Carbon dots synthesized from Hibiscus Tiliaceus L. leaves via microwave-assisted methods as a photocatalyst for sustainable organic transformation

In the field of nanotechnology, carbon dots (CDs) are gaining prominence as eco-friendly photocatalysts for wastewater treatment applications owing to their high water solubility, good chemical stability, and photostability. In this research, CDs were synthesized from fresh and dried Waru (Hibiscus Tiliaceus L.) leaves through microwave treatment for 50 min and 60 min. The synthesized CDs were analyzed through ultraviolet–visible (UV–vis) spectrophotometry and Fourier transform infrared spectroscopy, and the results revealed an absorbance peak in the wavelength range of 300–340 nm. n–π* bonds in the form of C = O and π–π* bonds in the form of C = C were attached to the surface state of CDs. Irradiation using a halogen lamp successfully enhanced the absorption properties of CDs as a photocatalyst, indicated by a decrease in the absorption peak of the UV–vis spectra. CDs synthesized from dry leaves through microwave treatment for 60 min exhibited an excellent pollutant-degradation efficiency of 87%, with an irradiation time of 30 min, while the fresh leaf-derived sample exhibited a degradation efficiency of 75%, with an irradiation time of 60 min. CDs derived from Waru (Hibiscus Tiliaceus L.) leaves present a new carbon source with high potential for eco-friendly wastewater treatment applications.