Synthesis and application of biomass-based carbon dots in deep eutectic solvent systems

Deep eutectic solvents (DES), renowned for their exceptional solubility and compatibility, have been explored as effective solvents and dopants for carbon dots (CDs) synthesis. However, their application is often restricted by requirements for high pressure or temperature. This paper introduces a simple method for utilizing DES in processing lignocellulose to synthesize CDs under mild conditions at 110 degrees C. The synthesized CDs exhibited excellent fluorescence characteristics, and maximum emission wavelengths ranging from 360 nm to 550 nm. Notably, the recycling of DES enhanced the performance of the CDs. Additionally, the study revealed discrepancies in the carbon precursors and the synthesis mechanisms of the CDs obtained from different DES systems. The synthesized CDs demonstrated great potential for detecting Fe3 + in water, with a limit of detection as low as 191 ppm. Furthermore, these CDs can be utilized in inks and the production of flexible composite films due to stable optical properties and exceptional chemical characteristics. This approach provides a new prospect for the synthesis and regulation of CDs.