Fluorescence Decoration of Defects in Carbon Nanotubes

Well-dispersed and functionalized carbon nanotubes exhibit visible fluorescence emissions due to passivated defects on the nanotube surface. It was found in this study that the defects in nanotubes could be decorated by an inorganic salt, which augmented the passivation effect of organic functionalization to result in dramatically enhanced emission intensities under both one- and two-photon excitation conditions. The structures and properties of the functionalized carbon nanotubes with inorganic coating were thoroughly characterized by using spectroscopy and microscopy techniques. The fluorescence decoration with the coating may serve as a tool in the study of surface defects in carbon nanotubes, and these brightly fluorescent pseudo-one-dimensional nanomaterials may be exploited for optical applications.