Evaluation of Thermal Behavior and Properties of Carbon Dots Prepared by Green Synthesis

Abstract

Carbon quantum dots are highly fluorescent, non-toxic, thermally stable, and water-soluble novel carbon nanomaterials. The dominance of quantum behavior has drawn scientists’ interest due to their good biocompatibility, low toxicity, high physicochemical and photochemical stability, and ease of synthesis. Carbon dots have shown applications in optoelectronics, photovoltaics, photocatalyst, biomedical such as biosensing, bioimaging, drug delivery, and detection for heavy metal ions in food and water samples. In this paper, we reported the microwave-assisted green synthesis of carbon dots using sweet lime as a carbon source and ethyl diamine as the surface passivating agent. The change in the optical and thermal properties are studied and analyzed with a change in the concentration of EDA in carbon dots. Synthesized samples are characterized by Dynamic Light Scattering and Zeta potential particle sizer to analyze the effect of EDA concentration on the distribution of particle size in the samples and change in surface charge of as-prepared carbon dots. The optical parameters are studied with UV- Visible absorption spectroscopy. Composition and molecular bonding are confirmed by Fourier Transform Infrared Spectroscopy. Thermal behavior and kinematics are studied by simultaneous Thermogravimetric Analyzer and Differential Scanning Calorimetry.