Emissive CdSe/ZnS@Fe2O3 Nanocomposites for Enhanced UV-Driven Degradation of Methylene Blue

This study reports the design and synthesis of high-performance PEGylated CdSe/ZnS@Fe₂O₃ yolk-shell nanoparticles (NPs) for the efficient photocatalytic degradation of Methylene Blue (MB), a dye-stuff with toxic effects in water. The novelty of this work lies in the synergistic integration of a narrow-bandgap CdSe core and a ZnS shell with a Fe₂O₃ layer, further stabilized by a precise PEGylation process to ensure superior colloidal stability and surface activity in aqueous media. The morphological and structural properties of the synthesized nanostructures were investigated through TEM and XRD analyses, and their crystal structure and phase formation were successfully determined. FTIR and EDX analyses validated the successful surface functionalization and elemental composition. Particle size and zeta potential measurements revealed that an optimal 20% PEG concentration prevents agglomeration and maintains a high photoluminescence quantum yield of 62%. Photocatalytic tests demonstrated that the PEG:(CdSe/ZnS@Fe₂O₃) system achieves an outstanding degradation rate constant of 63.12*10-3 min-1 under UV light, reaching 84.2% efficiency within only 30 minutes. These results highlight the potential of these yolk-shell NPs as a robust and efficient catalyst for rapid wastewater treatment.