Optical Properties of Tricarboxylic Acid-Derived Carbon Dots.

Herein, we report the characterization of two types of luminescent carbon dots (CDs) synthesized by the hydrothermal treatment of citric acid and -aconitic acid by using ammonia solution as a nitrogen dopant. The lateral size range of nanoparticles for CDs lies in the range of 3-15 nm. The intense blue photoluminescence (PL) was emitted by the CDs at around 409-435 nm under the excitation of 320 nm. The PL quantum yield of the synthesized CDs ranged from 26.4 to 51%. Our results of the structural and optical properties of CDs imply that molecular fluorophores are an important part of the structure; in particular, the main contribution to the PL is carried by the fluorophores based on citrazinic acid derivatives, which formed during the synthesis of CDs.