纳米碳点的制备及荧光性能研究-化学工程与技术专业论文.docx

AbstractCarbon nanodots (C-dots) is a new type of carbon nanomaterials, and is considered to be one of the most promising fluorescent material due to its low toxicity, good biocompatibility, stable fluorescence and so on. However, the existing preparation methods of C-dots always have low yield, complex operation and the obtained C-dots have poor uniformity, low fluorescence quantum yield, which seriously restrict the practical application of C-dots. In this thesis, C-dots were firstly prepared by liquid phase plasma discharge treatment. The effects of voltage and discharge time on the structure, morphology and fluorescent properties were studied, and the effects of C-dots concentration, solution pH and the variety of solvent on the fluorescent properties of C-dots were also studied. Besides, C-dots were modified by acidificating and oxide combined treatment, and we investigated the effects of modification on the structure, morphology and fluorescent properties of C-dots.Carbon nanomaterials were prepared by liquid phase plasma discharge treatment, and the results of serial characterization (IR, XPS, Raman, HRTEM, XRD and PL) show that as-prepared carbon nanomaterials are spherical and uniform in size which is less than 10nm, the surface of particles contains large numbers of containing oxygen groups, the structure contains a small amount of graphite structure, under the excitation between 340nm and 420nm, the C-dots perform good fluorescent properties. By the above characterization results, we concluded that C-dots were firstly prepared by liquid plasma discharge treatment. The research on effects of voltage and discharge time on structure and morphology of C-dots shows that the voltage has a greater influence on structure of C-dots, whose crystalline and particle size increases with the increase of voltage, while the discharge time has little influence on C-dots.The optical properties of as-prepared C-dots were studied, results show the obtained C-dots have wide