TiO 2 Modified With Green Apple Peel Derived Carbon Dots for Anionic and Cationic Dye Removal

ABSTRACT This research focuses on the synthesis, characterization, and application of carbon dots derived from green apple peels (ACDots) immobilized onto titanium dioxide (TiO 2 ) The resulting TiO 2 /ACDot composite exhibited remarkable adsorption efficiency for the removal of Victoria Blue R (VBR), as confirmed by kinetic and isotherm studies. Optimal adsorption conditions were achieved within 90 min, at pH 9.0. The composite, containing 9% (w/w) ACDots, attained 89.0% removal efficiency, outperforming pure TiO 2 by 20% at pH 9.0. It followed a pseudo second order kinetic model, while isotherm studies indicated a stronger correlation with the Langmuir model, revealing an adsorption capacity of 68.83 mg/g. In addition, the hybrid nanomaterial demonstrated high recyclability, effectively removing VBR even after three consecutive cycles. In contrast, the TiO 2 /ACDot composite exhibited limited efficiency (14%) in adsorbing the anionic dye Reactive Black 5 (RB5) at pH 3.0, primarily due to favorable electrostatic interactions. This study highlights the synergistic advantages of incorporating low‐cost, biowaste‐derived carbon dots into hybrid nanomaterials, reducing dependence on expensive and chemically intensive synthetic processes. This work introduces a novel approach, demonstrating the potential of such hybrid materials as efficient, sustainable adsorbents for dye removal.