A nanocomposite containing orange emissive quantum dots for degradation of fluorescein sodium

Abstract

Obtaining high-efficiency photocatalytic materials responsive to visible light is crucial to eliminating organic dye pollution in industrial wastewater. The paper describes the optical characteristics of ZnO-decorated visible-light-responsive orange-emitting carbon quantum dots ZnO (ZnO/O-CQDs composites). The composite was tested for its photocatalytic capabilities through the photodegradation of fluorescein sodium, a dye. Despite its vast usage and irritant properties, this is the first report on the photodegradation of fluorescein sodium using a customized ZnO/CQDs photocatalyst. Under visible light, the photocatalytic degradation efficiency reached 96.3 % over just 40 min. We also investigated the structural and elemental composition of the ZnO/O-CQDs using TEM, FESEM, EDS, and XPS. The results confirm that O-CQDs with varying properties promote ZnO's photocatalytic activity. The degradation obeyed the pseudo-first-order kinetics model with a photocatalytic rate constant (k) of 0.082 min−1, significantly higher than that of pure ZnO (0.048 min−1).