(613c) Investigations of Properties of Carbon Quantum Dots Obtained from Hydrothermally Carbonized (HTC) Process Liquids

Carbon quantum dots (CQDs) are spherical nanomaterials with a particles size range of 2 to 10 nm. CQDs exhibit excitation-wavelength dependent photoluminescence behavior and they are considered as cost effective and nontoxic alternative to the conventional inorganic quantum dots. CQDs have wide range of applications such as medical diagnostics, bio-imaging, biosensors, solar cells, photo catalysis, and others. In this study fluorescent carbon quantum dots (CQDs) were extracted from hydrothermal carbonization (HTC) process liquids prepared from hydroxymethyl furfural (HMF), furfural, and cellulose. HTC experiments were performed at 200, 220, and 240 °C for a reaction time of 30 min. Dark brown and yellowish HTC process liquids were centrifuged at 10,000 rpm for 10 minutes and then fluorescent CQDs containing solutions were separated. CQDs containing solutions were filtered with syringe filter and finally, crystalline CQDs were obtained from vacuum distillation and freeze drying. Different properties of CQDs were observed by TEM, FT-IR, XPS, UV-Vis for different feedstocks as well as HTC conditions.