A Nanocomposite of ZnO and N,P-Co-Doped Carbon Dots for the Photocatalytic Degradation of Various Dyes and their Kinetic Study

Environmental pollution is becoming more severe by the day, and it is critical to discover an effective method to overcome and reduce pollution. Because nanomaterials are important in all fields, we employed a ZnO-based N and P doped carbon quantum dots (NPCdots) nanocomposite to degrade multiple dyes including Methylene blue (MB), Methyl orange (MO), and Rhodamine B (RhB). ZnO-based NPCdots nanocomposite (ZnO-NPCdots) was synthesized using a single step solvothermal technique, and the resulting nanocomposite was analysed using XRD, HRTEM, and XPS. These analyses unequivocally demonstrate that the ZnO-NPCdots nanocomposite was successfully formed. The prepared nanocomposite was then used for the photocatalytic degradation of the different dyes under UV light, and it shows an effective catalytic property. In addition, four different kinetic models viz., zero order, pseudo first order, parabolic diffusion model, and modified Freundlich models were used to analyse the reaction's kinetics and actual catalytic phenomenon behind the reaction. The modified Freundlich model was found to be effective, indicating the surface phenomenon of the catalyst.