Facile synthesis of stable and fluorescent carbon nanoparticles from brewery bagasse for value-added applications

Nanostructured materials are gifted with excellent physical, chemical, and biological properties due to their morphology and particle size, such as large surface area, pore size, and pore volume. Brewery bagasse was successfully turned into carbon nanoparticles (CNPs) via carbonization followed by functionalization. Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), and Ultraviolet–visible spectroscopy (UV–vis) were engaged to characterize the morphology and optical properties of the as-synthesized CNPs. The CNPs showed homogeneous spherical shape with sizes below 100 nm. Hydrophilic functional groups such as -OH and -COOH, which were responsible for easy dispersion and stability in aqueous medium, were confirmed in the carbon structures. The functionalized CNPs (FCNPs) were further treated by hydrothermal method to obtain carbon dots (CDs), then evaluated for metal ion sensing using UV–vis technique. Results showed that the CDs show selective sensing for Pb²⁺ ion.