Monodispersed carbon nanodots spontaneously separated from combustion soot with excitation-independent photoluminescence

Abstract

We present a facile, low-cost procedure by simple one-step combustion of small organic molecules to obtain ultrafine, hydrophobic, and fluorescent carbon nanodots (CNDs). Without further centrifugation and dialysis, we could easily separate CNDs from combustion soot through spontaneous sedimentation. Transmission electron microscopy and photoluminescence characterization demonstrated that the collected CNDs possessed a monodispersed size distribution with a diameter of 1.9 ± 0.5 nm and excitation-independent luminescence properties. Furthermore, after oxidization treatment, the oxidized CNDs displayed good water solubility and the highest fluorescence intensity in neutral solution.