Green Synthesis of Fluorescent Carbon Dots from Ocimum basilicum L. Seed and Their Application as Effective Photocatalyst in Pollutants Degradation

The application of Ocimum basilicum L. seed was considered in this study for the first time to achieve the synthesis of photoluminescence carbon quantum dots (CQDs) through a simple, fast, and inexpensive one-step hydrothermal method. The structural and optical properties of synthesized CQDs were investigated by Fourier-transform infrared (FT-IR), X-ray diffraction analysis (XRD), Field emission scanning electron microscopy and Energy-dispersive X-ray (EDX/FESEM), and transmission electron microscope (TEM), atomic force microscopy (AFM), Ultraviolet–Visible (UV–Vis), and Photoluminescence (PL) analyses. This product was observed to exhibit high water solubility, satisfactory optical properties, and an average size of 2.3 nm. The photocatalytic activity of CQDs in the degradation of Methyl Orange (MO), Methylene Blue (MB), Eriochrome Black T (EBT), and Crystal Violet (CV) dyes were evaluated under UV light and certain reaction conditions such as pH and the dose of CQDs were optimized. Moreover, an assessment was performed on the surface activity of this product in the adsorption of Pb (II) and Cr (III) ions of water.