The thesis is mainly focused on the better understanding of carbon dots (C-dots) formation in bottom-up syntheses, by identifying the key chemical processes and correlating them to the observed fluorescence. Therefore, several types of C-dots were studied, by systematically varying the used (molecular) precursor ratios and reaction times. Selected samples were surface functionalized by organosilanes to reveal the role of the C-dots surface functional groups in the overall photoluminescence. As better understanding of the ongoing processes finally achieved, the synthesized C-dots were applied in photocatalysis experiments by combining them with titania and an appropriate C-dot was tested as a nitrite ion sensor
