, and extend the scope to excellent correlation with non-trivial, ca. one-third, electrical resistance and hydrogen adsorption, at double the CNT thermogravimetry-based purity.