Engineered Hydrogel Incorporated With Doped Carbon Dots Derived From Banana Peel for Pollutant Removal

The integration of photocatalytic nanomaterials into structured platforms is essential for advancing sustainable water treatment technologies. In this study, we present a multifunctional hydrogel composite comprising nitrogen and fluorine-doped carbon dots (N, F-BCDs) embedded within a poly (acrylic acid-bisacrylamide) hydrogel network. The green approach has been employed for N, F-BCDs via a hydrothermal route using banana peel (a sustainable carbon precursor). The doping enhances the optoelectronic properties and photogenerated electron mobility by π-electron delocalization and electron-donating sites. Further, the doped CDs are embedded into a hydrogel matrix and provide a porous, water-retentive scaffold that enhances dye adsorption, stabilizes CDs dispersion, and facilitates mass transport of reactants. The three-dimensional architecture of hydrogel concentrates pollutant molecules near active sites and prolongs light-matter interaction, resulting in accelerated degradation kinetics. Using crystal violet (CV), malachite green (MG), and methyl blue (MB) as model pollutants, the N, F-BCD hydrogel composite demonstrated superior photocatalytic efficiency under both UV and solar irradiation, outperforming undoped systems and free CDs for its reusability.