Carbon Nanodots (CNDs) are emerging materials in the nanotechnology field as
attractive photocatalysts, owing to their high water-solubility, good chemical and photostability, tunable photoluminescence and photoinduced phenomena.
This study aims to synthesize CNDs from olive solid wastes to be used as photocatalysts for the photodegradation of Methylene blue (M.B). CNDs were synthesized from olive solid waste by pyrolysis at 600 °C converted into carbonized material, followed by a chemical oxidation in the presence of hydrogen peroxide. The as-synthesized CNDs were utilized in this work as
photocatalysts for the photodegradation of methylene blue at different conditions, such as; the catalyst concentration (dose), pH of the pollutant solution (M.B), salt content, light source distance, power of irradiation and pollutant concentration (M.B). The degradation efficiency and rate were studied for all aforementioned factors, finding that the increase the CNDs dose into the M.B solution increases linearly both the efficiency and the rate. On the other hand, the maximum degradation rate was observed at pH = 10.6 with an efficiency of 92% after 120 minutes of irradiation. Moreover, the existence of NaCl salt in the pollutant solution affects adversely the degradation parameters showing a slight decrease in degradation rate, each 2 mg/ml addition decreased the rate with less than 1.2 folds. The potential and the distance of the visible light source from the pollutant cell have an obvious effect on the degradation,
increasing the light power from 10 to 50 W, increased the degradation rate 16 times.