Abstract:

As a new type of nano-materials, carbon dots have unique optical properties and excellent chemical properties, such as easy preparation, low cost, high chemical stability and good biocompatibility. Three kinds of carbon dots were prepared by microwave, hydrothermal and pyrolysis methods, and characterized by infrared spectroscopy. The ultraviolet-visible absorption spectra and fluorescence spectra of the three carbon dots were measured and compared with those of small organic fluorescent molecules. The fluorescence quantum yield of three carbon dots was measured using quinine sulfate as standards. This experiment not only enables students to learn the preparation methods and the unique luminescent properties of carbon nanomaterials, but also enables students to have a deeper understanding of the structures, principles and applications of three kinds of molecular spectroscopy instruments based on the measurement of quantum yield. This experiment can be used as a comprehensive 10-hour instrumental analysis experiment for junior students majoring in chemistry, applied chemistry and material chemistry.

Key words: Comprehensive experiment, Carbon dots, Fluorescence, Quantum yield