Synthesis of Carbon Dots from Low-Cost Precursors and Study of Concentration-Dependent Emission Properties

Quantum Dots are nano-sized materials with interesting emission properties, which can be used in bio-imaging, sensing and anticounterfeiting applications. However, these materials are expensive to synthesize, and toxic in environmental and bio-applications. Carbon dots with similar optical properties are non-toxic materials which can replace quantum dots in various applications. In this thesis, the synthesis and characterization of nitrogen-doped carbon dots from low-cost materials such as citric acid, humic acid and brown coal precursors were studied. Herein, we showed that the emission properties of citric acid-based carbon dots could be controlled by simply varying the concentration and aggregation of the particles, resulting in emission red-shift from blue to greenish yellow. The emission of citric acid-based carbon dots was further studied in polymer matrix to evaluate potential solid-state applications.