The Research Of Fluorescent Carbon Dot Prepared With Hydrothermal Method And The Application

Carbon dots, similar to the metallic quantum dots, are a kind of nanoparticles thatcan emmit fluorescence when irradiated by light. The particle size is usually smaller than10nm, this leads to size effect and shows more special properies. Some traditionalmetallic quantum dots are restricted in application because they are extracted from toxicelements, like mercury and lead, especially when you use them in living organisms, thetoxic quantum dots may kill the cells. In addition to the advantages mentioned above, thecost of production is low, the preparation process is simple, besides, the carbon dots havegood biocompatibility. Due to the carbon dots, the application field of quantum dotsenters a new stage.In this paper, we discussed properties, preparation methods, applications andresearch status of carbon dots. Especially, we mainly focus on instruments, reagents andreaction process of synthesising carbon dots with hydrothermal method. We use TEM,AFM, XRD and Raman spectroscopy to detect the performance of carbon dots, then theyare applied to the fluorescent printing as the ink.In the experiment, we prepared water soluble carbon dots by ethylenediamine andcitric acid with hydrothermal method. The solution of carbon dots presented yellowilluminated by natural light and showed a blue color under UV lamp. TEM and AFMshowed that the particle size is around3nm and the carbon dots have good dispersion;XRD and Raman spectroscopy revealed that the prepared carbon dots are amorphouscarbon with low carbon-lattices-structure content; In the UV spectra, the absprbtion peakwas focused on332nm and the opitical excitation and emission wavelengths are at355nmand448nm. The emission peak redshifts with the excitation wavelength increasing.Besides, many factors may affect the PL properties, such as the ratio of reactants, reactiontemperature, UV irradiation, metal ions concentration and the pH of solution.Using the PL properties of carbon dots, put the solution into the cartridge of printerinstead of traditional ink and print on a printing paper without fluorescent background.You will get PL images when irradiated by UV lamp. Due to the excitation-dependent PLbehavior, the carbon dots can achieve multicolor imaging applications.At present, we still try to find more facial ways to fabricate carbon dots which aresuitable for industrail-scale production. Also, we will keep studying on improvingperformance and perfecting applications of carbon dots.