The luminescent carbon nanoparticles with controllable oxygen-related functional groups prepared by pulsed laser ablation in water

Abstract

Fluorescent carbon nanoparticles (CNPs) are obtained via pulsed laser ablation (PLA) of a carbon target immersed in deionized water. By tuning the laser power for PLA, the density of oxygen-related functional groups at the surfaces is controllable. While the crystallinities, sizes, morphologies and defects are nearly retained, the prepared CNPs show blue fluorescence under UV exposure and the photoluminescence (PL) intensities of the C-dots are dependent on the oxygen contents. Accordingly, the PL is attributed to the transition of electronic states caused by oxygen-related functional groups. This work sheds new light on the PL mechanism of CNPs and proposes an efficient way to prepare CNPs with controllable oxygen-related functional groups.