Enhancing Visible Light-Driven Photocatalysis for Water Treatment: Optimizing Fe3O4@SiO2@Cr–TiO2–S Nanocomposite Efficiency with Silver and Palladium Deposition

In this study, we developed a magnetically separable, visible light-responsive photocatalyst, Fe3O4@SiO2@Cr–TiO2–S, optimized via response surface methodology (RSM) for enhanced photodegradation of methyl orange in water. By doping with chromium and sulfur, and further surface modification with silver and palladium nanoparticles, we achieved significant improvement in photocatalytic efficiency under visible light. Our findings reveal that the optimal doping levels of Cr/TiO2 at 2.88 mol