Synthesis of Carbon Nanodots with Glucose Solution

MasterQuantum dots, one of the recently attracted nanomaterials, have many fascinating properties, so there are many applications using quantum dots, including biological and optoelectronic devices, and energy devices. However, a serious limitation of these quantum dots is the necessary use of toxic heavy metals. Carbon nanodot can be a good candidate to replace toxic metal-based or noble metal-based quantum dots currently in use. Here, we synthesized carbon nanodots via facile bottom-up methods, including hydrothermal, ultrasonication-assisted, and microwave-assisted synthesis. Furthermore, we made an effort to enhance the light absorption ability by controlling the reaction time to modify the size of synthesized carbon nanodots.In case of hydrothermal synthesis, synthesized carbon nanodots were too large (more than 80 nm) and had too broad size distribution. Using ultrasonication-assisted synthesis, we could prepare small-sized, mono-disperse carbon nanodots, but due to the use of acid solution, further process to remove it was required. Using Microwave-assisted synthesis, we could synthesize small sized, mono-disperse carbon nanodots, and by controlling the reaction time, we could modify their size and as a result absorption edge was shifted. Surface-passivated carbon nanodots were obtained by just one-step process within 10 mininutes