The Effect of Ethylenediamine as Passivation Agent on the Optical Properties of Carbon Dots from Molasses Using the Microwave Method

Carbon dots are renewable carbon nanomaterials whose role can replace toxic metal-based semiconductor quantum dots. Its high photoluminescence properties and low toxicity make carbon dots widely used in various fields of application. This study aims to utilize molasses as a carbon source and ethylenediamine as a surface passive agent that can improve the optical properties of carbon dots. Carbon dots synthesis was carried out using the microwave method with a power of 1100 watts for 20 minutes, centrifuged at 4500 rpm, and dialyzed for 24 hours. The optical properties of carbon dots were characterized using a UV-Vis spectrophotometer resulting in 1 absorption peak at a wavelength of 282 nm and photoluminescence characterization showed an increase in the intensity of the fluorescence peak from 800 a.u to 8500 a.u after the addition of passivation agent. The functional group analysis of the carbon dots was evidenced by the FT-IR characterization which showed the presence of a C=C group which indicated the core constituents and the presence of O-H, C=O, and C-O-C groups which constituted the surface state at the carbon dots and there was a C-N group which indicated that ethylenediamine was successful Passivated on the surface of the carbon dots.